Designer: J P Bertinat (ME Vols. 163-165). A twin cylinder marine steam engine with variable bore & slide or piston valves. Sheet 1. General arrangement, base (two versions), cylinder block (common), crankshaft, bearings, valve gear (piston & slide), reverser, flywheel, pistons, piston rods, eccentrics, connecting rods, trunk guides trunks. Sheet 2. Suggested set-ups for various operations. Sheet 3. Alternative crankshaft, piston valve engine, reversing arrangements & pipework for piston valve version, boiler feed pump.