Stay up-to-date with our progress. Diary 10: Making the Turn

A great deal of effort has gone into making sure that the Challenger II travels in a straight line. If you happen to see it changing direction quickly, cover your eyes, because what happens next isn’t going to be pretty. Although the car’s aerodynamic properties should do most of the work of keeping it level, an inordinate amount of attention has also gone into the steering. We’ve reserved enough packaging space to provide the streamliner with up to five degrees of back and forth maneuverability, but that number will probably be artificially restricted to a lower amount after our initial test runs. At Bonneville, slow movement is safe movement, and we’ve engineered the car to respect that.

Of course, some steering is necessary to get the liner off the track at the end of the run.  This is especially relevant during Speed Week and other SCTA/BNI events where many cars participate in quick succession. Fortunately, when you’re traveling at very high speeds, it doesn’t take long to cover the lateral distance to the recovery area.  And for the events mentioned above, that’s really all it takes. If we’re fortunate enough to get a record, we’ll load the vehicle onto the trailer and head to impound. We won’t have to make the return run until the next morning, which gives us a bit of breathing room and ample time to prepare. If we don’t make it, we’ll head back to the pits, perform adjustments, and try again.

Unfortunately, FIA runs aren’t that simple. In order to capture that record, we need to turn the car around and backup our previous run within one hour. In our case, that means adding sixty gallons of specially prepared fuel, changing the oil in both dry sump tanks, switching out 32 spark plugs, adjusting both engines, examining the tires, and quickly but thoroughly performing checks on all the streamliner’s systems. We also have to do something that we’ve intentionally made very difficult, which is turn the car around. With five degrees of steering, making a loop in the Challenger II would require almost a mile of runway. At 5500 pounds, it’s too heavy to easily move, and loading it onto the trailer in order to reverse it requires time that we probably won’t have. 

Luckily, the very smart Bob Skinner came up with an ingenious solution to this problem more than 45 years ago. Nestled inside the body of the Challenger II are four huge air jacks. When it’s time to turn the car around, a simple application of air pressure causes them to deploy downwards, elevating the entire streamliner six inches off of the ground. Next, two crew members will slide a purpose built lazy Susan underneath and rotate the vehicle 180 degrees. Once it’s facing the right direction, we’ll reverse the jacks and gently lower the car back to the salt. In testing, this takes a mere five minutes and allows most of the crew to continue working throughout.