LAND SPEED RECORD CONTENDER – USA
basis alone, must be regarded as one of the most likely contenders to break the current world record first. The aim is to do that and go on to 800mph. But, as with all the current projects, it’s all going to come down to finance. The principal personnel in this
joint USA / Canadian adventure are project manager and driver, Ed Shadle, and director of operations Keith Zanghi, who are backed up by a team of 40-odd volunteers who donate large chunks of their free time to maintain progress. The project began in 1999 when Shadle and Zanghi bought a scrap Lockheed F-104 ‘Starfighter’ jet fighter fuselage, which forms the basis of their design. The obvious temptation is to think the crew expected to just pull the wings off, bolt some wheels on and, because the Starfighter was capable of supersonic speeds in the air, that it would be a simple matter of repeating that feat on the ground. But nobody on the team ever thought that simplistically, and there certainly seems to be an atmosphere of pragmatic realism running through the team’s approach. So just what was required
to convert the airframe into a ground vehicle? Shadle explains: ‘an F-104 fuselage had some benefits but also some downsides. The benefits were aerodynamic streamlining by the best in the business. The inlet design was also perfect for our mission so we didn’t have to design inlets that would prevent a compressor stall as we approached supersonic speeds. The downside was figuring out how to support the fuselage and build a suspension that worked.’
CHASSIS AND SUSPENSION ‘After much head scratching,’ Shadle continues, ‘I figured out that if I placed a spacer plate between the tail cone and the
North American Eagle T
he North American Eagle land speed racer has already run at speeds of 400mph and, on that
fuselage, I could anchor the rear suspension to that. Steve Green at Eagle Machine in Canada made a 3/4in (19mm) T1 steel plate in the shape of the round fuselage with a hole in the middle large enough to fit the engine through. An extension was also cut at the bottom that extended down far enough to attach a beam that would hold the rear axle. The plate was fastened solidly to the fuselage and attachments were made to hang the tail cone. From there we created the rear suspension parts and set the rear axle width at 11ft 6in (3505mm). ‘For the front suspension we gutted the front landing gear bay and altered the internal stringers so we had a smooth wall. We built a steel box that would fit snugly up inside that cavity with a locating pin and two bolts to keep it in place. We built a front wheel carriage that pivots at the front and is steered with hydraulic cylinders at the rear. The front suspension is hydraulic / gas cylinder with overload springs with 2in (50.8mm) travel at the axle.
‘With a long wheelbase, it was necessary to prevent flex in the fuselage, so we sandwiched two steel plates to each side of the keel beam where the main landing gear was previously mounted. We installed Torflex axles through the beam and made them adjustable for loading. We add about 500lb (2230N) of load on the mid-wheels to keep the body from flexing. ‘We also had to fill in the wing
roots, so we used dense foam then layered it with Kevlar and fibreglass mat. We screwed the perimeter down every two inches then finished it and sanded it to a mirror finish.’
WHEELS Because of the high rotational speeds encountered at Mach 1 and above, wheel design comes in for detailed consideration. Shadle: ‘For early testing we built our system around rubber tyres. But we spent about a
year designing and building the high-speed wheels. We first had to understand the stresses on the wheels in three different applications. The nose wheel had to be designed with some steering authority, so we built two keeps on the wheel, and it also had to take side load. It is 24in (610mm) diameter and 7in (178mm) wide. The mid-wheels would be 20in (508mm) diameter and 4in (102mm) wide but will
run at higher revs, and the rear wheels would be 34in (864mm) diameter and 6in (152mm) wide. The rear wheels are built with three concave ‘valleys’ in order to resist side slip. ‘The rear wheels also have
the brakes installed, so special attachment points had to be figured into the design. Using 7076-T6 forgings was the answer as the modulus of elasticity met our requirements.
January 2012 •
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