Fast food power...
In 2005 I designed the TH2 engine for fellow Salford alumnus and ex- work colleague Jon London
to use in his excellent educational talks
This is a demonstration engine that can burn a clear plastic rod,
such that you can see the combustion occurring inside, or burn other novel
fuels (Salami) inside a clear plastic tube. Such engines always
make an impact with an audience and through a highly varied and
unlikely route, Jon ended up discussing some kind of food fuel demo for
For the uninitiated Brainiac is Sky TV's
"wacky" science show, and true to form they expanded some what on the
brief. So in July 2006 Jon and I found ourselves agreeing to
create a system that could compare the performance of differing fast
foods as rocket fuels; prior to using the winning fuel to propel a
The performance was to be gauged by running
three rocket powered skate boards (unpiloted...) simultaneously.
Fueled by Kebab meat, fish and chips and pizza!
The infamous C5
The C5 was created by Sir Clive Sinclair, an
electronics and computing millionaire in 1982 in an attempt to
revolutionise personal transport, think Segway, but less successful.
They were a pedal/electric hybrid vehicle; single ratio pedals
for slow speed manouvring and click on the single speed electric system
to travel at 15mph. It was a valiant attempt but was excessively
designed technologically, pushing up the price, and under-designed
ergonomically (no weather protection, indicators, throttle, adjustable
seat) pushing down its appeal. After becoming a definition
(unfairly) of a technological joke, sales were abandoned less than a
year after launch. Sir Clive continues to bring out gloriously
impractical attempts at personal electric transport every few years and
the C5 has become a cult classic. Interestingly when you describe
the pitch of a C5 to a group of high school children, something I would
do many times following this project, not only do they all want a go,
but they all want one... maybe its time has finally come!
the interests of speed and convenience we opted for a modular design
that would be kept the same across the skate boards and the C5.
We also plumped for clamping a cylindrical metal combustion
chamber between end plates, like the low pressure demo engines.
This was so that we could easily change the length of the fuel
block, and therefore adjust the mixture ratio if needed, which in the
end, we didn't.
In the interests of simplicity we chose Nitrous
Oxide, familiar to many hybrid rocketeers, for the oxidiser. This
is self pressurising and behaves much like CO2, it can be stored as a
room temperature liquid at around 53 bar, meaning you only need
one tank, no separate high pressure gas supply or pumping required.
It also runs at a high mixture ratio, making for small fuel
The engines were just bracketed on to the skate boards, but
the C5 has a plastic body (apparently the biggest injection moulded
piece ever at the time, maybe still) sat on a small metal chassis.
This necessitated an extension spar fitting to the chassis under
the body, that protruded out of the back of the vehicle to mount the
all machining and fabrication was handled by
Bolton engineer Roy Haslam, without Roy it would not have been possible
to accomplish the project at all! He turned,
milled and welded all the new bits together, while the C5 was stripped
(it had lived outside for many of its 24 years) and the fuels were
tinkered with. For the oxidiser system we used existing CO2
cylinders for the nitrous, controlled by a remotely operated manual
ball valve on the skate boards. On the C5 this was accompanied by
a non-return valve and a nitrous solenoid valve supplied by a very helpful company in Devon I can no longer recall or refined!
When finally everything was together
we tried the first tests. All my previous engines had used an
oxygen preheat and I had hoped we might be able to get round this and
light the engine with a trickle of nitrous. Unfortunately the
nitrous proved just too cold and too fast for the igniter and after a
frustrating afternoon we returned to oxygen preheat.
preheat everything started perfectly; initially we tested the engine
bolted to the restrained C5 and a ground supply of nitrous. We
started with the predictable perspex fuel, in this case formed from
laser cut discs, cut from scrap acrylic, then moved on to the food
The various foods were blended, compressed into spare
engine cases and frozen to bind them together. Meat worked fine,
we knew this had been done before for science demos, though I think
Mythbusters had been the first to try (relatively unsuccessfully) to
derive useful thrust from food rocket fuel. Pizza lived up
to our expectations of doing absolutely nothing, though it does
extruded itself out of the rocket nozzle in an interesting way if you
let it defrost in there.... The big surprise was fish and chips,
maybe it's the carbohydrates, or the cooking oil but it performed
better the meat or perspex, and even showed restart capability!
next step was mobile tests, we began with the skate boards and perspex
fuel. On our first attempt the skate board slowly trundled a
metre! Unfortunately the budget couldn't stretch to the necessary
equipment to measure thrust or characterised the presure drop across
the nitrous system. We just had to proceed quantitatively
and experimentally; so we drilled out the injector and tried
What would follow became the favourite film of many school
children visiting Bolton TIC (where we carried out the project) and
bore not a passing resemblance to Jackass. The camera was zoomed
in for a repeat of the trundle, the oxygen preheat lit up the engine,
no smoke but audible combustion, Jon pulled on the remote ball valves.
