Class 46 (BR/Sulzer 2,500hp Type 4 Diesel-Electric)

Following the success of the ten Class 44 pilot scheme Type 4 diesels BR went ahead with a production order which was split between one hundred and twenty seven Class 45s and fifty six Class 46s (there were originally going to be twenty more built but the order was changed to the Class 47 instead). The Classes 45 and 46 are very similar mainly differing from the electrical equipment used, Crompton Parkinson for the 45 and Brush for the 46 [1].

Number built: 56
Built: 1961-63
Builder: BR Derby
Motor: Sulzer 12LDA28-B diesel
Power: 2, 500 hp (1, 864 kW)
Formation: 1-Co-Co-1

From their entry into service in the early 1960s the Class 46s could be seen on cross-country expresses and long-distance freights though these services switched over to newer motive power like the HSTs during the 1970s and withdrawals of the Class 46 began in 1977, by 1984 all had been withdrawn from revenue earning service. All 46s were fitted with steam heating only which became a problem as the amount of steam heated coaching stock was reduced by BR [2].

Most were scrapped though one, 46 009, was destroyed as it was deliberately driven at speed into a nuclear flask (unmanned of course!) to test the strength of the flask [3] in the event of a rail crash. A couple entered service with the Railway Technical Centre to provide motive power for test trains, 46 035 Ixion was also used for a number of experiments including the performance of separately excited traction motors and equipment to reduce wheel spin [4]. Three (including both of the RTC 46s) have been preserved.
D182 at Kidderminster Town

46 035 at Rowsley South

46 010 at Kidderminster Town

Another view of 46 035 at Rowsley South

D182 at Kidderminster Town

46 010 at Kidderminster Town

[1] Brian Haresnape, Production Diesel-Electrics Types 4 and 5 (Ian Allan, 1984) p. 31
[2] John Vaughan, Diesels on the London Midland (Ian Allan, 1981) p. 75
[3] John Glover, BR Diary 1978-1985 (Ian Allan, 1985) p. 93
[4] Colin J Marsden, 25 Years of Railway Research (OPC, 1989) p. 81