The Sigma was unveiled on March 1969 at the Geneva Show and was a research vehicle never intended to compete in any Formula One races.
The main inspiration for the car was the high number of deaths in Formula One races, due to the low safety standards.
Among the safety feature were a driver survival cell, multi-layer fuel tanks, a fire extinguisher system, plastic fuel-tanks, a safety-belt-system, an engine with collapsible structures and sidepods protruding behind the rear wheels to prevent interlocking wheels.
The car, designed by Paolo Martin, was based on the Ferrari 312. It had a weight of 590 kg and was powered by a 436 hp 3 liter V12 engine.
The prototype was developed by Pininfarina in partnership with Revue Automobile and with the support of Enzo Ferrari, Fiat and Mercedes.
(Source: Pininfarina, Wikipedia)