Safety is
obviously of paramount importance. For this reason car manufacturers have to meet very
stringent regulations, and do crash tests on numerous vehicles.
Such crash tests are completely beyond the financial resources of the smaller companies
manufacturing replacement car seats. For this reason such regulations do not apply to
replacement car seats and therefore the question must be asked - are they safe ?
This question must be looked at under various headings:-
1. Strength
Series production seats are designed to a very tight cost and weight limits. Replacement
seats generally use much heavier components. For instance the seat belt anchorage on the
Gorman seat is 5mm thick steel compared with only 2mm on most production seats.
In general a replacement seat should be stronger than a production seat if
properly designed although it will be heavier. |
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2. Submarining
The possibility of the body slipping under the seat belt in an accident (submarining) is
greater that generally recognised. The seat pan of the Gorman seat is designed with
the latest understanding of this problem in mind. The seat pan is a strong monocoque
welded structure incorporating an upward sloping surface in front of the seat bones.
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In addition
the foam of any pelvic support seat has to be specifically designed to resist forward
slipping in normal use.
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3. Spinal Damage
A recent report by a road research organisation suggests that the most likely part of the
spine to be damaged in a rear end collision is the thoraco lumbar junction. The
whole principle of lumbar support, which tends to hyperextend this part of the spine which
would be likely to cause this damage. Pelvic support, on the other hand will avoid
this effect.
The back of
the Gorman seat is designed to give maximum protection to the spine both in a rear end
collision and when the body rebounds from the seat belts into the seat after a front end
collision.
The spine will be supported
along its whole length in a shape which is near the middle of the range of flexion for
each joint. (Note that this is not the shape that the seat will attempt to support in
normal driving.) Many production seats have incredibly little support between the frame of
the seat back. |
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4. Head Restraint
This is designed as a head restraint to avoid neck damage in an accident. In order
to achieve this the support must be behind the centre of the head and must not support the
neck directly. In the design of the Gorman seat it was considered risky to rely on height
adjustment or tilting of the restraint.
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Instead it is
simple, large and high and does not rely on adjustment.
It is however reversible so that the person who likes to sit with a non vertical seat
back, does not feel that the restraint is forcing the head forwards.
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Sharp Edges In
design of all parts of the Gorman seat sharp edges in the steelwork have been avoided
wherever possible. In addition the design has always tried to maximise the thickness
of the foam over critical areas - for instance on the "shoulders" of the
seat the foam thickness is 80mm compared with 18 mm in one typical production seat. (This
makes it difficult to achieve tight, smart looking upholstery in this area but has been
done purely for safety reasons).
Conclusion
With Careful design and no compromise with safety, it is probable that the Gorman seat
offers a greater level of safety than your standard seat.
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