A well engineered model Stuart vertical reversing triple expansion marine engine, the unlagged cylinders 3/4in., 1 1/4in. and bores x 1in. stroke supported on eight pillars, draincocks, displacement lubricator, handwheel and screw operated Stephenson's link reverse, I.P. crosshead driven feed pump, LP crosshead driven air pump, counterbalanced crankshaft and disc flywheel, unpainted -- 7 x 9in.(17.8 x 22.8cm)