When rehearsing a ‘three day play’ in TC3 (1964?) I was having increasing difficulty tracking Julian Tolkien, (no small gentleman!) due to a soft tyre on the offside front of his Mole boom. Eventually I found time to ring Mechanical Maintenance and Norman duly arrived with the nitrogen cylinder that was used to gas Vinten camera peds. He quickly re-inflated the tyre and as I was holding the studio ‘air lock’ doors open for his departure I asked how he judged the correct pressure. He explained that you just looked vertically down over the wheel and ‘pumped’ until there was no bulge at the bottom. At that instant, (need I go on?)…………..there was an enormous BANG and Julian was listing very much further to starboard than previously.