Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: ROSYTH on August 10, 2009, 02:11:14 pm
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Hi folks, just doing a little trawling off the net and came across this little beauty in engineering terms of a Model Steam Plant, not sure if i have or could get a boat for it to fit into but I would certainly like to try.
http://www.youtube.com/watch?v=NLndiRu_Gls
The video has only had 182 views so thought it was still new enough for others to have a look at and just wonder what the hell they were doing in their workshops compared to this fella {-) {-)
I think it would be a good idea to give this chap some feedback on his skill/s although I think he knows already :}
ENJOY
Cliff
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Wow, that's really impressive. I saw two Stuarts built in there too.
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WOW!!! Thanks for posting that- just stunning- wish it had a boiler to go with it- now if only we could nick it and we had a model big enough......... %) ;D
Greg
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Hi Kno3,
There are actually 5 ST engines in there- the two most obvious are the Sirius genny sets, but there is also a twin launch in there, a ST feed pump and a beautiful modified 10V- he's put an extra cylinder on top to make it into a steeple compound!!! Truly clever guy!
Greg
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WOW!!! Thanks for posting that- just stunning- wish it had a boiler to go with it- now if only we could nick it and we had a model big enough......... %) ;D
Greg
Okay, when do you want to go {-) {-)
What a piece of engineering though..............right down to that bloke walking up the steps having checked all his pressure gauges first off course..... {-)
CAN YOU FIND ANYTHING ON THE NET AS GOOD AS THIS..............IF SO POST IT FOR ALL TO SEE OK.
Cheers
Cliff
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Funny you should mention Mr Mini-engineer- the builder has gone to the trouble of making the steam plant probably one of the best model plants in the world- but his engineer is in 'blues', he should be in 'whites' if he's in the engineroom- blues are apprentices and plumbers- funny really- I wear blues every day at work, then whites on SY Gondola! {-)
Greg
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C'mon then folks, who would like to guess at just how long this piece of Art took to make............
Certainly longer than a month {-) but it must have taken a good few years assuming this chap had OTHER projects on the go then
it would most certainly have been his pride and joy.
If i had made it!!!!!!!! not much chance there then {-) I don't think I would have wanted to pass on to that big workshop in the sky
knowing someone else was going to get there mits all over it. So thank goodness for Glass Display Cases eh!
I think I will enquire a little more into it for us by contacting the museum directly and see what information they can pass on to us, thats
if folks would like to know!!
Cheers
Cliff
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Hi ROSYTH,
Double any guesses- look carefully in the background- there are two sets!!!!!!
Greg
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Funny you should mention Mr Mini-engineer- the builder has gone to the trouble of making the steam plant probably one of the best model plants in the world- but his engineer is in 'blues', he should be in 'whites' if he's in the engineroom- blues are apprentices and plumbers- funny really- I wear blues every day at work, then whites on SY Gondola! {-)
Greg
Whites (well more a sort of grey after some use) for Engineers and Apprentices. Blues for POs and ratings. Apart from that excellent (blue) boiler suit I got off the Yard Manager at a certain French docking.
Barry M
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Many thanks to Ruaridh for uploading this amazing video to You Tube. Don't know who the builder was though.
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There was a guy that was building a full steam set for a Yamato (from memory).
I'm certain I took pictures of it at a show once, I'll have a look later.
anyone else remember it?
Just found this but the link is dead....
Posted by: Jack Rose on 10/05/2003 20:36:26.
I am currently building a steam plant to fit into 9ft long 16 inch beam fibreglass model of the Japanese battleship Yamato (Westward Mouldings). The main propulsion is provided by 2 scale model (Stuart Turner) triple expansion steam engines, the auxiliary services (condensers cooling water pump, small car alternator - for radio control and other electrics, bilge pumps, etc.,) from a horizontal scale model mill steam engine (Stuart Turner No. 9) and feedwater supplied by a steam powered (Southworth Engines) duplex boiler feed pump. The feed pump is controlled by my own design of float controller in a small auxiliary vessel piped into boiler (similar to the principle of a toilet cistern water level control). All the engines have condensers and feed back to a water tank, which supplies the boiler feed pump forming a closed feedwater system. The boiler has been built to my design based on a scotch marine type with "Inglis" modification, essentially a return tube boiler with an additional return path, providing a 3-pass passage through the boiler for the flue gas, it is heated with a blowlamp run on liquid petroleum gas (LPG - propane). The boiler runs between 100 and 120 psi (The main part of the boiler is about 10 inches long by 7 inches diameter and there is a single furnace tube, 2 inches diameter - the main burner blowlamp is about 1.25 inches diameter).
