Barnett-class lifeboat

RNLB William and Kate Johnston (ON 682)
Class overview
Builders	J Samuel White, Cowes S. E. Saunders, Cowes Saunders-Roe, Cowes Groves & Guttridge, Cowes Rowhedge Ironworks, Rowhedge
Operators	Royal National Lifeboat Institution
Built	60 ft: 1923–1929 51 ft: 1928–1949 52 ft Mk. I: 1950–1955 52 ft Mk. II: 1957–1960
In service	1923–1987
Completed	60 ft: 4 51 ft: 13 52 ft Mk. I: 10 52 ft Mk. II: 10
Retired	37
General characteristics
Type	Motor lifeboat
Displacement	60 ft: 40–44 tons 51 ft: 27 tons 52 ft: 28 tons
Length	51–60 ft (16–18 m)
Beam	60 ft: 15 ft (4.6 m) 51 ft: 13 ft 6 in (4.11 m) 52 ft Mk. I: 13 ft 6 in (4.11 m) 52 ft Mk. II: 14 ft (4.3 m)
Installed power	60 ft:2 x 80 bhp D.E. 6-cyl. petrol 51 ft: 2 x 60 bhp Weyburn CE6 6-cyl. petrol 52 ft Mk. I: 2 x 60 bhp Ferry VE6 6-cyl. diesel 52 ft Mk. II: 2 x 72 bhp Gardner 6LW 6cyl. diesel
Propulsion	2 × pitch propellers in tunnels
Speed	9.5 knots (10.9 mph; 17.6 km/h)
Range	300 nautical miles (350 mi; 560 km)
Crew	6

The Barnett-class lifeboat consists of three types of non self-righting displacement hull lifeboats operated by the Royal National Lifeboat Institution (RNLI) from its stations around the coasts of the United Kingdom and Ireland between 1923 and 1987.