Is there a way that I can drive trains on routes that they are not designed for if you don't have any routes that have it? (I'm new to the game, and wondering if I can drive the green and gold HST on the WCML because I cant find it in the train list, nor do I have any routes that use it)
You should be able to do it easily in Quick Drive which sort of a sandbox mode where you can drive (almost) anything anywhere- just choose the train you want to drive, the route and then a start and end point. AFAIK the only restriction is that you can't drive an electric train on a non-electrified route. Another option is to find a scenario that already exists, make a copy of it then edit the copy to swap your chosen train into it which is quite easy and described here: Other than that there may be scenarios in the Workshop or you could learn to make your own. I've been using TS for seven going on eight years now and still haven't created a scenario though I have modified some satisfactorily.
Okay, thanks, quick drive didnt work and I don't really want to only be able to use it in scenarios, but I found a way to drive it, by using the Custom option in free drive, I can then make the train (only way i can think to describe it) and drive it, thanks anyway
Quite a lot of assets don't appear in the standard QD selections, but they can be made to appear if you create a custom QD consist. Just click on the Custom icon and take it from there.
You can run almost anything on any route. It does not matter if the train is smaller than normal - like a UK Train on a US Route. But it can cause problems running a big train on a route not designed for it The clearance between trains is where problems can occur.
The First Great Western livery you mention is in quick drive, it'll be listed under High Speed Train. It was actually the second or third DLC I bought, quite a few years ago now. That is unless you're referring to the AP version which I can't remember the QD name of.