MAKING PROGRESS

Based around the corner from the original Lotus works in Hornsey, north London, the Progress Chassis Company was the supplier of Lotus’s separate tubular steel chassis from 1953 to 1963. During this time Progress built most Lotus production chassis, with prototypes and pre-production chassis typically devised and fabricated in-house.

Progress constructed early cars from steel tubing with oxy-acetylene welded joints. With steel in short supply, scrap was used for frame brackets; the original MKVI jig was built from a cast iron bedstead with the springs removed for access.

When chassis were completed, two employees picked them up and walked with them from the Progress workshop in Ribblesdale Road to the Lotus works in Tottenham Lane.

Before work started on the MKVIII, Frank Costin asked Progress partner David Kelsey to make a 1:8 scale model for aerodynamic testing. Kelsey’s model resembled a Jaguar C-type, complete with rubber wheels, miniature leather seats, gearlever, transmission tunnel and steering wheel. In the absence of a wind tunnel, Costin tested it by shooting jets of compressed air at tufts of wool attached to the bodywork. Crude calculations made, he took a hacksaw to it, lopping bits off then reshaping them in Plasticine.

When Progress was contracted to build the production MKVIII chassis – essentially a MKVI structure with outriggers for the all-encompassing

bodywork – Kelsey soon realised that the bedstead jig was no longer viable. Trams had recently stopped running through Hornsey, so he bought up a load of old tram lines, burnt the old road tar away and used them to fabricate a new jig.

Said Kelsey in Jabby Crombach’s book Colin Chapman – The Man and

his Cars, ‘Wheelarches and body frame tubes were bent – usually by me, in a hole in an old railway sleeper, inch by inch, matching to a full size drawing on brown paper.’

In total the company built more than 1000 chassis units for Lotus, but the early Sixties saw Progress cofounder John Teychenne prioritise the fruit machine business over Lotus work, prompting Chapman to look elsewhere. Unirad and Arch Motors took up the slack until Lotus gradually moved away from tubular frames to steel backbone chassis.