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Rocket Car Legend - The "True" Story |
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Why The Rocket Car Doesn't Work -
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One thing I
want to make clear from the start is that I'm not pissing on the
Rocket Car legend purely as an academic exercise. When my friends
and I set out to build the vehicle we test-fired in the spring of
1978, a real-life jet-powered, road-traveling car was exactly what
we had in mind. Craig Breedlove was busy breaking land speed records
in the Spirit of America, Evel Knievel had graduated from "biker" to
"payload" while attempting to jump the Snake River Canyon
a few years earlier, and rocket-powered vehicles were a pretty popular
notion. Unfortunately, machines like this require a lot of time
and money and engineering skill to build and operate.
My friends and
I had none of these things.
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In
1978, I was 22 years old and still living with my parents. My father owned
a scrapyard, twenty-two acres of barren desert scrub ideally suited to
having junk thrown on it. The yard was a salvage smorgasbord, covered
with everything from dead water heaters to junked airplane cockpits. And
since we lived near a major Army storage facility, a lot of the scrap
my father bought and sold came from government auctions. To be brutally
honest, the main yard looked like a cross between Sanford & Sons and
Apocalypse Now. My father would go to the auctions held at the post from
time to time, bid on pre-marked lots of God only knew what, then send
me out he next day with the big flatbed to collect the latest pile of
junk he'd bought. Plenty of people who went to these auctions ended up
with nothing more than tons of unusable junk that was worth less than
they paid for it, but my Dad always seemed to find the lots that contained
valuable stuff. He also knew plenty of people who owned military surplus
stores, and usually had some idea of what was in demand and what wasn't.
But since the nearby Army base was a huge storage depot, the auctions
weren't the sort of affairs that the average man-off-the-street would
be interested in. The lots for sale were usually measured by the ton,
and if a lot seemed to have a few items you were interested in, you had
to buy the whole mess. Because of this, my Dad ended up with an amazing
amount of unusable military surplus, things like gas-masks and vehicle
parts that were worthless in the civilian world.
But
from time to time, we'd get weapons, too.
No
, he never bought a pile of crap and ended up with a crate full of M-16's
or a Shrike missile, the military was usually careful enough to keep THAT
from happening. But from time to time we did end up with stuff
we weren't supposed to have. Once day I opened a crate marked "heater
assembly" and found it full of smoke grenades. My Dad found a steel
ammo box full of blank M-60 rounds once. And even though these instances
were a rarity, the Army had a very strict policy toward scrap dealers
who found such things: You had to give them back. No two ways about it.
Before even being allowed to place a bid, dealers at an auction were required
to sign several forms, one of which stated that they'd return any "explosive,
ordnance, fuse, detonator, or other chemically viable part or assembly
of a weapons system." I remember that paragraph well, since it's
the only part of the Army red tape that ever directly pertained to me.
The penalties for non-compliance outlined at the end of the paragraph
sounded pretty scary (five-figure fines, possible imprisonment, etc),
and were enough to make my Dad return the crate of smoke grenades, but
not the blank ammo. These were judged to be too trivial to warrant a drive
to the base, and my Dad ended up keeping them draped over a file cabinet
in his office, as a decoration.
Of
course I'm telling you this because it's how I managed to get hold of
the JATO bottle we used for our rocket car. Actually there were four of
them, each in a long, hay-filled crate with "BARREL ASSEMBLY"
stenciled on the side. One day I went out to the base to pick up a load
of junk my Dad had bought at the auction, and while we were going through
the stuff back at the yard, I spotted the crates and took a look. And
even though I didn't know what the hell it was at first glance, I knew
it wasn't a barrel for anything. The JATO bottle was a round metal
cylinder about four feet long, and less than a foot in diameter. At first
I thought it was a gas cylinder of some sort, but written on the side
in red paint were the words "M-23 JET ASSIST UNIT". And rather
than the sort of valve assembly you'd see on a gas cylinder, the end of
the bottle had an inverted funnel shape to it, with a rubber plug at the
lowest point. It was obviously a rocket of some sort. And judging from
the weight (it took two people to even budge the things) they were still
full of something.
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Once I figured
out what they were, I decided I had to call Jimmy.
Jimmy
and I met in the third grade (or thereabouts), and were best friends for
most of our growing-up. His family lived just down the street, and his
father ran an auto body shop in town. On more than one occasion Jimmy's
Dad and my own traded parts or services, and our families were pretty
close. But while I went to work for my father after graduating high school,
Jimmy went to college to study mechanical engineering. He had a natural
talent for figuring out things in the physical world, but was never much
good at putting them into practice. He could design and visualize, but
when it came to hands-on applications, he just wasn't very talented.
