A Remarkable
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Pipe-carrying 1 0-wheeler
The Scammell Company's New Articulated Machine for Oilfield and Similar Service. It has a Most Creditable Cross country Performance and Hill-climbing Powers
WITH a view to developing a powerful machine capable of transporting long and heavy lengths of pipe, as used in oilfields, Scammell Lorries, Ltd., 52-54, High Holborn, London, W.C.1, has, at its Watford works, produced a special pole-type semi-trailer with four-wheeled trailing bogie, which can be used in conjunction with a six-wheeled tractor. The tractor is the standard Scammell Pioneer rigid six-wheeler for cross-country work, a -most successful machine which has been dealt with frequently in Tile Commercial Motor since it was introduced in
1927. •
The forward end of the trailer is superimposed upon the tractor chassis by means of a turntable mounting. The trailer consists of a central box-section girder with-fore and aft transverse girders, on which are mounted cradles for carrying the pipes. To the rear girder is fixed a heavy seating for the transverse, inverted semi-elliptic spring, this having 11 leaves. The ends of the spring are supported by another boxsection girder, at each end of which is mounted a rocking beam carrying the roller-bearing stub axles. The thrust and drag from the rear bogie are taken up by a substantial Vshaped perch-bar, -.khich has a spherical mounting at its forward end.
For the purpose of dealing with pipes of different lengths the distance between the tractor and trailer bogies can be varied by sliding the rear girder up the central boxsection member.
The tyre equipment of the vehicle Is most interesting, all wheels being shod with Goodyear 13.5-in. by 20-in. low-preksure single pneumatic• tyres, mounted' upon Goodyear K-type rims. Two spare rims with tyres are carried at the back of the driver's cab, special brackets and chain blocks being provided for slinging purposes.
Through the courtesy of the Mechanical Warfare Board Experimental Establishment a trial of the machine has been held at the Farnborough test ground, conditions there being probably quite as severe as any to be found in the majority of the oilfields. In some parts the sand is fine and loose, and varies from 2 ins. to 9 ins, in depth. The machine was loaded with 10 pipes, 40 ft. long and weighing approximately 9 tons 12 cwt., so that the gross laden weight was roughly 19 tons. Several Severe nullahs were negotiated with the greatest of ease, the free articulation of the tractor front aide, the driving bogie and the trailing bogie being quite impressive. On second gear the vehicle negotiated, with ample reserve of power, a hill with a very loose surface of soft sand, having an'average gradient of 1 in 6. On the level, over loose sand, the machine attained 20 m.p.h.
Various tyre pressures were tried out, the lowest being 20 lb., and even with this adequate pressure there were no signs of slip.