I have a question re 'propping'. ‘The Railway Employment (Prevention of Accidents) Act 1900’ had a wide range of objectives which affected a wide range of activities, practice and infrastructure on the railways, one section of which was 'Propping and tow roping'. Tow roping is self explanatory but can anyone explain 'propping'? I had in the past assumed it was propping of open wagon doors but as it is mentioned in the context of moving wagons I now think it is short for propelling - using a pole from the loco to wagons on an adjacent line. I know there are pictures of tow roping but I don't think I have seen one of propping. Whatever it is, done anyone know of any pictures?