The flow of LPG gas (at about 30psi) is controlled by a gas pressure controller that I have cobbled together for the boiler blowlamp (a standard Sievert/Primus No. 2942 rated at 15.5 kW, 1200 gms/hour propane gas, at 2 bar (26 kW, 2000 gms/hour at 4 bar), which is run between 2 and 4 bar mainly dependent on the electrical loading on the steam driven alternator). The controller consists of a metal bellows sealed gas valve assembly with the control screw removed and replaced by a diaphragm unit (taken from a pressure controlled electrical switch) to operate the gas valve. The sealed pressure side of the diaphragm unit is connected to the boiler and the boiler pressure pushes against the pressure tight diaphragm to operate a short rod on the atmospheric side (which formerly operated the switch) that pushes shut the gas valve as boiler pressure rises. There is a small blowlamp (a standard Bullfinch 1075 Btu/0.32 kW burner) connected directly to the gas supply to act as a pilot lamp.
You can see the pictures of my battleship, its steam plant and me at this website:
http://groups.msn.com/TELsGlobalModelEngineering/shoebox.msnw
under "Jack Rose Battleship" and "Rogue's Gallery".
I have, however, a major problem in that I currently only have one triple and need a second (I have the condenser for it), the person who was going to make it is no longer able to. Could anyone else who may be able to help please contact me.
Many thanks
Jack Rose (Lt.Cdr. (Submarines) RN retired), Brighton
http://www.steamboat.org.uk/hotair/hottopic.asp?view=%201,2,3,9,new,req&expand=yes&topic=40
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I have been in touch with the Museum and having had a reply from them as acknowledgement I am awaiting further info. I have also asked if they have a catalogue of exhibits on the Marine Engine side of things and gave them my name and address etc in case they should decide to put something in the post...........we shall see though........
If any other info arrives I will post it as usual for all to see.
Cheers
Thanks for that bit of info you had Martin, as you say the link is dead now but it might be worth following up from the SBA Forum link etc...........what say you?
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Rosyth,
I spoke to the maker of that engine a few years ago via email. He's an elderly German man, He has a model of the Titanics engine of similar size. He was frustraited with Harland and Wolf as they wouldn't give him the engine prints. His research suggested that the Titanic engine had tailrods, so he built it that way, but when video of the wreck became so famous, he was angry to find that Titanic did not carry tailrods.
The engine in the video is as discussed in the book "Steam At Sea" my study is a disaster at the moment and I can't put my hand on the my copy of the book, but it was one of the largest marine recip steam plants ever built....that is a model of it. I have more pictures of it, but needless to say, it ALL is functional....gauges too. The video doesn't even begin to do it justice
That steeple cylinder arrangement seems odd, but that is exactly how the original was built.
Dave
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Ahhhhh
found the pictures that he sent me of both plants
His name is Karl I am leaving his last name off, as I have not asked for his permission...as I remember he is a rather quiet man,and I don't know how private he wishes to be. If you guys think I am off base here, say so, as his skill is quite amazing and he should get the accolades. However, as the video was evidently taken in a museum, I am afraid the worse has happened....in which case it probably doesn't matter anymore......
The big model engine in the video is from the steamship "Deutschland"
(http://i164.photobucket.com/albums/u27/mcandrew1894/Deutschlandpictures.jpg)
I have pictures of the Titanic engine and an interesting cut-away of the Salvage Tug "Jjissel" with dual triples of the same level of quality.
As time permits I can post some more pictures.........
Dave
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:o :o :o
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Hey Barry and Greg....you'll notice the fresh water evaporators front and center? :o :}
Those are the ones I was talking about.....
Dave
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Got you Dave, cheers.
Greg
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Thanks for the pm Dave, appreciated.
