Chapter 2 - The venue

Introduction

In 1851 a prospector named William Nobles pioneered a new route to California. It passed Black Rock in North West Nevada and ran along the west side of the Black Rock ese rt to the hot springs near the present outpost of Gerlach. For the next couple of decades the wagon trains rolled along Nobles trail at 8 to 10 miles a day. The settlers and adventurers were harassed by Indians and at the mercy of the extreme weather. Their objective must have been to cross the infamous desert as quickly as possible for the waterholes at the southern end.

One hundred and thirty-two years later another Noble's track was laid out on the huge and desolate lake bed not far from its predecessor. Another pioneer called Richard Noble was attempting to cross the desert as fast as he could, in a jet car. He too would be at the mercy of the unpredictable desert and the violent weather. Both men had a lot in common, venturing beyond known boundaries and pitting themselves against the elements. How astonished William Nobles would be if he could see a fire-breathing self-propelled wagon hurtle across the desert, covering a days travel in 1(X) seconds.

Traditional sites

Without somewhere to run it, all the effort put into the car is wasted. The earliest Land Speed Records were set on lengths of highway accessible to the contenders. As speeds increased, more room was needed and beaches such as Pendine Sands became the place. These were subject to the vagaries of wind and tide and were often far from flat or firm. The ultimate beach venue was Daytona Beach in Florida where both Malcolm Campbell and Henry Segrave set world records. As the speeds approached 300 mph the search for yet more space and a better surface led Malcolm Campbell to the Bonneville Salt Flats in Utah where he raised the record to 300 mph. This established Bonneville as 'The World's Fastest Speedway' and 35 years later the last record of 622 mph was set there in 1970. However, the condition of the salt has deteriorated over the years, as the brine has been extracted by a chemical works, thinning down the crust and reducing the length of good salt to around eleven miles. This decline in condition, recent unseasonal flooding and the advent of metal wheels, has spurred the search for alternative sites.

Site selection

To better an existing record either the car must accelerate faster or take a longer run-up. As speeds build up towards the sound barrier, massive power and a long track are required. The surface must be level, flat and smooth. The cushion the the crust must cushion the metal yet be hard enough to stop them sinking in. Ideally the area in which these elusive Properties are found should be - accessible from a good road - near facilities to store and work on the car - accommodation for the crew, timekeepers and the Press. Even more ideally it should be within range of an industrial base capable of supporting aerospace technology and speaking English. The only areas that appear to fulfil these conditions are dry lake beds, often known as Playas, Flats or Pans. These areas are generally found in remote desert areas, notably North West America, South Africa, the Middle East and Australia.

Several potential sites such as Iran are ruled out for political reasons. Others, such as Edwards Air Force Base in California have been taken over by the Military. Among the remaining sites are unspoiled wilderness areas that are jealously guarded by environmentalists. All the possible sites are a long way from home and initial selection must be based on previous attempts, hearsay and desk research, as physical exploration is a major and costly undertaking. When a provisional choice is made the site must be visited and checked Out, contacts made and Authorities approached for permission to use it for Record Breaking. Inevitably the applicant will be expected to meet certain conditions, observe safety regulations and pay fora permit.

Playa formation

The Playas are formed where sediments and salts are washed into land-locked basins by winter rains and panned flat by surface water shifting in the wind. In the dry season the water evaporates and the surface crust is baked hard by the sun.

Playas vary considerably in composition, hardness and brittleness of the crust formation. The surface of each playa can also vary considerably from one area to another. The main constituents are salt, alkali, sand and clay. The two predominant playa types are salt and alkali (mud) flats. Each has its own particular characteristics.

The crust of a salt flat forms large polygons like ice floes, and pressure ridges are pushed up at the edges as the salt crystals 'grow'. These ridges are sharp and hard and have to be planed off and compacted before the surface is smooth enough for high speed driving. As the salt is always damp, drawing up sub-surface moisture, this process is continuous and requires constant dragging to prepare and maintain the track. Manufacture of a 'drag' with its grading blade and the laborious job of towing it up and down the course, is expensive and must be carefully done to avoid generating undulations.

Mud or alkali flats however, have very different surface properties. The surface crust is much drier and more delicate. It crazes into smaller more brittle surface polygons which vary considerably but could be likened to irregular earthenware tiles. These polygon flakes are resilently supported on the sub-surface mud providing a degree of give to each one. It is not necessary to prepare the surface and in fact grading it would destroy the flakes and turn them to dust. Preparation is left to the natural cycle of Mother Nature.

Locating the best patch for a track is not always easy as the flats can be vast and featureless.

The track

Project Thrust Track Layout, Black Rock Desert 1983.

In 1981 we prepared a track at Bonneville and intended to run up and down this much as we were used to doing on aircraft runways in the U.K. However, the solid wheels left ruts in the surface and when the car hit these on subsequent runs, the 'tramlining' effect made it unpredictable to control. It soon became obvious that we would have to use a virgin track for each run, consuming rather than re-using the desert. This dictated a much wider track, divided into a series of lanes, one for each run. On a salt desert this procedure increases the cost of 'dragging' considerably and is a point in favour of a mud flat where little surface preparation is needed.

Fifty feet was found to be an adequate lane width, with enough lanes to do two runs for each one planned. Sixteen lanes were proposed for 1983 making a track 800ft wide by 13 miles long with a six mile run-up available to the first timing light.

The track must miss the humps, bumps, dips and undulations all of which occur in good measure. When the most suitable area has been located it must be surveyed and marked out with stakes. The whole area has then to be 'defodded', that is cleared of all debris likely to cause damage by impact to the wheels or ingestion into the engine. This debris can be natural flints or the refuse of mankind such as cannon shells and beer bottles.

