Just as a matter of pure academic interest, "Sabot", or clog, is the French term for those clever little iron thingies on which the rail is mounted, originally made of wood. This is then firmly attached to the sleeper. During the Great War, it was discovered by certain interested parties in the occupied parts of France, that if these were removed, the next train along would come off the rails with a fascinating outcome. This hobby became known as "sabotage" and was heartily disliked by the German Army.