Aircraft Practice in
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BUS BODY CONSTRUCTION
Impressions Gained During a Recent Visit to the Medway Works of Short Brothers (Rochester and Bedford), Ltd.
ALL-METAL saloon bodies which, in the course of construction, resemble flying-boat hulls, and roof frames that look like the wings of aircraft. these .comprise the first impressions which one receives on entering the works of Short Brothers (Rochester and Bedford), Ltd., on the banks of the Medway. Here one finds all-metal doublesaloon bus bodies alongside Short Calcutta flying boats, a single-decker beside a De Ravilland Moth which is being equipped with floats and, accordingly, one is wont to make instructive comparisons.
Engineers and designers of the bus and coach department of the company study the methods of those engaged in the building of aircraft, and seek to emulate many of the constructional features of wing and fuselage, which make for strength, rigidity and lightness. During a recent visit we noted that the company is making both single and doubledeck passenger bodies of wood and of metal. Both types closely follow the practice generally associated with the manufacture of aeroplanes, and, although the all-metal vehicles attract the visitor because they are unique, it is SOOn realized when examining the structural details of the wood framed bodies that these also incorporate many ingenious ideas for reducing weight without sacrificing strength.
A most interesting example of allmetal coachwork at present to be seen at the Short Brothers works is a covered-top double-deck bus body, accommodating 50 passengers, this
being built upon an • A.E.O. Model 507 chassis;• 42 of these vehicles have just been conStructed to the order of the Birmingham Corporation. The
complete shell of this body is of patented construction, the materials used being the Northern Aluminium Co.'s 25 S.T. and 17 S.T. alloys and ordinary aluminium sheet. The alloys, which are used for frame-mentbers, have an ultimate tensile strength of 24I-28 -tons per sq. in., and, in addition, are said to be practically non-corrosive.
A close view of the framework of this body in it§ early stages of constreetion reminds one of the skeleton of a Zeppelin airship, the members being generally of channel section metal riveted at the joints. The roofs of both saloons are of aluminium sheet, suitably strengthened, and exterior roof sticks are employed, a patented principle being adopted in the case of the canopy covering the upper deck. Even the window frames are of metal, whilst the seat frames are of light tubular steel.
The only wood components in this model are the floor battens. These are made up in the form of mats on crossmembers of extruded aluminium bar, which are fitted with Rawlplugs so that the slats may be held down by ordinary wood screws.
.' By employing all-metal 'construction the manufacturer can • produce this double-saloon body within a weight of 34 cwt. 1 qr., whereas a wood body of the same capacity weighs 43 cwt. 1 qr. 16 lb. Thus the body weight per passenger is reduced from '97.2 lb. to 76.2 lb.
Some of the details of this metal bus body are particularly interesting. Per example, the electric wiring is carried in aluminium-alloy conduit tubing, which is fitted inside the hollow cantrails, a method which greatly facilitates rewiring and lengthens the life of the wire. No weddings whatever need be removed when installing new cables.
Another advantage " of the tubular form of construction is that water from the rain gutters is drained away down the hollow corner pillars of the body, thus dispensing with the usual type of outside drain pipe and improving the exterior appearance of the bus. The bus which we inspected was equipped with Beelawat sliding windows and all the hand rails were of steel tubing, covered with black Dover' te.
As we have already said, the wood-framed bodies built by Short Brothers, Ltd., also incorporate remarkable weight-saving features. A fine example of a light and strong wood-and-metal body is the 32-seater de luxe coach, of which the concern is constructing a fleet of nine for the East Kent Road Car Co., Ltd: The frame of this body, which is designed for a TillingStevens Express chassis, is of timber, having a section which appears rather light for the weight carried, but a closer inspection reveals that the members are cleverly flitched and reinforced with steel, thus affording ample strength.
Dealing with the interior of this longdistance vehicle, the most important feature is the use of metal pillars to support the roof, and these, being very narrow, give passengers a view which is almost unobstructed. The seats, which have metal frames of girder construction and laminated spring backs, are particularly comfortable, because of the good depth of the spring cases in the squabs and backs. They are covered
in moquette, which matches the interior panels of the bus and the back of each seat is fitted with a folding Erinoidcovered table, an ash-tray and a grab handle.
Other equipment which is worthy of note includes Sorbo cellular matting in the gangway's and on the footrests, cocci-nut matting between the ,seats and large rug boxes, one over each wheel-arch and another in the rear bulwark on the near side just behind the door. There are four ventilators in the roof, and the six windows on each 'side of the coach are fitted with the Rawlings lift. Above the main lights are glass louvres, which are carried in metal frames. The interior fittings are finished in polished walnut, which is cellulose-covered. The Numa air-bell system is used to provide communication with the driver.
From the exterior this forward-control coach has a pleasing appearance, the deep side valances concealing four large lockers, the spare wheel being carried in a similar locker in the rear panel. This is a vehicle which the East Kent Road Car Co., Ltd., uses upon limited stop services, and, although it is not strictly an allweather coach, it is one that is de lighttul to ride in during both summer and winter.
During our tour of the works we neticed a fleet of 19 single-deckers also using chassis of this model; these are being built for the Maidetone and District Motor Services, Ltd. In this type of vehicle the floor is covered throughout with Sorbo cellular rubber matting and the interior panels are finished in leather-cloth. One of this tleet has a special arrangement whereby hot water from the enginecooling system is led to a radiator fixed in the front bulkhead; ventilators carry fresh air past the radiator. For the same company we also observed in different stages of construction 14 open-top double-deck 48-seaters on Leyland Titan chassis; these bodies are also of the wood-and-steel type, a special feature being the fitting of a folding door to the lower deck, opening on to the conductor's platform. In this vehicle, too, Sorbo floor covering is used.
An interesting kind of metal bucketshaped seat is employed on the upper deck of this open-top bus. The seat board and back are carried on a laminated steel spring and the back panels are made of a metal-covered plywood.
Short Brothers, Ltd., is emestructing two all-metal double-deck bodies with open tops for the Southdown Motor Services, Ltd., and the East Surrey Traction Co., Ltd., respectively, for mounting upon Tilling-Stevens Ist10.A2 chassis. This is a chassis normally built to take single-deck bodies, but by the use of the Short patent all-metal Construction a double-deck body can be fitted to it. The reason for this will be readily understood when it is mentioned that the body in question weighs only 31 cwt. and the body weight per passenger is only 75i lb., 46 passengers being accommodated.