JIM CLARK MARCH 4, 1936 TO APRIL 7, 1968
FIFTY YEARS AGO, THE GREATEST DRIVER OF THE 1960 SW AS KILLED IN A FORMULA 2 RACE AT HOCK EN HE I M. SOME MONTHS LATER, AN INDEPENDENT INVESTIGATOR, WHOSE BACKGROUND WAS IN AIRCRAFT CRASHES, CONCLUDED THAT THE CRASH WAS A RESULT OF TY RE FAILURE, AND FIRE STONE—THE SUPPLIER OF THE TYRES ON THE ILL-FATED FORMULA 2 LOTUS— ACCEPTED CULPABILITY
It was widely reported that Jimmy Clark was killed in a minor Formula 2 (F2) race, but it was the opening round of the 1968 F2 European Trophy, and Clark was one of three world champions entered, along with teammate Graham Hill. Chris Amon was also there with Ferrari teammate Jacky Ickx, who’d had a coming together with Clark a week earlier in Barcelona when the Belgian rear-ended the Scotsman. Ferrari right-hand man Franco Gozzi related the incident in his autobiography, Memoirs of Enzo Ferrari’s Lieutenant, after Clark had been put out of the race with damaged suspension: “I remember with how much determination Clark came into our pits.
“‘Tell your driver [Ickx] to calm down’ he [Clark] growled furiously, ‘because driving like that, we’ll get hurt.’ He was right, and I asked him to accept our apologies, adding — to conserve a little dignity — ‘But you English are all the same, you get stuck in too, but when something happens to you, you get tough.’ He became even more annoyed. ‘I am not English, I am Scottish,’ he replied icily, ‘And don’t you forget it!’”
Team Lotus did not take the car back to England for repairs to the damaged suspension, and the car Clark raced the following weekend in Germany was the same one that had been hit by Ickx in Spain.
Fatal accident
Twenty starters lined up on a dull drizzly day in southwestern Germany. On lap four of the first heat, Clark’s Lotus crashed on a fast right-hand curve. The greatest driver of his generation was dead, his Lotus smashed against a tree. There were no skid marks. The car was taken back to England, and a Firestone technician and Peter Jowitt of the Royal Aircraft Establishment’s (RAE) accidentinvestigation branch thoroughly examined every item of evidence. Both came to the same conclusion.
Suspension failure was canvassed but ultimately dismissed. In his book Jim Clark: Tribute to a Champion, Eric Dymock states: “The most likely explanation was the explosive decompression of a tyre, throwing the car off course and sideways into the fatal tree. The tyre had lost pressure through a slow puncture, and although centrifugal force kept it in shape at speed in a straight line, side force in the gentle curve caused the beading to loosen from the rim and drop into the well.”
Peter Jowitt was a senior engineer at the Experimental Aircraft Department at Farnborough. He specialized in military prototype aircraft accidents and was highly experienced in technical analysis. He did the technical examination of Clark’s car after the crash, and wrote: “We had a piece of evidence of enormous value. A statement had been taken from the marshal who had been very nearly hit by the car, and it had been taken while he was white-lipped and trembling, and before he had time to rationalize. He said that he had seen the car, whilst coming towards him, start to break away at the rear end. There had been a correction which caused a sharp breakaway the other way, followed by another correction which caused a further, fairly gentle but progressive breakaway in the original turning left mode, which continued until the car hit the tree.
“Any oversteering accident will focus attention on the rear of the vehicle, and I found an oddly-shaped cut in the tread of the right-hand rear tyre. This cut went completely through the tyre, and I could not find any part of the wreckage which could have caused it. If the tyre had been punctured, there is an odd effect which I had seen before. At high speed in a straight line, centrifugal force will in fact hold the tread out so that it looks as if there is no puncture, and the driver will not know that the tyre has deflated.
