When John drove Babs to a life in the fast lane

The world's most powerful car is set to make its public debut at the London Motor Show next month. Propelled by two jet engines, which develop a total of 106,000bhp, the seven-ton projectile is designed to capture the land speed record - set at 633mph in 1983 - then hurtle on to break the sound barrier and reach 850mph.

The car's appearance at Earls Court heralds the start of a long test programme. If all goes to plan, the attempt will be made in 1997, probably in the US. The driver, Andy Green, is an RAF officer.

Masterminded by Richard Noble, who holds the existing record, the Thrust SCC Project has attracted more than 80 sponsors, many from the aerospace industry, and represents an investment of about pounds 5,000,000. The record attempt will involve 25 people.

It is fascinating to compare this budget and ballyhoo with what happened exactly 70 years ago. A solitary Welshman, John Godfrey Parry Thomas, was preparing to become the fastest man on wheels, driving a secondhand car for which he had paid next to nothing. At that stage his target was the 150mph record established during the summer by Malcolm Campbell and his 18.3-litre Sunbeam. The setting for the attempt was Pendine Sands, the six-mile beach on the Welsh coast between Saundersfoot and Laugharne.

Born in Wrexham in 1885, Parry Thomas went to Oswestry School and was nicknamed "Bullocks One" because his father was the vicar of Bwlch-y-Cibau. He became the chief engineer at Leyland Motors and was given a free hand to create the world's finest car. The Leyland Eight was a technical triumph, but too expensive to be anything other than a commercial failure. Parry Thomas left Leyland in 1922 and moved to a bungalow inside the super-fast Brooklands track at Weybridge, Surrey. He quickly became one of Britain's most popular and successful racers.

Record-breaking made headlines in those days, when road-going cars capable of exceeding even 50mph were rare. British contenders who had dominated the "speed king" scene since the Great War included Malcolm Campbell and Henry Segrave, whose supercharged, 4-litre Sunbeam is still raced in Vintage Sports Car Club events.

Determined to break the record, but lacking funds, Parry Thomas paid pounds 125 for a colossus called the Higham Special. Renamed Babs, after a friend's young daughter, this was one of several monsters built for swashbuckling Count Louis Zborowski. Although it looked and sounded impressive, the Higham Special was little more sophisticated than a 19th-century combine harvester. The burly Welshman spent another pounds 650 to make Babs a serious contender. He fitted four Zenith carburettors, improved the suspension and steering, and constructed a long-tailed body that resembled a gigantic insect.

Campbell and his Bluebird had proved Pendine's suitability, but the 152mph record attacked by Parry Thomas in April 1926 had been set a month earlier on the beach at Southport, Lancashire, by Segrave and the Sunbeam. "Bullocks One" favoured the land of his fathers. The engine misfired and belched black smoke from its 12 exhausts, and patches of soft sand made Babs weave from side to side, but the record was hoisted up to 169mph. The car ran better the next day, leaving Segrave, Campbell and other hopefuls to contemplate beating 171mph.

Sure enough, Campbell and his new Bluebird inched the target up to 174mph the following February. Pressure on Parry Thomas was increased by the knowledge that Segrave was heading for Daytona Beach, Florida, with a new, twin-engined Sunbeam whose 22.5-litre engines combined to deliver almost 900bhp.

Parry Thomas was recovering from influenza when he trailered Babs to Pendine on l March 1927. He hit a bump at almost 180mph, was bounced out of his seat - there were no belts in those days - and nearly lost his goggles.

Conditions were far from ideal on 3 March, but Parry Thomas made four preliminary runs before being clocked at over 170mph. He had just completed the mandatory second run - then, as now, world records depended on the two-way average - when the car went out of control, rolled over and virtually decapitated its driver. The cause of the accident is unknown, although there are several theories, and a broken timing wire made it impossible to tell if Parry Thomas had beaten Campbell's record fractions of a second before his death. "Bullocks One" was buried in Byfleet churchyard, near Brooklands. The battered remains of his car were dragged to the dunes at Pendine and dumped in a pit.

In 1969, all of 42 years after the disaster, Babs was exhumed by Owen Wyn Owen, an engineering lecturer and a dauntless vintage car enthusiast from North Wales. He set about what must be the most audacious restoration project in motoring history. The great car now runs again, blasting flames from its exhaust pipes, and makes occasional public appearances. It was one of the stars of this year's Retromobile exhibition in Paris and, a few months later, delighted the crowds at the Vintage Sports Car Club's speed hillclimb at Loton Park, Shropshire. In the words of one ecstatic spectator: "This is the greatest comeback since Lazarus."

The London Motor Show will be at Earls Court, Warwick Road, London SW5, from 19 to 29 October.