Thrust SSC - Supersonic Race Update

Issue 54 Lead Article - 30th September 1996

Lighting-Up Time!

by Jeremy Davey, ThrustSSC Webmaster and Satellite Communications Manager

Having completed the runway tests of ThrustSSC with a spectacular run of 200mph on full reheat (please see "160 to 200mph In One Second!"), the team had one final test to complete - the static tests at DTEO Boscombe Down. Apart from testing the car’s systems, the static tests were crucial to proving that the rear fuselage could take the battering of a reheated Spey’s exhaust. On their first trip to Boscombe the engines had surged at 95% of maximum revolutions (please see "First Engine Tests At DTEO Boscombe Down") and the team had had to return to their base at Q Shed, DRA Farnborough, to diagnose the problem and find a solution. There was no doubt that it was an air starvation problem, but why?

Vortices forming in the intakes and restricting the airflow were suspected, so the team made a second trip to Boscombe Down with ‘vortex mats’ to reduce the effect (please see "Tie-Down Tests Continue"). Although they had some effect, it was not enough, and once again the ThrustSSC team returned to base to reconsider their options. While at Boscombe, the airflow into the intakes had been studied carefully using a smoke trace and the engine team were able to confirm their theory that when the car was not moving, air was coming from under the car and tumbling as it made a sharp U-turn round the intake lip and was restricting the flow. The intake design was optimised for running with a ram-air effect at Mach 1, not for operating the engines on full reheat while stationary - something that would never happen during runs - and a solution was required that would enable the team to test the engines statically at full power without compromising the intake design.

A bellhousing was suggested - fitted over an intake for static tests it would stabilise the flow into the engine, or so the theory went. Chris Horne, son of ThrustSSC’s bodywork designer and builder Mike Horne, set to work and by the end of the runway tests the team was ready to give it a try.

Regular readers of this site will know that the weather over the last week has been cold, wet and windy. This morning was different - it wasn’t windy and it hadn’t started raining yet, but it was cold. By 0830hrs ThrustSSC was on its way down the M3 followed by the Land Rover Defender with the support equipment, and the Grayston White and Sparrow crane to lift the car from its trailer (where would the team be without them?).


Hawk trainer in the test cell
(Hawk trainer in the test cell. Photo: Jeremy Davey)

Boscombe was dry when the team arrived, but a glance at the grim, grey sky confirmed the weather forecast - it wasn’t going to stay dry. Unlike its last two visits ThrustSSC did not have the tie-down test cell to itself, but was third in line behind a Hawk and a Hunter which needed their engines testing. By the time the Hunter was in position the threatened rain had arrived with a vengeance, and there was little chance of it relenting for some time. DTEO Boscombe Down have been superb hosts throughout the static tests, and once again excelled - an empty HAS (Hardened Aircraft Shelter) was quickly opened up for the team and their vehicles to get into the dry.


Andy Green and Jayne Millington shelter from the rain
(Andy Green and Jayne Millington shelter from the rain. Photo: Jeremy Davey)

Hardly had everyone settled into their new home than the Hunter was finished and the tests could start! The car was quickly unloaded and while the technicians prepared it for action - including fitting the new bellhousing to the left intake - the remaining team members sheltered as best they could - in vehicles, under umbrellas...


Jeremy Davey is caught sheltering in an air inlet
(Jeremy Davey is caught sheltering in an air inlet. Photo: Dean Smith)

... or in the air-intakes!


Dee Campbell-Coombe makes yet another cup of coffee
(Dee Campbell-Coombe makes yet another cup of coffee. Photo: Jeremy Davey)

Everything is going so well for the team at present that it would take a great deal to dampen morale - but Dee Campbell-Coombe and Ninetta Hearn were taking no chances and had come armed with huge amounts of food and hot drinks (Ladies, you are life-savers!).

At long last everything was ready - and it had stopped raining! Andy Green briefed the attendant fire crews, the left- and right-hand engine crews took up positions, and everybody else retreated to safe positions with a high level of expectation.


Al Harkness signals 'Air On'
(Al Harkness signals 'Air On'. Photo: Jeremy Davey)

DTEO Boscombe Down’s Palouste was started and connected to the left-hand engine. On Andy Green’s OK, Al Harkness gave the signal for "Air on!" and with a whine the left-hand Spey spooled up. The air hose was disconnected and passed under the car - and the right-hand engine was started. The first test was to take the left-hand engine to ‘Max Mil’ to check the bellhousing worked. Andy Green pressed the throttle down and the Spey stabilised at 90% of maximum revolutions. Next he took it to 95% - and still no problems. The acid test was to come, and as Andy pressed the throttle further the left-hand engine accelerated to 100% and stabilised. The bellhousing worked!

