dibber25, on 13 Jul 2013 - 18:55, said:
There is no difference in this respect between a trap point and a derail. Either can be left independent of the main line switch or rodded to it to work together, and it is the provision or not of the linkage not the type of device that makes the difference. In a situation like this it is unlikely rodding would be provided in either case as it would make it very difficult for the crew to operate the switch, especially under a few feet of snow and ice.