What stopped the train?

So, I spent all day yesterday working on the Tangara, with very little to show for it, other than a few smoothed edges. Im still learning gmax, so I dont know if its my methods or the less-than-intuitive software that is causing the problems (probably the former) but nothing seemed to work. I cant seem to get the curvature of the roof right at the front. Maybe I just have to approach it a diferent way. I'll think about it some more and try again next time.

Another thing I've been wanting to model is a Train Stop (see the picture). This gizmo sits next to a signal and when the signal is red, the little arm near the back is raised up to activate the brakes on any train that tries to go against the signal. In Sydney, the suburban trains often trip past them, meaning they stop at the red signal, wait a couple of minutes, then move forward a few feet until this thing trips their brakes, then stop again (duh) and wait for the brakes to recharge.

In Trainz, if a train passes a signal at stop, the emergency brakes are activated. Why? What trippped them. Maybe the driver is asleep and didnt see the signal, and so cant operate the brakes either? This little baby is the answer, and will forever banish the question: "Ok, but what exactly stopped the train?".

I have the model about half way finished already (its fairly simple as you can see) but the hard part will be scripting it. I know there are a few existing scripts that do something silimar to what I need, so hopefully I can use them as a learning tool, and combine a few ideas from each to create what I need. (With credit where its due of course).

I finally figured out that the S Sets on the DLS must have the required attachment points for a cab. Its a pitty about the one chosen though - I feel like im driving a truck. Pedels and a round wheel like thing? What the!? Im thinking about doing an upgrade. Building a cab and dropping it in. I'll see how I go. I might do an M Set cab as well, for the bug.