In response to XV410's posts above I have a reminiscence from what was then HSA at Holme on Spalding Moor. The airfield was surrounded by farmland away from the village in an area known locally as Land of Nod. We had a similar engine running bay with two ramps for the main wheels of the Phantoms and a 'venetian blind' type of jet blast deflector at either end. In the 1980's we were investigating a problem reported by the RAF - the good old days when they raised F760 which were followed up by industry investigations. The aircraft had a pair of fuel transfer pumps in tanks 4 and 6, one electric, one driven by a hydraulic motor. The electric pumps ran continuously when electrical power was available. The hydraulically driven ones ran when running in reheat, to keep the collector tanks full under the high engine fuel flowrates, or in the event of an electrical failure. However the hydraulic motors would occasionally fail for some unknown reason, possibly vibration when running in reheat or possibly a pressure fluctuation in the utility hydraulic system.
We instrumented an aircraft by fitting pressure transducers in the hydraulic motor supply lines and recording fuel contents from the aircraft gauging system. As a first step we decided we would do a sustained engine run from full internal fuel down to the level where tanks 3-7 had emptied so we knew the motors had experienced the transition from the pumps pumping fuel to pumping air. I always enjoyed an aircraft engine run so I was outside alongside the aircraft while my instrumentation colleague watched the paper spool out of the UV recorder in the cabin. After about five minutes running in full burner with two Spey 202s thundering away while swallowing around a 100 gallons of Avtur a minute, the concrete behind the aircraft began to spall and saucer sized chunks of concrete began to be hurled into the jet blast deflectors, bounced up into the air and rained down on the surrounding countryside including the road that ran around the airfield perimeter. At the end of the run I walked back into the cabin to look at the traces and the phone rang. I picked up the receiver and the irate voice of a local farmer on the line asked 'What the f*****g hell are you b*****s up to now, your'e driving my bullocks berserk' I explained that we were carrying out a special test, we had finished for the day and it was not going to be a regular event.
Subsequent analysis showed there were large hydraulic pressure spikes as the pump transitioned from pumping fuel to pumping air. Alas there was no easy solution, at least not within the MoD budget or inclination, so as far as I can remember, nothing further was done.
Walbut