TRAILERS
Page 46
Page 47
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for all purposes
FOR some time trailers of various kinds have been manufactured in small quantities by J. Brockhouse and Co., Ltd., West Bromwich, but it is only recently that the company has commenced to produce vehicles in ap
preciable numbers. The decision to enter the trailer market was followed immediately by an enlargement of the factory, and now a large self-contained shop is in existence, with administrative offices, stores, machines and welding outfits under one roof.
when we visited the factory a batch of adjustable and fixed-pole trailers was being constructed to the order of the Great Western Railway Co. ' The fixed type has a wheelbase of 12 ft. and can carry six tons, whilst the larger trailer intended for timber haulage can carry eight tons, with a possible variation in wheelbase of 18 ft. to 24 ft. Both the 6-tonner and 8-tonner are shod with twin pneumatic tyres, the former having 27-in. by 6-in, equipment, whilst in the latter case 32-in. by 6-in. tyres are used.
Four substantial oak bolsters are provided on each machine and in the smaller type they are positioned so that any size of container employed by the G.W.R. can be carried and lashed to the chassis by utilizing the securing eyes fitted intO the ends of the bolsters. The pole itself is built up with two channels which are plated top and bottom at various points throughout their length, to form a box-girder construction. Attachment to the under-car riage is effected by securing pins which pass through plates fixed on to the bolsters and to the longitudinal channels forming the main framework of the fore-and-aft carriages.
An interesting point in the design concerns the manner in which the axles are carried on the springs. The undercarriages for the 6-tonners and 8-tonners are of identical layout, but as the tyre equipment is different, some arrangement has to be made to allow working clearances for the tyres of the larger outfit when the drawbar (together with the front axle) is positioned angularly to the longitudinal centre line of the vehicle. The front axle is placed above the springs, whilst the rear axle is below them.
To compensate for the difference in tyre sizes, packing pieces are placed between the front springs and the axles of the 6-tonner. If it be desired to change over to the larger tyre equipment, these packing pieces are removed from the front and placed above the axle and under the spring on the rear undercarriage of the larger model. Thus
The parts are interchangeable, and full advantage may be taken of the small tyres to obtain a low loading height (3 ft. ins. with 27-in. by 6-in, tyres, and 3 ft. 7i ins. with 32-in. by 6-in. equipment).
The turntable is a substantial structure with east-steel stops to limit the extrema angular movements. The stops engage rubber buffers mounted on to the main framework of the forecarriage, so that " dead " shocks are avoided even under impact conditions. The drawbar is arranged to hook up into a vertical position when not in use and, upon being released, is held, by means of a pair of torsion springs, in an approximately horizontal-position.
Braking is on all four wheels, but when the outfit is being towed, shoes are applied only in the front drums by the tractor. The Brockhouse Bulldog brake gear is fitted on the rear axle. This mechanism is actuated by a handwheel which rotates a worm carrying a collar and a cable communicating with the brake camshaft levers.
Another interesting trailer is a 13tanner, the overall dimensions of the frame being 21 ft. 6 ins, by 7 ft. 5 ins., so that a useful platform space is provided. Like all other Brockhouse products, the structure is of a substantial nature, the main channels being 4 ins. deep with a strengthening sub-frame amidships. The wheelbase is 12 ft. and with 86-in. by 8-in. tyres the height to the top of the frame is a little under 4 ft,
The rear undercarriage has four wheels carried on two semi-elliptic . springs, the wheels being arranged in Fairs at each side of the springs. To allow complete freedom of movement in all directions, the springs are mounted on swivelling brackets from?. sub-frame. Short square-sectioned axles carry a wheel at each extremity, the centres of each pair of wheels being set 2 ft. apart.
There is, therefore, a large " base," as it were, to resist the collapsing couple caused by a horizontal effort, such as centrifugal force, when cornering. In this model the turntable has a 4-ft.-diameter wheel plate mounted on another sub-frame. which
is, of course, well flitched on to the main frame.
One of the brake controls is operated from the towing vehicle, whilst the other is applied by a lever on the
trailer. The two systems are interconnected by cables, a cross-shaft, running immediately aft of the hand lever on the trailer, communicating by additional cables to 16-in, diameter drums on all four wheels.
We also inspected one of the company's PuLimore six-wheelers, which is said to be capable of dealing with 8-ton loads. This particular machine uses as its basis a Studebaker Pierce-Arrow .4-5ton chassis having a wheelbase of 12 ft. 9 ins.:. the trailer axle is some 12 ft. aft of the centre driving axle and the overall length of the complete out fit is 31 ft. With 34-in, by 7-in, twin tyres, the height to the top of the frame is 4 ft. 2 ins.
One of the most interesting features of this particular vehicle is the braking arrangement. The vacuum servo installed on the vehicle is coupled up by pipe lines to an additional servo housed beneath the main frame of the trailer, whence cables lead to the Bendix duoservo shoes on the rearmost axle. The
drums are 16 ins, in, diameter and the width of the shoes is 2i ins.
The vehicles described do riot by any 'means represent the whole of the company's activities. The works are particularly well suited to the production of any special design of trailer.