LightAuto

The evolution of light car bodywork.

When the light car became a distinct type around 1912, the bodywork fitted to cars had evolved to the point were the passengers sat within it. Even if it didn't enclose them above the shoulders. The body an appendage, was mounted on top of the chassis almost as an afterthought and mostly built by someone other than the manufacturers of the mechanical parts of the car. The bodies fitted to early light cars, usually had only two seats, due to the limited power output of the engines fitted restricting performance if excessive weight was carried.
  1910 Jowett
The lightest body type in use at the time and the type most commonly fitted to light cars, was the tourer body. Consisting of a panel wrapped around the rear of the seat, with a small door or doors between that panel and the dash or scuttle in front of the seats. This structure consisted of a framework made of a hardwood such as ash. This was covered in wood or metal panels. A wooden floor completed the weather protection at the bottom of the car. To protect the driver and passenger from inclement weather touring cars were fitted with a folding hood that reached to the top of the plate glass windscreen. This didn't keep out the wind as there were large gaps for the wind to blow through. Flexible side screens were often used in an attempt to do that. The body was completed with metal panels to cover the engine and simple mudguards over the wheels. These were usually linked by a platform between them. This was used as a step to assist entry and also to mount accessories such as spare tyres and batteries.
After the First World War, the power output from light car engines had increased sufficiently to allow four seat tourer bodies to be fitted on some cars.

