Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: DBS88 on November 16, 2020, 10:14:06 pm
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I am on a journey to build my own twin engined steam powered WW2 Black Swan Sloop, my Grandfathers ship, HMS Wren U28. On the journey I have made some diversions and this is another one, the restoration of a Torpedo Boat Destroyer. The reason for the diversion was having seen photos of this model I believed there was a lot I could learn from it, lessons that would improve the build of HMS Wren. Any way by chance I came across the seller and ask him questions about the boat, he is a dealer in fine model boats, and he honestly confessed his knowledge of this model, its specification and its history was a bit thin. So after waiting weeks for him to bring the model down south from where it was stored I finally got the chance to see it. Now to be truthful, I thought that I could learn all that I needed to from viewing this boat, so had no intention of buying it. I was fascinated by the engineering, by the mechanical set up, so wanted to see it first hand. From the photos I had been sent I knew it had a large boiler with twin engines and the plumbing looked great so an ideal set up to learn from. Again from the photos I could see the boat was not finished and was not that struck by the looks of the model. So when I saw it i was taken aback by just how good the model is, the quality of the hull and fittings matched the amazing quality of the engineering so that was me a lost cause, and I duly parted with the money and became the proud owner of this Torpedo Boat Destroyer - it was un named and had an uncertain history, so here is the story of the restoration that has begun but is not yet complete. This is the photo of how i first saw this model in the flesh.
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Interesting story. More photos please!
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Is that a TBD or a torpedo boat? It appears to have a bow tube.
Colin
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Here is what I knew about the boat when I bought it. It has a large boiler, 12 inches long by 5 inches in dia, the boiler was unusual in that it had two chimneys, unknown manufacturer. The steam was used to drive twin Stuart Turner engines, the seller believed they were Sirius Engines. The engines drive twin 3 1/2 inch props. The boat is 8 feet long, so just as well I have an estate car!!! The boat had suffered some minor damage in storage and transport. So no paper work, no idea who made it, no idea of when it was made, no idea what it was a model of and a concern that more than person had had a go at getting this to run.
On closer inspection, when I had got the model home and into the basement, I began to believe that this model may never have been run on a lake or possibly ever been fired up. So plenty of red flags or warning signs that should have put me off buying this.
Here are some more photos as I first saw the model and a photo that possibly explains some of the damage, but also, they begin to show the true majesty of this epic model.
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What exactly is damaged?
I didn't realise the boat was 8 feet long. That's going till be a challenge to move and store.
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Hello!
This is a hell of a boat and we are curious to know everything on it.
Is the boiler a return flue? I don't understand why there is two chimneys.
I agree with you that the boat is too clean to have been fired up once. Even with enclosed engines's crankshafts..
Mine are oily after the first sailing and the oil goes everywhere I can't clean!. :embarrassed: But I am the bad example!!
Yes, More photos will be greatly appreciated.
Congratulation for the purchase.
And no doubt that the way you behave when you go step by step , through your steam plants, we shall enjoy the happy smoke soon!
(Mayhem does not provide the flagrance of the hot oil , yet! Pity!!) {-)
Have fun!
Regards.
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From looking at it, whilst it has two funnels it looks like only one on the actual boiler. Its an early type, possibly Daring or Boxer as both had bow torpedo tubes and and an open gun platform and twin funnels. There were very many different types of that vintage as the navy gave specifications but no general designs and the builders just built what they wanted so some had two funnels and other four or even six!
I'll do a bt more research.
Interesting model though and thanks for posting.
Cheers
Geoff
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In hindsight it may be a composite as the bow torpedo tubes were a feature of the very early destroyers but the midships mounted twin (pointing in different directions) was a much later feature and that it is mounted on a deckhouse seems incongruous due to weight considerations.
Early destroyers were not very stable and whilst typically carried a number of tubes the aft tubes were more typically single deck mounted. Nevertheless its a very fine model of a typical destroyer from the 1895 period which deserves restoration and sailing.
Cheers
Geoff
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I believe images of this steam plant may have been posted in MB in.....1989?....our Colin Bishop may be able to throw a closer light ....[I subscribed to that Publication in that era, however I think the magazines came out by Convict Sea Freight ...or 3 Months behind the UK]
The Sirius engines engines being without a reversing function were connected in this build via a 3 shaft 1:1 reversing transmission to one engine, so both engines provided counter outboard rotating propeller shafts
The images you post confirm a similar layout with the transmission box athwart ships
I do not remember the engines being bed mount offset with the Stdb engine being Fwd by say 1/2".....but assume this was to minimise the overall engines footprint necessary courtesy of the headcap banjo fittings
Again, I have no memory in the magazine of the boiler in the steam plant
So suffice to say, you appear to have some quality 'near vintage' steam components .....& in one boat
Would be interesting to understand the vessels displacement/weight.......and more so, if the 8' long vessel could suspend the steam plant...and float?
I do not say this in any critical sense.......as you have questioned if the boiler had ever been fired up?
Derek
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Me again - on looking at the model in more detail I think the purpose of the raised aft superstructure, on the model, it to provide clearance for the engines. - maybe?
Cheers
Geoff
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Geoff is right, it could indeed be a very early TBD. The tubes aft on some of these were 14 inch as opposed to the much bigger bow one. There are some illustrations in David Lyon's book 'The First Destroyers'.
Derek, I will see if I can find anything in MB in 1989.
Colin
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The more I look at this model the more interesting it becomes, the bridge deck gun bulwarks are probably a little low when compared to the deck railings forward - also on the real ships these were invariably canvas covered and not solid. From a modelling perspective, and from experience, I think you will suffer from oxygen starvation as I can't really see how air will reach the boiler. Again I think the model is in an unfinished state and the real purpose of the construction, and size, was to see if it could be made steam powered hence the large boiler for the engines.
However for whatever reason the project was not finished, maybe the original builder became unwell. I would suggest you try to work out a scale from the size of the guns and how tall a crew member would need to be as this can guide you as to the rest of the fittings.
A really fascinating find!!
Cheers
Geoff
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Thank you for the feedback. The damage to the model is fairly minor scuffs and knocks to the paint, bent railings etc. Have included a photo of the props, since the photo clearly shows the sort of damage, but more interestingly gives a second clue to the identity of the model, the first clue being the bow torpedo tube. From the photo of the props you will notice the second clue is the beautiful sculpted hull over the props. These two clues lead me to believe this to be a model based on HMS Daring/Decoy built by Thornycroft in 1894. At the time HMS Daring was reported in newspapers as being the fastest boat ever!! So your thoughts and initial research appear to suggest that Torpedo Boat Destroyer HMS Daring is a strong contender for this model. The front torpedo tube was dropped on later boats because the boats were faster than the torpedos so risked overtaking there own torpedo!!!!
Have also included a photo of the boiler sat on the bench so that both funnels can be clearly seen. The boiler is a return flue boiler, will post photos of the internals at a later time.
The engines are not Sirius engines, they are the smaller Sun engines, which provides another clue to the age of this model. Sirius engines have cast on there side Stuart, Sun engines have cast on there side ST. Stuart Turner ceased production of the Sun Engines about 30 years ago - so now believe the model to be at least thirty years old. I have next to no information on Sun Engines so any help greatly received.
With respect to the displacement I will work it out along with the scale speed etc. Save to say I have put in the grandkids paddling pool to check for leaks. Yes it rolled alarmingly so anyone putting on the water would have feared for its survival. That said its a solid wood, carved out, construction so naturally buoyant, so I put a few kilos of lead in down low and this improved matter no end so I am hopeful all will be well. From the photo you will see that the water is above the painted water line.
I agree with Geoff and believe there has been some modellers licence used to raise deck heights to cover the engines and boiler so it will never be a true to scale model. Talking of scale if we assume the model to be HMS Daring/Decoy they were 185 feet in length so at 8 feet this model is approx 1:24 so allows for good detail to be added.
Lastly here is a photo I found on the internet of HMS Daring moored on the Thames in 1894.
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Hello!
I am still intrigued by the boiler and :
- What the second chimney for?.
- The steam path (overheating) toward the engines.
- The 2 clack valves seems upside down ! But are they ?
And at he end, I wonder if , with such an available power, the boat won't turn around the propellers ! %)
Very interesting indeed! Clean and promising!
Must be a flying dragon on the water. :-))
Regards.
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Yes, I would agree, the model is based on Daring/Decoy. Material in David Lyon's book seems to support this and the semi tunnel stern is a Thornycroft givaway. Daring had her funnels raised around 1900 and Decoy's funnels were also higher by then from the drawings.
There is a model in the the Science Museum collection (now no longer on display) which looks very much like Daring. It is in the bottom left corner in the photo below. It shows the typical original all black colour scheme including the underwater hull. Lyon's book devotes over two pages to various alternative colour schemes that were tried out both for wartime and something a bit smarter for peacetime i.e. red inside cowl vents and grey turtlebacks so there are probably plenty of otpions there. The current paint scheme on the model seems to be very unlikely! Decks appear to have been a mixture of bare steel and corticene.
I'm no steam expert but this You Tube video says the Sun engine was introduced in 1927. The fact that the model is carved from solid wood suggests it might even be pre war as by the 1950s bread and butter construction was the usual favoured method. (Is it possible that the model is in fact B&B and carved inside as well?).
https://www.youtube.com/watch?v=fSZrDMEQxFc
I have looked at the 1988/89/90 issues of model boats and cannot obviously see anything relevant. There was an article covering an exhibition by Stuart Turner which may be what Derek is thinking of but there are no photos of this installation in it.
Colin
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Good evening.
Maybe the following is of interest !
I was doubting that the boat has 2 Sirius = 2 monsters.
The SUN are good enough.
The STAR a bit weak.
Regards.
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The 2nd Chimney is interesting in that it obviously takes heat out of the boiler so reduces the heat available for the return flue, so at face value not ideal. I think the idea may have been to achieve smoke from both chimneys, but as we know, the exhaust from the boiler alone is not going to do that. I will experiment with the boiler, but my gut reaction is to use the smaller chimney to light the boiler, then cap it while its running to make full use of the heat. To achieve steam from both funnels I aim to direct the exhaust steam out through them both to achieve the steam smoke from both funnels. I will post more pictures of the boiler another time.
Re the clack valves, in the photo they are upside down, the photo was taken the first time I filled the boiler to check for leaks, they are normally round the other way.
I have not seen this boat run, in fact to date I have not even used the boiler to turn the engines, although I hope it won't be too much longer.
The video of the Sun Engine was both interesting and informative so thank you for the link Colin, it is appreciated.
Re the construction of the hull, I am not up to speed with the terminology for construction of model boats, I am still learning, so have attached a photo taken of the inside looking from just below the front gun towards the bow and torpedo tube. Please feel free to describe what you see in terms of the construction - its definitely not plank on frame!!! and looks to be very sturdy.
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Looks like the hull is carved out of at least 2 pieces of wood which were glued together.
I think your plan to cap off the second boiler exhaust is a good one. Routing the engine exhausts to both ship funnels should give you a nice display of "smoke".
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At 8 feet long you are almost talking about hollowing out a tree! Imagine the effort involved.
There are no obvious bread and butter steps but they could have been carved away. But then there are no obvious signs of any joints either. If the hull is old then one might expect to see some evidence either inside or outside. It's certainly a puzzle.
Colin
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One point not mentioned with the boiler, is it Char or coal fired?... I don't seem to remember gas firing in portable plants such as this [40 years ago]
No need to calculate the displacement, just put it on a set of bathroom scales......I am guessing about 12kg..including the 1kg of boiler water
Thanks Colin.....I do remember a few Stuart engine discussions with photographs from that period, but the article I remembered was a stand alone on the vessel [I read & re-read the magazine's on the 60 to 80 minute train trip each evening after playing with big guns & missile launchers]
The more I think about this, it is the reversing gearbox to one engine that stands out...[as the means to attain the counter rotating propellers]
Derek
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Re the Boilers fuel source, it is a centre flue return boiler and it came with an LPG torch burner, not sure when model steam plants started using LPG, may be that helps with the dating.
I have just removed one of the deck covers to give it a clean and found another possible clue to the age of the boat - an old rc receiver, its a Futaba FP-R122JE AM 2 channel receiver. Please see photos.
One of the reasons I believe more than one person has worked on this boat is because it came with a modern 2.4Ghz Futaba Receiver - thank you most useful.
Have also attached a photo that better shows the knocks and scuffs to the paintwork that will mean a respray is required. Thanks to Colin I now have some colour options with Turtle Back Grey looking favourite.
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Most important to this restoration is a working boiler, if the boiler is not right (size, capacity) or is faulty then this boat would be going no where. The boiler came supplied with a burner although it was laying loose near the boiler, see photo, its installation was obviously incomplete. So whilst the boiler looked in good condition I removed it from the boat to begin checking it over. The boiler usefully has the working pressure stamped on it at 80psi. The boiler contained some water so drained it off and then began to fill the boiler to find its capacity, a healthy 1.4 litres. With the boiler out of the boat I carried out a more detailed visual inspection, the main fire tube, 2 inches in dia, looked clean and most important was dry. I removed the end cover to check the steam dryer and cross tubes, then reassembled. It looked to me as though this boiler has never been fired, it looked very clean inside. To move on further I needed to pressurise the boiler to check for leaks, I did not have a pump to hand, so with it being full to the brim of water I thought about apply some gentle heat to bring up the pressure very slowly. I then turned my attention to the burner, it has type 40 stamped on it, I have no idea what that means? Anyway I needed to know a few things about the burner, whether worked and where in relation to the fire tube to place it (inside, level with, or outside) so a great chance to do some practical experimentation. With this in mind I set up the boiler on a bench in the garden. First I lit the burner!!!! Wow was not expecting that, as friend said, the flame would not look out of place beneath a NASA Rocket.
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Not sure what that burner is Dave but by god its very impressive :-))
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Regarding your burner: usually this kind of torch burner is placed a few mm outside the flue. Your flue seems to have ample space before the water tubes start, which means it is meant to use a burner with a longer flame, such as you have.
Make a suitable ring to fasten the burner in such a way that you can push it inside the flue and outside, to have room for adjustment.
