Steamer Ben Ain

**Bunkerbarge** · 25-07-2005

I thought I would share a few pictures of the progress of my steam boat with the members of the forum and maybe pass on a few of my own trials, tribulations and ideas.

The first couple of pictures show the very early stages of hull preparation and a few modifications I made to the basic kit. The kit is a Mountfleet models “Ben Ain” North Sea Steam coaster and consists of a fibre glass hull, a set of plans, a collection of strip wood and printed ply panels and a box of white metal fittings. One of the first things was to think of how I wanted the steam plant to work as this has a direct impact on the internal layout. I did want a boiler feed tank so that I could pump up the boiler with feed as it was used so that meant I had to include a feed tank in the construction. As I wanted to balance the weight of the boiler and engine at the aft end and I wanted as much space available as possible I decided to make the feed tank in the bow.

One picture shows test fitting the tank in the bow before putting the top on and inside can be seen the baffles to reduce free surface effect of the feed water. Another convenience of having the tank here is that it can be easily be connected to the accommodation vent cowls for filing and venting the tank, which I did at a later stage. The tank was made of polystyrene sheet which should give suitable water resistance and was easy to work with. Inside the hull can be seen the gloss cram paint finish which serves the purpose of being easy to wipe clean when being used. I used a radiator paint to resist any heat effects of the boiler and put a total of three coats on to smooth out the fibre glass internal finish. Also in the hull shot can be seen the boiler and engine mounting frames and the fist piece of wood to be used as a bearer for the steam plant. After the initial bath trials I estimated that about 30-35 lbs of ballast was going to be needed so I manufactured two steel plates, 16cm x 16 cm x 8mm thick and laid them in the bottom of the hull. This area was dammed with the three wooden bearers and completely encased in resin so that the brass base plate had something to screw to when it came time to fit. Also the inside of the bilge keel can be seen and the tabs used to locate them.

The aim of the effect of the finished boat is that it will look weathered and as realistic as possible from the outside but when it is opened up this will contrast with the insides, which will be the gleaming pristine brass and copper steam plant. That is the theory anyway. To help with this effect the outside of the hull had rivet detail added on the platework. I tried to emulate the correct rivet arrangement as used on real coasters of the time and used thick gel superglue to create the rivets. Riveting the hull took me most of my spare time for a week with regular rests to regain the feeling in my hands.

One last thing of note is the fore deck planking. The kit includes a printed ply overlay, which has all the grain going across all the planks. To improve the effect I planked the deck myself using lime strip wood and finishing off with a mixture of weatherproof PVA glus mixed with black powder paint. The resultant mix was rubbed into all the caulking and saned down to give the overall deck finish. The deck was then coated with three coats of matt yacht varnish and rubbed down between coats.

adzam · 25-07-2005

very nice BB

ajg141 · 25-07-2005

I really like that rivetting - must have been a labour of love though.

Andrew

**Bunkerbarge** · 26-07-2005

The next step in the project was to decide just how the main components of the steam plant were going to be placed in the hull.

Two of the shots show the first placings of the boiler and engine unit in the hull. The assembly is a John Hemmens unit and came complete with the optional base plate. Unfortunately the base was too wide to get the plant into the hull and it quickly became apparent that the boiler needed to be as far astern as I could arrange. The best solution was to make a new brass base plate, which had a step in it, and put the engine at a higher level than the boiler. This was designed to have the boiler as low as possible for Centre of gravity considerations, and have the engine at the correct shaft height. The first fitting of this assembly is shown in a couple of the pictures and was where I decided was best to place the unit. Of course it must be borne in mind right from the start that the boiler and engine must be removable after the model is finished so this also dictates the configuration of the components and the size of the base plate made for the boiler and engine. I also fitted a new stern tube with proper ball bearings on the recommendation of John Hemmens and purchased a double universal joint for the shaft to ensure that any misalignment was taken care of.

