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[harry]

 HI


  I am after some advice on a boat that i have been given . The company that make the model are called veron or i think it may also be vosper thornycroft   . The model is meant to be a fast patrol boat , it is 52" in length and 12" in width .

  It was designed to be used with ic power 10cc or 61 cu.ins in size . But i would like to use steam to power it . I have been looking at a thread that was started by Archibald h about the twin steam cylinder engine by pm research . My question is would this engine be big enough for this model.

http://www.modelboatmayhem.co.uk/forum/index.php?topic=9960.0

  Thanks Harry

[SteamboatPhil]

Hi Harry,
It would  push the boat along, but at a snails pace. As the hull is designed to plane it might look a bit strange just puffing along. I'm afraid you may have to consider a small scale hull to suit the plant if you wish to get into steam. There are high speed steam plants that would push the hull that you have, but you would have to build it from scratch. (I do have the drawings and a few castings should you wish to go down this route)
Sorry to be the bearer of slightly not good news.

[andyn]

For the hull you have, I would be very tempted to put a Zenoah or equiv in it, as its blooming massive compared to the 37" one I have.

[tigertiger]

I also think that the power to weight ratio would also be compromised and you may have trouble balancing the boat.

These high speed boats are not designed to be 'ballasted down'. A steam plant would be a lot of ballast.

[Martin (Admin)]

OK, so in theory, what would it take to get a fast launch up on the plane?
I'm thinking of flash steam boiler that Phil shown me, wouldn't that do it?

..... obviously my steam knowledge is limited to a small Mamod finger burner!  :-\

[SteamboatPhil]

A boiler around 7 in long with 6 semi flash coils under it (basicly loops). You need a good source of heat (which is the most important part to getting a good fast boat) Gas will freze because of the high discharge rate, so a vaporising petrol blowlamp will do the trick (like the old parafin lamps, but laid flat) An single cylinder engine of around 3/4 bore and stroke with good valve timing. 2 1/2 in prop 2 bladed with around a 4 in pitch. If it all goes together right you should be able to push a 4 - 5 ft boat at around 15 -20 mph.
Thats it in a nut shell-----hummm
( I will have one of my fast ones in Llanberis)
Phil

[kno3]

Phil, any chanche to see a video of your fast steam boat? I'm curious about its performance.

[John W E]

aye there

Martin Mayhem - as far as I can recall - a guy from our Club, Mr Bob Kirtley, holds one of the World Speed Records for steam hydroplanes.   I believe it is in the excess of 100 mph for a 'flash steam' tethered hydroplane.

I do know the boiler is a tubed figure of 8 construction and I am sure the steam engine is similar to a flat twin slide valve engine.   When I speak to Bob next I will ask him more details because I am sure Steamboat Phil will know Bob....because, Bob is heavily into 'straight running' as well.

We used to watch the lads run their hydros on South Shields Lake a good number of years ago and to be honest, all you could see was a Wall of Water and a bit of Steam  , until our great Council in their wisdom declared that it was unsafe for the public!   I suppose though if one of these boats broke their tether, it would be similar to a Low flying missile, so I suppose they may have a point.

If you ever get the chance to go and see them run, it is well worth it.

aye
john

[grasshopper]

flash steam boiler, and then you could do with a steam turbine engine or two on seperate shafts -
don't know if they are retailing these:

http://www.instructables.com/id/RC-Steam-Turbine-Tank/

but with a few of the right bits - why not steam?

[tigertiger]

I stand corrected 

[harry]

Hi Harry,
It would push the boat along, but at a snails pace. As the hull is designed to plane it might look a bit strange just puffing along. I'm afraid you may have to consider a small scale hull to suit the plant if you wish to get into steam. There are high speed steam plants that would push the hull that you have, but you would have to build it from scratch. (I do have the drawings and a few castings should you wish to go down this route)
Sorry to be the bearer of slightly not good news.

Hi Phil

   Thanks for the reply . i would be interested in the plans and castings that you have can you give me some more info on the steam engine
   and do you have any pictures of it ?

    Could you tell me what sort of boiler you are using or are going to use for this steam plant . It seams to me that this could be complex subject and any infomation that people from this forum  could give me would be appreciated .

     Thanks Harry

[Bunkerbarge]

Harry,  I think the subject of high speed steam is one that only a few have ventured into and is a completely different subject to the normal reciprocating oscillators that the vast majority of steam enthusiasts use.

For your first venture into steam you might want to consider something a bit simpler and easier to understand and put together before you become involved with something so specialised.

If you feel confident have a go but I would suggest cutting your teeth on something more straightforward first.  In that case we are obviously back to the original issue and that is the hull you have is not suitable for a heavy slow speed steam plant so you need to consider either buying a launch hull, such as one made by Kingston Mouldings to put a reciprocating plant in, or stick an electric motor in your fast planing hull.

[SteamboatPhil]

Hi Blubird
Bob's speed for the world record was 120.92mph using flash steam (24 ft of coil) and it was a hell of a sight, He spent a lot of years devolping his hydro, with just a few pitfuls along the way. Yes I do know Bob we have run boats side by side in the past.
Harry I will post some pics for you in this section in a while to give you some idea of engine, boilers etc.
Video-----hummm have to find some 10 year old to put it on that u tube thingy.

[Bee]

Coming back to the original post. The kitmaker is Veron and the full size was made by thornycroft.

There is nothing wrong with making a small plant to start with and having the boat pootle along. You will still get great satisfaction from the achievement. You can then decide whether your main aim is to make this particular boat go fast, with IC or electric, or to make a slow boat to suit your steam plant, or to make a bigger steam engine for it.

