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-foot: 1923–1929; 51-foot: 1928–1949; 52-foot (Mk. I): 1950–1955; 52-foot (Mk. II): 1957–1960;
In service	1923–1988
Completed	60-foot: 4; 51-foot: 13; 52-foot (Mk. I): 10; 52-foot (Mk. II): 10;
Retired	37
General characteristics
Type	Motor lifeboat
Displacement	60-foot: 40–44 tons; 51-foot: 27 tons; 52-foot: 28 tons;
Length	51–60 ft (16–18 m)
Beam	60-foot: 15 ft (4.6 m); 51-foot: 13 ft 6 in (4.11 m); 52-foot (Mk. I): 13 ft 6 in (4.11 m); 52-foot (Mk. II): 14 ft (4.3 m);
Installed power	60-foot:2 x 80-bhp D.E. 6-cyl. petrol; 51-foot: 2 x 60-bhp Weyburn CE6 6-cyl. petrol; 52-foot (Mk. I): 2 x 60-bhp Ferry VE6 6-cyl. diesel; 52-foot (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 1988.