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Bonjour,
To complete Calin's message, I have learnt that the hotest point of the flame of a torch burner is the the end of its light blue interior triangle. This point should be 4-5 mm before the first transvesal pipe to avoid any possible fusion of it.
I am not able to measure the boiler pipe on the picture but if its length respects this assumption, and if the torch has enough air (as mentioned by Calin), the air at the chemney should smell nothing (proving all gas is burnt) and everything should be all right.
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I must admit I like the era that your model represents- it was an era of new technology and innovation which created some fantastic vessels like the TBDs. Before I was put into forced isolation I fetched out my tiny 1/96 scale HMS Velox hull which I had fitted the four 2mm diameter prop shafts and the equally minute props from Prop Shop. As previously mentioned by Geoff and others, the excellent book British Destroyers is a stunning history of the destroyer (my copy took a few years to find at a price I could afford) but Norman Friedman’s book is equally just as good.
I’ll look forward to your progress :-))
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Hi David, to save you much possible frustration later on, I think you should do a steam test of the steam plant as soon as you can, to see if the boiler provides ample steam for both engines. This kind of engine is known to be steam hungry and two of them will be even more so. If you can, do the test with the propellers in water, so the engines have a load. Then you can measure the rpm that the boiler can keep up.
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Thank you for the advice re the burner, thats most helpful. With the boiler full of water, no air gaps, I thought I could find out two things, a position for the burner so I could make up an adjustable holder for it and also by applying some gentle heat, expand the water and raise some small pressure to test for leaks. So with the boiler in the garden, I nervously introduced the flame into the fire tube. I moved it forward and back, listening to the roar of the flame and watching its colour and also the overspill of flame as a back pressure forced some of the flame back out of the boiler fire tube. I was not convinced the burner was right before I started, now I was even more convinced it was wrong, far too much flame and the fumes stunk, they were awful, made my eyes sting, so definitely incomplete combustion. Anyway the heat did raise the pressure, just a few psi, less than 10 but enough to show me leaks from fittings that would need addressing before I could get the boiler pressure and steam tested for its safety ticket. So the outcome - research for a new burner and strip the boiler fittings required.
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Jerry at Clevedon Steam can make custom gas burners. He builds a type with metal gauze-like surface which gives a shorter flame. Why don't you ask him if he could make you one?
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Another :-)) for Jerry at Clevedon Steam, he's an incredibly knowledgeable and helpful chap on all things model steam.
That's an impressive looking boat and power unit. If it's the one I think it is (offered for sale by Paul D) I was very tempted myself were it not for the size ...
I'll watch this thread with interest.
Mark
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Thank you for the tip about Clevedon Steam, I knew they did replacement burners and adaptor rings were available to order so that the burners would fit different size fire tubes, i didn't realise custom size burners were also possible, so lesson learned. I find Jerry to be both helpful and quick in supplying parts.
Anyway having to strip the boiler down is proving to be a blessing because it has revealed some things that may have caused a problem either at the pressure test or once it was up and running under steam. One job that needed to be done before the pressure test was to replace the broken union cock valve used to isolate the sight glass, it was siezed solid and in the process of trying to unsieze it, I snapped the handle off. I disconnected the sight glass assembly and then removed the fittings connecting it to the boiler and here is what I found. There was chalk deposits, despite having used descaler, the fittings had been sealed with dubious sealant and also been soft soldered in place to prevent them turning or leaking - I believe an older and previously fairly widely used practice
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While I was removing the sight glass a shard sheared off rendering it useless, so I had to replace it, well it was a 3/16 dia glass and the drama surrounding its replacement is the subject of another thread under Steam R&D called cracked sight glass, so I will not repeat here what happened, save to say thank you to all involved especially Steamboat Phil who went above and beyond the call of duty to help me. Any way it was that thread that prompted the start of this one, so in terms of a time line we are now almost upto date with where I have got to. Probably one more post to follow re the boiler then we will be in real time.
Now I have never silver soldered anything before. I understand its very strong so thought I would try to use silver solder to repair the broken handle from the union cock so heres the results
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During this project I have been helped by a number of people, both from my club and from this forum, I would not of made such good progress without you, thank you.
Having removed the fittings from the boiler i set about cleaning them up. First soaking them in descaler to remove any deposits and by mechanical means, wire brush etc to remove other muck. Then I resorted to the blow lamp to de-solder the fittings since the excess solder was unsightly and i was uncertain what the boiler inspector would make of it? Now whatever had been used melted at a fairly low temp and did not run like normal plumbing solder, it was a sticky mess - any wire brushed the worst off while it was still liquid. I then used a 5/16 26 die to clean the male threads for the fittings and a 5/16 26 tap to clean the female threads to the boiler. I then reassembled using copper washers to space the fittings so that when tightened they ended up in the correct orientation. I reassembled the fittings and got the boiler ready for its pressure test.
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You have cleaned them up very well. Take care with those valves as they are prone to leaking. You might need to lap the conical part to get them tight.
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This is an amazing boat and I take my hat off to you for trying to preserve it using the fittings and burner supplied. I am terrible for ripping out the old stuff and upgrading it for modern. This just removes the heritage and what the boat is about. Really good luck with your build - what a treasure you have there :-))
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Now I was lucky in regards to timing, I booked the boiler test with my clubs boiler testers, which happened to be the last day before we went into the second and current lockdown. Now club boiler testers really are unsung heroes so I am truly grateful to anyone who undertakes this roll so that we might be able to keep our steam boats safe on the water. So it was somewhat nervously that I attended the test venue, we socially distanced. The boiler was visually inspected and the test equipment set up. Now anyone thats waited for one of these tests will probably tell you its a scarey time, you arrive with a very expensive boiler and could leave with a worthless pile of scrap if it fails. Because of the boilers size 1.4 litres, its working pressure of 80psi (just over 5 Bar) and its unknown manufacture it had to be tested to twice the working pressure so 160 psi. The pressure was ramped up in 10 psi increments, we listened and watched 50, 60 psi a small leak from the union valve showed up, this was duly tightened, 90, 100 psi the pressure was holding, the pressure continued to be released and then reapplied, 120, 130, now I was sweating, hoping all would be ok. The consequences of the boiler failing filled me with dread. 150 then 160 now we waited, the boiler had to hold this for 10 minutes. After an eternity all was declared well and the pressure released. Then followed a further visual check. Next came the steam test so the boiler was emptied to about half full of water and then fired up. The boiler began to hiss and bubble, a minor weep of water came from the freshly fitted safety valves, the pressure began to rise and the leak stopped. The pressure rose slowly to start with 20 psi then 30, there was a whiff of steam from the union valves, so they were again tightened down, the pressure rose faster 70, then 80 psi then the safety valves lifted, first one, then the second, their opening stopped the pressure rising and then they closed again. So after being nervous I was now elated, the doom and gloom, the fears of the boiler failing had vanished and the project to restore this glorious torpedo boat destroyer was now a real possibility.
The burner was made specially for the boiler by Pendle Steam, it was machined from a solid 2 inch brass bar, its flame is much more stable and less spectacular, than the previous torch burner, I will try and get some better photos of it. Gone was the bad smell from the previous burner, now just a steady burn, we will have to wait and see how both the boiler and burner perform together later, to see if they can produce the steam that is required to drive those twin Sun Engines that have sat idle for far too long. I am however confident that the new burner will give the boiler the best chance it has of producing as much steam as it is capable of.
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Wow what great news O0 I too would have been very nervous! So you went for a Pendle burner - Nigel is a top engineer and really knows his stuff. The back up he supplies with his products is amazing. Mind you I'm biased as he's a mate of mine O0 Good luck with your build and keep the pictures coming!
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Nice burner. Is it ceramic or some other type?
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Hello!
It will be interesting to know how long it takes with each burner to reach 3 b, for example.
Also , to see which one keeps up the pressure when the engines are running at the same RPM.
Cheers!
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You!
And the jet size also is important to know.
Thanks DBS88! :-)
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Have tried to take some better photos of the burner, however, not easy since it needs to be dark to see the flame. Anyway heres the photos, the burner, its constructed from solid brass bar and is not ceramic, it is a push fit into the 2 inch dia fire tube. Re the gas jet size its fitted with the jet supplied, a No 5 jet which is small at 0.2mm dia to deliver 59 grams gas per hour at 15 psi. I did discuss the jet size with Nigel from Pendle Boilers and he said that increasing the jet size does not always result in better performance, it can just use more gas without the expected increase in heat output due to the nature of the combustion in the fire tube. So will have to experiment. I don't mind it taking a while to get this boiler hot so long as when its up to temp it maintains the best possible amount of steam, so will have to give it a few runs on the bench with the No5 and a No8 to compare. No8 uses 93 g/h, No 12 - 135 g/hr and No 16 184 g/hr. Obviously using the gas faster than needed is wasteful but leads to pressure problems with the gas cooling effect. Re comparing it with the torch burner, that I feel is unlikely, the fumes from it made my eyes sting and it stunk, it was not burning nicely.
A closer look at the photos also shows that I wasted my time using polish to clean the brass and copper work, the heat from running the boiler upto 80 psi for the steam test has coloured both the brass and the copper.
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Your photography is superb!
Colin
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Ooh, another exciting project for the winter! These early destroyers are superb machines to read about and see. I have one of the books on these early vessels and they were mostly powerplant and fuel with a few nooks for ammo and crannies for crew. Thy even got 'Hard Lying' rates (Like submariners) as they were so unpleasant to serve in {:-{
When I read about your issues with soft solder I was concerned for a moment that the boiler had been home made and soft soldered together which is a real no-no these days, and you cannot reliably silver solder soft soldered joints, thus making a soft soldered boiler an expensive ornament.
Re the hull, there is no evident layering of timber though there are hints if straight lines which might show bread and butter. If sanding the hull down well for a repaint, Might I suggest a sand down to the wood where it needs repairing as then we can all see some model archaeology!
A far as carving a solid block into a hull, while not easy, it may be no less difficult than cutting lots of layers out and finishing the shapes off, you are just replacing one set of efforts for another. Mind you, a solid piece of timber can move and split etc, and if the baulk was an edge piece, it may have had sapwood in places. Bread and butter comes from the way casting patterns are made from layers of timber built up and shaped. There are interesting You tube videos showing this occurring from way back.
She's a gorgeous model and I look forward to reading your updates.
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That is an impressive 2" Pendle gas burner Dave :-)) neat compact installation and todays technology over the 'unwieldry' Plumbers Gas torch <*<
Many will talk about Stainless mesh elements over Ceramic inserts for superior heating performance, however many also comment on the 'Howling" from the top of the boiler funnel under burning load
Does this burner with the Ceramic insert create Howling?
Secondly, increasing the gas jet size and corresponding gas flow when combined with the same gas supply tube bore sizing can introduce the freezing issues in the supply tube as evidenced by the icing on the externals etc [adiabatic? heat transfer]
Derek
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When I first realised that some of the joints on the fittings (including the seats to the union cocks) that had been screwed into the boiler had been sealed with a type of soft solder my heart did sink, I feared the worst. But rest assured, it was not anywhere on the boiler itself. It appears to have been done to lock the fitting in the correct orientation and to stop leaks at 80psi. Some limited research also indicates that this was an older and commonly used practice. To overcome this I cleaned all the threads and reassembled using a variety of thicknesses of copper washer so that when the fitting was in the correct orientation it was also tight. Thankfully some patience and persistence in doing so paid off because the joints did not leak at 160psi. The only problem on the pressure test was with the sealing the union cocks, not the joints I had made, but with the rotation of the lever through 90 degrees. These had to be rotated back and forth a few times and then tightened down before a decent seal was achieved.
Re some model archaeology - it looks to me like some thick pieces of wood have been glued together and then the inside taken to shape using an adz type tool. From the paint damaged areas, there are multiple layers of paint, it goes wood, white, grey, light blue, grey. The quality of the finish to the wood is astonishing, not a sign of any grain and a perfectly smooth finish, not a run or brush mark to be seen, whoever did it was a true craftsman. It has left me with a really good base to work on, once I find out what colour Turtle Back Grey is?
Re howling from burners, I have only fired the boiler for the steam test and it did not howl, the burner is made from solid brass, here is a link to an interesting video, from Pendle Steam/products/video demonstrations on how the burner was made and how it performs even in a sealed tube [size=78%]https://youtu.be/OLDE_MJfjBI [/size]
In terms of freezing i will be doing all I can to avoid it and keep the gas temperature up and to ensure the gas pressure remains constant.
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If the hull is very old it could be made of yellow pine which was quite difficult to get back in the late 1950s but famed for its lack of knots and smooth grain.
Colin
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Colin, At the start of the 1900's all the big flour mills that had 5-6 floors of milling machines used Yellow pine to make the spouts that carried the ground wheat by gravity from floor to floor had spouts made of yellow pine.
In 1955 when I started my engineering apprenticeship it was in the Largest Flour mill in Scotland, it had 6- flats of milling machines 6- across and 12 in the length all powered by a triple expansion engine which stood about 20 ft high.
In the joiners shop there was a stack of yellow pine boards from 12 ' wide to 24 " wide planks all wedged down to stop any warping.
The mill went on fire the year after I left and the capacity was moved to Leith out side Edinburgh,
During a visit there the spouts were all made of round Aluminium tubes as Yellow pine had become very difficult to get and expensive, I think that this was the same at The Baltic Mill in Newcastle.
Today I know of no place that sells Yellow pine but if any model maker wants some keep your eyes open for any old church that is being demolished as most had the pews made from Yellow pine, the seats were 18" wide x 1'' thk and if you talked to the demolition team telling what you wanted some seats for they are only too willing to help,
The seats are usually carved with the initials of the Sunday school pupils taught but being so thick can be plained down, it's a useful source of timber and then you can talk nicely to some joiners shop to rip it up into strips for you.
It's a beautiful wood to work with and some excellent finishes can be had as you can see in Dave's M.T.B. which is built on the bread and butter method.
I must say it was an excellent find for Dave and I don't blame him for buying the boat and this new burner with a brass perforated plate from Pendle steam is also an excellent buy, mind you Think he should rename it H.M.S. Hernia, it will be a big lift, it's a good job that has an estate car.
Keep up the good work Dave it's interesting to see how an old boat was made and as to how advanced you have become since starting out on steam vessels..
