PASSENGER BODYWORK
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and how it li
)rogressing
Tendencies in Construction and Equipment as Reflected by the Methods Adopted by Leading Bodybuilders and Those Concerned with Meeting their Requirements
ARETROSPECTIVE review of passenger-vehicle bodywork, as exemplified by the recent exhibition at Olympia, results in the formation of a number of fixed impressions. One was pleased to observe the general tendency towards simplified lines in dosign and construction, and the avoidance of " frills " in equipment which are neither useful nor ornamental, the bodies of coaches and buses possessing, on the whole, a much more workmanlike appearance than in the past.
The use of kitchenettes and lavatories on long-distance coaches has passed completely out of favour, and no real progress is to be reported in the direction of observation saloons. It must not be thought, however, that there is any stagnation of ideas amongst bodybuilders, but rather are they giving added attention to the improvement of accepted types than to the creation of what may be regarded as " stunt " designs.
Progress is apparent in a number of channels, but certain perennial difficulties still exist and there appears to be much uncertainty as to the best way to overcome such problems as the intrusion of the rear wheel-arches, and the disposal of passengers' luggage on coaches.
There have been no revolutionary changes in super-structure layout and, although the use of heavy ash and oak timbers is a thing of the past, the fetish for saving weight in the shell itself has reached a stage when a further reduction would considerably weaken those vital framework members, which have to bear considerable stress, and impair the rigidity of the whole structure.
Parts are now often made of smaller section, reinforcement being provided by steel knees and by 'flitch plates which, in some cases, extend throughout the
part treated. Bodybuilders are, however, turning their thoughts in other directions to obtain lightness, such as the use of aluminium panels which, in the average double-decker, saves up to 3 cwt. as compared with steel and the use of steel-tube seats and aluminium and light alloys for interior fittings. On the score oft lightness, the body framework built of all metal is without an equal, but, although in some quarters it has staunch advocates, it has not achieved general acceptance, possibly
because the first cost is usually higher and doubt sometimes exists as to the ability of the metals to resist corrosion.
Short Brothers (Rochester and Bedford), Ltd., of Rochester, has had much experience in building lightweight metal bodies, and at the Show the company displayed a 49-seater body, with main frame-members of duraltimin and aluminium-sheet exterior panels screwed to wood packing pieces fixed to the faces of the box-sectioned pillars—a good maintenance point.
Another company proceeding on somewhat similar lines is the MetropolitanCammell Carriage Wagon and Finance Co., Ltd., Saltley, Birmingham, which had on view a 48-seater body incorporating special constructional features. In this system the question of maintenance has also been kept well to the fore, and steel sheeting, forming the inner casing, is riveted to the metal framemembers to give structural strength, whilst the outer aluminium panels are secured by screws to wood fillets inserted in the tubular pillars and metal rails, thus enabling panels to be easily replaced in the event of damage.
At the Show another all-metal body was displayed by the Arlington Motor Co., Morley House, Regent Street, London, W.1, but, in this case, steel was used for the shell and the panels were of aluminium sheeting, the panel sections being riveted instead of spotwelded.
A noteworthy and unusual contribution to body structure is that by the Northern Counties Motor and Engineering Co., Ltd., Wigan Lane, Wigan, in which the rear quarters are composed of a series of spring-steel slats of different length, these being bent to the shape of the corners and held by screws to the reinforced framework. The slats are protected by Fin, three-ply rubber sheet, having canvas interleaving, the final covering being leather, or leather cloth, painted to conform with
the, usual finish. Moulding strips
secured by round-head screws render the parts easily accessible in case of need.
This method provides a flexible form of construction at those points where panels often suffer much damage. The panels will withstand an impact without fracturing and can easily be made to return to their normal shape. An Albion chassis was used to display a body with this meritorious feature, which costs about £8 extra for a coach body.
