In this classic horror film, two major slip ups occur. Firstly, whenever the train is shown speeding past the camera, those shots are glaringly model shots. And then, in the final minutes, the rest of the train is unhooked from the main engine by Christopher Lee and Peter Cushing and it crashes over the cliff, where it explodes. Huh? What is there in a wooden train carriage and caboose that will make it explode?