George.
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Thanks for that info George, really interesting. When I started modelling and used bread and butter for the ic Smeed Empress of Britain liner I had to settle for Parana pine which had knots and tended to split. I did make the hull but it was too heavy really and unstable so the model never got finished.
Colin
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Just to add a note regarding the burner, if it howls it is simply not correctly matched to the flue correctly. Of the many hundreds I have made two howled and were easily sorted by altering the air flow into the sides of the burner. This air is purely to combat unwanted harmonics and plays no part in the combustion process (theres a lot more to making a good burner than meets the eye!). This burner has a brass gas/flame interface but I also make ceramic burners for our twin flue boilers as the all brass design is simply too brutal at start up. The ceramic ones are a much softer burn, that said, there is ceramic and there is ceramic. The stuff you can buy from UK model outlets will melt rather quickly in our burners unless you turn the heat right down. Our ceramic will not melt under any bench test conditions (and subsequently costs an arm and a leg!).
Nigel @ PSB
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Nigel
Thanks for that, even the ceramic that you can buy as Silver Smiths anvils will melt if the burner is 2" dia, in some cases it will not melt but will sag unless a bracer is made across the dia
It always amazes me when people talk about howling burners, some how they never experiment to see if it will stop by adjusting the position of the gas jet.
George.
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Thanks for that info George, really interesting. When I started modelling and used bread and butter for the ic Smeed Empress of Britain liner I had to settle for Parana pine which had knots and tended to split. I did make the hull but it was too heavy really and unstable so the model never got finished.
Colin
Hi Colin,I don't want to high jack Dave's Thread but old Churches are a source of Yellow pine , well seasoned and knot free.
George.
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To answer a couple of earlier questions about the displacement for this boat here is my rough calculations
HMS Daring 185 feet long, 19 feet wide, speed 28 knots
Model length 92 ½ inches - waterline
Model Scale = 185 feet divided by 92 ½ inches = 1:24
Approx displacement = Length x breadth x displacement x coefficient for a destroyer
92 ½ x 9 ½ x 4 x 0.505 = 1775 cubic inches = 29087cc = 29 kg displacement.
For 3 inches displacement = 1331 cubic inches = 21811cc = 21.8kg
Scale displacement = 3 inches, model will sit deeper in water upto 4 inches so displacement should be 22 -29 kg
Whilst this boat is long, I can carry it on my own without too much trouble, it’s not massively heavy, so these back of a fag packet figures seem about right.
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With the boiler on the bench waiting for me to have the time to fire it again and experiment with the gas jets, I thought I would share with you the boiler room in the boat.
Its also time for me to start to clean and understand more about the engines, their lubrication and the boiler filling arrangement. So heres some photos of the engine room. The twin sun engines are linked by a gearing arrangement in the green metal box, on top the square is an oiler drip feeding oil to the gears. Looking at the fourth photo, a close up of the gearing arrangement, looking at the flywheels, notice the grub screws that secure the flywheels to the crankshafts, they are at 90 degrees to each other. I learned from refurbishing an earlier version of the Sun engine, the MTB 1B, that the position of the screw (Left Hand Engine) means that one piston is top dead centre. This leads me to believe the pistons in the right hand engine are at 90 degrees to the left hand engine. In effect the engines appear to be tied together by the gearing, if one engine is turned they both turn and at the same rate, so what appears to have been created is a four cylinder single acting engine with 3/4 for and 3/4 inch stroke.
The lubrication for the engines is complex, see photo 5. The cranks, conrods and anything below the pistons is via a splash system contained in the crank case with a type and grade of oil yet to be confirmed, but probably light engine oil. The top of the engine, the valves and cylinders is lubricated by firstly the normal displacement lubricator, this appears to be for the initial phase when the engines are cooler. Then secondly by a mechanical lubricator, about which I know nothing and have no experience with. My thoughts are that this has been provided because the boiler has a steam dryer and is capable of delivering high pressure steam that has been dried and at a higher temperature preventing the displacement lubricator from working due to very little condensate. The mechanical lubricator is driven from the engine and ensures delivery of oil into the steam line to lubricate the top end of the engine, again note the drip feed oilers to provide lubrication to the pumps.
In addition to driving the lubricator the engine also drives a water pump which takes water from an inboard tank, the water circuit is fitted with a bypass valve so will need to experiment with that to make sure the boiler water level is maintained - again I have no experience of setting up a mechanical bypass valve.
A lot of thought has gone into this layout, so it will be nice to finally get it into steam. I also noticed the steam delivery pipe size that goes into the side of the engines and that the exhaust piping is at an increased diameter as it leaves from the top of the engines to minimise back pressure allowing the engines to spin freely.
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What fabulous workmanship. I suspect that the original builder was an engineer of some description or a very skilled amateur and really build the boat to take the steam plant as that was his real forte. I wonder who the builder was?
Either way a very interesting thread so please keep the info and pictures coming.
Cheers
Geoff
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Hi Dave,
Taking the lubrication off the engines.
The bottom of the engine use auto engine oil as a splash lubricant, not too much as it will also push out thro' the holes and coat everything with oil. I have often wondered why Stuart never made oil fillers, 1- with a cap on it and the other with a small breather hole.
I don't see any need for the on- line lubricator as you have a mechanical lubricator ( the black box ) which can adjust the oil delivery by lengthening or shortening the ratchet lever and it should be filled with steam oil, inside the black box is a little oscillating pump that should be submerged with oil, the mechanical lubricator is operated via the gears on the end of the starboard engine. This type of lubricator is mainly used in Loco's.
The online lubricator works with the oil filled chamber. and as the steam comes thro' the line steam filters into the chamber and condensates and as oil floats on water it is pushed up thro' the small hole and into the steam line and then to the engines and in my opinion is not required in this set up.
The small box drip feeding the gears use auto oilfor the gears and the water pump.
[/size]
[/size]The box with the drip feed over the gears to the stern tubes use auto oil
[/size]
[/size]Timing of the engines.
[/size]Time them with the drawing that I gave for the older Sun engine and do them individuallyI don't know if the grub screws have anything to do with the timing other than indicating T.D.C. with No 1 cylinder ( cylinder at the flywheel end )
[/size]Water bypass valve is easily adjusted once you get to know the boiler requirements, so don't worry about that, it will pass needless water back into the onboard tank. Once you get the boat into the water or ( the big P/Pool as long as the kids are out ) you can time the length of the boilers needs as a guide before you let it go on the lake as the requirements will change under load.
[/size]Pipe sizes.
[/size]All steam engines should have exhaust pipes 50% larger in dia than the steam supply line for maximum efficiency but on smaller engines it's not very noticeable.
[/size]The steam drier is the same it should be 50% larger to let the steam expand and store an supply greater heat to the engine.
[/size]Always remember at the end of a sail check the exhaust trap to see if it needs emptied, again by experience you will get to know how much exhaust oil is collected.
[/size]It's a well thought layout it's a pity that the builder never seamed to have a run with it as you say the boiler looks as tho' its never been fired in anger, the engines certainly look as tho' they have never been worked as the paint still looks brand new,
[/size]Like the new burner Pendle has done you proud.
[/size]
George[/font]
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Geoff, thank you for your kind comments, just wondering if there is anything in the book British Destroyers 1892 - 1953 by Edgar March about HMS Daring or HMS Decoy, or possibly Boxer that would be useful? if so I will try and find a copy.
George your help and support with this and previous projects is greatly appreciated, your advice on the burner, engines and lubrication has been invaluable.
Having got the boiler well on the road to being sorted, the next most important thing I have learned from this forum is getting the props right. So I have been looking at the props, they are 3.5 inches in dia and wondering if they are the so called "steam props" - props with a ratio of greater than 1:1. How do you tell if the pitch is steeper, as for a steam prop at 1:1.5? How can I find out what the pitch is?
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Geoff, thank you for your kind comments, just wondering if there is anything in the book British Destroyers 1892 - 1953 by Edgar March about HMS Daring or HMS Decoy, or possibly Boxer that would be useful? if so I will try and find a copy.
George your help and support with this and previous projects is greatly appreciated, your advice on the burner, engines and lubrication has been invaluable.
Having got the boiler well on the road to being sorted, the next most important thing I have learned from this forum is getting the props right. So I have been looking at the props, they are 3.5 inches in dia and wondering if they are the so called "steam props" - props with a ratio of greater than 1:1. How do you tell if the pitch is steeper, as for a steam prop at 1:1.5? How can I find out what the pitch is?
Dave ,
I don't have much knowledge of props but I do make my own and I silver solder the blades at 45deg on the hub and then do at bit of twisting to see how they work , never having had a twin prop set up I can't say much other than when these engines are at full revs and the boiler can keep up the pressure these props in my opinion are just about right.
Your props look professionally made with a coarse pitch and I would leave them as such until you get on the water, but somebody better qualified than me will no doubt give some
sound advice.
George.
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Yes, the props appear to be coarse pitch which should be suitable for relatively low RPM compared with electric motors. Given the attention to detail for the engines and the boiler it would be a reasonable assumption that the fitted props should be matched to the power plant output. Maybe it has never been run but you don't know the reason for that so I would think that the best bet is to test the installation as it stands as clearly a lot of competent thought has gone into it.
Colin
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Hi Dave,
From experience running 5incch gauge locos, the mechanical pump is filled with steam oil containing lanolin and the mechanism is to actually force a small measured amount in for each cycle as the oil is thicker (certainly at room temperature) than other oils), though being near the engine, it will probably soften some. By the way, is the phot deceiving us as it looks like the gears are not meshing.
As Colin and George said, make sure your engines and steam plant works and then get testing those props to see if they are actually right for the type of vessel and powerplant you have. These early destroyers often had a series of small props on each shaft. I havn't read my book on early destroyers for a couple of years and so might not be right about multiple props on reciprocating plant.
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this era was of great experimentation, the quest for speed was a hard fight,, creating boilers that could maintain steam, engines that could survive the high RPMs,, the turbina tested multi props on the shafts,, many torpedo boats and destroyers had staggered props and engines,(so one prop wouldn't "steal" water from the other, and keep the hull narrow as possible) this was also the start of test tanks for hull shapes,, The USS Vesuvius on of the fastest in her time had the prop shafts angled outward, but her narrow stern could not fit a large enough steering engine and she couldn't turn at speed..
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I think the props on the model are about right as steam tends to be relatively low revolutions so large coarse props are perfect for this. Real destroyers had to have smaller props as they would otherwise cavitate at the tips due to the rotational speed. One of the issues with early turbines were they turned too fast so they had to have smaller diameter props and go to four props to get the power in the water.
Personally I would bet if you get both those engines warmed up and going it will go like a rocket!! Long thin hulls take very little effort to move. I suspect the two engines are used to make it self starting.
We should also consider the age the model was built and suspect radio control was probably not possible so it may have been a free runner albeit radio has been added later.
I await the next installment with considerable interest!
Cheers
Geoff
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Thankyou for sharing your views and advice about the props being the steeper pitch props, its reassuring since it makes such a difference to the engine revs required and to the amount of steam that the boiler needs to produce for those revs to be achieved. I am not looking to change the props, I just wanted to see if they were the steeper pitch props, and I agree totally with getting the boat running before seeing if anything needs changing.
If anyone knows anything about who built this boat I would love to hear from them, I would love to chat to the builder, to buy them a pint and learn from them, after all they have done a fantastic job and it would be a nice for them to know that the boat will be going under steam soon and hopefully running free on a lake not to long after that.
From what I have now read, it appears that in 1894, following HMS Darings first sea trials a study was undertaken and that is the first time cavitation had been identified as a problem.
To illustrate the effect of the propellors pitch on the revs required to achieve the desired speed on the water heres another back of a fag packet calculation, the difference in rpm is dramatic
Scale speed = square root of scale x true speed
1 Knot = 0.514 m/s therefore 28 knots = 14.4 m/s
Square root of 1/24 x 14.4m/s = 2.939 m/s = 6.6 mph
Prop RPM to achieve scale speed.
Prop dia 3 ½ inches 9cm, pitch 1:1 therefore 1 revolution moves forward 9 x 1 = 9cm
Props only 75% efficient therefore moves 6.75 cm per rev.
Scale speed = 2.939 metres per second
Revolutions to move 2.939 m = 293.9cm/6.75cm = 43.5 per second
Revolutions Per Minute = 43.5 x 60 = 2610
If Prop is 1:1.5 then 1 revolution moves forward 9cm x 1.5 = 13.5cm
Prop 75% efficient so moves 10.125 cm per revolution
Scale speed = 2.939 metres per second
Revolutions to move 2.939 m = 293.9cm/10.125cm = 29 per second
RPM = 29 x 60 = 1740
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I have been following this for a while, it is a fantastic model. One think I have noticed is none of the piping is lagged, this should be done especially the steam feed pipes, as you want to keep the heat in and not lose the benefit of drying the steam.
Gerald.
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Hi Dave
PM system doesn’t allow pictures to be attached so I’ve put them on your thread. The Edgar J March is a very interesting and informative book but costs a small fortune to get a good copy. It has five pages in the subject more dedicated to the working of the hull and engines. The Norman Friedman book differs by having plans drawn by AD Baker III of Daring (and Havock of which is very similar to Daring/Decoy) and some very good clear photos one of which spreads over two pages.
As promised here is my tiny Velox (still not started properly!)- just has the prop shafts and tubes stuck in place, note how tiny the props are!
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Some more pictures
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When we started this discussion it was unclear what ship this was a model of; now with the info from Nick together with the other contributions we can now be more certain than ever that this model is indeed HMS Daring or her sister ship HMS Decoy. Putting a name to the model and finding out the history of the real boats is really bringing this project to life for me, its given it a personality, so thank you.
Gerald, those props on your Velox are things of beauty, good luck with your build, I will follow with interest. Re the lagging, Gerald, you are right that is on the list of things to do, first is to get it all running, then I will go through and make improvements and finish off things like the pipe lagging. Have seen pipes insulated with silicon tubing (Mark T) that look very effective so may give that a go, happy to listen to suggestions on the best ways to lag the pipes to keep the heat in and stop the fingers from being burnt!