The skate board roared like a banshee (at least all the ones I've
met...) and leapt off the starting block. We were at one end of a
fenced in hard football pitch, running across the width of about four
pitches. At 10 metres it yanked the nylon control cable out of
Jon's hand and carried on it's merry way until something upset its
balance about halfway across and it continued on, to ram into the far
curb, still running, on it's side. The brackets were somewhat
damaged but the engine and tank were unscathed and at last for certain
we knew we could make it work. In future we ran the skate boards
along guide wires...
Next came rolling tests with the C5.
Initially it suffered from the same reduced thrust, Jon had the
first attempt, creating beautiful Mach diamonds on a dusk run, but no
movement. I took the second attempt, moved from a sand sports
ground to a level tarmac area, this did just manage to role along but
barely. After more modifications Jon took the third, running
across the sand pitch and from then on we had an excellent rate of
travel. First with perspex, then frozen minced beef as a stand in
Finally we had the skate boards working, full required duration from the C5 and everything was working reliably.
first it seemed we would be on indefinite hold when presenter Richard
Hammond had a massive accident in a jet powered dragster, filming for
Top Gear, but the producers soon called to say "Richard's actually
already left Brainiac, we've got Vic Reeves now." For anyone
unaware Richard Hammond made a complete, nothing short of miraculous
So we found ourselves heading down to Surrey and by
chance the Top Gear airfield. We set-up early with the Casino
Royal 747, whose Bond sequences were also filmed at the airfield, in
the background. The skate boards were to run across the width of
the runway on three guide wires. The producers perhaps finally
appreciated the power of the system when the unconstrained skate
board we showed them in the morning managed to back flip into the
grass. There was then a mad rush to source tougher guide wires from
B&Q Guildford before the filming was scheduled to start.
was in place when the crew and presenters arrived from filming
elsewhere in the morning. All were very intrigued by the project
and presenters Vic Reeves and Jon Tickle both came over pleasingly
well. We prepared the skate boards while the crew did all the
explanatory segments and mock-up fuel production for the cameras.
we really did use liquid nitrogen to fast freeze the food fuel
Unfortunately the ball valves were stating to struggle with
the low temperatures caused by the nitrous fill and by the time we lit
up most of the nitrous had gone and the skate boards lurched forward
but didn't run. The presenters filmed an immediate reaction to
this non-event just in case, and we hurriedly reset everything.
Next time everything was ready and waiting for the fill and the
boards lit up properly; the fish and chips streaking across the runway
and kicking up the wire when it ran into the stop; the kebab followed
up reasonably quickly but not as vigorously and the pizza just issued
forth its unused nitrous. Fish and chips was the perfect surreal
result for the programme and it was onto the C5.
The idea was a
40 metre drag race against a vehicle Brainiac considered equivalent to
the original electric C5, a mobility scooter.
Vic Reeves was to
drive the C5, in tweed, and Jon Tickle the scooter, in motorcycle
leathers. Everything was in place, the first one lit but again the
nitrous ran low and Vic finished the last 5 metres or so with the
pedals. Again it was all filmed so it could be used and again we
reset. The second attempt went perfectly, which was just as well
as we had about 20 minutes usable daylight left. Watching the
sequence from the side on view (I was following up behind at the time
making sure the engine was behaving), the scooter zooms ahead to start
but quickly reaches top speed while the C5 continues to accelerate
while the engine burns. Slowly over taking the scooter and
winning the drag race! At no time did Vic have to resort to the
pedals, though it was an awful lot closer than they make it look.
Vic's pretty tall and therefore rather heavier than the test
drivers, and I didn't pump the tires up hard enough, so the performance
is less than during the tests but it really worked!
I believe we
are the only people to have made controlled trust with actually edible
food powered rockets, the only people to have propelled a human
carrying vehicle with food powered rockets, the creators of the only
rocket powered C5 (there is a jet one around(!)) and I very confident
that we are the only people to have even tried fish and chips, let
alone propelled anyone with it, as a rocket fuel. Though do mail
me if you know otherwise!
Yes I did get to keep the T shirt...
Jon and Roy prepare Vic for his mission, while Jon Tickle plots his race strategy