Although Cobb returned after the war and further developed his car to exceed 400 mph (640 km/h), Thunderbolt never attempted the record again.

The leading Land Speed Record cars of the period had taken two approaches to obtaining power; using either the latest and most sophisticated aero-engines available or combining multiple engines.

Each engine was of 36.5 litres capacity, supercharged, and had an individual output power of 2,350 bhp (1,752 kW; 2,383 PS).

Handling all this power through a single driven axle required great innovation in metallurgy and in manufacturing the geartrain, as well as water-cooling the completed transmission.

At the rear was a large triangular tailfin, flanked by a pair of hydraulically activated air brakes.

During the first attempts, the new photo-electric timing equipment had failed to detect the polished aluminium car body against the brilliant white salt.

A rounded nose now filled the previous radiator air intake and the stabilising fin was removed, all leading to an appearance more like Cobb's Railton.