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The standard method for lagging model steam pipes is thin string wrapped spirally round the pipe (takes ages but looks good) and then sometimes painted to prevent it absorbing moisture and any oil which would reduce the effectiveness. Its a fun process particularly when fitting it retrospectively!
Cheers
Geoff
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Just caught on the plans that it does indeed have two torpedo tubes together pointing in different directions! I stand corrected as I thought this was a later concept so another identifying factor making it Daring or Decoy!
Cheers
Geoff
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Hi, regarding lagging steam pipes: I have found that winding piles with thick cotton twine is very effective for insulation. You can paint the twine over so it doesn't get stained by oil. I have painted them with white correction fluid (liquid paper), which gives a very matte appearance, like plaster. But normal paint is fine too.
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The others have beaten me in replying. I have always used the string method for insolating model pipes, It's not that different from doing the full-size ones, which I have done in the past. you wrap the pipe with something that will trap air. fiberglass for the full size cotton string for the models, then you add something to protect the insolation. With full size we used a tape that you wound in the opposite direction to which you wound the insolation, you then paint the tape. With the models you just paint with ether white out or paint. I have not tried the silicon tubing, but will try it in a future model.
Gerald.
PS The last full size piping I did was over fifty years back for steam heating, housed in a six foot round underground tunnel four miles long. We first had to strip and clean the pipes of the original asbestos, which was done in full hazmat suits with breathing gear. Once we had the pipes and tunnels clean and asbestos free we check and repaired any leakers, then recovered all the pipes. This was done during a very cold January during which the steam could not be shut off and temperatures in the tunnel sometimes reached 90 degrees F.
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Great tips on doing the pipe insulation, very helpful. There is a lot of piping to do so it will take a while. At the moment, due to Santa arriving soon, the basement has to be cleared so that Santas helper (me) can make some presents for the Grand kids, so with that HMS Daring is now safely up on a shelf, waiting til I can get her down again to do any meaning fun work. So I have taken the opportunity to start cleaning and repairing bits. Since Geoff has confirmed the twin torpedo tubes were a feature of HMS Daring/Decoy, here are some photos of them cleaned up together with a section from the as fitted plans for Decoy that I have just got hold of.
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Very interesting and nice. On my model of Velox at 1/48 scale I used some stainless steel old fountain pens as the torpedo's - right colour and size! Note that on the plans you can see the tops of the cylinders for the engines. Sometimes these were sufficiently tall to reach above the deck so an oblong covering was used to give clearance - the first TBD's were very small!
Cheers
Geoff
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I have continued cleaning up a few bits, Have made a start from the front, so heres the front three guns. When I got them they were dirty and going rusty, however, I decided against trying to make them look like new, so have taken them apart and given them a sympathetic restoration. Hopefully they still look old, but good.
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Bonjour Dave,
Incredible work on these guns ! Your project is just amazing ans is worth the energy you put in this restoration :-))
They could have been operational...
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Those working mechanisms on the guns are very nice.
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Are the barrels bored? If so, I reckon they could be fired back in the day, as the efforts on the seating of the breech blocks is impressive for display models.
Lovely work on an ever more gorgeous model. She will look amazing on the water.
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Very nicely done with the guns and I think you have done the restoration absolutely perfectly - well done
Cheers
Geoff
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Have today managed to get back into the basement after clearing up a few odd jobs and have know got the burner and boiler back on the bench. So have this evening been experimenting with the gas jet sizes and positioning in the holder to achieve the best flame before I put them into the boiler. The first three photos are the No 5 gas jet, the next three are the No 8 jet and the last three the No10 jet. The outcome was that the No5 & 8 jets work well, the No 10 can't get enough primary air through the holes so burns with a yellow orange tinge. This is as Nigel of Pendle Steam said it would be, so no real surprise. The point was to find the best positions for the jets before putting them in the boiler, since I know they will behave differently there, so at least I now have a starting position from which to experiment. As you will see the size of the air hole increases with jet size, which is as you would expect, more gas flow from a larger jet needs more air to burn it cleanly.
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One trick I learned from a forum was to put the burner is a glass tube of a size close to the boiler flue. then light it and observe the flame. That way you can see if it burns well or not and adjust the jet etc accordingly.
Because I didn't have a suitably large glass tube, I used a straight piece of copper tube and looked inside from the other end with the burner alight - from an appropriate distance, of course.
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Thank you, I like the old school ways of doing things and appreciate the suggestion of using a glass or copper tube, I will remember that, particularly for another boiler which has in the past proved a challenge to get right. Fortunately for this boiler, due to the design of the burner, it is possible to see through slots in the side of the burner, the flame while adjusting the gas jet in or out to achieve the brightest blue flame possible. From the photos, using gas jet No 5, you will notice with the burner in the boiler to achieve the best colour flame, the gas jet is slightly further out then when it was on the bench.
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Steam/engineering can be frustrating. I seem to have suffered with a number of blocked gas jets that have hampered progress. As a result the boiler was taking forever to heat up. Then the union cock valves that isolate the sight glass started to leak, again delaying the boiler getting up to pressure. So lapped in the valves, refitted them and started again. One is cure, the second, the lower one is much improved and now the boiler gets up to temp and pressure fine, the safety valves operate and there is plenty of steam. So it seemed a shame not to use some of the steam. Some of you will have seen that I have renovated a Stuart MTM 1B 180 steam engine, its over a hundred years old. Well I have been waiting a long time to get the chance to run it for the first time on steam so here is a video of the boiler and the MTM 1B 180 all working. All in all a great day. https://youtu.be/D74NHK5-z9s (https://youtu.be/D74NHK5-z9s) Thank you to everyone that has helped me on the way to making this possible - I hope you enjoy watching as much as I did playing.
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David that is just brilliant :-)) :-)) :-))
What a great engine it certainly looks the part and goes great too! I too occasionally get blocked jets but George suggested to me just to blow compressed air backwards through the jet. This works for me every time.
I love steam as there is always something to do ;)
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I’m a true novice but could the second funnel be a means to access air for the boiler?
The more I look at this model the more interesting it becomes, the bridge deck gun bulwarks are probably a little low when compared to the deck railings forward - also on the real ships these were invariably canvas covered and not solid. From a modelling perspective, and from experience, I think you will suffer from oxygen starvation as I can't really see how air will reach the boiler. Again I think the model is in an unfinished state and the real purpose of the construction, and size, was to see if it could be made steam powered hence the large boiler for the engines.
However for whatever reason the project was not finished, maybe the original builder became unwell. I would suggest you try to work out a scale from the size of the guns and how tall a crew member would need to be as this can guide you as to the rest of the fittings.
A really fascinating find!!
Cheers
Geoff
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Hi I am not sure about why the second funnel has been added to the boiler. Now that the boiler is back on the bench the plan is to run a few experiments with it. My hunch before I start is that the boiler should be make better use of the heat from the burner by having the small funnel capped. The thought is to use the small funnel for lighting the burner, then put on the cap.
I filled the boiler with water to a reasonable level and have put it on the scales 9.532Kg. Now as you can imagine it takes a while to heat this boiler and get to pressure. The idea is to then time how long it takes to heat the boiler and achieve a pressure of 50psi. Once the boiler is cold again (a long time), refill it to the same weight and heat it again, this time making a change. The variables I wish to understand are whether it heats quicker with one funnel open or both? Also whether a No5 gas jet or a No8 gas jet heats the boiler quicker also with one or both funnels.
What I have found from running the boiler so far is that I need to manage the gas temperature as well since it burns for so long, the burner pressure drops, I can definitely hear a difference, so to keep the pressure steady have started to put the gas tank in a water bath - this does maintain the flame. My first task is to stop the minor leak from from the bottom union cock valve that isolates the sight glass, then with no leaks I can start the experiments properly.
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On y model of Velox I use computer fans to force air into the boiler room which seems to work well under all conditions. They are light and use virtually no power and can shift a lot of air dependent on size. The early TBD's had very large cowl vents for this purpose and blowers to draw air in to the boiler rooms and this element seems to be missing from the model, hence my belief its in an unfinished state.
Obviously first get everything running with the deck off and then see what happens when you put the deck on. Note with a steam powered battleship it all worked well in the bath but the flame kept going out on the lake despite large cowl ventilators. Forward motion on the lake stopped a bubble of hot oxygen starved air over the boiler getting out until eventually it put the flame out. Air flow-through is the key for proper working. Not all cowl ventilators necessarily point forwards - some point aft to create a suction and draw air through.
Lovely to see your progress and one of the more fascinating threads I have seen,
Cheers
Geoff
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Are you going to measure the gas consumption under different conditions too?
Gerald.
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Thank you for the tip about using a computer fan to draw air in I will keep that in mind. As far as measuring gas consumption I have not planned to do so, I not overly worried about how much gas is used, just that it burns properly and that the boiler heats as quickly as it is able to.
Well the experiments with the No8 gas jet were very short lived - with the burner in the boiler the combustion was incomplete (dangerous) the carbon monoxide and unburnt gas can be seen burning above the funnel. Note closer to the funnel is does not burn because the mixture is too rich, its not until more air is defused into the mixture a few inches above the funnel that it becomes flammable again and can be ignited. please accept my apologies for the poor photos it was difficult to take them in the low light needed to show the problem.
For completeness I have also tried to ignite the exhaust with the No5 gas jet, the fumes did not ignite and did not smell off, so thats a much better result, not healthy, but much better than with a No8. When running the boiler in the basement I do so with he door open to fresh air.
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That's a useful experiment. What jet size have you chosen in the end?
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I've just had an off the wall thought about the second funnel. Given the age of the steam plant I wonder if it was intended to use paraffin blow lamp as the heat source as I suspect this pre-dates the universal use of gas? Such being the case this may be a little smokey and hence the second funnel to get smoke out of both funnels.
Looking forward to the next installment.
Cheers
Geoff
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Have started to fire the boiler up and time how long to get to 50 psi and 70 psi. I have settled on using the No5 gas jet. The first run was yesterday with both chimneys open. I am happier now with the position of the gas jet in the burner tube and with the flame its producing. The biggest variable seems to be the gas pressure which I am trying to minimise by placing the gas tank in a bowl of luke warm water.
Todays run was with the small chimney closed off, it was inconclusive, at the start the gas spluttered a couple of times and then ran ok but did not sound as strong as yesterday. There was no appreciable time difference it was about the same. I am going to discount this test and wait till tomorrow when its all cooled down again. I will double check to make sure the gas jet is clear and run it again.
Re the second chimney and a paraffin heat source - it may well have been. If capping the second chimney is not going to make a marked improvement in heating times my thoughts are drifting towards using some of the heat or flue gases from the second chimney with some of the engines exhaust steam to ensure a good steam plume - in the same way as the main chimney is set up with the engines exhaust steam. That way when its on the water there will be two decent plumes of steam, one from each funnel.
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In my experience, mixing steam with exhaust gas makes the steam plume LESS visible. I got the most visible steam plume when letting the steam exhaust through a pipe fixed to the outside of the chimney.
Like here, exhaust pipe in front of the chimney:
https://youtu.be/wdoQ8Haun4k
And pipe inside the chimney:
https://youtu.be/_W9EAvcVjjg
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Bonjour,
To have a nice plume from the chemney, a friend offered me this accessory (installed since on several other boats):
https://www.youtube.com/watch?v=heBFpO57Na4
The result :-))
https://www.youtube.com/watch?v=IRfg9KpRaPU
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Re the steam plume thank you, whilst I wish the plume to look realistic, I would not want to achieve it at the expense of boiler performance, so need to know if there is a benefit or not to running the engine steam exhaust into the boiler chimney?
Here is a link to my first steam tug running in-between lockdowns its engine exhaust does feed into the chimney and its the sort of plume that I would like to achieve. I can see how effective the device Raphael is using is at dispersing the steam plume so that it appears more natural. https://youtu.be/UwBvcPzb3W4 (https://youtu.be/UwBvcPzb3W4)
I have the just run the TBD boiler again tonight with the small chimney closed and it did get to temperature and pressure quicker. With both chimneys open it took 17 mins to 50psi and 20 to 70psi, with the small chimney capped the times were 16 mins to 50 psi and 18 to 70 psi, so a marked improvement. There is still a minor leak on the bottom union cock so when thats stopped the times should be even quicker. Now bear in mind this is a big boiler at over 9kgs so it also takes forever to cool down again, I checked it after 6 hours and it was still noticeably warm to the touch!!
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In my opinion, with a gas burner, running the exhaust through the chimney brings no benefit to boiler performance.
As to the steam plume, there are many variables that can influence the looks. Temperature of the ambient air, of the exhaust gas etc. A diffuser, as shown by Raphael, slows the steam down and makes it look more like smoke (notice that in my video there is no diffuser and the steam exhausts with speed, in a thinner plume).
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I think running the steam through the chimney increases the gas flow through by the venturi effect. Certainly Cheddar Models built their units that way. Interestingly I found the length of the tube inside the funnel was quite critical as if too short when you stopped the engine it caused a shock wave which put the burner out!
Tube had to be pretty near the top of the funnel but never had any issues since. To be fair I had reduced the diameter of the funnel to fit so this may have been the cause.
Interesting to see how you are proceeding.
Cheers
Geoff
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Wow this certainly is a monster thread for a monster boat and steam galore. The destroyer model detail is amazing and brought to life by such marvelous photographs. Thanks for sharing all the info about your boat and steam engines.
I am late seeing this thread but I have to compliment all you guys for such a lively and informative discussion. There is such a lot to learn from these 4 pages!
Maybe I read too fast and missed it-- have you said what the displacement of the model is?
Keep it up! Sure hope to see her go.
-Carl
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I have followed up on the steam from the engine exhaust entering the funnel and have been informed that on a gas powered boiler there is no advantage to running steam through the chimney where as on a coal fired boiler it is absolutely essential.
Also depending on how the engine exhaust is installed in the boiler chimney it may have a detrimental effect on a gas powered boiler. Have been advised that the safest option is don't put the engine exhaust into the boiler exhaust, but if you do then run it into the chimney, not the flue. So at least I now know how I am going to plumb the engine exhaust steam in when I get the boiler back in the boat.
