S102

S102 was commissioned in November 1988, built under Lloyds survey and launched in April 1990.  The design was similar to S101 employing the same reliable air powered variable ballast system but using a new design of transmission.

This modification enabled the diesel engine to drive the main electric motor as a generator to charge the battery whilst underway or tied up in dock. The pressure hull was increased in diameter to 1.3 metres and had closely spaced frames to increase the diving depth to 220 metres . Also added were bow hydroplanes to accurately control the sub at ‘periscope' depth, the periscope consisting of a small camera on a rotating mast.

The build period was short because of a fixed contract with the Swedish Navy. At launch, only 4 days remained for sea trials in Plymouth Sound. Immediately afterwards the submarine was trucked overnight to Stockholm.

Just 5 hours after arrival the first contracted operation with the Swedish Navy commenced.  In darkness the two Swedish pilots faced rapidly deteriorating weather but completed the 40 mile mission, 15 miles of which were dived.  The Navy were very impressed and subsequently signed a long term lease contract with the owners. S102 operated for 8 years, exceeded all initial performance estimates and proved remarkably robust.  Frequently stationed in Lulea, just 80 miles from the arctic circle, considerable under ice operation has been logged.  The boat has proved very economical to operate, requiring just a truck and the two pilots, and has consumed very little in the way of spare parts. When the contract with the Navy was finally completed S102 was sold to a treasure hunter in the Philippines.