You could always sell the kit and get or make a more suitable hull for whatever you really want to do. What would be a shame is to get half way on the wrong track and leave the hobby through dissatisfaction.

[harry]

 Thanks for the advice . I  have spent some time and money on this project and i don't wont to start a new boat as i have got this far with it . the boat came with ic power but it was changed to electric and that is how it is at the moment

   I like the idea of steam and this is the way that i wont to go with it .  but what is the best way to do this ?
   thanks for the advice
   
   Phil could you tell me more about you steam plant

    Harry

[tobyker]

You need to find a copy of "experimental flash steam" by Benson and Rayman. Pub MAP 1973, ISBN 0 85242 352 7.

[SteamboatPhil]

Hi Harry (and all who are interested really) here are a few pics, the boiler is semi flash, the coils underneath have a short end (water flows in) and a long side ending just below the boiler's top (steam flashed out), a fast steaming boiler with the advantage of having  steam in reserve. The fash engine has a large bore and short stroke on this one of mine it 7/8 bore x 3/4 stroke (my latest one is 1 in bore x 3/4 stroke) the engine also drive the water pump (I've pinched the gears from the front of the engine for my new plant) The flash coil is 18 ft long, and does just that, cold water pumped in, flashed into steam, then superheated (very important) as superheated has a greater expansion rate. The high speed engine is 3'4 bore and stroke (with a balanced crankshaft--so no flywheel is needed) This engine was Alan Raymans, and described by him in his book High Speed Marine Steam, in which he shows the construction of this engine, boiler and blowlamp, proabally a better book that his and Johns Experimental Flash Steam (which I have been asked to re-write, with permission of John and Alan) as its a tad dated now, and we have a few more tricks up our sleeves.
More pics to follow

[SteamboatPhil]

Here we see my high speed engine that I'm working on the moment, and of course the all important heat source, a vaporising petrol blowlamp, this shows how much heat you can get, I use one on my boats, Bob use's 3 on his hydro !!!!!!! If you get it all right, you can get a 4ft 6in boat to 22mph+ (Paprika) if you get it really really right you can-----well see the pic
If you need more info, just ask (I could go on for hours !!!!)
Or you can attend one of the lectures that I will be doing at the Midlands model Engineering show (its free--well the lectures anyway)

[John W E]

Hi there,

Sorry for a slight sidetrack but I think this may interest one or two people. I have spoken with Bob this morning - he filled in a few blank spaces of the details of his hydroplane.   the steam engine or shall we call it, motor, was designed by himself years ago and basically it is based on a 2-stroke petrol motor.....it is a single pistoned motor with a bore of 1  ³/16 ’’ x Ύ’’ stroke – it has a poppet valve intake and it has flow ports for the exhaust around the base of the bore.   She is a closed in crank case – the crank shaft is running in ball racers & by the sound of the way Bob spoke it is of splash lubrication.   As I have mentioned before, it is flash steam boiler of a figure of 8 construction – now this bit is not for the faint hearted – when I asked him ‘What pressure does the boiler run at’ there was a long silenced pause – he said the last time he put the pressure gauge on it – it wrecked the pressure gauge at 1000 psi.       After a little more silence on his behalf he was saying he has known some flash steam boilers to run in excess of 3000 psi.    He would not confirm that his boiler runs at this pressure, but, I do have a sneaky feeling it runs at that knowing Bob. 

If anyone is interested in seeing his Hydroplane run over the coming Bank Holiday weekend Bob is running at St Albans …..


Please note Flash steam boiler safety notices above: http://www.modelboatmayhem.co.uk/forum/index.php?topic=12244.msg116553#msg116553

Aye
John e
Bluebird

[SteamboatPhil]

I will be at St Albans on the Sunday running a V4 flash steam straight runner (not quite as fast as Bob's hydro)
Phil

[John W E]

hi there one and all

I have been asked to point something about in connection with my above-posting with regard to flash steam boilers and normal boilers......

The Flash steam boilers used in Bob's hydroplane and other high pressure /high speed vessels of a similar nature; working at extreme pressures; are purposely built from stainless steel tubing - in order to withstand the high pressures

Standard boilers which are tubed; DO NOT operate at anywhere near the said pressure of my last posting.   

These tubed boilers require a test certificate as they contain a greater quantity of boiling water than a flash steam boiler.

aye
john e
bluebird

[SteamboatPhil]

Beat me to it Bluebird, and just ,if I may add, all joints on the high pressure end are welded, silver solder (certainly on Bobs) would melt.
Although saying that the joint on the steam end of one of my coils is silver soldered with high temp SS (contact Keith at Cup Alloys) but then the temp at the hot end is only around 600 c with a pressure of around 500psi. All my other coils are welded.
 

[harry]

i have taken you advice and orderd a copy of high speed marine steam . hope it gets here soon

 hi Phil   can you tell me where the midlands engineering show will be and also is there an engineering magazine that i can get about steam engine?

[SteamboatPhil]

The book is a good buy and will take you through all the elements of a successfull steam plant. On the magazine front, sadly at the moment most of them tend not to touch on marine plants, but saying that there are some useful bits and bobs that appear, so its worth scanning through Enigineering in Miniature, or Model Engineer.
The Model Engineer exhibition is 17th-21st October at the Warwickshie Exhibition Centre Fosse Way, Nr Leamington Spa
www.meridienneexhibitions.co.uk
I will be doing my lectures on High Speed and flash steam on the Friday and the Monday (lots of other good lectures as well)
Don't forget to come and say high
Phil

[harry]

Thanks for the information.   Can you tell me what sort of welding you use on your boilers? Thanks for putting up pictures.  Your engines look quite complicated.
Thanks.  Harry.