Ahh, yes. MRD's.
Sat inside a 'sound-proof' box with a dodgy comm to the bowser driver only (he spoke to Ops so had the radio) with a GUO Derwent Mk 8 either side waiting to shed their turbines and take you out in stereo. The only device I can think of where the operator of engines multiple had no control of direction or brakes, but could remotely reverse a full bowser.
For a number of years, I had the dubious pleasure of maintaining the two at Valley, coupled with giving training to reluctant 'volunteer' operators. The rules in those days limited the running of Her Majesty's engines, whether installed on aircraft or otherwise, to SNCO airframe and Electricians, and Engines, all ranks above JT. The Ground Use Only Derwent's differed from the fliers due to lack of altitude compensators, and more worryingly, no acceleration control units. Hence the important part of the brief "NO slam accels", often totally ignored by the 'trainees'. The resonance vibrations and long licks of flame out of the 'snoots' certainly caught everyone's attention. If you forgot to switch on the Nitrogen bottle, you couldn't raise the Machine, and further melting of all things tar was guaranteed. If we couldn't get a hold of a Houchin, the poor MRD would complain noisily and visually on initial start when using a Trollyacc. Never remember using this pair in anger, but, as mentioned above, excused all other Station Duties.:
The only jet engine I ever worked on where the book said if the turbine to shroud clearance was below minimum due to blade creep...install a wider shroud.
I used to know the poor chap who welded up all 75 pairs of exhaust snoots. Even he admitted it had a detrimental affect on his mental stability.
Happy days.
RRNemisis,
The unintended consequence of an innocent decision. Something most of us can relate to.
Camlobe