Friday, August 01, 2014


We chafe at limits.

We don't like being told something is impossible, even -- or maybe especially -- if it is. Virtually anytime someone says "it can't be done", you can find someone willing to put the matter to the test. And whatever can be done, you can be sure someone's on the prowl looking for a way to do it better. A way to go higher, or farther, or faster.

For most of human history no one ever traveled faster than a horse could gallop. The steam engine changed that. Man got his first taste of higher speed in 1804, when Richard Trevithick built his "Puffing Devil" steam locomotive. Towards the end of the century, the first automobiles were built, and were soon faster than locomotives themselves.

It's understandable and perfectly excusable if you think that electric cars are a recent innovation, but that's actually not the case. The first land speed record held by an automobile, set in 1898 by the French vehicle Jeantaud Duc, was set by a car with an electric motor. Steam engines were too heavy, and gasoline engines too unreliable, so in the early days of the automobile electric engines were the motors of choice. That didn't last very long, though. Four years later, a steam-powered car overtook the electics with a then-blistering speed of 75 miles per hour. Lest you think that steam was making a comeback, it was displaced in mere months by a gasoline-powered car driven by the American driver William Vanderbilt. This would begin an American dominance of land speed records that would last ... oh, about five years. A Frenchman would take the lead in 1909, and then an Englishman in 1914. The English would hold the record for a while. Almost fifty years, in fact.

Their dominance came to a temporary end for two reasons. First, they were hitting a hard limit with what could be accomplished with wheels. Second, some might say that the Americans ... cheated.

First, the problem. If we go back a few years, I wrote about the maximum speed a running man could achieve. It's the same basic principle with cars. You can only drive the wheels so hard before they start slipping. You can make the tires extra-sticky, you can hold the test on the most favorable ground possible, but there's only so much direct drive can do. Which means ... you have to do something that isn't direct drive.

Purists would call what comes next cheating. If direct drive doesn't give you enough satisfaction, you heed the maxim "everything's better with fire", and use a jet engine, or better still, a rocket.

Which is exactly what Craig Breedlove did in 1963. Granted, the Spirit of America only raised the speed record from 403 to 407 miles per hour, but it showed what a jet-powered car could do. Two other Americans would yank the record away from Breedlove before he came back to the ring with a new and improved Spirit, this one called Sonic 1, built around an engine from an F-4 jet fighter. He set a record at 555 miles per hour, then broke his own record a few weeks later when he hit 600 miles per hour. The record rested comfortably in his hands for about five years. Then, Gary Gabelich comes along with the Blue Flame, a rocket-powered car that hit 622 miles per hour in 1970. This is where the record would stay for another thirteen years. It would stay there, because engineers were beginning to reach another problem.

Compressibility becomes a huge problem when you get that close to Mach 1. That's true for any vehicle. That's doubly true for a vehicle that has to maintain contact with the ground. The shock wave really wants to get between you and terra firma, which would be ... a problem. And not "a problem" as in "this is a really sticky equation," but "a problem" as in "holy mother of God, I've been flipped like a pancake at 700 miles per hour." Only there'd be a lot more screaming and loss of bladder control involved. It would take some high-power computational wizardry to figure out how you build a car that can go that fast without killing its driver.

Richard Noble started the climb up that steep hill in 1983 with the Thrust 2. This car, built around a Rolls-Royce Avon jet engine, hit 633 miles per hour. Nowhere near Mach 1, but it did claim the record. Noble would spend another fourteen years designing and building its successor, Thrust SSC, powered not by one, but two Rolls-Royce Spey turbofan engines. Power was only half the problem. Control was the other half. Thrust SSC has a triangular control surface on its aft fin, to help keep the vehicle on the ground during high-speed runs. Appropriately enough, the car was driven by a Royal Air Force fighter pilot, Wing Commander Andy Green. And in October of 1997, Thrust SSC broke the sound barrier.

That's where the land speed record stands. There are a couple of teams at work trying to beat it, but no one's succeeded yet. It's the longest gap between broken records, and it's liable to stay that way for a while.

But don't feel too bad for rail-based vehicles, so unceremoniously left behind in 1898. They got the last laugh. In 2003, at a test range near Holloman AFB, a four-stage rocket sled pushed its payload to the staggering speed of 6,416 miles per hour -- EIGHT AND A HALF times the speed of sound -- as a test of the High-Speed Test Track.

It's ... gonna be a while before anyone drives that fast.

No comments: