COMMERCIAL BODYWORK FOR SPECIAL USES.
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Body. Equipment for the Builder, the Glass Merchant and the Livestock Dealer. Constructional Features which are Essential.
A LTHOUGH a standard type of delivery van or .rilorry will serve many purposes, there are industries which, by reason of the nature of the load carried, or of its unusual dimensions or bulk, require specially designed bodywork in order that the commodities concerned may be transported economically and safely. The carrying of livestock is an instance where the provisionag motor vehicles of improved patterns has facilitated transport to such an extent that less effective methods have not only been superseded, but it has led to an increased use of this form of traction. The
carriage of goods by road has also been rapidly extended during recent years, owing to the introduction of the trailer, as well as the flexible and rigid types of six-wheeler, thereby solving many problems of heavy haulage, whilst an increasing number of all types of vehicle have a greater range of usefulness owing to the extra speeds attainable by the adoption of pneumatic tyres.
The Builder's Lorry.
The builder requires a lorry on which poles and ladders can be carried copveniently. As these are much longer than the body, and often exceed the overall length of the vehicle, the only way to carry these articles is to provide a gantry or raised sup port immediately at the rear of the driver's cabin, so that they may rest in a slanting position and Project well forward and above the roof of the cab. The loading portion of a lorry should be mounted independently of the cab, otherwise, when a heavy load is carried, the back of the cab is unduly strained. For this reason, the gantry should be mounted in the forward part of the loading portion and not consist of an upward extension of the rear pillars of the cab.
A simple way of ensuring rigidity of the gantry is to brace it by means of a pair of diagonal stays bolted to the sides of the body. If the sides of the body hinge, then either these stays must be dispensed with, or bolted only to the bottom framework. A compromise may also be made by hinging only part of the body side, so that a fixed portion remains for the attachment of the gantry stays.
Complete hinging of the body side may simplify loading and unloading, but it is constructionally unsound, especially if the hinged side be, say, 10 ft. or 12 ft. long. As a means for reinforcing the hinged side there should be at least one rear stanchion or pillar on each side to take the thrust of an easily shifting load, such as road material. These stanchions may be removable and they are also of value when the tailboard is let down.
Increasing the Number of Gantries.
The gantry should have its side members or horns projecting well above the cress-rail or bearer, so that a large load may be piled up with safety and without danger of shifting sideways. With a small lorry, the poles or ladders may rest on the hind bar or back edge of the floor, with or without the support ol the open tailboard. This hind bar should have a bevelled top surface so that it conforms approximately to a straight line drawn from this bearing to the crossbar of the gantry.
. For a larger lorry, one or two intermediate gantries or bolsters will be provided, so that not only is the weight of the load better distributed, but the load itself is better supported and less affected by the movements of the vehicle. The intermediate bolster is usually mounted so that it may be adjusted in two or three positions and is also removable so that the lorry may be used for other purposes. If the closed tailboard be used to take the rear hearing, then usually it is well plated on top and is about 6 ins, shallower than the normal pattern. The tailboard hearing has the advantage that the angle of the load is less acute and there is less downward thrust.
The Cab with a Sloping Roof. .
Since the height of the back of the cab is the chief factor which decides the angle at which the load is carried, some builder's lorries are made with a slanting roof, which is more or less parallel to the normal angle of the load. The headroom at the back of the seat is thereby, of course, unavoidably reduced to a minimum. For extra long poles or girders, a gantry is sometimes mounted at the dashboard position. The lower ends of the uprights are bolted to the chassis or held in sockets, whilst they are secured at the top by means of stays flapped to the canopy rail. If a lorry is to ,be
used exclusively for carrying girders and other items of constructional steelwork, body sides are unnecessary and the opportunity may be taken of building the gantries so that they form part of the body structure rather than being in the nature of attachments.
A builder often finds a pair of standards about 3 ft. 6 ins, high very useful for loading purposes if mounted near the end of the body. This pair of rear standards forms a convenient , support for window
Pipe and Bar-iron Transport.
If part of the load only consists of long lengths of material and be not of undue weight, there is no need for a gantry, but the awkward part of the load, such as piping or bars of iron, is easily accommodated by allowing it to lie beside the cab. The front of the body, between the side of the loading portion and cab, is made detachable, and a horizontal stay or stirrup is fastened to the dashboard, or the side of the body may be extended to form a shallow trough beside the cab. This special loading device is usually confined to the off side. If made on the near side it must not be too large to prevent the driver climbing over it. Another method is to make the cab much narrower than Usual, or the back of the cab may have a detachable panel through which the load may project, suitable provision for the passage of the load being made by the adjustment or construction of the windscreen. A sided lorry, with a narrow driver's cab, makes a very useful bill-poster's lorry, as this design provides a simple way of carrying two or more light ladders.
