| The pulse
jet engine reaches temperatures of 600 degrees C and is
so noisy that it hurts Andy's ears, even though he wears headphones
and a crash helmet. The engine is powered by gas and liquid
fuel and explodes 40 times-a-second to propel the trolley.
Amazingly, Andy only became interested in jet engines by accident
when he tried to buy a heart rate monitor from the internet
to help improve his fitness. He put in the word "pulse"
on a search site and found references to pulse jet engines
and from then on he was hooked.
He found patent documents and began to build his very own
pulse jet engine out of a discarded stainless steel restaurant
worktop. He decided to put the engine on a Lidl supermarket
trolley when he saw one dumped in a river as he walked his
daughter to school. Andy attached the gas supply, liquid fuel
and engine. He then added much sturdier wheels, an accelerator,
brake and steering device.
| The project cost a total of £50
and took him several weeks to build at his home in Beccles,
Suffolk. But on his maiden trip things went wrong when
the engine exploded, burning Andy's face and hands.
However, he persevered and he now can boast the fastest
shopping trolley in the world. Andy, a microlight instructor,
said: "People think I'm off my trolley but when
it gets going it is exhilarating. It is quite bumpy
because there is no suspension and the driving position
is a bit cramped. I only got into it by accident. I
was trying to buy a heart rate monitor off the internet
and came across a site on pulse jet engines. I just
became fascinated with them and decided that I had to
build one. I looked up the patent sites and designed
my own - it is similar to World War Two doodlebugs."
Andy recalls, "I used an old stainless steel worktop
to build it with and then I saw a shopping trolley dumped
in a river as I walked my daughter to school and I decided
to use that. I hooked it out and made a few alterations.
I replaced the wheels with those used on baggage trolleys
at airports. I then fitted a steering wheel and a brake
and accelerator then put the engine in. |
|
The gas supply is fitted to the front and beneath the trolley
is the liquid fuel supply. Any liquid fuel will work - even
chip fat. To start the engine I make a spark using car indicator
relays and an ignition coil which ignites the gas. The liquid
fuel is then injected and that causes the explosions that
propel the thing at over 50mph."
"I don't know how fast it can go because when it gets
over 50mph it becomes really unstable. The first time I started
it the engine exploded and I got quite badly burned - I had
to pencil in my eyebrows for a few weeks. I had never seen
a pulse jet engine work before and I had no idea what I was
letting myself in for. It is extremely noisy and if you stand
too close it hurts your ears. Thankfully my other half, Sue,
lets me get on with it and my children just think I'm mad."
"It can't be driven on roads and it is not very efficient
- to run it for an hour would cost 300 pounds. It uses 13
kilos of gas for every two minutes. I am now working on a
much bigger pulse jet engine which I hope will propel me even
faster." |
