Six Hundred at Bonneville
By Sam Low
I spent a few months with Craig Breedlove and his team on the flats at Black Rock, Nevada, a few years ago. At the time, Craig was sixty years old and preparing to drive a car through the sound barrier on land. He and his colleagues told me many tales. This is one of them.
It is late November, 1965. A cold front moves north from the Gulf of California, passes over the Grand Canyon, the Escalante Desert , Indian Peak , Haystack Peak and Dutch Mountain . Dense air carried by the system settles over the Bonneville Salt Flats and picks up speed as it moves unimpeded over the vast ancient lake bed.
Gusts rise to 25 knots. Rain slicks the hard surface of the salt.
To the east, the white landscape blends with the sky behind slanting rain. At the southern extremity of the flats, three men huddle in the lee of a pickup truck. A 200 horsepower air compressor sits in the truck's bed. A large diameter rubber tube descends from the compressor and snakes across the salt to a jet powered car which bears the name - Spirit of America. The vehicle is aimed down a single black line etched on the flats. It runs north and vanishes beyond the earth's camber. The line renders a strange order on the blank wilderness, like laying a meridian across an ocean. It has the sense of conceptual art, something simultaneously finite and abstract, mathematical and dreamlike. It defines the shortest distance between a point just beneath the car's wheels and another twelve miles away, the beginning and the end of the International Course at Bonneville where world land speed records have been set for almost 100 years. A week earlier, driver Art Arfons had piloted his car down the line to a terminal speed of 577 miles an hour. Now, with winter approaching, Craig Breedlove will try to go even faster. He has set his goal on an even number - six hundred.
As she sits poised to accelerate down the course, Spirit of America resembles a rocket ship oriented to the horizon rather than the havens. A single fin extends vertically at the ship's tail and rises about six feet above the exhaust of her 20,000 horsepower General Electric J79 jet engine. Her afterburner cone is blackened with carbon residue. There is a faint aroma of jet fuel – reminiscent of the smell produced by a kerosene lantern.
The car sits on four forged aluminum wheels of very large diameter. Its low aspect pneumatic tires are made of 18 fabric plies, hand laid and bonded with a rubber compound so secret that to this day Goodyear will not reveal it's chemistry. They are pumped up to a pressure of 250 pounds per square inch, about ten times what you or I would put into the tires on our everyday sedan. Only about four inches of the tires are visible, the rest is tucked inside the fuselage or enshrouded within curved fairings for aerodynamic streamlining. From a pointed nose the fuselage sweeps back and rises past a curved windshield to a gaping air intake in the shape of a scimitar. About midway between the intake and where the wheels touch the salt, on either side of the car, two horizontal fins are angled down - aerodynamic trim tabs that channel the flow of air to provide downward force on the front tires to prevent the car from flying.
Spirit of America was designed by two men - her pilot, Craig Breedlove and her chief designer, Walt Sheehan. Working under tight time and financial constraints, they have achieved a shrewd compromise among dozens of conflicting variables such as weight versus engine thrust; aerodynamic stability against drag; mechanical friendliness and ease of maintenance against structural integrity. Spirit cost over a hundred thousand dollars to build and at last 10,000 man hours donated by a passionate army of volunteers whose skills span a spectrum from backyard hotroding to aerospace engineering. But Spirit's visionary is Craig Breedlove.
Craig's talents are not schooled. They are congenital and osmotic. In 1948, when he was twelve, he first traveled to the Bonneville Salt Flats on the window ledge of a 1947 Ford hot rod driven by a neighborhood teenager, a member of the Culver City Igniters car club headquartered across the street from Craig's family home. When he was thirteen, Craig learned to wield an acetylene torch to jigsaw a sedate 1934 Ford coupe into a sleek roadster capable of extreme terminal velocity. By the age of fifteen, he had mastered the arcane skills of breathing on an engine - of porting, polishing, blue printing, cam grinding, crankshaft balancing, and intuiting the convoluted flows of explosive gas-air mixtures - to render from an eight cylinder standard issue Ford power plant of modest muscle a racing engine that produced over 300 horsepower. Craig mastered these skills so well that when he took his roadster to Bonneville he defeated every car in his class and bettered a four year standing speed record of 148 miles an hour. He was sixteen. Now, at twenty-six, he intends to pilot his ultimate hot rod to over six hundred miles an hour and thereby become the fastest man on earth.
At about noon on November 15, during a lull in the gusting wind, Breedlove makes his initial run down the course and passes through the measured mile at 594 miles an hour. At the end of the course, Spirit of America is turned around and pointed back the way it came. Craig opens the canopy, a broad smile creasing his face.
"What are you smiling at?" says Nye Frank, his crew chief.
"Hell, Nye, that was a great run! One more and we've got the record."
"Take a look at your car," says the crew chief.
The sight is astonishing. From just behind the driver's cockpit, running four feet aft, it looks like a giant fist had smashed down hard on Spirit's fuselage. Breedlove gets down to examine his machine.
"Holy shit," he says.
Walt Sheehan surveys the damage, and shrugs. About the work of the giant's fist, he says, "if aerodynamically that is where the body's shape is, that is where it wants to be. It will be all right."
There is a history to this particular problem that gives Sheehan a measure of comfort. On previous test runs Spirit's body panels had bowed up because of negative air pressure along the top of the car. To fix the problem, the team punched dozens of louvers in the fuselage so the pressure inside might find a balance with the pressure outside. But that solution had failed. So Walt decided to weld a bracket to the panels and tie cables from the frame of the car, up to the bracket, and down again. "They will bow no more," he thought.
And they hadn't. They had compressed. So now Walt figures that aerodynamic forces had continued to suck the body panels up and, meeting the resistance of the cables, the panels had relieved the pressure by oil-canning down. He was certain, relatively certain at least, they had finally achieved equilibrium.