Morris Minor tourer
The tourer type body has been used in refined and developed forms until the present day. The only production car to use the type of construction I have described above, is the Morgan 4/4, manufactured at Malvern, England.
Enclosed bodywork had been fitted to some heavy cars from almost the beginning of the motoring era and small versions of these were fitted on light cars. But they were relatively heavy compared to a touring body severally limiting performance.   The answer was a lighter method of construction. This came in the form of the fabric body. The best-known fabric body type was the Weymann system. Devised by a Frenchman Charles Torres Weymann in the early nineteen twenties. It consisted of a rigid wooden framework connected with metal fittings, covered in waterproof fabric, often with padding to produce a contoured form. Bodies were produced using the Weymann system under licence by many major coachbuilders throughout Europe and fitted to some very expensive cars. Less expensive versions of this type of construction were devised to create saloon and coupe bodies for light cars. To limit weight, these tended to be compact and as was the style in the nineteen twenties quite upright, thus predating the present fashion for compact upright small cars at the beginning of the twenty first century. Wooden framed bodies were never very durable and the fabric covered variety were even less so.
A fabric bodied Swift Cadet
The durability problem by was solved by Edward Gowen Budd an American industrialist. He had devised a method of constructing all metal bodies for cars and railroad carriages from a number of steel pressings welded together. Andre Citroen had met Budd on a visit to the USA and decided to use the method to produce bodies for some of the light cars he was making at the time. He purchased tools and presses from Budd to start producing bodies in a new factory. This required a great deal of investment and although Citroen was one of the French top producers and this helped to solve the problem of producing sufficient bodies for it's increasing output, it put a great strain on the companies finances. The first Citroen with an all-steel body was the B10 Conduite Interiere of 1922.
Such financial outlay was not possible for most manufacturers and the other methods of construction were carried on into the nineteen thirties, although the fabric body was gone by then. It was only when they're were fewer manufacturers making a greater number of cars that all steel bodies became commonplace.
  Austin Seven 1930's
The use of wooden framed bodies allowed even the smallest manufacturers to offer a wide range of body types. Tourers were the cheapest to produce and so were still produced until the end of the nineteen thirties, convertible's, Sports roadster, coupes and cabriolet were also on offer. The cabriolet type of body, described by the Oxford English dictionary as A convertible body with fixed sides and a folding top, was to be made in the millions in the form of the Citroen 2CV.
Citroen 2CV
The saloons which were the first body type to be available in all steel form was increasingly popular. When the all-steel body became the only acceptable type, the range of body types became restricted.
The next step in the evolution of body production methods was unitary or monocoque body/chassis form of construction. Composed of many steel pressings welded together to form a strong structure that was lighter and stiffer than the equivalent separate chassis and body combination. This required and even greater investment in tools that were mostly to be found in specialist factories. Citroen was again in the forefront of this revolution with the Traction Avant of 1934. In the next few years General Motors joined them with their Opel Kadett in Germany and Vauxhall Ten-Four in Britain, Also Morris in Britain with the Ten Series M, had introduced cars with a unitary chassis/body. By 1950 the light car with a separate chassis was almost a thing of the past.
Morris Minor MM an early unitary body
The front engine, rear wheel drive configuration in use from the beginning by the designers of light cars didn't give much opportunity for advances in packaging. By packaging I mean the utilisation of space for the occupants and their luggage in a car. The usable space in early light cars mostly consisted of one compartment located behind the engine and above the transmission, with either four seats or two seats and a small space for luggage, with access from inside the car. During the nineteen thirties fold down racks at the rear of the body were provided to carry luggage on. Later provision was made to carry small items in a boot or trunk in the same place, the lid of which folded down that could be used in the same manner as the rack. By the nineteen forties this had grown into a bigger compartment with an upward opening lid and therefore light cars bodies were similar to the heavier types. In 1958 Austin in the UK produced a small car using a body form designed by Pinin Farina the Austin A40 Farina. This was a front-engined rear wheel drive car, so was not very space-efficient. But Farina produced a design a body with the luggage space enclosed within the main profile of the car and fold down rear seats, thus giving us the two box form that is widely used today. One version on the A40 produced by Innocenti in Italy had a full depth, lift up door or hatch, giving access to the luggage area.
Austin A40 farinaRenault R4L
The Renault R4L of 1961 was one of the earliest if not the first two box hatchback to enter production. It was not a compact design as it had an early form of front wheel drive layout. But the flexibility of its cabin design made it a very popular car.
An unusual rear engined car that was produced as a hatchback in the early nineteen sixties was the Autobianchi Bianchina Panoramica, a derivative of the Fiat Nuova 500. The engine was located under the floor and a lift up hatch was used to gain entry to the luggage space above.
Autobianchi Bianchina Panoramica
The rear engined and early front wheel drive cars did allow the floor to be lowered and creating an uncluttered box for the passengers. But the front wheel drive cars still had the machinery taking up too much of the wheelbase and the rear engined layout was always dogged by a lack of luggage space. It was the advent of the transverse engined front wheel drive cars that allowed packaging to advance. Alex Issigonis with the BMC Mini led the way in 1959, producing a design that utilised the maximum possible proportion of the space available for the passengers and their luggage. But the original Mini did not go all the way to become the pioneer of the modern light car; The saloon was fitted the drop down boot lid similar to the cars of the nineteen thirties and the estate car had van doors at the rear. Only one version of the Mini was ever fitted with a rear hatch. That was the Innocenti Mini 90 and 120, a Bertone body design, again produced in Italy in the 1970's.
By the nineteen seventies the use of the hatchback was widespread. By the nineteen eighties only a few light saloon cars were available, the hatchback being the popular choice.
One of the outstanding examples of the art of packaging of the nineteen nineties was the Renault Twingo. An early example of the" monobox", concept, were bonnet and windscreen (hood and windshield) is blended into one continues facet of the car's profile. The engine and transmission only occupy a small proportion of the overall length of the car. This combined with a flexible seating arrangement made the Twingo a very well packaged car.
Renault Twingo
In the late nineteen nineties designers went one step further to take the monobox concept and increase the height of the car allowing the occupants to sit in a more upright manner so increasing the volume of the interior.  The latest idea in packaging for the small car is to add flexible seating to these taller cars to create the compact MPV (multi purpose vehicle).
The two box hatchback of moderate height is still the dominant form. But the trend in light car bodies at the beginning of the twenty-first century is towards taller compact cars of the monobox hatchback form. The saloon and estate types of body have almost disappeared as the newer body forms evolve. The lightweight coupe has always been relatively rare and remains so, as does the convertible. With the universal use of the unitary form of body construction the tooling required to produce cars of limited demand has made these body forms relatively expensive. Because of the nature of the unitary body form, in the case of the convertible the advantages of the past have been reversed and it is usually heavier than the enclosed forms. This is due to the strengthening of the floor pan this is required to replace the stiffness provided by the roof.
The Fiat Idea  a tall  monobox
A Simple History Part six.
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