British Rail Class 29

British Railways Class 29

300px D6121 in BR green livery with white stripe and large yellow warning panel and headcode at Inverness MPD, August 1968

Type and origin Power type Diesel-electric Builder North British Locomotive Co. Build date 1958–1960 (original class 21) Rebuilder Paxman Rebuild date Rebuilt: 1963, 1965–1967 Number rebuilt 20

Specifications Configuration Bo-Bo UIC class Bo'Bo' Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Wheel diameter 3 ft 7 in (1.092 m) Minimum curve 3.5 chains (231.00 ft; 70.41 m) Wheelbase 37 ft 0 in (11.28 m) Length 51 ft 6 in (15.70 m) Width 8 ft 8 in (2.64 m) Height 12 ft 8 in (3.86 m) Loco weight Fuel capacity 460 imp gal (2,100 L; 550 US gal) Prime mover Paxman Ventura Engine type V12 diesel Generator DC generator Traction motors 4 GEC DC motors Transmission Diesel electric MU working ● Red Circle Train heating Steam Train brakes Vacuum

Performance figures Maximum speed 80 mph (130 km/h) Power output Engine: 1,350 hp (1,010 kW) Tractive effort Maximum: Loco brakeforce

Career Operators British Railways Numbers D6100–03/06–08/12–14/16/19, D6121/23/24/29/30/33/34/37 Axle load class Route availability 6 (RA 5 from 1969) Retired 1969–1971

The British Rail Class 29 were a class of 20 diesel-electric Bo-Bo locomotives produced by the re-engining of the British Rail Class 21 units. The units were designed for both passenger and freight trains. The outwardly similar Class 22 shared no mechanical parts with the 29s.

Background

The machines were produced from 1963 onwards from the North British Class 21 by replacing the original unreliable licence-built MAN of the Class 21s with Paxman Ventura V12 engine at Paxman's Colchester works.

The first unit to be re-engined was D6123, a further 19 machines were re-engined in 1964-1965 at Glasgow Works and mostly Inverurie Works, along with other modifications including the fitting of four-character headcode displays in the nose ends (D6123 retained its original front ends and so did not receive a headcode panel). After rebuilding, they returned to service from Eastfield depot in Glasgow.

Withdrawal

Although these offered more power and much improved reliability over the original Class 21s, they did not survive much longer, due to their small class size and the use of a non-standard high-speed diesel engine. D6108 was withdrawn in May 1969 and scrapped by McWilliams of Shettleston in 1971, while the other 19 were withdrawn between April and December 1971 and scrapped at BR's Glasgow Works in 1971-72. No Class 21, 22 or Class 29 locomotives survive today.

Numbering

The rebuilt locomotives were numbered:

• D6100–03
• D6106–08
• D6112–14
• D6116
• D6119
• D6121
• D6123
• D6124
• D6129
• D6130
• D6133
• D6134
• D6137

Models

Hornby produced a OO gauge ready-to-run Class 29 in the late 1970s in BR green and blue liveries. Jouef produced an HO-gauge ready-to-run Class 29 in 1975.

Sources

• Ian Allan ABC of British Railways Locomotives, summer 1966 edition

External links

• Paxman Ventura engine - at Richard Carr's Paxman History pages