I will do a little chasing and see what happens, but as you say if its now in the Museum.......................!!!!!!! I will find out though for sure.
What a craftsman, those images you posted make it seem more detailed than i remember in the video.
A WORK OF ART.
Thanks Dave
Cliff
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Maybe this weekend all with the pictures.....a lot going on at the moment
Do let me know Cliff, and your welcome, it's Karls masterpiece and it should be seen by all.
Dave
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When the Mersey Dock board disposed of their Massive Leviathan suction dredger .i was with the crowd who shut her down for her trip to Holland ,her pumps were powered by huge triple ex ,a lot on the lines of these .A Local photo person took pics ,as they were so impressive .and you must see the Beauty of these steam wonders .I am lucky to have worked on the real things ,on a ship . fantastic to whoever put these on .well done .nice to see a bit of real /common coming thro .
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Apparently he has some of his work on the web already.....so I don't feel obliged to withhold anymore
http://titanic-model.com/db/db-03/hahn.html
Karl Friedric Pohlmann....here's a link to the Titanic's engine model. I have pictures of this also.
Dave
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Steamer ,many thanks . just looked at the pics you posted .Fantastic .
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Your welcome Dave!
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OK Here is some more pictures of the Deutchland and the tug Jissel in 1/25th scale....this takes a while to do.
(http://i164.photobucket.com/albums/u27/mcandrew1894/scan0001-5.jpg)
(http://i164.photobucket.com/albums/u27/mcandrew1894/Karl2.jpg)
(http://i164.photobucket.com/albums/u27/mcandrew1894/karl3.jpg)
(http://i164.photobucket.com/albums/u27/mcandrew1894/karl4.jpg)
(http://i164.photobucket.com/albums/u27/mcandrew1894/karl5.jpg)
(http://i164.photobucket.com/albums/u27/mcandrew1894/karl6.jpg)
(http://i164.photobucket.com/albums/u27/mcandrew1894/karl7.jpg)
(http://i164.photobucket.com/albums/u27/mcandrew1894/karl8.jpg)
I still have pictures of the Titanic's Engine to scan....
Dave
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I've had a reply from "Jack"! Result!!
Dear Martin
If you go to:
http://www.flickr.com/photos/commander-popeye (http://www.flickr.com/photos/commander-popeye)
you can see all my photos. A selection of photos of the Yamato and its steam plant are in the photo set called "Jack Rose Boats and Train", at the end of the list of sets. I have many more on my computer, but these provide a good summary and explanation of what each picture shows.
Regards
Jack Rose
(http://farm3.static.flickr.com/2323/1756356283_43b0fa53df_b.jpg)
http://www.flickr.com/photos/commander-popeye (http://www.flickr.com/photos/commander-popeye)
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WOW, thats the only word for that kind of model plant, the amount of hours put into that thing!!
My one and only criticism is that the engineering is first class, the layout spot in, but the plumbing is attrocious- such a shame to ruin a beautiful plant with plastic tubing, 'pigoen droppings' solder and fittings that are skewiff- if he re-piped it and took his time it would be far better in my eyes- not that I would say no if he offered me it O0 :-))
Greg
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Yes I noticed that Greg, 'hose-clips' etc but when asked Jack said it was a very much evolving engine and changing all the time, so when something finally worked properly and harmoniously with the rest of the plant, it was remade to a polished finish.
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Blimey--now having seen that little lot, I feel inclined to hang up my tools. {:-{
really amazing work, how could you ever top that :-)) :-))
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Phil I know exactly the way you feel , I feel it too when I see a model like that or a musician playing and instrument like you and I breath, its very intimidating. The mountain suddenly seems very big!
But I think thats a short sighted way to look at it really, we should enjoy the beauty and wisdom of a master and learn from what he or she is teaching us...
We should then just strive to be better.....
I think it took Karl a lifetime to combine the skills, experience and knowledge to create that master piece ....We can not begrudge that. .I suspect it will take us no less if that is vocation of choice for our hobby outlets, but look at the path already cut! It's all there for consumption and study in photographic form. We should take advantage of this as a learning opportunity. "How did Karl do it?"
Dave
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I knew I had photos somewhere... actually taken by my mate John Bass.
