The heart
of a Formula 1 car is the monocoque. The most important component of a
driver’s comprehensive protection package, this carbon-fibre safety cell has
to withstand extreme loads in an emergency. As Brian O’Rourke, Chief of the
Composites department at BMW WilliamsF1 Team, says: “The monocoque plays a
key role in the safety of Formula 1.”
Formula 1 has indeed become safer since Colin Chapman, the legendary
de-signer and Lotus team chief, installed a riveted lightweight metal case
into his Lotus 25 in 1962 instead of the classic tubular frame – the first
monocoque in grand prix history. McLaren sent the first cars with a safety
cell made of carbon fibre out onto the track in 1984. Since then, this life
insurance for drivers has been constantly enhanced.
The technical regulations of the Federation Internationale de l’Automobile
(FIA) define the monocoque as a survival cell. “When developing a car, we
have two goals: build a fast racing car and at the same time protect the
driver as well as we can,” said O’Rourke before the Bahrain Grand Prix. “You
can see just how safe the monocoques are from the fact that after a major
collision, the cars are often seriously damaged but the drivers can climb
out of a virtually intact monocoque uninjured.” |
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The monocoques
are made of carbon fibre, a composite material twice as hard as steel but
five times lighter. And in Formula 1, every gram counts. The monocoque
consists of up to 12 layers of carbon-fibre mats, in which the individual
fibres are five times thinner than a human hair. A honeycomb-shaped
aluminium layer is inserted between the carbon-fibre layers, which increases
the rigidity of the monocoque even more. The whole shell is then heated
under pressure in an autoclave – a giant oven – and completely hardened
after two and a half hours. Even so, the baking procedure is repeated twice
more for safety reasons, be-cause, at the end of the day, the safety cell
should not only come from just one mould, but will also need to stay in one
piece in an emergency.
The monocoques used in Formula 1 are tough enough to be able to survive even
the most critical accidents. However, to protect the drivers, the cars must
also have a certain amount of flexibility. This is the task of the
compulsory crash structures in the car nose, sidepods and rear, which
act as a preliminary safety cell to absorb some of the impact energy.
The load capacity of the crash structure and the monocoque is guaranteed by
static and dynamic crash tests which have been stipulated by the FIA since
1985 and made more and more stringent over the years. Before then, the
safety measures were largely left to the discretion of the teams, but the
new regulations ensured a high safety standard that was compulsory for
everyone. “The fact that the teams do not always pass the crash tests right
away proves how important the tests are,” says FIA President Max Mosley.
The tests are carried out under the supervision of the FIA and are usually
held at the Cranfield Impact Centre in Bedfordshire, England. As an example,
to simulate a head-on collision, a nose is fitted to the monocoque, the fuel
tank is filled with water and a dummy weighing 75kg is strapped into the
seat. This test construction weighs a total of 780kg and is driven into a
solid wall at a speed of 14 metres per second (50.4km/h). The rear and side
crash structures and the roll-over bar are also tested.
Passenger cars are also subjected to a variety of crash tests, but have to
fulfil completely different requirements. For instance, Formula 1 drivers
are extremely physically fit, sit in tailor-made seats with excellent
lateral and rear protection, and are also secured with integral six-point
harnesses. In passenger cars, on the other hand, the impact speed is
generally much lower and the seats have to provide protection and safety for
passengers with a wide variety of body sizes. Passengers are secured with
comfortable three-point automatic safety belts which give them the necessary
freedom of movement to be able to reach the controls in the vehicle. As in
the monocoque in Formula 1, the occupants in a passenger car are protected
by the passenger cell, which protects the survival area and at the same time
provides sufficient rigidity for anchoring the seats and the safety belts.
The situation becomes particularly critical for the occupants if the
passenger cell is crumpled inwards in a serious collision. “That is a real
problem in the case of side impacts,” says Dr. Hartmuth Wolff from the
Allianz Centre for Technology (AZT). “In that case, side airbags –
especially ones that protect the head – are particularly useful and can help
to prevent serious injuries.”
And did you know…
... that rear crash tests have only been compulsory in Formula 1 since 1997?
This new development led to the crash structure of the cars being
strengthened even further. Giancarlo Fisichella benefited from this
improvement in the same year, when he crashed backwards into the safety
barrier at Silverstone. An evaluation of the black box showed that his
Jordan braked from 227km/h to zero in just 0.72 seconds. In purely
mathematical terms, 227km/h is the equivalent of a fall from a height of 200
metres. The monocoque as life insurance: Fisichella came away with just a
minor knee injury. |
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