Part of the Acorn Archive

Hearts of Oak



PTF Nasty


Steve Palk's Nasty Class PTF, fast attack vessel, built for Norway.


In Penzance Harbour; 15th Nov 2006


This ship is one of the 11 “Nasty” Class PTFs, held at Horten, and sold by the Norwegian Government in 1981. Stev Palk has brought this ship from Scotland, and then to Padstow, where extensive works were carried out. She has been towed to Penzance, and Steve continues his untiring restoration. He has hopes of having her seaworthy by 2009. The prospect of  power and speed around Wolf Rock is extremely enticing. The Napier Deltics have been sold, and Steve is awaiting delivery of the two new engines, shortly.


In Penzance Harbour 2007; Engines removed, see below.




Napier Deltic engines.

Both were in working order. But rather expensive to run!! And very tricky to get started. Even more tricky to service. The "gearbox" is in fact the gear phasing arrangement for the three crankshafts. (one at the bottom, two at the top in inverted triangle). The output shaft can just be seen as the unpainted metal. As built for the RN the Napier Deltic had a continuous output rating of 1875 bhp at 1700 rpm. British Rail had similar engines in the "Deltic Class" diesel-electric locomotives built by English Electric. Two engines were fitted in each loco with a combined output of 3300 bhp at 1500 rpm. It is effectively an 18 cylinder two stroke engine. As fitted to Coastal minesweepers (Ton Class ) 2 x main engines and one "pulse" generator.



PTF Nasty’s were fitted with Two Napier Deltic Engines.

Each 18 cylinder, 36 piston, turbo-charged diesel engine; 3,100 bhp @ 2,100 rpm

Overall weight : 19,500 lbs.




The User’s Guide to the Napier Deltic (pdfs)

Napier Deltic info at


Raymond Forward

24th October 2007