The MV Royal Iris is a twin screw, diesel-electric, Mersey Ferry. The vessel was built by William Denny & Brothers of Dumbarton (Yard No. 1448) and launched in December 1950, costing £256,000. The engines were produced by Ruston & Hornsby Metropolitan-Vickers. Propulsion: 4 oil 4SA, each six cylinders driving four generators, each 300 kW/300v DC-connected to two electric motors, each 730shp and 2 shafts. The maximum speed is 12 knots. The ship measured . Length is 159 feet long and 48 feet wide, with a draught of 9 feet. At least during the first decade of its life, the ship's diesel-electric propulsion made it more economical to run than the other vessels in the fleet. Since 2002, the vessel has been laid up in a berth on the River Thames, close to the Thames Barrier in Woolwich. As of 2022, the ship continues to sit derelict and half submerged at its moorings. Career in service Royal Iris ran the trials on the Skelmorlie Mile on the River Clyde on 24 April 1951. Arriving in the River Mersey on 28 April 1951, it was initially owned and operated by Wallasey Corporation and carried the borough coat of arms on the front of the superstructure. Upon entering service on 5 May 1951, it was licensed to carry 2,296 passengers on normal ferry duties, or 1,000 for cruising. Originally painted in a green and cream livery, the ship was distinctive in having a forward dummy funnel near the bridge and two exhaust stacks amidships, on both sides. Onboard amenities included a dancefloor and stage, tea room, buffet, cocktail bar, even a fish and chip saloon. The latter likely affording Royal Iris the nickname "the fish and chip boat". On Friday 7 September 1951 the battleship HMS Duke of York was under tow on way to being broken up at Gareloch when she collided with Royal Iris off Gladstone Dock. Royal Iris was temporarily out of control and the floodtide carried it against the warship. The ferry was approaching the end of a cruise organised by the Amalgamated Engineering Union. Some people were hospitalised as a result of the accident. During the 1960s numerous acts associated with the Merseybeat scene performed on the ferry. Duke Duval played on the first Cavern Cruise, followed by The Beatles and Gerry & The Pacemakers. Paul McCartney referenced performing with the Beatles on the ferry in his song