WJS Kent branch

Report of meeting

28th February 2008

Project Thrust 2 Vehicle Frame: Ken Sprayson captivated an audience of 56, when he recounted his experiences of constructing, modifying and repairing the 'Thrust 2' frame for Richard Noble's jet vehicle, which captured the land speed record of 633.438 mph, for Great Britain, on 4.Oct.1983.

With the aid of many slides throughout his talk and a recording of Richard Noble, Ken explained that Richard Noble's enthusiasm for speed was triggered when, at the age of 6, he saw John Cobb practicing for the water speed record on Loch Ness. Ken then took us through the events of the first jet-propelled Thrust vehicle, which Richard crashed (seized wheel bearing) up to the time (c. 1977) when Reynolds Tubes offered to supply the material and construct the frame.

It was at this point that Ken became involved. However, the vehicle's design hadn't been finalised yet by John Ackroyd and it was to be another year before Richard was ready for the frame to be started. During the intervening year, Reynolds Tubes had undergone reorganisation and the idea of supplying the frame was then met with some hostility. However, Ken as Development Engineer, Welded Assemblies, managed to prick the conscience of the Directors and the frame was started. Ken only had a 25 ft long workshop in which to make the 27ft long frame, so the front end was constructed separately and welded on afterwards. In addition, whilst most of the material was 2 inch (50mm) square hollow sections, 16swg (1.6mm) Reynolds 531 tubing, the main longitudinal members had to be 4 x 2 inch, 14 swg (2mm) mild steel RHS, because of draw bench limitations for the section size in 531 material. Ken explained how he fabricated the frame and how the tubes were MMA welded with Murex, Fastex 5. The trial fit of the Rolls Royce Avon 302 engine at the TI Research & Development site, Walsall Airport, amidst live BBC filming, was somewhat compromised by an attachment to the underside of the engine, which fouled one of the frame members, but the BBC audience were not made aware of it. Ken and his welder subsequently modified the frame before it was transported, together with its engine, to the Isle of Wight to be fitted out.

Richard Noble was a master of publicity and securer of sponsors, so the basic vehicle fitted with rubber tyres was displayed at various locations for publicity and trials on RAF runways. The rubber wheels were only rated to 240 mph and on one occasion, during the final run of the day, Richard took the vehicle up to 300 mph causing the tyres to expand and foul the wheel arches! As the end of the runway approached and with the brakes already burnt out, Richard decided to steer into the uneven grass verge, rather than risk a head-on collision at the end of the runway. Nevertheless, the left hand front of the vehicle and frame were damaged and the grass, dirt and stones ingested into the engine did severe damage too. Ken repaired the frame and the RAF came to the rescue by re-building the engine!

The final vehicle, with all its fairing and solid aluminium wheel with a single circumferential ridge, was shipped to the Bonneville Salt Flats, USA but on two separate occasions, unseasonal rain caused the flats to flood, preventing further trials, so the team transferred to the Black Rock Desert, Nevada. Here the wheels were changed for a wider version with 2 circumferential ridges. After several attempts, Richard finally succeeded in wresting the record from the USA on their home ground. The vehicle is now preserved in the Coventry Transport Museum along with its successor Thrust SSC, which Andy Green drove for Richard Noble, to the current record of the supersonic 763.035 mph on 15.Oct.1997.

This was a joint meeting with CQI (Kent), IRTE (SE section), IMI (East and West Kent Member Associations) and CILT, hosted by WJS (Kent) and held at the Conference Centre by kind permission of BAE Systems, Rochester. Attendance: Total 56, WJS 12.

N E Baldwin - Chairman, Kent Branch