What was also obvious was that no matter how far astern I was going to be able to get the boiler I was not going to get the funnel to line up with the models. Rather than try to force the boiler even further back and compromise access to the engine and other aft components I would make a new funnel with a dogleg in it. I actually tried a test funnel when I was at work on my ship and found that I had, quite by accident, estimated the offset perfectly so I decided to use the test piece. The new funnel can be seen in the later pictures, which also show a lot more of the other components being fitted into the hull.

All that huge space that I started off with very soon became eaten up with the pieces and a great deal of thought and care went into where they were going to be placed from an access, stability and trim point of view. The port side tank is the exhaust separator and was sized to give about half of a full boiler capacity. This would be the normal amount of water that I will want to use before filling the boiler again so filling the boiler and emptying the separator can take place at the same time. On the other side of the boat is the gas tank. One of the biggest problems that modellers seem to find with steam boats is the fact that the gas tank cools down considerably when the gas is being used. This can get to the point where the gas pressure drops so much due to the reduced temperature that the burner suffers and the boiler does not generate enough steam to power the engine. I wanted to avoid this so a couple of ideas that I developed as the bits went into the hull included using a gas pressure regulating valve on the tank, warming the tank from the nearby separator tank and using a gas control system to maximise the gas supply to control the boiler pressure. More about this as it goes in later.

From the last two shots you can also see the brass base plate used to mount all the hardware. This gave additional ballast and a suitable base to drill and tap to fit all the gear in with stainless machine screws. Also the finished feed tank with sight glass and outlet valve is visible in the bow.

**Bunkerbarge** · 05-08-2005

The next stage of the construction was to fit the major parts of the steam plant to the base and then work out the details of the rest of the installation. As can be seen in the attached pictures the boiler and engine assembly has now been fixed to a brass base, which should allow removal from the model as one piece. This was tested through the hole in the Quarterdeck many times to ensure that this was achievable. The base is held down by brass screws that are set in resin in the bottom of the boat and I made a wier across the hull to try to contain any water leaking from the engine and the stern tube which could then be easily removed when the boat comes in for a fill.

The alternatives with the feed water system was to use an engine driven pump with either a controlled or a manual three way valve that can fill the boiler or return to the feed tank or a manual pump connected up to the boiler. As I was apprehensive about sapping power from the engine I went for the manual pump option so I will have to bring the boat along side to fill the boiler. This isn’t a bad thing as I will have to bring it in anyway to empty the separator tank and I am hoping for a duration between fills of about 25-30 minutes.

Also worthy of note is that the construction of the kit would have allowed me access to the internals through the forward hatch and the aft accommodation block only. This would have been quite restrictive to operate and considerably more difficult to remove items when the model is finished. To greatly help this I followed the advice of John Hemmens and I am making the entire bridge section removable as well. This makes for considerably more thought as regards the construction of the bridge and its locating means but will be well worth it in the long run.

Any steam plant seems to have one or two inherent challenges, the most irritating seems to be the fact that the gas in the on board tank cools as it evaporates to the point where it cools the tank itself. This has the knock-on effect of slowing down the evaporation rate of the gas and hence the flame in the boiler reduces. This affects steam production and the whole thing slows to a halt. The cooling of the gas tank is directly proportional to the rate of gas use so the obvious starting point is control that use. For this I purchased a Cheddar gas control valve, which controls the release of gas to the burner depending on boiler pressure. This means that if the engine is not being used much the burner shuts down to a pilot flame and conserves gas.

Another main factor in this effect is when the boiler is brought up to pressure in the first place. This obviously requires the burner to be on full for a considerable amount of time so when the boat is first put in the water the gas tank is already cooling down. To get past this I have made a valve arrangement on the gas tank, which enables the initial pressure raising to be done with an external tank. When the boiler is up to pressure and the gas control valve is operational then I change over to using the on board tank prior to putting the boat in the water.

