Section drawing from the drive end of a Deltic engine. The air chamber surrounds the intake end of the cylinder, and the exhaust manifolds are mounted to the outer sides of the engine. Note the rotation of the crankshafts. (Napier/NPHT/IMechE image)
Later they spent a large number of years laid up at RAF Kalafana which was also a seaplane base, changing over to a Royal Naval Aircraft Repair Yard.
As the former seaplane base was developed into a container terminal now called the Malta Freeport, the Dark class boats were moved up the road to the former Transmitting station.
Both Dark class vessels were broken up in June 2001.