A Triple Expansion Marine Engine
Although this model is not based on any particular make it is typical of a 2,000hp engine that was produced by many makers from the mid 1800s to the 1950s. At the front it has steel columns as opposed to the back having cast columns, because of this they were known as ‘open front engines’. The advantage of this in a model is that we can see the ‘workings’ better.
As we can’t scale nature and to get the engine to run smoothly (marine engines never had a flywheel, though the propeller acted as one), the 3 cylinders have been made all the same at one inch diameter, with the outside retaining the look of a true triple. It is to an approximate scale of 26 to 1.
Other valve gears were used on marine engines but the vast majority had Stephenson which is also used on this engine. The turning gear shown on the left hand side in the left photograph is only engaged when turning the engine for maintenance. For extra safety on some engines, the worm was removed and put on a peg welded to the engine room floor.
The condenser, air, bilge and boiler feed pumps are on the outside finished to full size practise though they are not working. However if constructors wish the insides can be finished.
26 castings are supplied with the base in cast iron and the rest in gun-metal, along with O-rings for pistons & glands. Also supplied are 4 sheets of drawings along with a smaller sheet showing a jig for making the front columns and an engine stop valve. Sheet 1 has the assembly drawing along with a list of item numbers shown on the assembly that are detailed on the other sheets.
It is advised that customers intending construction should get the drawings first to evaluate the project.
Width 9½ inches, Depth 7 inches, Height 9¼ inches,