A Heavy-duty Trailer of Welded Construction
Page 58
If you've noticed an error in this article please click here to report it so we can fix it.
ONE of the first trailers to be produced by R. and W. Hawthorne, Leslie and Co., Ltd., at its locomotive works, Forth Banks, Newcastle-onTyne, was a 20-ton type sold to the Newcastle-upon-Tyne Electric Supply CO., Ltd. It was specially designed to early 20-ton transformers in the extensive area covered by the undertaking in question.
This manufacturer is now able to provide trailers of various sizes and types. One of the particular features of the model under review is the all-welded construction; neither bolts nor rivets have been used—all in-lie-lions being made by electric welding. Despite the fact that the trailer is intended to carry pay-loads of 20 tons, and was actually subjected to its first test with a load of 25 tons, the unladen weight of the outfit is 4+ tons. Naturally, with .such heavy burdens, it is desirable to have a low load-line, thus minimizing labour costs. It has been possible to provide a platform level of 2 ft. 6 ins., largely by reason of the twin-tyred rear wheels being mounted within the overall width of the frame.
For this purpose, the semi-elliptic springs which carry the bogie arms are mounted directly below the main frame members, and the pivots of the rocking beams are located below the centres of
the springs. In all cases, the wheels are of the double-disc type equipped with Timken roller bearings and Henley solid tyres, 26 ins. by 6 ins. by 20 ins. The two front wheels are carried upon a swivelling axle, controlled by a solid drawbar with a spring-loaded eye. Above the fore-carriage is the seat for the brakesman • the brakes can be controlled either by the man on the platform or from the ground or tractor.
• Roller bearings are used throughout for the wheels, and these have proved most effective in decreasing the rolling resistance of the machine. Removable oak battens form the platform, which affords a load space of 12 ft. by 7 ft.