The engine is water cooled, and in the case of those in the
forward and after cars the original system consisted of an
internal radiator supplied by an auxiliary water tank carried in
the keel. It was found on the flight trials that the cooling was
insufficient, and external radiators were fitted, the internal
radiator and fan being removed. In the case of the centre car no
alteration was necessary, as external radiators were fitted in
the first instance.

The engines are supported by two steel tubes held by four
brackets bolted to the crank case, these being carried by twelve
duralumin tubes bolted to the bearers and transverse frames of
the car respectively. The drive from the engine is transmitted
through a universal joint to a short longitudinal shaft, running
on ball bearings. This shaft gears into two transverse shafts,
which drive the propellers through the medium of a gear box to
the propeller shafts, making five shafts in all.

The engines in the centre car being placed transversely the
transmission is more direct, the engines driving the propellers
through two gear wheels only. The propeller gear box is
supported by steel tube outriggers attached by brackets to the
framework of the car. The petrol is carried in a series of tanks
situated beneath the keel walking way, and are interconnected so
that any tank either forward or aft can supply any engine, by
this means affording assistance for the trimming of the ship.

Four-bladed propellers are used throughout the ship.

Water ballast is carried in fabric bags also situated beneath the