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High speed car chases that end at a police roadblock are not just a
cliche of ‘cops and robbers’ films. They happen in real life as well, and
the image of a fiery crash into three patrol cars parked across the highway
is not one that makes law enforcement officers happy: they would much rather
deflate the suspect’s tyres and bring the pursuit to a quiet, safe end.

Now, a retired Utah Highway Patrol trooper and a design engineer have
joined forces to invent a rugged, inexpensive ‘spike system’ which is light
and cheap enough to be standard equipment in every police car. Donald Kilgrow
first began working on his Stinger Spike System after participating in a
chase that the police ended by erecting a roadblock of two police cars and
a commandeered semi-trailer.

The suspect chose to ram his car into the trailer. The crash cost the
city of Monticello $19 000 – ‘enough’, Kilgrow says, ‘to equip every car
in the district with a spike barrier’. But Kilgrow found that existing British
and American barriers all had disadvantages: they were expensive, too heavy
for one officer to deploy in the few seconds available, they failed at slow
speeds and they worked in only one direction.

Kilgrow, working with design engineer Mel Pedersen, believes he has
come up with the better system, and he has already sold it to dozens of
North American police departments and a few overseas. The spikes themselves,
Kilgrow says ‘are stainless steel, and they will punch right through a steel-belted
radial tyre and deflate it, through their hollow cores, in about 20 seconds’.

The spikes are mounted in a base made of Zytel FN, a new ‘nylon alloy’
produced by Du Pont, a chemicals company in Wilmington, Delaware. Zytel
FN proved to be ideal because it remains flexible at any highway temperature,
from sub-zero to baking desert heat.

The inventors received a patent on the system’s rocker design, which
tilts the hollow, detachable spikes into the proper angle to penetrate tyres
and remain inside them. This means that tyres will still deflate irrespective
of the direction from which the runaway vehicle approaches the spikes. Stinger
also sells replacement spikes that can be mounted on the system with a tool.