ModelPlan 106

TRIPLE EXPANSION STEAM ENGINE

by Michael Adler - 16.80

Triple Expansion Steam Engine

One of the most dramatic stories in steamship history is that of the triple expansion steam engine which powered Liberty Ships and several other classes of cargo ships during World War II. Powering these ships with high powered turbines would have caused serious production problems. Sufficient suitable production equipment was simply not available at the time. The U.S. Maritime Commission chose more easily manufactured 2500 H.P. triple expansion engines, originally designed by North East Marine Engineering Ltd.

Boiler pressure steam at 220 pounds per square inch is supplied to the high pressure cylinder, then exhausted into the intermediate valve and cylinder, and finally exhausted into the low pressure cylinder. As the cylinders are progressively larger, the work done in each cylinder is the same despite the drop in steam pressure. The valve gear is of the Stephenson link type

Michael Adler has built the Meccano model to a scale of approximately 16:1. It consists of a bedplate with the main crankshaft bearings, the six columns and crosshead guides; the connecting rods with big ends, small ends and crosshead slides; the Stephenson valve gear, and various ancillary equipment.

The instructions start with a wealth of information on the prototype, followed by some sixteen pages of instructions, illustrated with seventeen colour photographs and ten isometric drawings.

Designed, described and illustrated by Peter Matthews with valuable assistance from Roger Hill, the originator of IsoMec, these are freelance models similar to many Industrial locomotives of the past.  Arranged for two rail operation running on Marklin or any other suitable one gauge two rail track.

In each case, nine pages of instructions are illustrated with twenty four highly detailed groups of IsoMec Drawings.  Motorisation is by a Meccano 700 6 volt motor but a stronger motor is advised for pulling heavy trains for long periods.

The front covers have a coloured IsoMec drawing of a three quarter view of the entire locomotive and comprehensive illustrated parts lists are also provided.