“As soon as a side load is put on, in cornering, the tyre becomes unstable, and cannot generate the cornering force the driver would expect. With the right-hand tyre deflating, the effect in a right-hand corner would be some oversteer. Correcting this by steering left would put a heavier cornering load on to the unstable righthand tyre, which would give rise to vicious right-hand oversteer. Correction in the opposite sense, at high speed on a very wet track, would clearly be difficult. The tachometer in the car, a mechanical type, indicated that Jim had the power on right up to impact, clearly trying to hold the car. There are, however, situations when even the unearthly skill of Jimmy Clark will not suffice.”
Suspension failure
Not everyone was convinced that the fatal accident was due to tyre failure, and it was suspension failure that those people were pointing to. In the May 23, 1993 issue of On Track magazine, Fred Gamble (a former Goodyear tyre director) wrote a letter headed “Time for the truth”:
“Concerning the circumstances of Jimmy Clark’s death … maybe it is time the truth is told. I was privileged to be a part of that era and a friend of Jimmy’s, so was just as devastated as everyone else when he was killed. His car had a rear suspension failure; sadly one of the frequent and well-known results of the brilliant but fragile Lotus cars of that era.
“I was Goodyear’s first director of international racing at the time and, as Firestone was contracted to Lotus, after the accident and rumours of a tyre failure, Firestone engineers showed me the tyre off the Clark car, not deflated or failed, but obviously dragged sideways after a suspension failure.
“A friend of mine examined Jimmy’s tyres, along with the wreckage, at Farnborough, and observed large braking flat spots on the left front and right rear tyres, in both cases covering the full width of the tread, very light scuff marks on the right front and slightly more pronounced ones on the left rear. I believe it would be reasonable to assume that this would indicate very heavy braking just prior to impact. These marks support the view that the right rear tyre had sufficient inflation at the time of the heavy braking, but they do support the very real possibility that the left rear suspension had partially or completely collapsed, and that the left rear was being supported by only the rear anti-roll bar.
“In all the years that have passed since the accident, I have always had a problem believing that a failure of the right rear tyre was the cause. I was running identical tyres that day, lapping at a very similar speed, and I can say with almost 100 per cent confidence that had I suffered a failure of the right rear tyre at the very same spot, I do not believe it would have resulted in an accident — there was just not sufficient cornering load on the car for an inside tyre failure to have been a major problem at that point. I feel strongly that it would be nice if the circumstances surrounding the demise of a person who was, is and always will be such a hugely important part of the sport and its history, had a reasonable chance of being factual. I’m certain the incident with Ickx at Barcelona damaged the Lotus’s suspension, and was pivotal to the whole thing.”
Competent scrutineer
Chris recalled Jowitt as “a very affable person, a very competent scrutineer, and because of his profession, [he] was obviously an expert in aircraft accident investigation. One of the tools used by aircraft accident inspectors is data recorders or black boxes, because it is often impossible to establish the cause of an accident purely based on examination of the wreckage.
“For any person to have had a realistic chance of pinpointing the cause of this accident, they would have had to have expertise in examining broken or damaged parts of the car structure and suspension etc., to have expertise in all tyre aspects and to have been an expert in vehicle dynamics. I have not seen anything to suggest that Jowitt claimed expertise on tyres or vehicle dynamics, but he would certainly have been very well qualified for the first of the three requirements.”
Jowitt was not paid by Chapman to carry out the investigation; however, he may not have had sufficient information to conduct his investigation in ideal circumstances. Seemingly, Jowitt did not consult any independent tyre expert. For half a century the general consensus has had ‘the tyre’ as being the cause, but people who were there, and/or know more about these things than most, remain totally unconvinced by the tyre conclusion and are also adamant as to the suspension breakage as being the most likely cause. In fact, the people who seem to have the strongest-held views to support ‘the official line’ are historians …
All photos are from Bill Pottinger’s book Tasman Series Memoirs 1968–71, available from Bill Pottinger, rowbillpotty@gmail.com.