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Hi Martin,
You wouldn't happen to know why he used a fairly low speed mill engine using a gearbox with chains instead of just using a high speed vertical with direct drive 'a la originale'?
Greg
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Now I have seen Johns pics before, and I have to say with engines like those, why oh why did he use a standard ST diplacement lubricator, not sure he would have got enough oil into those triple expansion engines........ still nice expermintal work, which after all is what most of what we do is (my excuse--and sticking to it)
gonddolier--high speed engines (in small size) not as efficient geared as the triple is stand alone, I do say there is an awful lot of bits on there, which====== well we all have our own ways (but commercial plumbing fittings---after all that work------------yuk) Other than that, labour of love :-)) :-))
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Hi Phil,
I wasn't talking about the main engines, I was asking about the ST mill engine (No.9?) which has a chain driven gearbox running a 12V alternator- a much easier/efficient/lighter way of doing it would be to hook a Sirrius, or even a Cheddar Puffin with a double speed gearbox (much easier to engineer), with direct drive to the alternator shaft- all that chain and gears- non of it with tensioners on so will have so many loadings on it you won't believe- I bet he uses so much fuel it would scare a lesser man!
Greg
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Just thought i would pass on an email I received back from the Museum with regards to my initial enquiry on the builder of the Fantastic Steam Plant.
===========================================================
Dear Mr. Smith,
thank you for your query concerning one of our steam engines. It is the portside engine of one of Hapag's express liners named "Deutschland" (1900). The model was built in 1990 to 1995 by Karl-Friedrich Pohlmann, scale 1:20. It is a four cylinder compound engine with 17.000 PSi (indicated horse power).
Builders: A.G. Vulkan, Stettin; 16.502 BRT; Length 208,5 m; Width 20,5 m; 34.000 PSi; 22,5 knots; Crew: 557; Passengers: 429 I. Cl., 226 II. Cl., 284 III. Cl.
Yours sincerely
Dr. Axel Griessmer
Internationales Maritimes Museum
Peter Tamm sen. Stiftung
www.internationales-maritimes-museum.de
____________________________________
Vorsitzender des Vorstands: Prof. Peter Tamm (Vorsitzender), Lutz Erntges, Heiko Hermans, Prof. Dr. Hermann Schäfer Sitz Hamburg
And the Second reply back to that...................................
Dear Mr Smith,
yes, Mr. Pohlmann (aged about 80) is still with us and is working on the portside engine of R.M.S. "Titanic"! We have no catalogue concerning our house or literature concerning those modells. We only have them in our exhibition. Sorry for that. But please see the adress of Mr. Pohlmann. I think he will be very pleased if you contact him:
***Personal details removed by moderator***
I am sure this man has a lot valuables in his workshop.
If you wish to contact the gentleman concerned, please PM Rosyth for details.
Kindest regards
Dr. Axel Griessmer
So having that information I will shortly be writing to Mr.Pohlmann, yes WRITING as i suspect he doesn't do email :o and hopefully if he replies I hope he will include a few images of his latest project that will make up the pair of Steam Engines to complete his project.
Off course i will post any pics and reply he sends me and i hope to see more of his work in the near future.
Cheers
Rosyth
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Rosyth,
He did do email....unfortunately, that address died with my last PC......Please say hello for me!
Dave
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What a shame you lost his email............oh well back to pen and paper I guess but I will off course mention you in writing and the Forum too.
You never know he may just sign on as a member 8).
Cheers
Rosyth
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One could only hope!...
Here is one of the port engine of Titanic.
(http://i164.photobucket.com/albums/u27/mcandrew1894/Titanic1.jpg)
Dave
PS here is the back of the bottom picture
(http://i164.photobucket.com/albums/u27/mcandrew1894/backof1stphoto.jpg)
These engines are similar to the engines of a Liberty ship that controls the link position.
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What's this fitting / feature?
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Martin,
That would be the Thrust bearing assembly. The brass tubes are for water cooling.
All propeller thrust is directed to those bearings( there are several lined up one behind the other). That's what makes the ship move essentially
The pump in the foreground is the cooling water pump for the bearings.
Dave
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Absolutely perfect!
