Development of the motor car body----Brief history

The first motor car bodies and chassis frames, madebetween 1896 and 1910, were similar in design tohorse-drawn carriages and, like the carriages, weremade almost entirely of wood.
The frames were generally made from heavy ash,and the joints were reinforced by wrought iron brack-ets which were individually fitted. The panels wereeither cedar or Honduras mahogany about 9.5 mmthick, glued, pinned or screwed to the framework.
The tops, on cars which had them, were of rubber-ized canvas or other fabrics. Some bodies were builtwith closed cabs, and the tops were held in place bystrips of wood bent to form a solid frame. About1921 the Weymann construction was introduced, inwhich the floor structure carried all the weight of theseating, and the body shell, which was of very lightconstruction, was attached to the floor unit. Eachjoint in the shell and between the shell and the floorwas made by a pair of steel plates, one on each sideof the joint and bolted through both pieces of timber,leaving a slight gap between the two pieces. Thepanelling was of fabric, first canvas, then a layer ofwadding calico and finally a covering of leathercloth. This form of construction allowed flexibility inthe framing and made a very light and quiet bodyframe, but the outer covering had a very short life.
As the demand for vehicles increased it becamenecessary to find a quicker method of production.Up to that time steel had been shaped by hand, butit was known that metal in large sheets couldbe shaped using simple die tools in presses, andmachine presses were introduced to the steel indus-try to form steel sheets into body panels. Initially thesheets were not formed into complex shapes orcontours, and the first bodies were very square andangular with few curves. The frame and inner con-struction was still for the most part made of wood,as shown in Figure 1.1. About 1923 the firstattempts were made to build all-steel bodies, butthese were not satisfactory as the design principlesused were similar to those which had been adoptedfor the timber-framed body. The real beginning ofthe all-steel body shell came in 1927, when pressesbecame capable of producing a greater number ofpanels and in more complex shapes; this was thedawn of the mass production era. During the 1930smost of the large companies who manufacturedmotor vehicles adopted the use of metal for thecomplete construction of the body shell, and motorcars began to be produced in even greater quantities.

Owing to the ever-increasing demand for privatetransport, competition increased between rivalfirms, and in consequence their body engineersbegan to incorporate features which added to thecomfort of the driver and passenger. This broughtabout the development of the closed cars orsaloons as we know them today. The gradualdevelopment of the shape of the motor car bodycan be clearly seen in Figure 1.2, which shows aselection of Austin vehicles from 1909 to 1992.That is, from Edwardian to modern times.

The inner construction of the head roof of thesesaloons was concealed by a headlining. Up to andincluding the immediate post-war years, this head-lining was made from a woollen fabric stitchedtogether and tacked into position on woodenframes. However, the more recently developedplastic and vinyl materials were found to be moresuitable than fabric, being cheaper and easier toclean and fit. They are fitted by stretching overself-tensioning frames which are clipped into posi-tion for easy removal, or alternatively the headlin-ing is fastened into position with adhesives.

Comfort improved tremendously with the use oflatex foam rubber together with coil springs in theseating, instead of the original plain springing. Thegeneral interior finish has also been improved bythe introduction of door trim pads, fully trimmeddash panels and a floor covering of either remov-able rubber or carpeting.
Then came the general use of celluloid for win-dows instead of side curtains, and next a raisingand lowering mechanism for the windows.
Nowadays the windscreen and door glasses aremade of laminated and/or toughened safety glass.The window mechanism in use today did notbegin to develop until well into the 1920s.
Mudguards, which began as wooden or leatherprotections against splattered mud, grew into widesplayed deflectors in the early part of the twentiethcentury and then gradually receded into the bodywork, becoming gracefully moulded into thestreamlining of the modern motor car and takingthe name of wings. Carriage steps retained on ear-lier models gave place to running boards which intheir turn disappeared altogether.
Steering between 1890 and 1906 was operatedby a tiller (Figure 1.3). This was followed by thesteering wheel which is in current use. The posi-tion of the gear lever made an early change fromthe floor to the steering column, only to return tosome convenient place on the floor.
Some of the first vehicles, or horseless carriagesas they were known, carried no lights at all; thencarriage candle lamps made their appearance. Latercame oil lamps, acetylene lamps and finally theelectric lighting system, first fitted as a luxuryextra and ultimately becoming standard and finallyobligatory equipment which must conform withlegislation of the day.

When windscreens were first introduced suchaccessories as windscreen wipers and washers wereunknown. Then came the single hand-operatedwiper, followed by the suction wiper and finallyelectrically driven wipers.
The design of the wheels was at first dictated byfashion. It was considered necessary for the rearwheels to be larger than the front, a legacy from theelegant horse-drawn carriages. Wooden spokes andiron tyres were the first wheels to appear, and withboth rear and front wheels of the same dimensions.
Then came the wooden-spoked artillery wheel withpneumatic tyre (Figure 1.4). The artillery wheelgave way to the wire-spoked wheel, and this inturn to the modern disc wheel with tubeless tyres.
Great strides have been made in the evolutionof the motor car since 1770, when Cugnot’s steamwagon travelled at 3 mile/h (4.8 km/h), to the modern vehicle which can carry driver and passengers insilence, comfort and safety at speeds which at onetime were thought to be beyond human endurance;indeed, special vehicles on prepared tracks are nowapproaching the speed of sound.
It must be borne in mind that the speed of the vehi-cle is governed by (a) the type of power unit, (b) itsstability and manoeuvring capabilities and (c) itsshape, which is perhaps at present one of the mostimportant features in high-speed travel. Whatever themechanical future of the car, we may rest assuredthat the shape of the motor car body will continue tochange as technical progress is made