Yes they are an interesting class of work vessel and where employed by the Admiralty on a very wide field of work other than the salvage/mooring work that they where designed for. They carried six fold blocks below which you connected to the working winches forward to lift over the bow (2 x sets of tackles), the winches where 35t swl, reduced later to 25t because of the physical strain of man handling the working mains and shackles etc. Had a fixed 180t per hour salvage pump, plus in the hold numerous air, water pumps and welding equipment. Had high and low air pressure systems to operate various systems, such as air lift pumps, pneumatic tools and support divers including a compression chamber for divers. This precludes numerous lengths of different size chain, shackles, blocks, wires, so as to be able to carry out refurbishment to moorings and carry out salvage tasks. The original spec demanded 12 knots speed in most weather, although they where very good seaboats, I would not push them at that speed in bad weather, though a mate of mine pushed the Salmaster through a SE 8 to 9 in the Pentland Firth ( he was 12 hours late on his eta for Rosyth). But yes I had 4 interesting years on these craft and I enjoyed them.