Was commissioning a 600 mega watt steam turbine, the shaft would have been close 900 mm dia so you can imagine the size of the bearing housings as the turbine got up to its critical speed it started vibrating pretty severely, I thought the top of the bearing housing where I was standing would pop off. One of the engineers who would only have weighed about 70 kg jumped onto the bearing housing straddling it, I was hoping he would take off his hard hat and start twirling it around his head it would have completed the picture I had in my mind of the association of the engineer and Slim Pickens riding the atom bomb in Dr Strangelove.