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Well its been a while since I last updated, have been busy with other things and have not got near my boats for a while, any way to cut a long story short, I had been experiencing a leak from the union cock used to isolate the sight glass. So after spending time lapping in the valve and testing it, then doing it again and again, I then overtightened the nut on the end of the cock, stretching it and snapping it off. So replaced the valve and began lapping again, I now have finally achieved a steam tight seal. Today the boiler was up at 80psi, the safety valves lifting as they should. So happy, its now ready to go back in the boat.
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Hello!
Very interesting @ exiting project to follow up! I treally tke pleasure at it !
but if you do then run it into the chimney, not the flue.
I agree with KNO3 and maybe I can share my experience on this matter as I did some trials :
- Engine steam outlet entering in the bottom of the chimney = burner blow off when steam full open.
- Engine steam outlet inside a pipe along side the interior of the chimney = OK , no bad effect if the pipe is out by just a bit.
The Diameter of the chimney is designed for the amount of burnt gas and it has to be free to flow. Opening up the steam when engine outlet is inside the chimney creates a back pressure that changes the air/gas ratio and blows the burner off.
Remember that the gas combustion requires to be in ratio between 3 to 9 % by volume of air. Let say 6% is a good mixture.
Thus, knowing this , it is possible to know the flow rate of the smokes , ex :
- 100 g of gas per hour = +/- 160 cc of gas per hour represents +/- 6% of the total mixture .
So when we know the total volume of smokes passing through the funnel, we can calculate the surface opening to let the air inside the boat.
Although we can use the formula to calculate the surface needed to let the volume of fresh air intake , with common it shows that the size of this opening has to be a bit over the one of the burner surface. Obvious !
To make sure to be in the picture , add 50% minimum of this surface .
Fresh air= small volume IN through a 5x5 cm opening is plenty enough as the big volume of burnt smokes escapes from the boat through the top of the chimney
That is why I removed the computer fans that I first installed. There is always a way to create an opening above the burner big enough to supply with fresh air. It can be several entrances.
Hope it helps.
Regards.
[/i]
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Thank you KBIO, that's very useful, I did experience the steam extinguishing the burner flame on another model, it happened in the middle of the lake when the safety valve lifted with he steam being expelled through the funnel. It took a few moments to realise the flame had gone out, as the boat slowed down I turned for the shore, only for it to stop close enough to be reached with a fishing rod - so I will not be putting safety valve steam nor engine steam out the funnel unless the pipe is as you say exiting very close to the top of the funnel.
It occurs to me that I have not shown a photo of the union cock valve that has been causing me issues so here for completeness it is.
Also from the photos you will notice the gas tank sitting in water. Well this time I started with out the gas tank in water to see how well it worked. The boiler runs fine, it was quieter than on previous runs and as time went by the tank got colder, bearing in mind it takes 17/18 minutes to get this boiler up to temp. So after ten minutes I put the gas tank in the bath of warm water you see in the photo, well after just a few seconds the burner was louder and the flame visibly brighter. So there is a definite need to be warming the gas tank for this installation. The options are to use heat transfer (conduction) from the boilers burner via a metal sheet to the gas tank or to use the heat from the oil separator. However this second method would not supply heat to the tank in my case for about 20 mins so probably not an option. Anyway case proven for careful gas tank warming to maintain the pressure. One more thing to try/rule out or compare will be the performance with a disposable gas tank, since there is space for a c250 canister, will it be affected by chilling in the same way? it has a larger surface are for the gas to be produced from, will this be ok?
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Good morning DBS.
I agree with you that a canister will be better to reduce freezing the gas tank.
It has a larger exchange surface between liquid & gas : vapor pressure .
And the large surface of the envelope allows a better heat exchange between in & out !.
Now ! I am not sure that your N°5 jet (60 g/hr) is enough to supply enough heat to this boiler. Two Sun engines need a tremendous lot of steam They have to run fast and have no torque >> need a small pitch & size on the propellers , thus consuming a hell of steam.
Setting a larger jet size will improve the flame but will help cooling down and lower gas pressure faster , with the consequences you know.
It will not enlarge the boiler heating surface anyway. {:-{
i am very interested in you project and I shall take profit of it. Thanks for sharing. :-))
Sunny days are coming , I am eager to see your boat in the water ! :-)
[size=0px]only for it to stop close enough to be reached with a fishing rod[/size][/u]
And then you realize that there is no beer left in the cool box !! ;-))
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Please Admin , erase this one.
I knocked the wrong button! %)
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I can't remember if this has already come up. To keep the tank warm in my models I use the oil separator/exhaust steam/condenser which sits touching the gas tank. This provides a gently warmth and at the end of a sail the gas tank is hand warm which is just about right. The exhaust steam then goes out through the funnels (pipe exits at the very top). Have a look at the Velox thread which shows the layout.
Hope this may assist.
Geoff
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About the fuel tank cooling, you have to be very careful that you do not get the tank too hot. There are some burners that have been designed to be feed by the fuel in liquid form and then vaporize the fuel into gas. I built a tank and burner designed by Peter Arnot that did this, you started on gas and then switched over to liquid. I have a number of camping burners that are designed to do that.
Gerald.
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Hello!
I agree 100% with Geoff.
Although a gas tank can stand pressure well above 20 b ; a bottle of domestic propane can stand in the Maghreb's sun for days without any problem. Look at the thickness of an aluminium lighter refueling canister and you’ll be amazed of its capacity to stand pressure.
What about a simple cigarette lighter forgoten behind the wind screen of you car when you are at the beach for hours? ( Some accidents happened though!)
Storing the gas is not a problem. Our problem is how to manage the pressure on the line.
Chart.
When there is a need for a big jet and if when the gas tank is small , the better solution as Geoff says, is to feed the burner in liquid form and then vaporize the fuel into gas .
Remember that roughly, 1 drop of liquid is equivalent to 270 time of this volume gazeifed at standard conditions = +/ 1 b abs.
It is so easy that when you used it once, you never get away from it.
Ex ; https://youtu.be/-DOlBcpjUAo (https://youtu.be/-DOlBcpjUAo)
-The liquid comes directly out of the tank (notice the small size =+/- 100cm3) and flows around the burner. I did place a coil behind the burner to cool down the (hot) gazeous phase before entering the Gas attenuator & regulator to avoid any damage on the membranes.
Note that the jet is a 45/100 = +/- 300 gr/h and the pressure remains the same all along the video. It cxan las for ever though !
-The second video shows where to position the coil to manage the flowing temp. Fingers are the best tool.
You can have a direct line from the tank, around the burner sleeve and to the jet if you don’t use these accessories.
https://youtu.be/_OtxLoBW3Ww (https://youtu.be/_OtxLoBW3Ww)
Last is a pic of the simpliest set up I use when I am too lazy to install regulator or other attenuator.
Hope it helps and that my explanation is not too dumb Regards from the Frog ! ;)
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KBIO
I noted in the first video that you have a pressure gauge on the fuel tank, what pressures where you getting and was it steady or did it vary?
Gerald.
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Hello !
I forgot to tell : the flowing pressure remains steady @ 1 b (gauge) all along the video but can stand this pressure as long as there is liquid in the tank. ok2
we should be able to read the gauge pressure on the video at some time.
Take into consideration that the ambiant temp is 11°C .
With a summer temp of 20 °C, the tank pressure would be 2 b (gauge).
Would it be possible to share a drawing of Peter Arnot burner , please ?
Thanks for reading.
Cheers !
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KBIO thank you I will look into using liquid gas, that certainly looks like a useful option.
While I was looking at the video links I came across another of your videos testing a lovely looking Stuart Sun engine [size=78%]Tests with a 90mm / 4 blade propeller[/size]
The rotation speed obtained is 850 RPM at 2 b. The optimum speed is 750 RPM without pressure drop. Would love to know more about the boiler used to achieve those figures and anything else that may help. As you know the Torpedo Boat has twin Sun Engines and Twin 90mm 3 Blade Props, the boiler is designed to operate at uptown 80psi (5Bar) and drys the steam a little so your experiences are very valuable, thank you Dave
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Hello !
I forgot to tell : the flowing pressure remains steady @ 1 b (gauge) all along the video but can stand this pressure as long as there is liquid in the tank. ok2
we should be able to read the gauge pressure on the video at some time.
Take into consideration that the ambiant temp is 11°C .
With a summer temp of 20 °C, the tank pressure would be 2 b (gauge).
Would it be possible to share a drawing of Peter Arnot burner , please ?
Thanks for reading.
Cheers !
I loaned my copies of the Model Boats Magazines that had the article in them and they were not returned.
I think the plans for the Arnot V4 are available from one of the plans services.
If I find a copy of the plans I will post them.
Gerald.
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KBIO thank you I will look into using liquid gas, that certainly looks like a useful option.
While I was looking at the video links I came across another of your videos testing a lovely looking Stuart Sun engine [size=78%]Tests with a 90mm / 4 blade propeller[/size]
The rotation speed obtained is 850 RPM at 2 b. The optimum speed is 750 RPM without pressure drop. Would love to know more about the boiler used to achieve those figures and anything else that may help. As you know the Torpedo Boat has twin Sun Engines and Twin 90mm 3 Blade Props, the boiler is designed to operate at uptown 80psi (5Bar) and drys the steam a little so your experiences are very valuable, thank you Dave
Hi here for interest is the link to the video [size=78%]https://youtu.be/W3wWIkaz6_Q (https://youtu.be/W3wWIkaz6_Q)[/size]
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Good morning.
I do not recommend this type of boiler as it is vertical and weights 5 kg all wet ! The blow torch (now that I know how to name it ok2 ) is a 150 g/h
Also, in the video , I mention that the maximum RPM I can achieve without a steam pressure drop is +/- 800 RPM.
The Sun is designed to run faster but in the water with this propeller and the shape of your boat , 1000 RPM will be plenty enough I guess .
Also it is designed for Higher pressure. A 60/80 psi in a boat will make it.
I would personally use a double Scott boiler for your setting. But this is a personal opinion and there people on this forum who can tell more.
I think of Ooooyah who knows very well both of Sun and the Scott.But there some other too ! %)
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The inside !
12 x 5 mm boiler tubes.
It takes 5 mn to get 4 b.
Cheers !
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Peters burner was a modified Sievert blowlamp head
I have a similar design and will do a few pics next time in my playroom
cheers
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Before putting the boiler back in I thought I would try to see if my air brush compressor would supply enough air to run the engines, just wanted to make sure it all works before putting steam through. Well here is the result and yes I am a very happy man now. Next is to clean oil and double check it all over. Anyway here's a link to the long awaited time when we see these engines running.
https://youtu.be/wb_XawShVXY
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Ok things are moving on nicely now, have started disassembling the drive train to check all the lubricators work and to clean things up, after all this has been sitting idle for a long time. I am now more convinced than ever that this has never been run on steam. The unions and other fittings were only hand tight, all the paint looks pristine and there is no discolouration to the fittings. The photos of the engine are exactly as it came out of the boat I have not cleaned it at all. Also looking at the engine I have taken apart, my guess is that its a factory machined and assembled item. Bearing in mind its at least thirty years old its in stunning condition inside and out. I have now reassembled the engine and put some good quality engine oil in the sump and have cleaned and lubricated everything. Looking at the base that the engine has been fixed to, I believe that is far too clean for this to have been run. The second engine needs to come out next which is a bit more involved, so I am going to tackle that tomorrow.
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Have today taken the second engine out, stripped, cleaned and reassembled it. Having cleaned and lubricated both engines I have had them running on the bench on air for a few minutes, they are so smooth and vibration free, very happy. The engines run at 10 psi from my air brush compressor and turn over at a decent number of revs. So just need to clean the rest of the lubrication system and start reassembling ready to try it out on steam, hopefully over the weekend.Here is a video of one engine running on air
[size=78%]https://youtu.be/8sISydlrbCk (https://youtu.be/8sISydlrbCk)[/size]
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Today the engines went back in the boat and the boiler was connected. The weekend has been interesting, these engines are like new, one had a slight tight spot so has been run on the bench on air for a couple of hours and is now improved. One engine was definitely strong than the other, the one with the tight spot rotated slower and was easier to stop. I disassembled and reassembled, I believe the tight spot was with the shaft that transmits the rotation from the crank up to the valve. Anyway its now sorted. While the engines were out I took advantage of the improved access and place a kilo of lead sheet in the bottom of the hull. The boiler is resting in the hull in the right place and connected so I fired it up tonight. There are a couple of minor leaks to sort and a list of other jobs to do to complete the refurb, but tonight was a major milestone achieved. Here is a link to a video https://youtu.be/LSvODiIzG0U
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Yves,
Further to your post No 110. Feb. 24Th regarding fitting 2 - Scott boilers to Dave's boat as you can see that it's far too narrow to fit double Scott boilers.
I think that his existing boiler is large enough to power the 2- Sun engines, but how how fast and long will have to be tried out at the lake.
You must remember this is a truly untested model and will require lake side testing.
George.
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Your engines run very nice on air. Looking forward to the steam test.
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I am going to start with a big thank you to everyone who has helped me get this restoration to this stage, it is appreciated, and you have certainly made the task easier. This afternoon I did some problem solving, which I enjoy. From the first run there were some leaks, a couple were easy fixes just tightened the bolts to the banjo fittings that connect the steam and exhaust to the engines. The next problem was steam passing down the oil pipe from the mechanical oiler. To solve this the main steam pipe assembly was removed. Then the small fitting that takes the oil into the pipes was removed. The nut at the top was seized solid so had to be persuaded loose with some heat from a blow torch. The ball valve and seating were cleaned and reassembled, then the whole steam manifold reconnected.
As you will remember these engines are geared together, so in effect they are one engine. One thing I had learned from stripping the engines down was that the timing on the engines was the same, they were connected at 180 degrees, so there were always two pistons up and two down. I moved the timing so that the pistons were at 90 degrees. The aim was to make the paired engines self starting and hopefully run more smoothly and quietly. The next thing I wanted to learn was the effect of putting the gas tank close to the burner, so rigged the refillable gas tank up to the burner and placed them together in the hull. The boiler was then fired and run, I was hoping to learn if the working temperature would be achieved quicker, but I had not filled the gas tank sufficiently and it ran out of gas after ten mins (what an idiot) anyway it was refilled and the boiler fired again, what I can say is that the flame burned consistently strong and the gas tank was warm to the touch not hot. Here is a link to the video of the second run on steam, the engines did run smoother, there is still more things to learn. [size=78%]https://youtu.be/dZJYVJrQiSc (https://youtu.be/dZJYVJrQiSc)[/size]
(https://youtu.be/dZJYVJrQiSc)
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Good morning !
