the running surface for the trailing wheel, but by placing them in a tandem offset arrangement all objectives were met. A common design of suspension leg sufficed for both installations, the only difference being the gear driven steering at each top; the gear ratios were different in order to accommodate the 'Ackermann' steering effect, and were left/right handed because the suspension units were effectively 'back to back'. With only one half of the weight/energy attributed to the rear of the vehicle a single brake sufficed, and with narrower wheel treads a wheel mounting hole housing a single set of bearings became practicable. A single strut connected each suspension leg to the Spaceframe, each strut housing a gas over hydraulic passive unit, an active unit, and an abort unit.
Technical books and journals are bereft of information on the control and steering of a vehicle through solid metal rear wheels at ultra-high speed, particularly on a running surface of low adhesion and shear strength. A case study at Leeds University on the dynamics of rear wheel steer
ARRANGEMENT OF SUSPENSION & STEERING EQUIPMENT - SSC
gave a cautious green light, though other authorities were less enthusiastic. Rebuilding a Mini into a rear wheel steered version with a scaled SSC wheel plan gave confidence to the proposal by demonstrating stability at speed and ease of
positioning, but with rubber tyres on tarmac and one tenth of the predicted SSC speed range it was still short of conclusive answers. A further run of the MiniRWS by a race-driver, followed by another brief technical investigation, concluded that the system would probably work if the steering inputs were no greater than 1Hz; quicker inputs would cause a divergence of input and effect at the wheels.
On rubber tyres and tarmac the Thrust SSC steering operated well, but on the desert with solid wheels and at much higher speeds it's driver found greater difficulty in controlling the vehicle. On one significant day Andy Green decided privately to ignore all advice and applied steering inputs greater than 1Hz, he regained control of the vehicle! Thrust SSC was never an easy vehicle to control, but with skilled hands and fantastic control reactions Andy Green drove a rear wheel steered vehicle faster than any before it.