Lorries for Carrying Large Sheets of Glass.
The transport of large sheets of glass requires a special form of bodywork. The more or less upright position is the best, not only because the glazing of a shop front is often wider than the legal limit permitted for a lorry, but owing to the fact that the glass can be carried straight from the lorry to the shop front without having to turn it over. Lorries for carrying glass are provided with a skeleton wood framing, which slants at an angle sufficient to keep the glass from shifting, apart from any retaining device which is used as a precautionary measure. This framework may be provided on each side of a high-sided lorry or may form a wedgeshaped erection down the centre of a low-sided lorry or one of the open-platform type. A loading frame may also be mounted on the near side of an ordinary lorry. The base of the frame is mounted much lower than the floor of the lorry itself and may be detachable. The side frame is useful for a builder's merchant who does not wish to devote a vehicle entirely to this part of his business.
The high-sided lorry is the pattern most in favour. As each side only has to support half of the load, and B38
this is well distributed over a large area, as well as over the floor or bottom, framework, the body side may be lightly built. The weight of a comparatively large body is also reduced to a minimum either by dispensing with the roof or allowing it to take the form of a loose sheet, supported on four or five light ribs and lashed down at the upper part of the sides. The wind resistanceof a large body of this type must not be ignored, so that, in order to reduce it, the front is often wedge-shaped and louvres are inserted. By this means the currents of air pass through, instead of being obstructed by, the front of the lorry.
If large sheets of glass be transported in a crate the body may be provided with side stanchions having adjustable screws which can be turned from each side so as to hold the crate securely. Another method is to hinge the deep side of the body so that it may lean against the crate and be held in position by adjustable screws or bars. Smaller sheets of 'glass are occasionally carried in a horizontal position. A low-sided lorry has a skeleton wooden platform mounted on it, overhanging the sides. This platform is covered with felt or a blanket, whilst another blanket is thrown over the glass. The platform has side irons which drop into sockets screwed to the inside of the body sides, so that it may be easily detached. The dimensions of the platform seldom exceed 9 ft. 6 ins. by 6 ft. 6 ins.
Livestock Lorries.
Although all bodywork should be designed so that it may be easily cleaned, this feature is particularly desirable when the vehicle is made to carry livestock. The body has slatted sides spaced closer together at the bottom than at the upper part to prevent the animals getting their legs through. The boarding is fastened on the inside, thereby forming a flush surface. It is an advantage if the boarding be protected by means of easily removable wire guards. This arrangement saves the woodwork from being gnawed and allows the slats to be spaced wider apart.
The best style of floor is one which has rounded corners at the sides and front and is covered with sheetzinc, sloped so that drainage is facilitated, and overlaid with removable wooden mats. As loading platforms are seldom available, the hind ramp is an essential feature of all livestock lorries. It should, when let
down for use, not have a greater angle than 30 degrees. It is provided with cross slats to give a good foothold, whilst side guards, made up as skeleton or slatted frames, are 'useful for keeping the animals from stumbling or escaping. The higher the floor the longer the ramp must be if it is to afford easy loading; but, at the same time, if there be Some 8 ins. or 9 ins, of space available between the floor and chassis in order to prevent the formation of a large wheel arch, this space may be used as a locker for the side guards of the rarap.
A comparatively recent development of the livestock lorry is the introduction of the double and even tripledecker for carrying sheep and pigs. The double-decker is often built with a removable upper floor which rests on detachable crossbars, To ensure easy removal this deck is made up in sections. As the upper deck requires a very long ramp, if the animals have to mount from the ground level, this floor is sometimes mounted on pulleys and chains at each corner, or a rack-andpinion gear is employed. If this rorin of " lift " floor be used the animals must be loaded on the upper deck first, which is then raised into position.
The ideal form of livestock carrier is one which can
be loaded fromthe rear and unloaded at the side—a plan adopted for the horsebox. This arrangement is an advantage, as it saves reversing the animal, and, when sheep are carried, it is possible to load or unload at either end, whichever be the more convenient.
Insulation.
Any motor body which is double panelled throughout is insulated owing to the air which is confined between the two panels. But if the degree of insulation is to be made more effective, the space between must be filled or lined with a good non-conducting material, such as cork, felt, sawdust or silicate cotton. All joints between the boards must be well sealed and similar means for insulation used for the floor, roof, front an rear doors. The doors have felt attached on the shutting surfaces so as to make them as airtight as possible, The insulated van, either as a box or sling van, is extensively used in the wholesale meat trade. Smaller vans are useful for carrying ice and ice cream. As food of all kinds is maintained in a much better condition if carried in an insulated van, it is thought that a much wider use might be made of this class of vehicle.