The defining of the lanes to guide the driver, also varies. At Bonneville, where racing is traditional and established, a Black Oil Line is laid down, but on more unspoiled locations where the environment is protected this is not permitted. Here we created a precedent by using tyre tracks to mark the lanes. The Jaguar fire tender was driven from end to end stake at a time, and then driven back over its own tracks at high speed to straighten out any kinks. The tyres crumble and impact the surface leaving guide lines which the jet car driver must follow in his high speed dash across the desert. These tracks are not ideal as they vary in density with lighting conditions.

Each mile of the track is indicated and numbered by 6ft square flags mounted on a collapsible frame. Unfortunately, high winds can spring up, sending the track team into a frantic chase to furl the 'sails' before they take off into the vast beyond. The flags form a perspective 'funnel' stretching to the horizon into which the driver aims. As he drives over the earth's curvature, distant flags pop up over the horizon, hover in the mirage and then settle back down to earth to be replaced by the next pair.

A good indication of the car's behaviour can be seen in its wheel tracks, and these are examined after each run to look for any unusual loading or wandering.

Running the car

Speed is built up in steps hopefully culminating with a record. The car is always driven at full bore, for maximum acceleration and the speed is increased by taking progressively longer run-ins. In this way the driver's procedure is always constant and the performance results for each run can be extended to predict the next increment.

Surface interaction

The machine and medium cannot be considered in isolation as each has an effect on the other.

The car does work on the surface, compacting and pulverising the crust and raising a huge contrail of dust. This work represents energy which is deducted from the resultant performance. The softer and more crumblythe surface, the greater the loss and slower the car. The dust has other effects - it impinges on any following surfaces eroding them and creating drag. It penetrates every minute chink and then sets up corrosive action - not very nice for delicate electrics or mechanisms. After the start it also obscures the reheat flame so its behaviour cannot be judged.

The wheels come into intimate contact with the surface and their treads are effectively 'impact peened' by the myriad small particles they encounter. This is probably beneficial provided a hefty object is not missed by the 'defodding' team. Dust also tends to build up and pack onto inside rims which could throw them out of balance so they have to be meticulously cleaned after each run.

Weather

Weather effects both the formation of the playa and the running of the car. This is the great unpredictable element.

'Normal' seasonal patterns must be assumed for forward planning, but for the third year in succession we had been frustrated by 'freak' conditions. At Bonneville and Black Rock the surface should be suitable froth July to December, but as we know to our cost, deluges or sudden snow melts can turn the desert to a lake almost overnight. To run the car we had to have clear visibility and a maximum crosswind of 3 to 5 mph. Early mornings before the heat of the day rouses the winds and mirages can be the best time.

Mirages are an almost permanent part of the desert scenery, especially on the vast and featureless Playa beds. The distant mountains appear suspended above their miraged reflections as though floating in water - hence 'Floating Island' in the Bonneville Salt Flats. Marker flags and vehicles float high in an apparent lake moving into shallow water and 'hopping' onto dry land as they are approached. Unfortunately the same phenomeno to the guide lines so it is advantageous to run before the mirage is at its worst.

Black Rock Desert

The Black Rock venue was found during a desparate search for an alternative site after we had been flooded out at Bonneville in September 1982. Although chosen by default rather than selection, it was in many ways ideal and certainly had advantages over the traditional Bonneville.

The desert is situated in North West Nevada 110 miles north of Reno. The nearest base is Gerlach at the southern end of the playa. This was a friendly and isolated little outpost, but ideal for our needs. There was a garage for "Thrust 2", a small motel for the crew, dining facilities at Bruno's, a filling station and the Miners Club. At the same time it was too small and remote to accommodate hordes of onlookers who would be a nightmare to control and organise.

The mud flats are part of the bed of the prehistoric Lake Lahontan, lying in the Great Basin. The surface varies across the flats. Generally the south (Gerlach) end is harder and stronger than the north (Black Rock) end which tends to be soft and friable. The increased rolling resistance in the soft areas could be clearly felt in conventional cars slowing them down as though the handbrake was applied.

When wet, the top layer becomes very slick; further wetting causes the mud to cling and clog; still further wetting results in slip, clogging and sinking- definitely a situation to avoid.

The timekeepers

The timekeepers confirm that the rules are adhered to and verify the speed making the record official. They also act as stewards and lay down safety standards to minimise risk to participants and spectators.

The timekeepers precisely measure and mark one measured mile and kilometer. They set up timing lights which electronically time the passage of the record contender between them, and hence deduce its average speed over the distance. The timing stand from which the attempt is observed is set back a quarter of a mile from the track, opposite the measured mile. No spectators or vehicles are allowed closer than the stand to the track. In the United States the timekeepers are under the auspices of U.S.A.C. which represents F.I.S.A. Five members are required to double check and authenticate the results.

Conclusion

Historically record contenders have built a car and then set out to find a place to run it. Logically it would be better to establish a site first and then design the car to suit it. However, it would be a brave or foolhardy designer who spent his first sponsorship money dashing off to look at sites rather than producing visible hardware.

All the possible sites are overseas and the cost of mounting a record attempt so far from home is a major part of the overall budget.

To allow time to plan the operations and shipping, and obtain a permit, a site must be decided upon before it dries out, so it becomes a gamble that the surface and weather will come right in due course. The entire programme then has to be tailored around the chosen site and subsequent dates and deadlines set to suit its 'normal' seasonal pattern. However, the usual abnormal conditions ensure that frustrations, delays and 'cliffhangers' are the order of the day. But somewhere, sometime, it can all come right at the same time.