> So you're into physics, eh? I'm a bit rusty with massless volumeless theories, but if I recall correctly, such a train would be capable of achieving the speed of light without having to subscribe to the latest theories about creating warp bubbles around itself wouldn't it?

Not only that, but a massless volumeless train would be incapable of travelling at any speed other than at the speed of light, shown by no physical law more complicated than Newton's laws of inertia. Nevertheless, it is not uncommon for this assumption to be made about objects in physics problems, at least of the introductory academic variety, without also adopting the real-life properties of massless particles.