Another interesting feature of construction, typical of the company's attention to detail, was that adopted by Weymanu's Motor Bodies (1925), Ltd., Addlestone, on a Daimler double-decker, strips of fabric being used to cover the joins between the outer panels, before the mouldings are fixed, thus giving a perfectly watertight seal. On a coach body, by the same company, unobtrusive gauze buttons were used on the lining panels, thus acting as breathers, helping in ventilation and reducing condensation between the panels.
Passengers' comfort is, in the main, affected by seating design and layout. In
this matter the differentiation between service-type buses and limited-stop or long-distance coaches is much less than in the past, the equipment of the former having advanced appreciably. Furthermore, with the extended use of doublesaloon buses, top-deck passengers are given a degree of comfort vying with that provided for persons using the lower saloon.
Seating plans for single-deckers remain virtually unaltered, but designers still find it difficult to circumvent the rear wheel-arches. The simplest solution is, of course, the use of longitudinal seats, but, whilst this method is not viewed with disfavour for regular service buses, it is not welcome from the passenger's point of view on coaches, every person preferring a direct view ahead. Moreover, with operators expressing a penchant for the chassis with a low-loading line, the problem is accentuated.
In some cases at the Show seats were sacrificed in order that wheel-arches might be enclosed either to serve as a small container, or as a parcels platform. The former was an idea adopted
on a Brush-bodied Leyland 28-seater. In other instances, the arches carried aluminium strips, having rubber inserts,. and the passengers behind them bad an unusual degree of leg room, although not necessarily at the most comfortable angle.
W. Mumford, Ltd., of Salisbury Road, Plymouth, adopted the plan of mounting the seats on a raised platform at each side of the gangway, the enclosed space —7i cubic ft. in extent—below the seat being used for luggage and being reached by pulling forward a strap attached to the seat cushion, which is fixed to a steel plate hinged at each end and fitted about 24. ins, behind the front edge of the seat.
The question of doubledecker layouts deserves separate attention, as the subject is bound up with entrance positions and types, and we will proceed to a few comments on seats themselves.
Seat design has reached an advanced stage of development, and although orthodox arrangements of cushion and squab still hold the field, there are several new ideas worthy of special attention. At the Show, one—by Messrs. W. L. Thurgood, of Ware— was to be seen on a Thorny o r of t single-decker. An aecompanying sketch shows its constructional features, and it will be seen that the sides of the seat back carry a tube running in a half-round channel carried by the main framework, which is rigid. The back rest is attached to the cushion and moves up and clown with the movement of the passengers, Apart from preventing friction and chafing, such a seat is claimed to overcome the intensified bouncing set up by an ordinary well-sprung seat having a back rest devoid of vertical play. The idea is equally applicable to longitudinal seats, as well as to those facing to the front—which is not always the case with a seat having a sprung back rest.
Although it was not greatly in evidence at Olympia, we can foresee an extended use of the steel-tube seat, especially for double-deckers, where weight saving is a primary factor, and such examples were to be found on Wycombe and Beadle bodies.
A well-trimmed seat, built up on a steel-tube frame, may weigh up to 32 lb., but as a moquette-upholstered woodframe seat on an alloy pedestal may weigh very little more, it is to its other features, such as simplicity of manufacture, long life, ease of maintenance and adjustability, that bodybuilders will ultimately be attracted. Such seats should certainly make headway on service vehicles, but their future on other types of passenger vehicle depends upon the ability to provide a form of finish which will offer comfort over long distances.
Another interesting seat is the latest pattern marketed by Lamplugh Spring Seats, Ltd., Bushey Mill Lane, Watford, in which the company's patented form of slatted spring construction for seat and squab is combined with the Dunlop cellular air-cushion rubber pad, specially moulded for the purpose.
Rubber for upholstery has suffered from the disadvantage that a lack of ventilation through the material itself results in damp accumulating between 848 the rubber and covering material. With cellular air cushions, having a porous surface, there is a continuous circulation of air, due to the normal compression and expansion of the cushion when in use.