Smells and sounds good! :-))
Cheers!
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Great progress and lovely to see and very well done indeed. I think you may need a larger gas tank depending on gas consumption but experimenting will see how it all works.
Next step is on the water or in the paddling pool!
Cheers
Geioff
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Good job David, I can't see any steam leaks and the engines run very well on steam too.
It looks like the oil pump is turning very fast though. You should check that it doesn't feed too much oil to the engines at that speed.
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Nice one Dave :-))
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Something a bit different tonight, I was sent a picture of the Ward Room from a Thornycraft torpedo boat destroyer built two years later than HMS Daring, its the ward room from HMS Bruiser. Have also attached a section of plan showing the layout of the ward room as built, from HMS Daring. So while these ships did incur the extra payments for hardworking, the style, elegance and workmanship that went into building them are stunning. Anyway thought the pictures were of interest.
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Have taken three steps forward recently with this project and now a couple backwards. The third time I ran the engines I connected the engine driven water pump and the hand pump to fill the boiler. All appeared well, then I found a puddle of water below the tank, I know I had spilled some water, but despite my best efforts to dry it water came back, so being paranoid I took out the on board water tank to check it over. Also the engine driven pump worked, but not as well as I thought it should, so have stripped it down replaced the balls and reassembled it. Another job was the oiler to one of the propshafts was blocked, so took the engines out, disassembled the gearing and removed the prop shaft, gave it all a good blow through, oiled and reassembled it, being careful to make sure the timing for the engines is at 90 deg so they are self starting and run smoothly. Good news the tank was not leaking, I had just spilled more water than I thought I had . Anyway they were all jobs that needed doing so we are closer now to a run in the test tank, just a couple more runs on the bench first to learn as much as I can about the oiler, steam valve and gas settings.
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What type of new balls did you install in the pump?
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The balls in the pump were the nitrile balls, both the same size. The lower ball was sticking to some grease on the end of the pumps ram, it was therefore pulled sideways rather than dropping on to its seat. I changed the balls for steel balls because that’s what I have in my spares box, I also put in a larger, heavier ball in the bottom. I will hopefully run it tomorrow, to see if it now works?
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Steel balls work all right with proper seating, but rubber (nitrile, viton etc) are sealing even better. Can't you re-use the nitrile balls?
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Each time I run the boiler I try to achieve some progress so today I have run the boiler and engines again, this time with a slightly larger gas jet, a No6 which is 0.225mm, the No5 jet was 0.2mm, it was quicker to get the boiler up to temperature and it burned cleanly. When previously I tried the No8 0.25mm jet it did not burn cleanly, so No6 is better. I also tested the engine driven water pump and that works a lot better now. What today has shown is the need to fit a water bypass valve from the engine driven pump - there is not one at the moment so no way to set the amount of water entering the boiler. The onboard tank holds 1/2 a litre of water so will get the water to recirculate back to the tank with enough going to the boiler to maintain a steady level - I guess this will take a bit of trial and error to get the balance right. Also the oil separator is far to small so need to sort that out now as well.
I won a bid on Ebay for a Victorian Magic lantern slide of HMS Daring, not quite sure what I will do with it, but it is a nice thing, here is a photo of the slide, as you can see HMS Daring looked quite impressive on the water.
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It may be worth re seating the ball, easy to do drop the ball on the seat and tap it. I have found that nitrite balls can become out of shape after a while and therefore will not seat properly.
Keep up the good work
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If you do the re-seating, ideally you should use new balls as valves, as the ones used for re-seating can get distorted.
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Thank you all for the advice re the balls in the pump. I did clean the valve body out and indeed did give the steel balls a gentle - ish knock to seat them. Have run the boiler a couple more times since, the pump is working so much better now. Have also run the boiler at a higher pressure than previously, now 60 psi for the last couple of runs, it certainly seems to work better with he No6 jet and at the higher pressure.
Any way its time to move on to some other jobs. I may have made a novice mistake, if I have, feel free to laugh. To improve my knowledge of radio control I bought a book and it suggested that the servo for the rudder needed to be strong because the load on the rudder can be quite high and that the servo could stall and or draw lots of current and after all a boat with no steering is not a lot of fun. So being new to radio control and with this boat being larger than average I thought I would upgrade the servo. Now I wanted to buy a servo to install a remote on/off for the gas supply, so figured I would buy a new heavy duty servo for the rudder and re purpose the old one from the rudder to the gas valve. The old servo is a Futaba FP s148 which I have heard is a reliable servo. The new servo is a Ripmax Quartz, with metal gears and body, it has 17 - 20kg torque so significantly more powerful.
The push rods on the old set up had been bent, so upgraded to 3mm push rods and an aluminium servo horn. I dismantled rudder assembly. The rod holding the rudder is 5/16 inch dia, and the rudder solid metal, it weighs the best part of a kilo, a very solid item that's not going to get bent that's for sure. I greased it all and reassembled, checked it works and here's the results.
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That rudder is substantial indeed. Can't hurt to have a strong servo for it.
In my experience, reversing mechanisms on engines and steam valves can require some force (depending on the construction, they can get harder to move when they are in steam), so they might need a strong servo. I think you'll be able to tell during steam tests if the servos you are using are up to the job.
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I have been experimenting with a different burner set up, one that takes liquid gas from the tank, then vaporises the liquid in the pipe before the burner, will take some photos next time I have it set up on the bench. In the mean time I am trying to finish off a few jobs. One that I have been keen to install is a remotely controlled on/off for the gas supply so in the event of a problem, for example a fouled prop, the gas supply can be turned off from the bankside, also it saves taking off the covers to turn the gas off before lifting the boat out of the water. Next was to install a gas attenuator to turn down the flame at a pre determined pressure, in this case it will be 75psi, just before the safety valves lift at 80 psi. I have tried to install the gas valve, the servo and the attenuator all on one compact bracket.
I thought I had plenty of space, which I have, but it was still a fiddle getting the nuts all done up. I also silver soldered the joints, now this was only my second attempt with silver solder so quite pleased. On the small pipe, the two nuts are obviously captive, I inadvertantly overheated one of the nuts, softening it, as a consequence it went out of shape, which was a pain. I got it back into shape luckily with a bit of pressure and using a 1/4 40 tap to get it round again. Setting up the servo to was also a fiddle, but again I put this down to my lack of experience, I certainly learnt a lot. The highlight was using the mini pipe benders, shaping and fitting the pipes whilst trying to make the installation look neat. Have tested the servo operation, the gas goes on and off as it should so next is to fire up the boiler and get the attenuator set up - hopefully later today. The first photo show the bracket holding the gas valve, servo and attenuator, the second shows the complete set up with the gas valve closed and the third with the gas valve open.
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Lovely bit of work Dave
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Bonjour Dave,
I fully agree with you, all the boats should have a gas attenuator (often improperly called gas regulator) and a RC safety gas valve, even when this one has a problem ! https://www.youtube.com/watch?v=DNTjVqbhezs
1 failure for more than 50 steam plants, I would say it is a reasonable ratio ;)
Besides this, I always operate at about 30 PSI, it is quite enough to my opinion and saves steam / autonomy :-))
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Apologies for the lack of progress and updates, life and other distractions have got in the way. One of the distractions was another boat new to my fleet that shares something in common with HMS Daring, it too was the fastest boat in the world, so I have had some fun learning how to set that up and run it, it was an exhilarating experience. Anyway back to HMS Daring, previously I had set up the gas attenuator, together with a rc controlled gas shut off valve.
Well tonight I have used it for the first time but have had no luck with it, and I am a bit baffled.
With the pressure regulating knurled nut all the way to the right, where there is no weight on the spring the gas was not turned down, boiler reached 70 psi. (see photo from previous update above)
With the pressure regulating knurled nut 2/3 the way to the left, plenty of weight on the spring, the gas was not turned down boiler reached 70 psi. (see the photo for this update)
I thought maybe the screw for adjusting the pilot flame was the issue so have turned it in as far as it would go then back a 1/4 turn, still the pressure goes all the way to 70 psi without turning the flame down.
The attenuator is the P5 boiler pressure regulator from Jin in China, have connected it as per the instructions, any advice on setting it up will be most welcome thank you.
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Not sure what could be wrong, but have you looked inside, at the diaphragms, if they are in good shape and sealing well? Sometimes they can get distorted.
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Bonjour Dave,
Please watch my videos, even in French, I hope they will help you, I have several of them from Microcosm or other manifacturers :
Control the diaphragms ! https://www.youtube.com/watch?v=aU37YAuOkKM
Set Simple diaphragm : https://www.youtube.com/watch?v=7iE1wBIhKUc
Set Double diaphragù : https://www.youtube.com/watch?v=pvwAnXhN4WE
To summarize my procedure, if the membranes are in good condition, there are two parameters to manage, the cut-off pressure and the power of the idle flame, I recommend adjusting them one after the other. In any case, the large spring for adjusting the cut-off pressure must "float", it must always be at a minimum in tension. I can manage to operate my Microcosm regulators at around 1.5 bar : https://www.youtube.com/watch?v=Wzb2Y0TZU1U
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While we are at the gas system, have you considered adding a gas filter? In the past I have made my own, simply by inserting some cotton wool into the pipe close to the gas tank, but I have seen Regner sells a very looking gas and water filter that uses replaceable cigarette filters inside:
https://www.regner-dampftechnik.com/product-page/wgl-filter-m5x0-5
https://www.gardenrailways.co.uk/regner-20222-wgl-filter.html
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Cigarette filters! That's a clever idea.
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Hello Dave !
Nice set up ! :-))
If I can tell something concerning the adjustment of the screw controlling the pilot valve, I think that opening by 1/4 turn is far too much.
I would say that 1/8th to 1/16th is enough.
Here is a poor video that I did for an English friend who wanted to calibrate his Anton V71.
https://youtu.be/RdZVReZpGgw (https://youtu.be/RdZVReZpGgw)
Having troubleshooted some friends one, I would have a lot to say about this Chinese stuff! :D But it does the job, though !
The spring of those attenuators are ranged up to 3 kg on Anton's one. The one on the Microcosm are mostly set to 2 kg. At least those I had to trouble shoot. Which matches roughly to an average working differential pressure of 2 b.
You have a boiler pressure of 70 psi. Depending of the surface of the membrane you may need more gas pressure. Probably 40 psi.
70 psi - 40 psi = 30 psi = within the range of the spring.
But as I say, it depends of the membrane surface. It still different with a double one !
I hope it helps. ;)
Beer time !! %)
Regards.
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Thank you for the advice and helpful videos, they are appreciated. Before I removed the boiler pressure regulating valve from the boat I thought I would check to if there was any pressure from the boiler reaching the valve, so disconnected the nut and pumped water into the boiler, the result was water coming out of the pipe, so the pipe is definitely not blocked and there's a healthy plug of water in the pipe preventing hot steam from making direct contact with the diaphragm. So being out of options I removed the valve assembly. I then disassembled the regulator valve to see if there was anything wrong with the diaphragms and found a small tear to one side on the boiler pressure diaphragm. I then disassembled the rest to check the gas diaphragm, this looked to be ok. Now a spare set of diaphragms is supplied with these valves so I swapped them both over, reassembled the valve and refitted into the boat, hopeful that the issue would now be resolved. I have just tested it and it does not seem to matter where the knurled nut that controls the pressure is, if its complete loose or fairly tight, it made no difference. Adjusting the pilot screw makes a difference, the flame can be turned down or up with that, but its not being altered by the boiler pressure, the boiler still keeps increasing pressure, dependent on how far open the pilot is? So for some reason the boiler pressure is not closing the gas off. At least I can still run the boat without removing the valve. Here are the photos of the valve, your thoughts are welcome.
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I have just had a go at making an oil separator tank for HMS Daring, its a job I have been putting off for a while. I had a box of scrap bits like we all do, in it was a section of 42 mm pipe, a 42 mm straight coupling, some 8mm pipe and some 3mm pipe. Now its not the tidiest bit of soldering in the world, but it will do as the prototype to see if it works ok. Since the boat has two engine and two chimneys I decided to run the exhaust from each engine into the tank and then take two exhausts out of the tank, to run one to each chimney so that steam comes out of both funnels. Having listened to earlier advice, the exhaust will be run external to the boiler flues but internal to the models funnels to hopefully achieve realistic steam plumes, so that accounts for the 4 x 8mm pipes sticking out of the tank. The next thing I did was to insert a coil of 6 turns of 3mm copper pipe into the tank, this is two of the smaller 3mm pipes, the idea is to pump the boiler feed water through the coil and for the heat in the oil separator to heat the water so that hot water enters the boiler rather than cold. This should help the boiler maintain pressure and use less gas. The last 3 mm pipe is the pipe for emptying the oil separator tank. The square patch is where I covered a hole after deciding to re-sight the pipe used to the empty to the other end of the tank. Next job is to get it all plumbed in.
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I sort of see where you are coming from Dave.....however....just a little observation......you should not be able to see anything coming from the funnels, because if you are seeing something it means you are seeing steam vapour's, which means the steam into the engines is not being superheated enough and you are seeing the exhaust. On full size of course they were burning oil /coal which is what you see on their exhaust funnels not steam vapour.
The pre heat is of course a great help and as you say will help the gas consumption. Carry on the good work ( and don't worry about the soldering...the result works and that is the main thing)..
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Phil, thank you, you made me think and you are right about the steam dryer, it should mean no steam out the funnel once everything is up to temperature. On start up quite a bit of water flows until things hot up, then it decreases. The set up the boat came with had very limited capacity and long uninsulated pipe runs to the boiler chimneys as a result the water collected soon exceeded the capacity of the oil separator and pipe work so I had to do something. I made the oil separator with a massive increase in capacity. The idea was that the water would collect in the tank, then later, hopefully very hot steam would then pick up some of the water and then pass out of the separator to pipes that exited near the top of the models funnels. Like many ideas its not been 100% successful, more steam out of one pipe than the other, so some balancing required as well as some dispersion so the plume looks more natural. Next I will have to rework the pipes in and out of the oil separator since too much water was being carried out along the pipes to the funnel creating an unwanted mess. So not ideal, more work on it required. Any way here is a video of the engines and boiler running plus the red silicon piping for the oil separator. https://youtu.be/o5hhbtoC7To (https://youtu.be/o5hhbtoC7To) And here is a photo of the original pipework and small separator that I have removed.
