Running on the Spot - Begin!
While I was working in a large chemical factory in northern Germany, installing some new cell line shorting switches, I witnessed a potentially dangerous, but extremely amusing incident. My Boss and I had finished the installation of the twelve switches along the side of the Castner-Kellner chlorine producing cell, and the local operatives had lowered the tank lid into position and clamped it down with several tens of large plastic G-cramps. I was intrigued as to why they were using plastic cramps and not metal ones, I presumed that it was for electrical insulation reasons, but it was soon to become obvious why. I was in the control room observing as the switches we had installed were opened by remote control to divert the electrical current through the brine in the cell to begin producing Chlorine gas by electrolysis, and my Boss was outside on the production floor watching the operatives as they moved around on top of the tank making fine adjustments to the depth of the electrodes into the brine solution to equalise the local voltage drops. Suddenly, an alarm went off in the control room, and the Controller made an urgent sounding announcement (in German) over the Tannoy on the production floor. Every one of the operatives on top of the tank dropped their adjustment keys and turned towards the door into the refuge room. At that moment there was an enormous WHOOSH, and the tank lid, about 100 feet by 30 feet, lifted two feet into the air, firing the plastic G-cramps out sideways, and propelling the operatives vertically into the air, where they all commenced "Running on the Spot" in mid air, before landing in full panic mode back on the tank lid and scarpering towards and through the refuge room door, slamming it behind the last man in. A large brown cloud of Chlorine gas rolled across the production floor after them, engulfing my Boss and the Production Supervisor, who were not fast enough to reach the Control Room door before it did. The extraction system kicked in and soon cleared the gas out into the atmosphere outside the factory, and Boss and Prod Sup staggered into the Control Room and sat down to regain their breath. Although this was an extremely dangerous situation, resulting eventually in the untimely death of my Boss some weeks later, it was obviously well planned for by the Production Staff of the factory, and was, at the time, excruciatingly funny to see several blokes all swivel as if magentically attracted, start running in mid air, and, on landing, all make it to and through a narrow doorway into the refuge.