Old pilot boat gets a new turn of speed

Following 32 years of active service, Pendennis Ship Yard was commissioned to complete the £374,000 refit of the Falmouth Harbour Comissioners’ pilot boat, LK Mitchell. The vessel was named after the late pilot Captain Laurence Kerr Mitchell, who tragically lost his life in 1974 whilst attempting to board the P&O ferry Eagle during heavy seas.

Darglow worked alongside Scania, Wills Ridley, Ocean Engineering, and SW Commercials to bring the vessel up to modern pilot boat standards. Darglow Marine installed a completely new exhaust system designed and manufactured by Halyard, plus four blade propellers from Darglow Engineering.

Bob Doyle of Darglow Engineering visited Falmouth to see how the refitted boat is running. He told MJ that Halyard, working with Darglow, designed a bespoke exhaust system that routed out through the transom to reduce the noise levels from the new twin 575hp Scania diesel engines.

He said that back pressure to the new engines was one of the points that had to be addressed. ‘Back pressure is always difficult. Limits are laid down by the manufacturer, but the problem lies in getting a balance between size, which creates extra noise, and say, Scania’s limits.’ Happily, later sea trials showed the new system reduced this issue to well within the levels that the new engines required while keeping the noise down to a minimum.

The exhaust system included high risers, Duplex spray heads, 8” specially tuned inline silencers and an exhaust alert system to detect overheating. It was manufactured by Halyard in the UK and has enabled LK Mitchell to be smoother, quieter and faster, with the whole system working together to give a much higher speed than the old engines. The boat used to manage a maximum of some 17 or 18 knots but now has a measured top speed of 21.8 knots.

‘The LK Mitchell now acts as a highly capable all weather pilot boat for Falmouth. Her speed, safety, electronics, reliability and crew comfort have now been greatly enhanced, making her compatible with the Harbour Commissioners newer boat, the Arrow, said assistant harbour master William Davies. ‘Being able to field two similar specification pilot boats greatly improves the pilotage service available at Falmouth.’