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Apologies for the delay, Its been some months now since HMS Daring was on my work bench, I have been learning more about steam on other projects, so now its time to get back to finishing HMS Daring. Tonight was a gentle test run to refresh my memory as where I had got to. You may remember that I had a problem setting up the gas attenuator. Well on another project (Lady Sarah) I have successfully installed and set up an identical attenuator, so have brought the lessons learned to this project and after going through the process for setting it up I have concluded that there is actually a problem with this item, I cannot get the pilot flame set so will have to remove it and strip it down again to try to identify the problem. Anyway, it gives full gas flow as it is so carried on to warm the boiler and raise steam. The engines were run and the oil separator tested again, this time after running the engines for a few moments I emptied the separator and then continued to run the engines - the result was much less condensate being ejected, so will continue with it. Next steps then to sort the gas supply out and run the engines for longer. Here is a video clip form tonights test run https://youtu.be/ezn9fEKSv-k (https://youtu.be/ezn9fEKSv-k)
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Hello !
Always a pleasure to follow up your post Dave. :-))
Unfortunately , we cannot get away from the first condensation until the engine warms up.
I use to empty the separator when all is hot and put the boat in the water then.
I am eager to see your boat sailing ! ok2
Regards.
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Very interesting and I'm watching this thread with avid interest. Well done on the restoration. I recon it will be very fast in the water!
Cheers
Geoff
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With help and guidance from fellow mayhemmers I realise that the design of my horizontal oil separator could be improved upon so thank you for your input, as always, it is appreciated. For now I will make some changes to the piping to and from the separator and if it does not work well enough I will then change the design to include the ideas and feedback received, thank you.
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Some changes to tidy up the pipework for the steam exhaust have now been made. I re used and modified some of the original piping, so the exhaust from each engine now goes into a larger dia single pipe the steam the exits the larger pipe via two copper pipes and enters the oil/water separator via short red silicone tube connections. The steam then leaves the separator via two exhaust pipes which are temporally run up the sides of the two boiler exhausts. The boiler was run this morning and the new set up tested. The test was also to verify that the engine driven boiler feed pump was actually pumping water. The photo shows the newly arranged pipework and the video shows the results, the exhaust steam is now better balanced between the two outlets and the separator is working better. The lesson here is that even though the oil separator is bigger it still needs emptying very soon after start up, then it all runs a lot better - less messy once everything is hot. Good news the boiler feed pump is pumping. The original set up has the pump going direct to the boiler and no control over the amount of water going in; it may be that a clever engineer has set the gearing up so the right amount goes in, will connect it up and see what happens, however I suspect the next job will be to set up a bypass valve so that the amount of water going to the boiler can be regulated more precisely rather than just on engine speed. Here is a link to todays steam test of the oil separator and the boiler water feed pump. https://youtu.be/9iReAIsxd2A (https://youtu.be/9iReAIsxd2A)
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Vey nice and very well done!
Cheers
Geoff
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I had a bit of luck recently and obtained a genuine article from The Engineer published in August 1894, the article and pictures are about the engines used in HMS Daring and Decoy, so here for your enjoyment is the glorious engine that was fitted in Daring, Decoy, Ardent, Boxer and Bruiser. Each engine has Four cylinders, one high pressure 19 inches dia, one medium pressure 27 inches and two low pressure at 27 inches each with a 16 inch stroke. The crankshaft is an impressive 6 3/4 inches in dia
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https://www.gracesguide.co.uk/Main_Page :-))
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..... are some of those cylinders at an angle ???
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ooks like a V4 😊
Ned
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It looks like the cylinders are set at an angle to allow simpler connections between them with a straighter run of piping. It looks like the left cylinder is high pressure with the medium pressure third from the left and the low pressure second an the rear.
Jim
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So after a few assumptions %) ....[as have labeled cylinders 1, 3 and 4]
It appears there is a cast steel Steam spool piece between the exhaust of the No 1 HP cylinder, and intersecting between the exhaust of No 3 LP cylinder to the inlet of No 4 LP cylinder?
The text quoting the single Mediuum Pressure as 27", and the pair of Low Pressure cylinders as 27", maybe a typo?....
so...
1. what is that transition spool piece?
2. is there a dimensional typo with cylinder dimensions?
However as always I will stand corrected by others with far greater knowledge of such engines
Derek
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There's about half a page of explanation plus another drawing on the same page (p191) but I don't know how to separate a single page from a pdf file which is about 15mB. If anyone wants I'm quite happy to e-mail it.
Tony
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Here is the other picture of the engine which should answer some of the questions, will type up the relevant info tonight and post it here. Thank you for the interest and discussion
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So after a few assumptions %) ....[as have labeled cylinders 1, 3 and 4]
It appears there is a cast steel Steam spool piece between the exhaust of the No 1 HP cylinder, and intersecting between the exhaust of No 3 LP cylinder to the inlet of No 4 LP cylinder?
The text quoting the single Mediuum Pressure as 27", and the pair of Low Pressure cylinders as 27", maybe a typo?....
so...
1. what is that transition spool piece?
2. is there a dimensional typo with cylinder dimensions?
However as always I will stand corrected by others with far greater knowledge of such engines
Derek
I see that as the exhaust from no 2 the medium pressure cylinder at the back (not labelled by you) going into a link pipe to both the low pressure cylinder intakes. The linking pipe from no1 to no2 can't be seen as it is behind the front low pressure cylinder.
Jim
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I have the actual page, its 127 years old, here's the important info. "the principle feature in their design is the inclination of the engines, which there are four in number (This is referring to the number of cylinders) high, medium and two low pressure - over hanging to port and starboard, the low pressure engines are the after most. --- when one piston is at the top of its stroke the other is at the bottom. The foremeost couple of course give twice the power given by the after couple and exert their turning moment on the crankshaft at right angles to that of the latter. (This was done to stop vibration) The dia of the cylinders are as follows HP 19inches, MP 27inches, two LP at 27 inches each with 16 inch stroke. There were two condensers each of 2100 sq feet. The crank shaft is of steel, 6 3/4 inches dia at the journals and 7 1/2 inches day at the pins. The connecting rods are hollow steel. The cylinders are cast iron bolted together. Hope this helps, there is more, but my typing speed is not that great, so you have the most important info, thank you for your interest.
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So the explanation & confirmation of the cylinder/s location and orientation explains the cross over spool from the exhaust of No 2 Medium pressure cylinder, over equally to feed No 3 and No 4 Low pressure cylinders
Still, a very complex and compact engine.... O0 it is written, that matters of War deliver solutions beyond normal expectations
Derek
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For the second half of the equation, there's a very detailed and sometimes heated debate in the June 23rd 1894 edition of The Engineer regarding the benefits of the water-tube boiler over the locomotive boiler and the Thornycroft ones in Daring were used as an example. At that time destroyers such as Havoc and her sister ship Hornet would carry 2 locomotive boilers or 8 water-tube boilers respectively, with the same displacement, so direct trials could be carried out.Again, e-mail if you want a copy. About 15 meg
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Some free (has to be, Yorkshire frugality) PDF "splitters" can be downloaded. One I regularly use is "Bytescout PDF multi tool". Can split AND compile back. Splits to various options.
Clever Vee design reduces overall length of engine and solves individual cylinder valve chests not interfering with each other, look at triples.
Regards Ian.
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That’s been a useful discussion on the engines and thank you for getting involved. I have now seen this for sale on an auction site, it’s the drawings for the boilers, absolutely fascinating
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I suppose they're the forerunners of the flash steam boilers used in "racing" model steamers!
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"Yarrow" type, high steam generation, Flash steamers have no water space, coiled tube.
Regards Ian.
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OK Ian, a halfway point then %) but not Yarrow in Daring. Yarrow generally had straight tubes while the Thornycroft ones had the curved ones to allow for the tubes to take up any distortion caused by differences in temperature between different areas. The downside of the curved ones was the difficulty in cleaning the tubes. The Whites actually tried spiral water tubes as but had major trouble getting good enough pipe to bend and rejected a lot of it. That said, they built a prototype in 1890 for an Admiralty launch and it worked well apparently.
It's certainly a great subject!
Tony
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Its been a while since I posted any progress since I have again been distracted by other steam projects which I hope to share with you. I will be back and getting on with the renovation soon. In the meantime my research and interest in HMS Daring continues and I have recently come across this account of the Stoker on board HMS Daring, Frederick Paffett, who was awarded the Albert Medal. The Albert Medal (For Gallantry In Saving Lives At Sea) is one of only 216 that were awarded. The award was made for his very brave actions on HMS Daring in June 1901 when a disaster occurred to the torpedo-boat destroyer. An explosion in the number 2 boiler happened whilst Fred was in the stoke-hold. As a result steam filled the stoke hold and the five crew inside were severely scalded – two so badly that they never recovered. At the time of the explosion, Fred was near the ladder, he helped the men to safety before returned to the stoke hold and opened the steam valve of the starboard fan to prevent a further explosions. Fred was badly scalded by the escaping steam, in particular his left arm which was shielding his face. Freds injuries left him badly disfigured, his face was scarred and his left arm almost useless. This account is based on the story from the Portsmouth Museum and Art Gallery, for the full details and full information please visit.
https://portsmouthmuseum.co.uk/collections-stories/stories/frederick-paffetts-courage-at-sea/
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In the early years the navy was going for all out performance with ever greater speeds contracted for in future designs. So machinery ran at it's maximum, the structure of the hulls was as light as possible, and space was kept to a minimum to keep the hull as small as possible. Accidents like this must have been quite common until the navy realised that a slightly larger more capable all round design was superior, such as the River class and beyond.
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Also for your delectation:
Hopefully this will show up.... [size=78%]torpedo boat destroyer remains - Bing images (https://www.bing.com/images/search?q=torpedo%20boat%20destroyer%20remains&qs=n&form=QBIRMH&sp=-1&pq=torpedo%20boat%20destroyer%20remains&sc=0-30&cvid=8554A1653C4D4EEB9ED6D67F8508823E&first=1&tsc=ImageBasicHover)[/size]
[size=78%]3552048707_246e508bb1_n.jpg (320×110) (staticflickr.com) (https://live.staticflickr.com/3409/3552048707_246e508bb1_n.jpg)[/size]
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ballastanksian (https://www.modelboatmayhem.co.uk/forum/index.php?action=profile;u=14161) thank you for your sharing those links, its much appreciated.
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My pleasure. It feels wrong to let these pieces rust away there but as they are an incomplete article I am not sure what could be done with them unless the Historic dockyard could use them in a display.
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Hi, let me start with an apology for not updating you recently. When I started this thread in November 2020, I mentioned that the renovation of this lovely torpedo boat destroyer was a diversion from my main project, which is the building of HMS Wren, with two steam engines. I have not abandoned HMS Daring, she is currently residing on the top shelf in my busy (messy) basement work area, and I will continue and will finish it. In the photo HMS Wren is the bare hull sitting below HMS Daring, then to the right is my experimental workhorse the Lady Sarah an open steam launch with engine driven pump taking water from the lake, below that another fascinating steam boat and in the white box is the boat that started all this, a twin engined steam tug with full automatic boiler controls.
So in the background I have been working on developing HMS Wren, or things that I need to build HMS Wren. I have been learning about and experimenting with automatic boiler controls. I have been experimenting with different boilers. The engines I wish to use need two servos each (one to select forward or reverse and the other to control the throttle) so I have been looking into mixing servos so that 5 (5th servo is the rudder) servos are controlled on one tx joy stick. I have been looking at pumps to decide whether or not to use an engine driven pump or an electric pump and whether to use an onboard water tank or take water form the lake. All of these I am learning about so I can make final decisions for the build of Wren.
HMS Daring is close to being finished, I have learned a lot from the gas installation and it has an engine driven pump. The tasks left now are to reconnect the pumped water supply to the boiler, for this I am going to install a bypass valve, since original build does not have one. Then the boiler will need another safety test and certificate, then it should all be good to go. Thank you for your continued support with this project.
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We each have our own way of seeing and conducting our hobby and so if you take a break then take a break. A hobby is not a job. Try not to get bogged down by deadlines as that makes your hobby like a job. Budgets are different, as we need to eat as well as make models!
No one here would gripe at you if you were taking a break from a project, so apart from being courteous, you need not feel bad abut having slipped off the radar for a while. Your other models look great, and you are enlightening us with ideas, which is a silver lining.
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Hello !
I would say that ; the longer we are waiting, the better it is ! ok2
I love this workshop with several projects going on depending of the mood !
The sun is coming back soon and we all are on starting blocks ! :-))
Have a nice day !
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We all quite understand the distraction with other projects but glad to here its still alive and well and we will see more in due course.
Cheers
Geoff
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Wow, can't believe how fast the time has gone by. Its been 15 months since my last update on HMS Daring and in all that time she has sat on the same shelf patiently waiting. I am determined to finish off some projects so that my work space is clear. The club I belong to exhibited their boats at the Kempton Steam Museum recently, so knowing there would be a specially built pond there I took HMS Daring along to finalise the ballasting. I know she is sitting low in the water, this is because with less ballast the stability was fragile. The weight of the beautiful guns could not be in a worse place, so to compensate extra lead low down in the hull has been added
With the ballasting sorted the next step is to get the boiler steam tested and hopefully out on the lake for her maiden voyage, which will be a momentous day, since this model was started more than 30 years ago.
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I have now taken HMS Daring to our Clubs boiler testing day and am pleased to say that the boiler passed and as part of the steam test that the safety valves operated as they were designed to, operating at just below 80psi ensuring the boiler didn't get above 80psi.
Next step is to put the radio gear back into HMS Daring, to check it all works, check all the oil and water levels and get her ready for that first run on the lake. It needs to be soon since the weed is growing fast, and I don't wish to get caught out, so will arrange a day and time asap with fellow club members.