Driver and engine team were happy that all was well - the next stage of the test called for first minimum, then maximum reheat. A small glow of flames appeared out of the Spey’s jet-pipe, then with a roar it grew to a cone that extended some 6 feet beyond ThrustSSC’s tail. As the engine slowed to an idle, then stopped, the team were ecstatic - the reheat worked and there had been no adverse effects on the rear fuselage!

The next test called for ‘slam checks’ - the engine would be quickly taken to reheat and back. Again both team and car performed impeccably, and again the ground shook as the Spey converted 2 gallons of aviation kerosene a second to a spectacular cone of fire. Having only experienced a Spey on reheat from behind a glass screen on the test bed at DRA Pyestock, the sheer power of the sight caught me completely by surprise - the noise and vibration become indistinguishable as they shake you to the core.


Nick Dove discusses the test with Andy Green
(Nick Dove discusses the test with Andy Green. Photo: Jeremy Davey)

With the left-hand engine having passed its tests with flying colours, the bellhousing was transferred to the right while the car was refuelled. Andy Green’s only comment during the break was: "Outstanding!"


The right-hand Spey stabilises at maximum reheat
(The right-hand Spey stabilises at maximum reheat. Photo: Jeremy Davey)

The bellhousing had been proven, and the right-hand engine tests would now be done in one go - ‘Max Mil’, full reheat and slam checks one after another. The Palouste was fired up again, and in the gloomy light the spectators on the other side of the car were treated to the incredible spectacle.


Jet-pipe fire in the right-hand engine
(Jet-pipe fire in the right-hand engine. Photo: Jeremy Davey)

All through the tests the vortex mats had been tied down in front of the car - the team preferred not to have to take them to Jordan if they could avoid it, so a final test was planned: to try full reheat without the mats. If all went well, they could be dispensed with. The heavy steel mesh was dragged clear and the engines once more started - first the left, then the right. The rear of the right-hand engine lit up - but it was not at reheat yet: there was a jet-pipe fire! It was quickly blown out and the engine checked before restarting. Again flames licked at the exhaust, but once they had been dealt with the throttle was advanced to full reheat.


The right-hand Spey at full reheat
(The right-hand Spey at full reheat. Photo: Jeremy Davey)

Then, as the light faded to dusk, the right-hand Spey responded superbly - the mats were no longer required!


Andy Green is sprayed with champagne in celebration
(Andy Green is sprayed with champagne in celebration. Photo: Dean Smith)

The team were elated! Andy Green hugged Mike and Chris Horne in delight - their superb craftsmanship meant that the team now had a tested and working jet-car. Back in August at the launch of Internet Explorer 3, Microsoft’s Bruce Lynn had given the team’s Internet Coordinator, Jeremy Davey, a bottle of Möet & Chandon champagne to be opened when the car passed its reheat tests. Jeremy had it waiting on ice, and in Formula One style liberally sprayed Andy Green before the remainder was passed around the team!


ThrustSSC is craned onto its trailer for the journey home
(ThrustSSC is craned onto its trailer for the journey home. Photo: Jeremy Davey)

With the celebrations taken care of, and the rain returning, ThrustSSC was loaded onto its trailer for the journey back to Q Shed. Al Harkness was delighted with his day’s work in charge of the engine tests: "I’m very happy - maximum reheat from both engines using the bellhousing. We were confident it would work, and wanted to prove we could go to Jordan without the vortex mats."

Asked about the jet-pipe fires, Al saw them as no problem: "They got a little fuel in them - it used to happen on Phantoms, and the normal procedure is just to blow them through."

Ron Ayers, ThrustSSC’s Aerodynamicist, was also happy: "The rear panels stood up to the very worst we could put at them. They will never have as much load as that when we’re operating on the desert, because with zero forward speed the maximum resonance occurs in the panels. If they can survive that, they can survive anything!"


Leigh Remfry refuelling
(Leigh Remfry refuelling. Photo: Jeremy Davey)

Leigh Remfry kept his only comment simple and to the point: "We've had a nice little burn - now to try it in Jordan!"

What next for the ThrustSSC team? The preparation work on the car for the high-speed tests must now be completed - then the team and car can call in HeavyLift’s Antonov 124 and fly to Jordan. Needless to say, everyone is very excited at the prospect…





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