One can foresee an increasing use for rubber in the construction of cushions and squabs and the seat in which steel springs are completely discarded may prove to be the popular type of the future. In this connection a new form of construction adopted by Sorbo Rubber Sponge Products, Ltd., Woking, can be cited, this having rows of stout rubber cups, in place of coil springs, surmounted by a layer of moulded sponge rubber. In another design pro duced by this concern the cushion has coil springs carrying a sponge-rubber top, and the seat back is entirely of sponge rubber ; fuller details of this seat, which has a steel tube frame, will be given in a subsequent issue.
Another direction in which rubber is now being widely used is for floor coverings. Such material, whether in plain sheet form or having a sponge-rubber base, is silent to the tread, is easy to clean, insulates the interior from transmission noises and fumes from the engine, is durable and is attractive in the many plain colours and mottled designs in which it is available. Sponge-rubber facings for footrests also contribute to passengers' Comfort.
At the Show we noted, on a well-built body by Strachans (Acton), Ltd., North Acton, London, another use for rubber as insertions for aluminium tread strips for door wells, etc. Where space permits the rubber slides out and can easily be replaced, but failing that it is a simple matter to prise it out.
The seat back provides plenty of scope fo,r designers, and, consequently, there is little uniformity in shape. In some of those we tried at the Show the angle of rake, coupled with a contour which does not give proper support, seemed to have received scant attention. An exception was in the Northern Counties equipment on an Albion singledecker, in which an extension of the back formed a good shoulder support, being carried on spring-steel members, the rest having a slightly forward tilt. The advantage of such a seat is that a big angle of rake is avoided and the
distance between each seat is reduced to a minimum without affecting leg room, this being possible as the thickness of the back does not, at any point, exceed 2 ins.
A seat used in a bus body built by Midland Light Bodies, Ltd., Holbrook Lane, Coventry, and carried by a Morris-Commercial chassis, consisted of a single piece of plywood bent to such a shape as to ensure the maximum strength and the provision of ample knee room for passengeh this sheet being secured to laminated wood legs and bolted, in turn, through the floor.
While on the subject of seats we can, in passing, refer to the hair padding in sheet form as marketed by Trost (London), Ltd., 45, Hatton Garden, E.C.1. The hair is combed out and stitched down to a backing medium, thus giving even distribution and overcoming the risk of faulty laying, at the same time ensuring that an equal weight of hair is used for each seat.
Where head-rests are used, they do not always achieve the object in view, particularly where they are part of the seat back. On a Duplebodied Crossley 31-seater the rests were shaped at the centre, so that passengers could conveniently lean back without removing their hats.
On certain bodies detachable head-rolls, horse-hair, filled, were used, as on a Guy 20-seater with a body by the R.E.A.L. Carriage Works, Ltd., Popes Lane, Ealing, London, W.5, but unless provision is made for housing the loose fittings, this is not a method to be recommended. On an Arlington body, the fixed sprung head-rolls could be thrown back.
Appreciating the fact that the inside passenger on a transverse seat for two persons often suffers certain discomfort, H. V. Burlingham, Ltd., Newhouse Road, Marton, Blackpool, used deeply sprung padding at the garnish-rail level on an Albion_30-seater coach.
Two useful ideas on a Brush-bodied T.S.M. coach, recently built for the East Kent concern, are a draught-screen under each seat and a cushion which lifts so that the passenger's rug can be stored below it when not required.
In their-efforts to provide for passengers' comfort, bodybuilders are not overlooking the exacting lot of the driver, and his comfort is being studied by the provision of such excellent equipment as the Leveroll Busella seat mechanism, made by A. W. Chapman, Ltd., Ranelagh Gardens, London, S.W.6. This is capable of horizontal and vertical adjustment and locks itself automatically. It enables the individual stature of the driver to be met in the matter of comfort and control, thus reducing driving fatigue.
Emergency exits from drivers' cabs are also receiving increasing attention. Strachans (Acton), Ltd., claims to be the originator of this idea, for, over two years ago, it built single-deck bodies in which the off-side window is hinged at the top and when raised is held by a turn hook below the canopy. Two other methods are shown on the previous page.
In this article we have dealt with certain aspects of passenger-bodywork progress, but others will 'be covered in articles to be published later.