More often seen in the 3 inch size, this is a 4 1/2 inch scale Wallis & Steevens "Simplicity" roller. The full-size engine was a compact machine, only weighing three tons. Of the nineteen or so built, six survived into preservation.
Silver soldered copper boiler, working pressure 90psi, feed by mechanical pump with auxiliary hand pump on manstand. Twin safety valves, water gauge with protector and blowdown. Boiler blowdown valve beneath belly tanks. Single cylinder with slide valve actuated by Stephenson's valve gear with pole reverser in cab. Single road speed engaged by pin on the right hand hornplate, as per prototype.
In 4 1/2 inch scale the Simplicity makes an attractive size engine for rallying. It is big and heavy enough to pull a decent load, whilst it's simple design makes for an easy-to-maintain engine. By removing the chimney and canopy, it will fit into the back of an estate car.
Length 55 inches
Height 38 inches to top of chimney
Width 24 inches across rear rolls
Weight 500 pounds
scale | 4 inch |