Here is a photo of HMS Daring on the bench raising steam as part of her steam test.
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Lovely to see the progress and we all look forward to the next instalment!
Cheers
Geoff
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Amen! She looks a treat! I do like the guns (I wonder if I wrote that some time before?) They're still good O0
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I have now put the radio gear back into HMS Daring and have set up the rudder using the end points on the transmitter to give the maximum angle possible. I fear trying to turn this model round is going to take a lot of space, and lets not forget, there is no reverse! The next priority was to adjust and make sure the radio controlled gas cut off valve was working as it should via channel 5 a two way switch on the transmitter. That way if there is a problem I can remotely cut the gas supply.
Undertaking the boiler and steam test also confirmed that the small gas tank had enough gas to heat the boiler and do a run, also with the way the tank was placed next to the burner, the tank never gets cold, its just feels warm so the gas pressure dropping off is not an issue.
I also changed the way the oil separator was plumbed in, by using white silicone with a 6mm internal diameter, this has slowed the speed of the steam and stopped it spaying very hot water out of the exhaust and over the decks! Whilst I had the white silicone to hand I also used it to insulate the steam pipes from the boiler to the engines and from the engines to the oil separator - it looks nicer than the red silicone that I had previously used.
I have filled the boiler, topped up the engine oils in the Stuart Sun Engines wet sumps, filled the steam oil reservoirs and used all the drip feed to oil the prop shafts, gear box, mechanical oiler, water pump) and for the first time, I also screwed down all the various deck hatches, so HMS Daring is now ready for her maiden voyage.
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Yes Dave, this new white silicone sheathing is a huge improvement & cleaning of the inevitable oil on dust surfaces of the steam tubes will be a so easy :-))
Is the FWD chimney on the model just a dummy?, with all exhausts via the AFT chimney?
Have you resolved the splitting of the rubber diaphragm on the 6 bolt side gas regulator from May 21?
Derek
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The forward chimney is the main flue from the boiler. The boiler is a return flue boiler and unusually has a second smaller chimney which is the one with the brass end cap and silicone pipes, this I use to ignite the burner as you would for a normal center flue boiler. The way its set up at the moment, steam will only be visible from the second chimney.
Re the attenuator, I have learned a lot from installing it, setting it up, repairing it, running with it etc. That said its not working at the moment, the gas is in free flow and to be honest, for this model, its probably not needed so is likely to be removed. If gas control is needed, a far better and more reliable system is the Dénes Gas Control Unit. Here is a link to a video of me trying it out on my Proteus set up, its very impressive in the way its able to maintain the boiler pressure and best of all no issues with diaphragms, springs etc. https://youtu.be/_R2GHkaP1vM (https://youtu.be/_R2GHkaP1vM)
Help has been arranged (standby rescue boat and assistance at the lakeside) for the maiden voyage so will update you soon!
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Thursday morning, the day before Fridays planned maiden voyage, I received bad news from the lake, the sailors with their deep keeled yachts had got stuck in the weed and the electric rescue tug they used had not faired much better! The weather forecast for Friday is for a chilly morning with blustery winds, 15 to 25mph, so far from ideal.
My friend and fellow steamer visited the lake late in the afternoon and suggested that a clear route exists, he also confirmed he was happy to attend in the morning and undertake some weed clearance. So the car is loaded with everything I might need and I have slid HMS Daring into the car with her bow stretching out between the driver and passenger seats.
I decided to make a final decision in the morning at the lakeside, whether to sail or not. For the rest of the evening, I will be nervous and worried, the weed and wind are playing on my mind, and like any other maiden voyage a healthy degree of uncertainty is adding to the tension.
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Hello Dave,
Crossed fingers ! On our pond, we have the same concerns and, with 1.50 m deep and high boots, we manage, admittedly with difficulty, to get out of it in the event of a blockage.
Your beautiful boat deserves good conditions and even after more than 16 years of practice and a large fleet, I am also very nervous for my maiden voyages.
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As forecast, the morning weather is cold and I am concerned about the wind and HMS Darings stability as well as getting caught by one of those blustery squalls that appear out of nowhere. There are three large matts of weed visible and I know weed won’t be to far below the surface in other areas. My friend has cleared a route straight out in front of the jetty and history suggests that there is quite a large area in the middle of the lake that should be ok, but thats where HMS Daring will be at most risk from the wind. We debate using a tether and one of us using waders and keeping near the bank, but thats putting someone at risk, then there’s the weed and uncertainty about the turning circle. Long story short, it would be a long time before the weed dies down, so it was now or wait till the autumn?
Decision made, I filled the boiler with hot water from a flask and fired the boiler and checked that the rc gas cut off valve was working, very important with the risk of getting tangled in the weed, then relit the boiler. Waiting for the boiler to heat up and reach pressure gave me time to reflect on all the help and advice that I had received, without the support of members of this forum HMS Daring may never have been finished and brought to life. I have learned so much from you and working on her and have enjoyed making something work that had never worked before. This maiden voyage was very important for me but more so for HMS Daring who had waited more than thirty years for this moment.
The boiler pressure took what seemed like ages to begin to rise, the cold was not helping. With the gauge at 30 psi the steam valve was opened and the engines gently warmed, the oil separator was then emptied and the steam valve closed again so the boiler could get up to its working pressure of 80psi. The boilers steam valve was opened, the rc throttle was opened a little and the engines began to turn, carefully HMS Daring was carried to the lakeside and lowered gently on the water, the props made the water gurgle as they bit the surface. Now it was important to keep the revs up, since it was by no means certain that the engines would restart if they stopped and there is no reverse. My success criteria for the maiden voyage was for her safe return without mishap, that the ballasting was ok, that the rudder worked as it should and that we learned from the experience.
HMS Daring was swung through 90 degrees so her bow pointed out through the narrow weed free channel to the open water beyond. Whilst we held her back, the rudder operation was checked again as was the throttle, she was ready to go, but was I ready to let go? Is anyone ever ready to let go on that first voyage? Then in an instant she was off, heading for open water, the plan was for her to go out, do a large circle and come back the same way as she went. The steering and turning ability, bearing in mind this model is 8 feet in length and is not using tank steering, was a pleasant surprise. I feared how much she may roll in a turn, but again this was unfounded. The wind blew but again was not too much of an issue; it as not worth chancing things too much, so I stuck to the plan and turned her back towards the shore. To be honest, HMS Daring looked quite menacing as she steamed back. The speed was reduced since there is no reverse and no way of stopping her. Thankfully another club member was there and he filmed the return, so here for your enjoyment is a link to that video, you have been very patient waiting for this moment. Once again thank you for your support.
https://youtube.com/shorts/CpTrw6otAi0?feature=share (https://youtube.com/shorts/CpTrw6otAi0?feature=share)
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CHAMPAGNE !! :-))
What about the boiler pressure when you slow down for a while ??
Cheers !
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Bonjour David,
Un seul mot "BRAVO", ce voyage inaugural est une belle réussite :-))
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Bravo Zulu to you. Great to see her on the water after your restoration. Bet you are really proud of her :-))
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Yes Bravo..........she cuts across the wind with ease & I understand scale %) ...but you could consider an oversiized rudder to help attain tighter turning, but remembering she is an 8' long hull
Derek
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Congratulations and very well done. Really nice to see her in her proper element!
Cheers
Geoff
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Thank you all, I will admit that I had to look up what Bravo Zulu meant, every day is a school day, your support and well wishing is appreciated. Well what a difference a few days make, here is the lake one week after HMS Darings maiden voyage! No chance of being back on the water until the weed cutting and clearing has taken place.
I like to be straight with you and having reflected on the maiden voyage, whilst it was a success, in that we have a boat that looks and behaves properly, the ballast and stability were fine, the electrics, radio control, engines and boiler all worked, there is definitely room for improvement in terms of performance. Another positive is that the down time due to the weed will give me time to implement a few changes. So this is not the end of our voyage together, there is more to be done.
The issue is one that some of you, along with myself have suspected. In my case I probably didn’t want to believe it, I just wanted to get HMS Daring on the water and prove that she worked - which we have now done, so now its time to face the issue which is, we are not making enough steam fast enough. Its an age old problem faced by many steam boat builders. The boiler is a well made return flue boiler and is efficient in that very little heat leaves via the chimney, so the heat from the burner is going into the water. What needs to happen now is that I need to get a lot more heat, a lot faster into the boiler.
Initial research into getting more heat via the current burner reveals that this well made custom burner is performing at its best, so the gain in performance that I would like cannot come from this burner. That means I am now going to experiment with different burners and have been advised that this type of boiler works best with a blow torch burner. Now some of you may remember that this boat came with a brand new unused burner, that was not suitable, and to be honest, quite frightening!
My experiments are going to be with different types of blow torch burner with different gas jet sizes to get the best flame for this boiler. Since we are likely to be using a lot more gas, to combat the issues of gas pressure drop and tank freezing I will also have a look at using gas from the tank in liquid form and turning the liquid into gas using the heat of the burner. If you have experience of using gas blow torches in your model boats I would love to know the type of burner and gas nozzle size that you are using.
Here are photos of the lake yesterday and the original blow torch burner.
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The blow torch burner or heat output being sought, is to generate enough steam to run the pair of twin cylinder single acting Sun engines at a higher speed for longer that they currently do. The pair of Sun engines in this model are the equivalent of a Stuart D10. So the steam needed is for four cylinders, each of 3/4 inch bore and 3/4 inch stroke, times the number of RPM - Your burner or blow lamp experiences gained from powering a Stuart D10 or similar will be very relevant and help point me in the right direction - thank you
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Hello !
The SUN engine was rather designed to run on Flash steam (or Semi Flash Steam) for an optimal performance.
It is a single effect engine which requires a lot of steam to achieve high RPM.
Whatever the burner , the engine will take what the boiler gives and the boiler will give what its heating surface can produce. Your Stuart boilers are excellent.
Having a bigger burner will not help unless the ones you have are undersized.
A SUN engine can take 60/80 psi . So I would work out the propeller pitch to reduce the RPM for a maximum torque and a steady speed.
And remember ; the loveliest woman in the world can only give what she has ... ! %% {-)
https://youtu.be/kO-MtxlxLbQ
(https://youtu.be/kO-MtxlxLbQ)
https://youtu.be/zaq5XqA3gaQ
On the video , the gas supply pressure is 0,4 b (6 psi) . But can be 1 b (14,7 psi) Must be liquid supply with a loop around both burners tips for gasifying for a steady supply. The hotest is the gas , the better it is .
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I suspect with the cylinder piston volume you have, maybe an easier way to increase the speed would be to change the props for larger coarser ones. Not only should this increase the speed as they are creating more thrust but may also increase the duration by reducing steam consumption. I can't remember if the original props are three blade, if so go to four blade for the same reason.
On my Canopus I use 50mm four bladed props and once I made the change from much smaller three bladed the speed literally doubled as did the duration.
Its all a question of trial and error.
Good luck, she is beautiful!!
Cheers
Geoff
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KBIO thank you for the additional information and very informative videos, I am looking forward to experimenting further with the blow torch burner, different gas jet sizes and also with liquid phase gas supply, will update you on progress but it may not be for a couple of weeks now.
Geoff, you are right about prop sizing and about how much difference increasing the prop size makes, its certainly the easiest and most cost effective way of increasing the performance. I have considered changing the props, increasing their size and number of blades, but, decided the current props were probably OK. The model is fitted with two 3 1/2 inch dia 3 bladed props, I could go to 4 inches and four blades, but they would then be almost touching each other which I assume, being so close to each other would not help their efficiency.
Here are a couple of photos of the rear end of HMS Daring showing the rudder and the props, I love the way the engineer who built this boat has carved out such a magnificent hull shape to accommodate the props, its a work of art, and in my mind probably the most beautiful part of this model, its a shame that most people miss seeing the work that went into this area of the model.
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As an alternative would it be possible to bend some more pitch in the props. This would give more bite without needing the extra blade or diameter.
Jim
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The propellers appear to be soldered, so as JimG questions ...'would it be possible?' to increase the pitch of the blades
Propellers for steam often have a ratio approaching 1.5 pitch to diameter...the propellers fitted to the vessel appear to be in the order of 0.7 pitch to diameter
Constructing a simple wooden jig to hold or clamp 'a single blade', then used in conjunction with a fixture [bench vice] could provide a relatively uniform adjustment to the pitch of each blade
An increase in pitch would place a greater load on the engines, reducing the engines speed, increasing thrust and running time
Derek
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It would be interesting to know what the pitch of these props actually is; is there a way to find it out?
As it happens I have a four inch, four bladed Prop Shop, prop so have taken some photos of it besides HMS Darings 3 Blade props, this may or may not help the discussion about the pitch of the current props. How does its pitch of the 4 inch prop compare with the current 3 1/2 inch props?
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How To Measure Propeller Pitch
http://www.ricepropulsion.com/TNLS/Manual_Pitch.htm (http://www.ricepropulsion.com/TNLS/Manual_Pitch.htm)
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She looks fab on the water! Small scale steam does seem to be a great challenge that exercises the hobby, A chap wrote a series of articles in Model Boats back in the day where he built a metal model of Dreadnought and then installed dental drill air motors to use as steam turbines! I recall these having promise, but lacking power due again to lack of steam flow/pressure. I don't know how he got on as the articles were written about eight years ago.
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I have all these articles and it was a very interesting and valiant attempt and an interesting concept using dental drills. I seem to recall whilst he got it working the steam consumption was high and he had to start them with a drill as they were not self starting. I suspect the internals of a dental turbine are very different from a steam turbine.
Back to the TBD - if you have a prop shop prop would it be possible to fit it on one side and see if produces more or less thrust/speed. It would then give a direct comparison under identical circumstances which may provide some guidance. If its on the port side and the model turns to starboard then it would suggest more thrust.
A friend of mine commented that the "Sun" engines are best suited for high speed so a smaller prop and higher revolutions may give a better result, trouble is if you go that route the steam consumption will be higher. I always think of a boiler as having so many "bites" of steam so if you use them slowly you get duration, if you use them fast you get speed but less duration!
I look forward to the next instalment with interest. Very well done indeed.
Cheers
Geoff