SLOP ‘TIL YOU DROP
Roy explains that the building just to the left of the grey static tank is where maintenance teams would carry out necessary hot work on wagons. However, placing a welding torch near rolling stock used to transport highly-flammable gases and liquids isn’t the smartest idea. So, to prevent combustion, each wagon had to be emptied and thoroughly cleaned beforehand. “They’d pump everything off the wagon before steaming it to ensure that no flammable products were still present. “The waste product would then go into the grey static tank [pictured] and pumped into a system called SLOPS.” You’ll notice that some of Roy’s tank wagons carry the SLOPS lettering. The system was used to ensure that excess product could be recycled, and not wasted.