The Unofficial Mamod and Other Steam Forum

Steamnav · Posted: Thu Jan 17, 2008 3:45 pm Post subject: Control for marine steam plant.

In a moment of madness which has left me struggling to pay my tax bill this month I purchased a new Tucher & Walther tin plate rendition of HMS Dreadnought, as yet unsteamed, which is powered by what appears to be a Wilesco D52 single cylinder marine steam plant, or close variant. Scale model it is not, but it looks splendid, is about 1 metre long with plenty internal space, and cries out to be radio-controlled.

The rudder won't pose much of a problem, but the steam engine is a fairly simple solid fuel affair with no regulator or gearing and it might well prove impossible to fit any control to it.

Wilesco produce regulator valves and I was wondering if retro-fitting one of these to the steam supply pipe would in any way supply a useful means of varying engine revs? The alternative would be to connect a servo to the lever of the whistle already fitted to the boiler, and try to control revs by dropping total boiler pressure, but this seems a clumsy, slow and unreliable way of attempting this.

It might well be that the engine is designed to run at fixed revs and boiler pressure for a fixed time to prevent damage through boiling dry or raising excess boiler pressure, and if this is the case I will not be meddling. But if any experienced model engineers out there think there may be effective and safe modifications than can be made to exert a degree of rev control, I would be happy to hear from them.

Bogstandard · Posted: Thu Jan 17, 2008 4:10 pm Post subject:

Hi Steamnav,

I don't think it would present a problem making and fitting a control valve.

Your major concern should be if the engine should stop mid lake, which could easily happen if you are playing about with the steam control. Because of the single cylinder, it won't have a self start ability. If you had a bit too much propellant in there and a little less water, you would have to learn to swim rather quickly to prevent a meltdown.

The correct way to control a single cylinder constant speed steam engine would be to fit either a 'Kitchen' rudder or a variable pitch prop, both are in the realms of a good model engineer, but alas not to the beginner in metalworking.

John
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Les · Posted: Thu Jan 17, 2008 4:11 pm Post subject:

Welcome to the forums.

The boiler should be designed in such a way that when fired from full, the burner should extinguish itself before the water runs out and therefore preventing the boiler from running dry. As long as you top up the boiler each time you relight it there shouldn't be a problem.

Retro-fitting a regulator valve should not pose a problem.
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Les · Posted: Thu Jan 17, 2008 4:20 pm Post subject:

CCairns · Posted: Thu Jan 17, 2008 5:15 pm Post subject:

Or just make sure that the pond/lake you are steaming in is not too deep, and get a pair of waders.

I got a pair cheap off ebay, although I have yet to join a model boat club - no time to organise getting my steam launch checked out before public sailing, etc.

Will be interested to hear how you get on with the steam regulator as I've got a similar project lurking in the corner which has a solid fuel fired boiler.

IndianaRog · Posted: Thu Jan 17, 2008 5:17 pm Post subject:

Welcome SteamNav....sounds like a delightful T&W you have picked up. Can't help you with your question myself, but lots of experts on here who can.

cheers,
Roger
(from Indiana, USA)
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Steamnav · Posted: Thu Jan 17, 2008 7:30 pm Post subject:

What a fantastic forum!! I only posted my query about 3 hours ago- many thanks for so many responses. The issues about stalling single cylinder engines and weeds hadn't occured to me, but luckily I can run sea trials in our 8 metre by 4 metre garden pond. (My wife got a surprise when construction started as she though the plans were in feet).

As I am in the medical profession I know nothing about metalwork and engineering other than not to use ordinary electrical solder in pressurised live steam applications (!), but luckily one of the largest steam dealers/collectors in the UK is based just up the road (everything from vintage pop-pop boats to full size locomotives and triple expansion marine engines), so perhaps they can help me with modifications.

One other query. Living in a hard water area, and recently being made aware that de-ionised water is not the equivalent of distilled water, being highly corrosive to solder joints, I was thinking of steaming with condensed water which I collected and bottled from my air conditioner last Summer (waste not want not). Perhaps I am being too much of a cheap-skate and should just buy distilled water or get my own still from a laboratory glass supplier? I am not tempted to use water from the domestic water softener in case it's chemistry is not conducive to keeping the boiler seams happy. What do others do?

tmuir · Posted: Thu Jan 17, 2008 11:28 pm Post subject:

Water collected from your AC is fine to use and I have done that in the past. As long as its dirt and dust free it will be fine as in essance its is distilled water too.

Definately stay away from deionised water and would recommend staying away from tap water too.

I mainly use distilled water bought from the shops as at just a bit over $4 for four litres (2 pounds) its not an expensive outlay.

Any chance we could get a picture of your boat as it sounds great.

Also Welcome to the forum from Australia.

Tony
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johnreid · Posted: Thu Jan 17, 2008 11:53 pm Post subject:

I had a friend that liked RC boats and he always had a rubber raft with him when he took his boats out for a run.
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Les · Last edited by Les on Fri Jan 18, 2008 3:51 pm; edited 3 times in total

Atticman · Posted: Fri Jan 18, 2008 10:20 am Post subject:

Hi welcome to the forum,

Its a beauty isnt it

http://www.ministeam.com/acatalog/Boats.html

Its a very limited ed, so best not to do too much mod. I am sure that a regulator would be fine here though,

May be best looking on the loco section, as they do many more regulator / RC mods than the steam launches, I think mainly as the modern locos were/ are pretty unreliable runners!

MooseMan · Posted: Fri Jan 18, 2008 3:31 pm Post subject:

Hi, welcome!

I run my engines on unadulterated Welsh rainwater, filtered through a coffee filter

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