Just wish we could see a bank of four boilers all linked up and steaming it! :-)) :-)) :-))
Greg
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Now that would be a welcomed WISH indeed................1700psi full size.........it's a true monster of steam.
If only it could all be hooked up and run just once, filmed for all to see and archived with all us steam nuts........now i am dreaming but maybe I could suggest it
when i put something down on paper to our Mr.Pohlmann later this week :-))
Can't wait to get his reply 8)
cheers
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Ah! I see. Thanks for that... you can learn all sorts of stuff on here!
Next question what's the big worm gear set-up?
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Hi Martin that's the 'barring' engine- because the engine only has one high pressure cylinder, if that cylinder was to be at either TDC or BDC then it wouldn't start- also on starting such a large engine it takes at least a couple of hours for it to warm through, before then the steam condenses in the cylinders.
The barring engine would move the flywheel around so the engine was moving already when steam was admitted- it would also be used to slowly rev the engine with a small amount of steam on to warm the cylinders through without putting any power to the shaft.
Greg
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Steam turbines also use barring gears to turn the turbine over at slow speed when steam is shut off. This allows the turbine rotors to cool evenly and not hog. the same applies on startup. The turbine is put on barring gear well ahead of steam admission (several hours in many cases), this takes the droop, or sag out of the shaft to reduce vibration to within acceptable limits when steam is applied. When steam is admitted the turbine runs up and rolls off the barring or turning gear as rotor speed increases.
Before starting turbines, even on barring gear, lubrication oil is forced into the bearings under pressure to lift the shaft on a film of oil. This is done with high pressure jacking pumps. The jacking pumps continue in operation until there is enough turbine shaft speed to form a reliable oil wedge between the shaft journal and the bearing. I would expect a large marine engine such as that pictured would have a similar arrangement.
John
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Hi John,
Yes your correct, however due to a reciprocator not having anywhere near the same rev's it's nowhere near as complicated- although pressured oil systems were in use on relatively small plants, >30Hp, from around 1890, although typically it was just total loss some of the higher spec Belliss & Morcom, LIFU and Sissons engines employed pressured systems.
The pressure systems used the sump as a reservoir, pumping through a filter using a drive off the crankshaft- the most ingenious method was, I think, on a Belliss engine that had oil-ways in the shaf so oil was fed to one end, doing so lubricated the main bearings and the big ends- quite before it's time I think you'll agree.
Greg
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A very important use of the barring engine was for warm up. As Greg pointed out, steam engines condense a great deal of steam during warm up. Steam is compressable, condensed steam....otherwise known as water, is NOT compressable. If the engine has a large sum of water in the cylinder when started , it will in all likelyhood break a cylinder head, piston rod or connecting rod when the piston comes up against the slug of water in the cylinder.
At warm up, some steam is bypassed around the thottle and feed to the engine, but with the cylinder drains open. This is a small amount, and not enough to run the engine. Then if the cylinders are steam jacketed, the jacket steam is started to warm the cylinders. Not long after the the barring engine or turning engine as it is sometimes called is engaged, and it turns the main engine over slowly with the cylinder drain cocks open, distributing steam through the entire engine, instead of just where the steam can get to while the engine is stationary.
Big engines like this would move around a great deal, and warming them was a laborius and time consuming operation, but absolutely necessary.
Once warmed, the turning engine was disengaged and the engine could be started as usual.
Dave
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Ah! I see. Thanks for that... you can learn all sorts of stuff on here!
Next question what's the big worm gear set-up?
It has a couple of other uses as well. As has just been described prior to putting the engine on line you would turn the engine over with the barring gear (also nowadays known as simply turning gear) with the indicator or drain cocks open to prove the cyliners are clear of condensate prior to starting. If this isn't done there is a potential danger of hydraulic locking, which can seriously damage running gear if you try to start the engine. Turning gear is still used today on diesel engines and is still used to determine that the cylinders do not contain water from say a head joint, valve cooling jacket or injector cooling leak.
