of the 4-cylinder triple expansion 4-crank type, balanced on the Yarrow-Tweedy-Slick system, the cylinders being as follows: The common stroke was . The piston and slide valve rods were all fitted with metallic packing to the stuffing boxes, and all pistons fitted with packing rings and springs. The high-pressure valve was of the piston type, whilst the remaining ones were of the balanced type. The main engines were designed to develop at 185 rpm continuously. With the ships being twin screw, the engines were fitted with a shaft coupling to the crank shaft at the forward end, allowing the engine to be turned end to end to suit either port or starboard side fitting. Modifications for landing craft When the LST (3)s were ordered, the LST (2) programme was in full swing, and similar arrangements were made to enable the LSTs to carry the long LCT5 or LCT6 that were being built in America for the Royal Navy. The LCT needed lifting onto the deck of the ship, being carried on wedge-shaped support blocks; at the time of launching she was set down on the "launch ways" by simply slacking off bolts in the wedge blocks, allowing the launch way to take the weight. To carry out a launch, the LST was simply heeled over about 11 degrees by careful flooding of tanks in the hull. The height of the drop was about , and immediately after the launch the craft's engines were started and they were ready for operation. This method was used for moving LCT5s from Britain to the Far East, although there seems to be no reference to LST (3)s being used, most being completed late in or after the war. Even at the end of the war there was a need for more ships able to carry minor landing craft, and two of the LST (3)s then completing were specially fitted to carry LCM (7). These craft, which were long and weighed about 28 tons, were carried transversely on the upper deck of the ship. They were hoisted on by means of a specially fitted 30-ton derrick; This 30-ton derrick replaced a 15-ton derrick, two of which were the standard fit of the LST (3). The 30-ton derrick was taller and generally more substantial than the 15 ton one. The LCM (7)s were landed on trolleys fitted with hydraulic jacks. These ran on rails down each