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[Paul R]

I am considering building a steam powered model boat. Can any steam plant be used ie. mamod, willesco , chedder or is it just a case of how much you want to pay. Do you need a new boiler cert every year in order to sail at your local club and can all makes of steam plant be used to power a model boat?.

Regards

Paul R

[boatmadman]

Hi,
I hope I am safe in assuming you have little knowledge of steam plant in answering these questions .

When you get your steam plant, it is essential to understand how to run it safely, they are lethal in the wrong hands. Talk to a club member who already has one.

I suppose in theory you could use any steam plant to power a boat, but the size of the boat, and the prop, will dictate the steam plant size.

You need to be aware that the power output of an engine is dictated completely by the boiler capacity, you can have a big powerful engine, but it will only produce the power if the boiler can steam fast enough.

As far as boiler certs are concerned, you need one renewed every 2 years if you are going to sail it in public areas, this is for insurance reasons as well. There is however an exception to this, if the boiler capacity is less than 1.5 bar-litres then no test certificate is required. This value is calculated from the total internal water volume (in litres) multiplied by the working pressure (in bar).

However, it is good pracise and for your own peace of mind to get any boiler checked regularly. Any boiler purchased new from a manufacturer should come with a test certificate indicating a hydraulic test to twice working pressure.

The safety valve should be tested annually against a proper calibrated pressure gauge.

I got this information from a booklet on boiler testing issued by federation of model engineering societies.

As for the choice of steam plant, as I said above, the size of the boat will dictate the size of plant, but the type eg, oscillating engine or vertical engine will depend more or less on your preference. Oscillators are cheaper, verticles look nicer!

The design of boiler, vertical or horizontal, will depend on the type of boat its going in and the space available.

here are a few links for your perusal!

http://www.stuartmodels.com/
http://www.acs-engineering.co.uk/index.htm
http://www.modelsteamenginesuk.com/boilers.asp
https://vault1.secured-url.com/reeves2000/shop_home.asp
http://www.pollymodelengineering.co.uk/sections/bruce-engineering/index.asp
http://www.steamech.com/marine-engine-model.htm
http://66.249.93.104/translate_c?hl=en&u=http://fabrice.bretagne.club.fr/Page%2520d%27accueil.htm&prev=/search%3Fq%3Dfabrice.bretagne.club.fr%26hl%3Den%26lr%3D%26sa%3DG

I hope i have been helpful, any questions, ask away.

good luck

Ian

[tonyH]

Hi there Paul,

Ian is absolutely right about safety. Just a small amount of steam will scald and control valves etc. get hot. As far as boilers bursting is concerned, well, you don't want to know!

That said, provided a bit of common sense is used, steam is fun.

Mamod type units generally use fuel tablets or similar which, while fine for static, tend not to produce enough heat to give decent power nor do they have any real control. 2 cylinder oscillators of the Cheddar type and virtually anything above run on gas and are much more beefy - and expensive. They tend to run at about 40psi and provided the boiler holds enough of the wet stuff you'll get enough power for a decent size (36" plus) displacement hull and a reasonable run time.
The overall weight of plant and boat etc. is likely to be in the 20-25lb bracket and, of course, you can go as large as your wallet will allow.

If buying new, I reckon you should budget about £600-£700 for the plant and notwithstanding the 'completeness' of the package you buy you should be able to solder, preferably silver solder, because you will almost certainly need to make or modify some of the pipework. Most of the bits and pieces you will be able to buy from Bruce Engineering and the like and there are plenty around who will give advice. Also, there are a couple of books about on setting out in steam.

I currently use a Vee twin oscillator from John Hemmens www.steamengines.co.uk with one of his boilers and have recently used an oscillator in a 50" tug. That had plenty of power through a 75mm prop.

Believe me, when you first have the plant running, even out of the boat, it really does give a belt.

Best of luck

Tony

[boatmadman]

Hi again,

I forgot to mention about the gas. Ignore me if you already know, but, the gas used for these boilers is heavier than air, so, if you are using a separate re fillable tank, always fill away from the boat or else there is a chance of gas gathering in the hull.

If this happens, you can say bye bye to your eyebrows when you light the boiler, or even worse, damage the boat!

Re fillable tanks also need to be pressure tested and certfied.

Whether you use dispoable or re fillable tanks, dont leave in the boat when not in use, or the above may happen!

Good luck
Ian

[dougal99]

quote

If this happens, you can say bye bye to your eyebrows when you light the boiler, or even worse, damage the boat!



Spoken like a true modeller - go for it!


Doug

[justboatonic]

Hmmmmmmm. I think all the above has put me off getting a steam plant for a possible future project (MS Envoy). It all sound too dangerous (exploding boilers!) and think I'd rather stick with rechargable batteries and less hassle.

[tonyH]

Call yerself a Captin?

Steam may be a little bit fiddly at times BUT the satisfaction of getting it reasonably right is great.

If you're silly and play with the gas/boiler/fire combination then perhaps it's not the answer but, even if you're just installing a set-up that someone else has designed and engineered, the look, feel and smell of the job is worth the thinking time needed.

Luddites Rool!

Tony

[justboatonic]

Call yerself a Captin?

Nah, more of a junior seaman, me! 

Steam may be a little bit fiddly at times BUT the satisfaction of getting it reasonably right is great.

If you're silly and play with the gas/boiler/fire combination then perhaps it's not the answer but, even if you're just installing a set-up that someone else has designed and engineered, the look, feel and smell of the job is worth the thinking time needed.

Luddites Rool!

Tony

I note what you say but the previous posts almost seem to suggest you need to be a boiler expert. I haven't got time to become an expert on top of the 3 other subjects Im already an expert in! 

[boatmadman]

you dont need to be an expert, just need to follow a few basic safe operating procedures

Ian

[tonyH]

'ear 'ear Ian,

It's just a case of following simple rools like "don't mess with the safety valve" or "try not to let the boiler run out of the wet stuff".

There's no way that I'm an expert but there are plenty on this forum who are and they have all appeared happy to give solid advice.

Tony