Another important use of the turning gear is when maintaining the engine. The engine is regularly required to be turned during dismantling and reassembly of running gear and the engine is turned to the appropriate position to facilitate removing or replacing of fastenings. Finally the turning gear is required when checking the timing of the engine. Marks on the flywheel will align with a pointer on the entablature and will show the correct position of all pistons and valves to enable the timing to be checked. Once again this is still used today to check the timing on diesel engines and the flywheel will be marked with top dead centre for each unit and an angular scale to enable you to determine when valves are opening and closing as well as when injection starts and stops.
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You should see the barring gear on SY Gondola...it's a bar!!!! Takes some turning I can tell you!! O0
Greg
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Same thing on Sabino Greg,
Dave
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In answer to Martin's earlier question about the thrust bearing on the Titanic engine. I thought he may like to get some idea of what the inside of a thrust bearing looks. I've included three shots to show the thrust surfaces on the crankshaft, the lower thrust half in place and finally , the upper thrust half installed. The brass box on top is for bearing oil and the worsted wool oil wicks.
Granted this is a much smaller triple than the Titanic engine, but the principle is the same.
John
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Thanks Oldiron.....got any shots of the rest of your boat?
Dave
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Likewise, thanks Oldron, very interesting.
I was expecting roller trust bearings but with such a large lubricated surface the actual PSI (correct units?) would actually be quite low..... yes?
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Here's the rest of the vessel. She runs a triple in a 94 foot hull built in 1915. She was commissioned by one of Canada's financial elite, Timothy Eaton. The vessel has a composite hull. That is, its wood below the water line and steel above.
The engine looks a bit messy, but I took the picture after I'd finished reassembling her from a complete tear down.
John
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aHH YES the "Wanda" I have seen pictures of her before...you should put up a thread on her.
I am sure many here would love to see her.
Thanks for that!
Dave
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aHH YES the "Wanda" I have seen pictures of her before...you should put up a thread on her.
I am sure many here would love to see her.
Thanks for that!
Dave
Perhaps I will. I'm off to the UK this morning, for about three weeks. I'll look into it when I get back.
John
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And yes Martin the actual pounds per square inch would be low and with proper lubrication, so is the friction.
There was mention of the pressure used with Titantic as being 1700 psi.steam pressure.....No. Probably more like 200 psi steam pressure
The USS Ohio which was contemporary, was a fast ship with high specific output for the weight of machinery...for its time...and her 4 legged triple ran at 250 psi.
Dave
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Steam turbines also use barring gears to turn the turbine over at slow speed when steam is shut off. This allows the turbine rotors to cool evenly and not hog. the same applies on startup. The turbine is put on barring gear well ahead of steam admission (several hours in many cases), this takes the droop, or sag out of the shaft to reduce vibration to within acceptable limits when steam is applied. When steam is admitted the turbine runs up and rolls off the barring or turning gear as rotor speed increases.
Before starting turbines, even on barring gear, lubrication oil is forced into the bearings under pressure to lift the shaft on a film of oil. This is done with high pressure jacking pumps. The jacking pumps continue in operation until there is enough turbine shaft speed to form a reliable oil wedge between the shaft journal and the bearing. I would expect a large marine engine such as that pictured would have a similar arrangement.
John
I wouldn't stay around to see the affect of shutting off the lub. oil pump supply to turbine bearings. Oil is always supplied to the bearings under pressure and once rotating, the shaft creates the oil wedge. The oil supply not only lubricates the bearing, it also cools it and the oil, once it has passed through the bearing, drains back to the sump.
Shutting off the lub pump should cause the turbine to trip-out on the low-pressure trip. Should the trip not operate the bearing would empty, the shaft would drop and contact the white metal bearing which would then overheat and cause the white metal to run. Thereafter there would be much lamentation and cursing as engineers turn-to to fix it.
Normal lub oil pump discharge pressure as I remember was about 30psi.
In respect of the thrust block depicted in the Titanic engine model, thiat type of multi-collar installation became obsolete once Mr Michell invented his tilting bearing pads and the thrust collar was reduced to a single piece. Setting up a muti-collar thrust block must have been a bit of anightmare. The tilting bearing pads in the new Michell thust block allowed an oil wedge to form between the shaft collar and the bearing thus greatly increasing their load-bearing properties and removing the need for multiple collars/bearing rings.
