Low-loaders with their feet firmly on the ground
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by R. D. Cater • A short report about a range of groundlevel loading trailer equipment to be manufactured by Becorit (Engineering) Ltd. was published in CM, Feb 16. And last week the company held a demonstration which served to prove the validity of its original claims.
Becorit, a mining-machinery producing company, intends to enter the trailer and semi-trailer market solely by producing ground-level loaders in sizes from 15cwt capacity to 15 tons. At the time of the demonstration only 15cwt and 3-ton models were available, both of these being of the closecoupled drawbar-type.
Both models displayed appeared soundly constructed, and incorporated several attractive features. The first of these is the ability of the wheels to stay in contact, at full load, with the road surface under all normal conditions. The degree of articulation in each bogie assembly allows for the two wheels on one side of the trailer to be riding on levels of up to 12in. variation.
Although the bogies are interconnected transversely by lin. square torsion rods, both trailers could be towed over a lft-high ramp staggered so that the highest point matched a diagonal through the leading and trailing axles. Passing over this ramp the nearside leading wheel and the offside trailing wheel were raised to the maximum travel allowed by the suspension, without any tendency for the remaining wheels to shed part of their load or leave the ground. This is an important factor on a close-coupled design because of the substantial towing hitch rise and fall which can occur causing extremely high overloads on any one pair of tyres.
Overrun brakes are used on both trailers, standard rod and cable mechanism serving adequately on the 15cwt model, but to provide enough efficiency on the bigger version the overrun mechanism operates through a Lockheed dual master-cylinder, one circuit serving each side of the trailer. Singlepull handbrakes are connected to the rear wheels only via Bowden cables. Brake units on the smaller version are 7in. by 1.125in. and on the larger are 10.5in. by 2.5in.
Becorit designers have succeeded in procuring quite useful deck widths; on the smaller model it is 72.125in. with a clear width between the wheelboxes of 50in. The larger model is supplied at 7.5ft overall width, with 5ft 8.5in. floor width between wheel boxes.