Dual locomotive F3 Model Bo-
The railway locomotive leads a rugged existence, and only the fittest survive. Evolution has thus tended to move in moderate steps, and few successful developments have been sufficiently dramatic to merit the term "revolutionary". One such step was the pioneer four-
By 1939 EMD had some six years' experience of powering high-
Their ability to outrun the best steam locomotives had gained them acceptance in many parts of the USA, but this was a specialised activity, and even the most diesel-
Dilworth had faith in the diesel, and his company shared his faith to the tune of a four-
Gauge: 4ft 8 1/ 2in (1,435mm).
Propulsion: One EMD 567B 1,500hp (1,120kW) 16-
Weight: 230,000lb (104.4t) (minimum without train heating steam generator).
Axleload: 57,500lb (26.11).
Overall length: "A" unit 50ft 8in (15,443mm), "B" unit 50ft Oin (15,240mm).
Tractive effort: 57,500lb (256kN).
Max speed: Between 50mph (80km/h) and 120mph (192km/h) according to which of eight possible gear ratios fitted.
Service entry: 1945.
Most of the passenger diesels built so far incorporated the lightweight Winton 201 engine, which EMD had acquired, but in 1938 EMD produced its own 567 series of two-
The units were built on the "carbody" principle, that is, the bodyshell was stressed and formed part of the load-
Not least amongst the startling qualities of No. 103 was its reliability. Throughout the 11-
By the end of the war the freight diesel was fully accepted on many railroads, and total dieselisation was already in the minds of some motive power chiefs. The first postwar development was production of the 567B engine rated at 1,500hp (1,120kW) to replace the 1,350hp 567A model. After 104 interim units designated "F2", there came a four-
Simplicity of maintenance, and improvements in the engine to reduce fuel consumption, were two of EMD's claims for the "F3", and these same claims were repeated for the next model, the "F7", launched in 1949. The main change from the "F3" was in the traction motors and other electrical equipment. With the same engine power, the new motors enabled 25 per cent more load to be hauled up heavy grades. The model was offered with the usual options, including eight gear ratios. The "F7" proved to be a bestseller too; 49 US roads bought 3,681 "F7s" and 301 "FP7s", the version with train-
By the 1960s steam had been replaced totally, and manufacturers were now selling diesels to replace diesels. Trading-
The "F" series, more than any other model, showed, showed that improvements in performance and economies in operation could be achieved in all types of traffic by dieselisation, despite uncertainties about the life which could be expected from a diesel locomotive.