In describing chronologically the Diesel traction developments on the broad-gauge and narrow-gauge lines of the North Western Railway, India, the author covers the Beardmore branch-line Diesel-electric locomotives, the Armstrong-Whitworth mountain-line railcar, the 1,300 b.h.p. mainline locomotives, and the eleven Ganz Diesel-mechanical railcars introduced in 1939. Electrical transmission troubles were the main cause of poor performance of the small locomotives, and led in 1940 to a decision to scrap the two locomotives after an aggregate mileage of only 163,000 had been attained in ten years. The small Diesel-electric railcar continues to give good service; apart from teething troubles, the principal defects have been a cracked cylinder block caused by a circlip breakage, three cracks in a bogie frame, and, some years ago, burning of the combustion chamber Venturis. The two main-line Armstrong-Whitworth locomotives were intended for the Lahore-Karachi mail service, but one failed during the preliminary trials and the other only ran about 1,000 miles on trial. As the results were unsatisfactory it was decided to recondition both locomotives, and the Diesel engines, generators, and traction motors were returned to England. Shortly after this the makers asked for cancellation of the contract, and this was agreed to. The paper is mainly concerned with the operation and maintenance of the Ganz railcars. They were intended for fast service on branch lines and were therefore based on Jullundur (about 100 miles east of Lahore), where there is an extensive system of branch lines. In addition to the Jullundur service an intensive short-distance suburban service was operated in the Karachi area for some months, due to an emergency arising from the withdrawal of motor bus services because of severe petrol rationing. Originally these cars were maintained on a mileage basis by the maker. Within the first seven months an aggregate mileage of over half a million was built up, but frequent troubles in traffic then led to the withdrawal of the cars for modification. The failures were connected mainly with the compressed air system, starter motors and battery, Hardy flexible couplings, main clutch, and engine water-cooling system; the gearboxes gave good service. There were no less than 74 failures during the seven months' service in 1939, giving the extraordinarily low mileage of just over 7,000 per failure. After reconditioning, a modified four-car service was introduced—the modifications, together with the taking over of the maintenance by the staff of the North Western Railway, greatly improved the service, so that at the end of the three-year period (1st October 1940 to 30th September 1943) the mileage per failure had been raised to 173,854, as compared to 88,312 miles per failure for steam locomotives during approximately the same period. During this time the cars completed a passenger mileage of 1,043,122. The operating and maintenance costs are discussed, and the author also discusses the relative costs of Diesel-electric as compared to Diesel-mechanical railcars. Brief reference is also made to a two-stroke Diesel engine which has recently been fitted to a narrow-gauge (2 ft. 6 in.) railcar.
The vegetation of lateritic crusts in Northwestern Benin (Atakora region)