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Nevertheless, he was
the first person I showed the JATO bottles to.
Actually,
I didn't show them to anyone right away. The campus where Jimmy took classes
was almost 150 miles away, so he spent his weekdays in a rented room and
only came home on the weekends. I found the JATO's on a Wednesday, which
meant I had three days before I could tell Jimmy about them. More than
enough time for me to cook up the idea of the Rocket Car. As a matter
of fact, as soon as I realized what that dull metal cylinder represented,
I thought about attaching it to a car and taking a jet-propelled ride.
I spent the rest of Wednesday, Thursday and Friday planning how it could
be done. The principle certainly seemed simple enough. Nail the rocket
onto one of the junkers in my Dad's field, point it down a straight stretch
of road, and light the mother up. Sure there'd be minor details to be
worked out, but the basic idea was fairly straightforward.
All
I can say is thank God I consulted with Jimmy before actually doing anything.
If it wasn't for his intervention, I'd have probably ended up a damp spot
on a highway somewhere.
Jimmy
came over to the house on Saturday morning, we drove to the yard, and
I showed him the rocket. He immediately knew what it was, or at least
what it seemed to be. A solid fuel rocket, the kind they'd used in Vietnam
to give cargo planes a kick in the ass when they needed to take off from
short runways. Very simple, very straightforward. Also very dangerous.
I described the idea of the Rocket Car to him, and at first he was pretty
enthusiastic. But after thinking the whole thing over for awhile, he not
only lost his enthusiasm, but made me promise I wouldn't actually do
anything with the JATO until he had time to check a few things out. I
agreed, mainly because I knew I'd need Jimmy's help if I was ever going
to make the Rocket Car work.
We
talked about design possibilities for the rest of the weekend, and when
Jimmy went back to campus, I stashed the JATO's in the back of a wasted
milk truck rusting in the field. When Jimmy came back the following weekend,
we sat down at his kitchen table and he explained precisely why
the rocket car wouldn't work.
It
was a sobering (and depressing) lecture.
The
main problem was control. Jimmy explained that the JATO bottle would produce
something like 2,500 pounds of thrust (albeit for a very short time),
which sounded like more than enough to ensure a fun ride. Unfortunately,
this huge amount of thrust would not only be unstoppable once it was started,
it would probably have to be applied to a point on the car that wasn't
designed to handle such a such a force. Under normal circumstances, a
car gets it's forward thrust from the back axle, by way of tires against
the pavement. Which means that a normal car will never exceed a certain
amount of thrust due to the fact that the tires have to touch the
pavement to move the car forward. Jimmy described the whole thing using
top-fuel dragsters as an example. When the driver hits the gas, the back
end of the car tries to lift into the air due to the sudden force applied
to the rear axle. But as soon as the ass end starts to lift, the tires
lose traction, and the thrust decreases. The back end drops, thrust is
restored, and the process starts all over again. So a car of a given weight
using driven wheels can only get so much forward thrust. The limiting
factors are the weight, the distribution of the weight, size of the tires,
and torque applied to the wheels. The fact that a car uses driven wheels
creates a self-damping system that ensures the wheels will stay on the
ground (at least most of the time). The only reason dragsters and funny
cars pop wheelies is that they use oversized tires that screw up the relationship
between torque and traction. Unfortunately, a rocket car has no such restraints.
A massive amount of thrust is suddenly being applied to a point on the
car that wasn't designed to handle it, and there's no telling what happens
next. Maybe the front end lifts off the ground. Maybe the rear. Maybe
the ass end would slew around sideways. The only thing that was certain
was that the car would not go in a straight line, and would continue
to not go in a straight line at a very high rate of speed.
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Naturally I
asked how Craig Breedlove managed to drive the Spirit of America at 600+
miles an hour, but I knew the answer before I even spit the question out.
He hired a team of aerospace engineers and rocket scientists to design
a car that was built to have a jet engine sticking out it's ass.
After
hearing this, Jimmy didn't even have to outline the rest of the reasons
why my idea wouldn't work, but he did anyway. There was also the fact
that store-bought tires couldn't handle the sort of acceleration a rocket
would provide, which was why all land-speed record cars used custom-made,
solid-rubber tires. Simply spinning a regular tire at rocket-car
speeds would probably create enough centrifugal force to tear it right
off the rim. And if that wasn't enough, there was the problem of stopping
the thing once it got rolling. And structural stress. And so on and so
on.
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By
this time I'd pretty much decided that the whole idea was stupid and suicidal,
which was why I was amazed when Jimmy proceeded to tell me exactly how the
rocket car could work. |
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