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. |