Barry M
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I wouldn't stay around to see the affect of shutting off the lub. oil pump supply to turbine bearings. Oil is always supplied to the bearings under pressure and once rotating, the shaft creates the oil wedge. The oil supply not only lubricates the bearing, it also cools it and the oil, once it has passed through the bearing, drains back to the sump.
Shutting off the lub pump should cause the turbine to trip-out on the low-pressure trip. Should the trip not operate the bearing would empty, the shaft would drop and contact the white metal bearing which would then overheat and cause the white metal to run. Thereafter there would be much lamentation and cursing as engineers turn-to to fix it.
Normal lub oil pump discharge pressure as I remember was about 30psi.
Barry M
True oil is supplied to the bearings via a pump at all times, however, there is a separate circuit for jacking oil to create sufficient pressure to raise the turbine shaft from the bearing surface. The regular lube oil pump doesn't create sufficient pressure by itself to do the xjacking, but more in the way of volume to carry out continuous lubrication.
John
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John,
Having sailed with turbine plant from 12,000 to 32,000shp, I have never come across a turbine plant with separate 'jacking pumps'. The standard lube oil pumps were all that were needed to create the oil film and lift the shaft sufficient for starting. Once the shaft starts to revolve, it and pump pressure, create the oil wedge itself as its tries to climb the bearing wall.
What ship did you see the system on?
Barry M
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John,
Having sailed with turbine plant from 12,000 to 32,000shp, I have never come across a turbine plant with separate 'jacking pumps'. The standard lube oil pumps were all that were needed to create the oil film and lift the shaft sufficient for starting. Once the shaft starts to revolve, it and pump pressure, create the oil wedge itself as its tries to climb the bearing wall.
What ship did you see the system on?
Barry M
I've worked steam power plants for many years, from 300MW to 700MW units and they've all had separate jacking oil pumps.
John
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John,
Are you talking about marine plant?
Barry M
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John,
Are you talking about marine plant?
Barry M
Nope, stationary plant.
John
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Hi,
Heres a qoute on Titanic's machinery;
"Titanic's hungry furnaces consumed 825 tons of coal per day, generating 51,000 horse power. During normal operating speeds, Titanic's steam pressure was set to function at 215 psi. Reciprocating engine revolutions were 77 per minute and her turbine revolutions were 127 per minute. 14,000 gallons of drinking water [read pure water- evaporated probably-greg] were used each 24 hours."
Greg
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Great to see and read all this Steam ,from my experience ,the turning gear was the first thing to be engaged after F W E .then it was a case of the usual before a hammer test .Steam men will know all this .All i have from my days are a lot of memories ,but kept a drip feed lub cup ,and a fusible plug from a coal fired job .. But these photos that you are bringing out ,they are Brilliant and the memories flood back . Well done and thankyou .
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Hi Dave301,
What was the coal fired vessel you served on?
Greg
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Sabino....as a volunteer engineer for 12 years....burned soft coal
Dave
oooops wrong Dave.....Sorry Dave301
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{-) Oh, I know about you Dave, I know ALL about you Dave..... :-))
Greg
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Nope, stationary plant.
John
John,
Thought so; it's certainly not marine practice.
Cheers,
Barry M
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Any word on Karl Rosyth?
Dave
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Hi folks, well I sent the letter off quite some time ago now but as of yet still not received a reply from the good man himself.
This could be down to his work level or build time or just old age!!!!
All i can do is wait really and hope we get a reply on what he is currently building and at what stage he is at with the other engine to match the one in display.
I will off course let all know when and if something drops through the door ok.
Some good stories and info been generated here on this piece of kit and steam in general so thanks, keep it going.
Cheers
R
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Thanks Rosyth,
Well in the vain of keeping it going.......
Here' one I helped to restore......19.75 x 29.5 x 30 compound from the tugboat "Pegasus"
I'm the big guy with dark hair hanging on the reverse lever with both hands.........somebody in a time long ago "disabled" the throttle balance valve and if not careful would pick you up off the ground at 25 psi. :}
(http://i164.photobucket.com/albums/u27/mcandrew1894/Daveatpegasus-s.jpg)
Dave
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Lovely compound Steamer, what make is it? Looks very simillar to a Sissons, but they tended to be smaller than that? Did it go back into the tug?