A final modification not yet in the pictures but will be the next step is to introduce some heat into the gas tank. This is going to be done with a copper saddle fitted between the gas tank and the separator, which will transfer heat to the gas tank. I hope that this will warm the gas tank enough to ensure excess pressure, which will then be controlled by a Cheddar pressure regulating valve. As soon as the plant is in operation the separator becomes quite warm so there is a good supply of excess heat.

The final points to note are the separate batteries for the radio gear and the Cheddar Gas Control Valve as interference could be an issue with the valve and the temporary servo set up at the back end. This is simply to provide control ready for the first sea trials and to see if the whole thing actually works.

Grief · 20-09-2005

Hi Bunkerbarge.
I have just ordered my Ben Ain model today. Your pictures look great, I love the steam plant, although mine will be electric.
The riveting is very realistic and worth considering.
I have managed to find a few pics of the Doris Thomas and her sister ships on the net. So i'm studying the detail at the moment
Please keep posting on this thread so i can follow your progress.
Very jealous of the steam plant. Good luck with the rest of the build
Regards
Chris

**Bunkerbarge** · 20-09-2005

Chris,

To be honest I had given up on this due to the lack of response to the quite time consuming contributions. If you are interested I will post a few more to bring you up to where I am now.

If you have uncovered any pictures I would be very interested in seeing them although I probably already have them as I have searched the net for hours now looking for pictures of the Ben Ain, Doris Thomas or other steam coasters of the same age. You really need to get hold of any of the C.V. Waine publications, one of them actually has a plan of the Doris Thomas in it which is usefull for getting a few details correct. If you need any details let me know. I also got another set of plans from the Ramsey Steam Ship Company and an interesting couple of photo's of the Ben Ain. A couple of things I noticed from those was the colour of the superstructure, the fact that the rising sections of the hull in way of the bridge actually have a Tumble Home and a bit of a feel for the detail of the hull openings.

I also visited Frank Hinchcliffe and took a set of photo's of his original Ben Ain, which have proved usefull so far with my construction.

I think one of the most usefull things to consider is that the kit can be dramatically improved upon dependant on how much time you want to spend on it. The rivets took me most of a weeks leave but the end result was well worth it. I have made completely differrent bulwark stays as the kit items are not very realistic and I have also riveted the deck plates and the forward bulkhead platework.

The biggest job though was the focsle planking and the individual hatch coaming planks. A lot of work but well worth it.

Anyway if you have any questions regarding the model please feel free to ask as I would be more than happy to share any of my last two years researches with you.

All the best

Richard

Engineman · 20-09-2005

Quote:

Originally Posted by Bunkerbarge

Chris,

To be honest I had given up on this due to the lack of response to the quite time consuming contributions...

Oh please, don't give up. I really admired your posts and photos, it is extremely interesting.
I also own John Hemmens RIBBLESDALE steam plant but never run it on the pond only on the bench. So your experience and your improvements of the propulsion system tend to be not only interesting but very useful for me. Please, don't stop with your 'chronicles'.

Regards,
Roman

**Bunkerbarge** · 20-09-2005

Roman,

Thanks for your encouragement. I will put together the next chapter and bring the story up to date.

Best regards

Richard

Grief · 20-09-2005

Thanks Richard.

I only found the forum yesterday. Its sounds like your way ahead of me on the research and the build. Any links you have or pictures you can post would be appreciated. I'm at that hungry for info phase.

I dont mind putting the effort into the detail. As you point out its worth it in the end.
If you post updates and info I will try to reciprocate.

www.amlwchdata.co.uk/ships/nancythomas.htm
www.manxmodelboatclub.org/ look under 2001 for a few pics
www.rhiw.com/y_mor/coastal_vessels_photos/vessels_03/ships_03.htm

The last link has pictures of sister ships
You probably have these already from the sounds of it but you never know.
Have you got any close up pics of the riveting on actual ships.
Dont give up posting. I look forward to you next chapter.

Regards

Chris