British Rail Class 27

BRCW Type 2
British Rail Class 27

27001 at Bo’ness

Type and origin Power type Diesel-electric Builder Birmingham Railway Carriage and Wagon Company Serial number DEL190–DEL258 Build date 1961–1962 Total produced 69

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 5 chains (100 m) Wheelbase 39 ft 0 in (11.89 m) Length 50 ft 9 in (15.47 m) Width 8 ft 10 in (2.69 m) Height 12 ft 8 in (3.86 m) Loco weight Originally: 72.50 long tons (73.7 t; 81.2 short tons) 71–76 tonnes (70–75 long tons; 78–84 short tons) Fuel capacity 685 imp gal (3,110 l; 823 US gal) Prime mover Sulzer 6LDA28-B Generator DC Traction motors four GEC WT459 DC traction motors Transmission Diesel electric MU working ★ Blue Star Train heating As built, Steam generator subclass 27/2, Electric Train Heating, Houchin 120 kW (160 hp) alternator powered by Deutz 8-cylinder air-cooled diesel engine, type F8L413 Train brakes Initially 14 dual-braked, 10 fitted with additional air brakes later on. Remainder vacuum only.

Performance figures Maximum speed 90 mph (145 km/h) Power output Engine: 1,250 hp (932 kW) @750 rpm At rail: 933 horsepower (696 kW) Tractive effort Maximum: 42,000 lbf (187 kN) Continuous: 25,000 lbf (111 kN) Loco brakeforce 34 long tons-force (340 kN)

Career Operators British Railways Numbers D5347–D5415; later 27001–27066 Axle load class Route availability 6 (RA 5 from 1969) First run 1961

British Rail's Class 27 comprised 69 diesel locomotives built by the Birmingham Railway Carriage and Wagon Company (BRCW) during 1961 and 1962. They were a development of the earlier Class 26; both were originally classified as the BRCW Type 2.

Original allocations were D5347–D5369 to Glasgow Eastfield, D5370–D5378 to Thornaby and D5379–D5415 to London Cricklewood for Tilbury Boat trains and Cross-London freight services. In the period September to December 1963, some of the Cricklewood allocation were transferred to Leicester and in December 1965 the Thornaby allocation was also nominally transferred to Leicester to join them. Traffic changes combined with reallocation of Class 25s led to the gradual transfer of the Leicester and Cricklewood locomotives to Scotland during 1969 thus concentrating the whole class within Scotland and being part of the replacement fleet that allowed the withdrawal of the poorly performing Clayton Class 17 locomotives from traffic. For many years they were extensively used on the West Highland Line. By September 1986, the final vacuum brake only locos had been withdrawn, regular passenger services had ceased and only 21 locos remained, allocated entirely to Eastfield depot. A mass withdrawal in July 1987 due to the presence of blue asbestos left 27008 as the last in service. Its final working was on 13 August and the loco was officially withdrawn on 19 August 1987. The Class 27s were actually outlived by the older Class 26s, whose less powerful engines were more reliable.

By the late 1960s, the Swindon-built Inter City DMUs operating the Edinburgh Waverley - Glasgow Queen Street express service were becoming unreliable. In 1970 the decision was made to replace them with locomotive-hauled carriages. So between 1971 and 1973, twenty-four Class 27s were fitted-up with dual (vacuum and air) brakes and reclassified Class 27/1, while 36 Mark 2 carriages (7 brake second opens, 22 open seconds, and 7 corridor firsts) swapped their vacuum-operated shoe brakes for air-operated disc brakes and were though-wired with "Blue Star" control cables to enable "top and tail" push-pull working. It was later decided that as the Mark 2 stock was dual (steam or electric) heated, to convert half the 27/1 fleet to electric train heat, by replacing the train heating boiler with a Deutz 8-cylinder, air-cooled diesel engine and alternator. The conversions were then classified as Class 27/2, and were used on one end of the train, with a 27/1 on the other.