Craig and Walt regard each other without speaking. Breedlove is just under six feet tall, almost aerodynamically lean. He wears a simple cotton jumpsuit of flame proof material and cradles a helmet between his right arm and body. He is handsome in the way of California big surf riders. Walt Sheehan wears trousers of some material other than natural fiber and a heavy parka now sodden with rain. He is well over six feet tall. Strands of hair, like straw, visor his face. His eyes are blue, and clear. He is slender. Seen here in the open vistas of Utah , he looks like a cowboy, but nothing could be further from the truth. Walt is a trained aeronautical engineer with the requisite degrees and experience to prove it. The two men face down the track and regard the black line that stretches to the vanishing point. Then Craig turns, nods to Walt, approaches the car and climbs back into the cockpit.
Walt moves under the car, pulls off the engine's access panel and begins to adjust the throttle linkage with hands numbed by the cold. He stands in three inches of water. His nylon bomber jacket is soaked through. Craig motions Nye over to the cockpit.
"Ask Walt if he really knows what he's doing," he says.
Nye, shielded from the rain in a slicker that carries the Spirit of America logo, crawls under the car.
"The boss wants to know if you know what you're doing?"
"I don't have the faintest idea" Walt says, "just tell him to get ready to make his run and not to worry."
But Craig is worried. To set a record, he will have to make one more run within an hour. The official speed will be the average of the two runs. These are the rules as set down by the Federation International de l'Automobile, the organization that sanctions Land Speed Record attempts. Craig worries about the weather. The gusts had picked up again, would they subside in time? He worries about the standing water on the track - will it slow his car? But what worries him most is Spirit's tendency to lift her nose at high speed. On his last run, Spirit pitched up just before he deployed his chutes. This was extremely dangerous because if she were to actually lift off the ground, the flight would be short and deadly.
There has been a previous Spirit of America. In existence still, in the museum of Technology in Chicago , she allowed Craig to be the first man to exceed 400 miles an hour in 1963 and five hundred miles an hour in 1964. But not without incident. On October 15th, after passing through the measured mile at an indicated speed of five hundred and fifty miles an hour, Craig pressed a switch that ignited a powder charge in a parachute canister embedded in the tail of his car. He felt the explosion and a slight tug as his chute opened. Then nothing. The chute had failed. Spirit number one continued on past a marker that indicated three miles of track remaining for deceleration. The speedometer read 490 miles an hour. Craig punched the button for his emergency chute. Nothing. When he saw the markers indicating the end of the track, he tried his disc brakes. His foot went to the floor. Shaped to slip easily through the air, Spirit of America continued off course with great velocity, glanced off a telephone pole, climbed an earthen dike that constrained a pool of water, and flew. At two hundred miles an hour she skipped across the pond in a series of ever tightening arcs and came to rest, nose down, with her cockpit in six feet of water. Craig emerged unscathed and with a new world record of 526.277 miles an hour.
The fates had not been so kind to others. In 1963, driver Athol Graham had crashed his City of Salt Lake and was killed and a year later Glenn Leasher perished in the wreckage of his jet powered record car.
To obtain the world land speed record, Craig has merely to proceed back down the course at the same speed he had come. But his goal is to exceed 600 miles an hour, an objective he had announced during a press tour in a moment of euphoria in some large convention hall. Now he considers the odds. At an indicated speed of 610, Spirit's nose had lifted. To set an average of six hundred, he will have to go even faster on this next run - perhaps 620. Would Spirit fly? There is magic in the double zeros. He had been the first to 400, then 500. But was there enough magic to try for 600? He calls Walt over to the cockpit.
"I want to do an average of six hundred miles an hour and no faster," Craig says. "I don't want to go six hundred and one. I want to go six hundred."
Sheehan nods and goes back under the car. He now focuses on the job at hand, to do the math and set the throttle. By his calculations, Craig must average 606.2 miles on hour on the return run to set an overall average of 600. He takes into account the half mile or so that Spirit will travel over rough salt before entering the smoothed track of the International Course; the puddles and the rolling resistance they engender; the temperature and density of air that will affect the engine's thrust; and how the cold dense air will act over the car's aerodynamic surfaces. It's a time before the advent of laptop computers and sophisticated software, so Walt works out this complex calculus in his head. He resolves all the factors into the placement of a single bolt in the car's throttle linkage. By sliding the linkage forward, he can increase the power that Craig will have available when he opens the throttle. On the last run, Walt had set the linkage to give him 95% power. Now, he moves the linkage forward a notch - 100% power.
Craig looks down the track through a windshield sprinkled with snow flakes. The car rocks gently in the gusting wind. He waits while the clock ticks down. Thirty minutes left. Twenty minutes. With only eighteen minutes remaining before they will have to cancel the first run and begin again from scratch, the wind dies. Craig moves the throttle forward. A rooster tail rises behind Spirit of America as she picks up speed over the half mile of rough salt, then dissipates as she takes to the course.
In the cockpit, the ride smoothes at about three hundred miles an hour. Craig focuses way down the course, aligning his car to the single line marked with black dye on the surface of the salt. At four hundred miles an hour, tiny motes of salt sift into the cockpit. Craig breathes clean air through a surplus Air Force Oxygen mask. Entering the measured mile, his speedometer indicates 600. Craig feels the nose rise slightly but vibrations in the steering wheel indicate that the nose wheels are still on the ground. Spirit establishes an angle of attack to the rushing blast of air and stabilizes. She feels rock smooth. Exiting the measured mile, the speedometer indicates 620 miles an hour.
The final result, when tabulated by the FIA timer, is 600.16 miles an hour. Walt Sheehan's calculus is right on the money.
Copyright Sam Low