Greg
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IIRC it was made at Mare Island along with the tug. The HP piston and piston valve have no rings ( !) Just a good fit.
Not unlike some Stuarts I've seen.... O0
Dave
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IIRC it was made at Mare Island along with the tug. The HP piston and piston valve have no rings ( !) Just a good fit.
Not unlike some Stuarts I've seen.... O0
Dave
Yes, your quite right about some ST engines not having rings, the D10 i'm building doesn't have any, however a slow revving compound is one thing, but a HP twin working upto 2000rpm is quite another thing, even if it is only 3/4" + 3/4" x 3/4", so i'm putting rings on my pistons.
Greg
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I suspect the purpose of not using rings on the tug engine was reliability. No ring issues...period.
If your hauling railroad car barges or petroleum in New York Harbor.....failure is not an option.
All the bearings where water cooled....including the crossheads.
She's about 750 BHP @ about 120 rpm. That puts the average piston speed at 600 feet/minute.
30/12 feet x 2/rev x 120 rpm= 600 feet /minute.
With a Stuart D10... your piston speed at 2000 rpm is 250 feet/minute.
.75/12 feet x 2/rev x 2000 rpm = 250 feet/minute
So the Tug piston is traveling on average more than twice as fast.......funny how math works 8).
Dave
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I suspect the purpose of not using rings on the tug engine was reliability. No ring issues...period.
If your hauling railroad car barges or petroleum in New York Harbor.....failure is not an option.
All the bearings where water cooled....including the crossheads.
She's about 750 BHP @ about 120 rpm. That puts the average piston speed at 600 feet/minute.
30/12 feet x 2/rev x 120 rpm= 600 feet /minute.
With a Stuart D10... your piston speed at 2000 rpm is 250 feet/minute.
.75/12 feet x 2/rev x 2000 rpm = 250 feet/minute
So the Tug piston is traveling on average more than twice as fast.......funny how math works 8).
Dave
Can't argue with that- always forget the piston speed consideration! :embarrassed:
Would change of direction per RPM change your consideration of whether they should be fitted or not?
Too, my pistons are brass on cast iron cylinders- they will wear, rather have cast on cast to get even mating of the piston/cylinder wall, does that make sense to you?
Greg
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".....Too, my pistons are brass on cast iron cylinders- they will wear, rather have cast on cast to get even mating of the piston/cylinder wall, does that make sense to you?..."
YUP!
Brass's Coefficient of Thermal Expansion (CTE) is higher than iron.
You will need some clearance to avoid the pistons expanding and seizing in the bore......
Some Data to review
Red Brass.....half hard
http://www.matweb.com/search/DataSheet.aspx?MatGUID=8d2bad4a1e69429fb69b6e47cc16f521&ckck=1
Durabar continuous cast iron bar stock...
http://www.matweb.com/search/DataSheet.aspx?MatGUID=383ea2d3274d40f2b2e7f36c94252cf1
You can see that brass is something like 10.4/1000000 and iron is 6.4/1000000 or Red Brass expands 10.4 /6.4 = 1.624 times more for a given change in temperature. On a 3/4 " bore that would be calculated via Delta L = Lo * CTE * (T2 -T1)
Lets say you build your engine at 68 F and run it at 250F T2 -T1 = 250 - 68 = 182 F
Furthermore assume you build the piston with no clearance with bore at room temperature.
If we use the difference as the CTE we get Delta L = (.75 ) x (10.4 - 6.4) x (10-6) x (182F)
The end result would be a .0005" press fit. This press fit would go away when it cooled off.
Needless to say you would never get to full steam and the run would be short. O0
So we run piston rings to avoid this problem as it allows the piston to have some clearance in the bore.
:-))
Dave
Oh and yes the tugs HP piston and piston valve are cast iron on a cast iron cylinder.
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Thanks Dave, exactly what I thought.
...You will need some clearance to avoid the pistons expanding and seizing in the bore......
So we run piston rings to avoid this problem as it allows the piston to have some clearance in the bore...
Youv'e seen my machining tolerances then :-))
Greg
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Hey Rosyth....any word on our model maker?
Curious....
Dave
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Nothing as of yet, I guess he is just to busy or isn't replying to mail anymore...................
R