Built in 1968 and 1969 at Cooks at Wivenhoe for the Port of London Authority to work as wreck lighters and buoy maintenance vessels the pair served with the PLA until 2012 and 2013 when they were sold and replaced by London Titan.

Specs when sold in 2012 were as follows:

Dimensions: Hull length: 34m + 3m extra of bow roller above deck.
Beam: 9m Moulded depth: 3.3m Draft: 2m (aft) GT: 252
Deck Crane: 120tm telescopic boom ‘Effer’ – 16.2t @ 6.88m, 4.65t @ 19.48m – see duty chart.
Main engines: 2no. x Caterpillar 3406 x 300hp each
Generators: 3no. x Caterpillar (low hours), water cooled, but can also run from ballast tanks if vessel aground.
Speed: 8.5 knots
Main Deck winch: 2 x 20t – which have sheaves for 3 x falls on each winch and linking together to achieve 120t line pull over the bow roller.
Aft Deck Winch: triple drum 10t capacity + 2 drum ends + roller fairleads for each on transom.
Capstans: 2 x hydraulic capstans either side at bow.
Ballast Pumps: 6”, 4” & 3” pumps, includes salvage suction valves and overboard discharge.
Fwd ballast tanks: 64t capacity
Aft ballast tanks: 60t capacity
Fuel capacity: 20t
Fresh Water capacity: 11t
Accommodation: 10 persons
Cargo hold: removable deck hatch for rigging store/small machinery.
Deck Cargo capacity: 1150t, subject to stability.
Hull thicknesses (Shell plate): 25mm bow, 20mm deck, 18mm sides, 13mm bottom

The following superb photos were kindly scanned and sent to me by The Nottage Maritime Institute at Wivenhoe who have a number of items related to cooks shipyard: