The CRYPT Mag

Bodyshells and bodywork.

Submitted by - Chris Skelhorn

In the beginning, there was the cart. And man saw the cart and thought, "This is no good, where's the wife and kids going to sit?"
Many of these carts were originally designed to have loads placed on them, and passengers were simply not considered. In fact, a driver was only required to walk alongside, so he could control the animal pulling it! This could be oxen, horses or donkeys.
It was only later that cart-builders provided their customers with seating.
Any seat was just a plank slung across the front to enable the pilot to guide the animals by remote-control, or reins.
Eventually, it was decided that passengers could be carried on such vehicles, but as they were then constructed, travelling was only for short distances, and were most perilous! It was common for even adults (whether asleep or drunk) to fall off the swaying, bucking machine, and either break their necks, or get crushed under the wheels.
So, a method of being able to seat passengers was devised. Initially, again, boards were pressed into service, which also allowed goods to be carried when the passengers had alighted.
Some boards were arranged horizontally for sitting on, whilst further boards were mounted vertically to reduce the risk of people vanishing over the side.
Refinements were continuous, and soon the boards gained padding, whilst the axles were mounted on huge leather straps to act as rudimentary suspension.
It was soon reasoned that if two rows of passengers faced each other, they occupied the same amount of space as three rows of passengers facing the same way, so some carts had the seats facing in the direction of travel, rather than longitudinally.
There was no central aisle, so to allow entry and egress, holes were cut in the sides. More upmarket vehicles had doors of wood or canvas to temporarily block the holes. Whether powered by horses, petrol, or Diesel, these vehicles were known as Charabancs, from the French Char-a-banc, meaning a seated carriage. A British charabanc would have upwards of 4 rows of seats.

The Charabanc.

Generally, these bodies were constructed almost entirely of wood.
Later vehicles had roofs, and shortly after that, side screens in an effort to protect the passengers from the worst of the elements. By this time, construction was still using timber, but this time it was only for the skeleton, which was dressed with canvas, painted, and then varnished.
As the coachbuilders' art improved, carts became carriages, and extras included windows with real glass, interior lighting, blinds, and plusher seats.
As these vehicles got bigger, it was also necessary to beef up the underpinnings. The chassis was the first thing to be assembled for virtually all vehicles, and as it held both the bodywork and the axles, it had to be sturdy.
For the most part, a chassis is made using two longitudinal members and several cross-members. It comes as no surprise to learn that this is called a 'ladder' chassis.
Alternatives include a perimeter chassis, which has the main chassis rails running around what would be the bottom of the body, the backbone chassis also has two main rails, but these are mounted closer together, the cross-members mounted atop the rails, and the outriggers extended from the cross-members in order to support the body.
The body itself needed a sturdy frame that wouldn't disintegrate at the first sign of a pot-hole, it also needed to support not only its own weight, but the weight of any occupant or cargo placed inside.
This had the disadvantage that, as any chassis members were for the most part, dead straight, any body fitted was going to be very high. This caused problems not only with entry and egress, but any body-roll during other than the simplest curves in the road could hurl the occupants into space.
Sides were definitely going to be needed, and they would have to be strong!
The chassis members, therefore, had to be curved so that the floor was as low as possible both for loading and unloading, and to keep the centre of gravity as low as possible, whilst leaving room for the mechanical bits underneath.
Axles too had to be re-thought, so as to bring the centre of gravity even lower. Wheel size would have to await improvements in the roadbuilders art!
The first major improvement came when the chassis and the underframe of the body were built as one single unit. This allowed the body builder to utilise the strength found in the chassis.
Body styles also changed according to use and country.
The horse-drawn Surrey, which was just an open cart with an umbrella on the top to afford shade without restricting air flow, was popular among Americas better-off, but didn't do very well in the cooler, damper European markets.

Horse-drawn Surrey.

The Hansom Cab (the original Hackney Carriage) was a closed, two-wheeled carriage with doors at the front (dangerously close to the back end of the horse!) where the passengers sat. The driver sat high up behind the passengers, with his knees level with the roof. This layout did not catch on in the States.

The Hansom Cab.

However, the Doctor's Coupe, a short two-seater with a closed roof, and virtually no luggage space, sold very well in both markets. The expression has since been contracted to simply Coupe.
Early cars were, quite simply, horseless carriages, ie just the horse-drawn carriage minus the horse, but taking the shapes and descriptions of their older counter-parts. Thus, we still have Broughams, Landaus, etc.

1905 Vauxhall Hansom Cab.

A Landau has a closed section where the driver sits, and a convertible section at the back so that the rear passengers may enjoy the adulation of the crowds that they pass.
The Queen uses a vehicle similar to this, but the once-open rear section is now covered by bullet-proof glass. One hopes that the air-conditioning is up to the task!

1936 Rolls Royce Landau.

Similarly, the Pope-mobile of the 1980's was a development of the Landau, even if it wasn't much more than just a hacked-up Range Rover with a phone-box stuck in the back!
The Brougham, conversely, has the rear roof closed, while the driver is exposed to the elements.

Lincoln Brougham.

Cabriolet, or cabrio, is another that has stayed with us for eons. The description when applied to a horse-drawn vehicle is a light, two-wheeled, hooded chaise, and the equivalent for the car is one with a folding top.
A simpler description for this style is convertible.
The horse-drawn coupe is simply a four-wheeled, two-seat carriage, whereby the driver sits outside. It's mechanical counterpart is an enclosed car, usually with only two seats, but may have more.
The gently sloping tail (also known as a Fastback) on modern coupes does not denote a coupe at all. This is just an aid to streamlining, but it does allow for more passengers and/or increased luggage space, by stretching the roof further back.
As roads improved, wheel size was allowed to decrease, and mudguards became a more integral part of any design as wings, eventually covering the wheels entirely. Revised suspension systems further reduced the ride height, bringing the chassis rails lower. This had a 'knock-on' effect inasmuch as as the suspension changed, the coachwork was allowed to take up the space previously designated for running gear movement.

Wheel spats.

Also, as there were differences in the stresses imparted throughout the body, the body itself had to be re-developed, with the areas with most stress receiving more strength.
This, coupled with the fact that bodies were now made of pressed steel rather than wood, enabled manufacturers to absorb chassis type strength into the shell, and dispense with the chassis altogether!
One vehicle that made the best of this new advantage was the 1951 Hudson Stepdown. So-named because one had to literally 'step down' to get into the car!

Hudson Stepdown.

Some vehicles, however, need to retain such a structure, such as commercial vehicles, which need a chassis to enable the fitting of a wide range of bodies suitable for a wide range of applications.
There are also those vehicles that cannot have a 'proper' chassis as weight and build restrictions will not allow such. Double deck buses have not had a formal 'chassis' for many years, instead relying on the integral strength of the monocoque construction. Thus the weight of the vehicle can be kept down.
The Bristol Lodekka of the late 1950's was one of the first to lose its chassis. This enabled operators to send a double-decker along routes with low bridges where previously only single deckers were able to travel.
Two other devices were used to lower the roof of this vehicle; one was the propeller-shaft delivering the power to the rear wheels being offset so that the central floor could be lowered, and the other was a side aisle on the upper floor. The upper deck had seats that were 4 passengers wide as opposed to the standard deck, which had twin seats either side of the central aisle.
The lower deck thus only had limited height along the offside, which really only affected those passengers seated next to the windows along that side.

Bristol Lodekka.

Bristol Lodekka on the left, standard double decker on the right. The height difference is approximately two feet. The seats are picked out in blue, and the grey blocks represent the suspension.
There were also half-deck coaches, whereby a single gangway had steps up or down into several smaller 4-seat compartments. This would allow the upper forward-facing passengers to sit directly above the lower rear-facing travellers.
This also resulted in a lower overall height, but the seating arrangement was too complex, which meant that this was a very short-lived design.
As headway was made in seat construction, designs changed, and seatbacks became slimmer, more seats were built into any given length of floor-pan, thus increasing carrying capacity.

Improvements in chassis and suspension technology have also played their part in bodyshells.
One of the most endearing buses on British roads is the faithful old AEC Routemaster. This is the archetypal 'London' bus, and many are still used regularly despite being de-commissioned 30-odd years ago!
The Routemaster was of a modular design, so that components could be easily removed for replacement or repair, without having the vehicle stripped down to a shell.
Several commercial chassis manufacturers toyed with either a bespoke engine, like the Commer Avenger which had 6 pistons in three cylinders, two crankshafts and ran as a two-stroke Diesel, or bought a Perkins, Gardner, or Leyland engine that was designed to be fitted laying on one side! Mounted between the chassis rails, these engines allowed a lower, flatter floor.
The 1960's saw the introduction of the Leyland Atlantean. This was a monocoque design with a transversely-mounted, vertical Diesel engine fitted in the distinctive 'bustle' across the rear of the bus. The doors were fitted at the front of the body. The major two-fold effect here was that not only was the floor height just about the lowest in its class, the driver could also do the work of the conductor!
The only alternative to this design was the Bristol VR.
In more recent times, we've seen the arrival of such vehicles as the estate car (shooting brake, station wagon), MPV (Multi-Purpose Vehicle), Mini-MPV, SUV (Sports Utility Vehicle), hatchback, coupe-cabrio, and a plethora of vehicles that blur these descriptions, such as the 'soft-roader'.

Honda HR-V Soft roader.

All these vehicles were developed from different ideas based on the original cart.