I was on the tube before joining the mainline and there are significant differences between the two, many of which have already been highlighted:
Tube stock:
- fixed train length (blindingly obvious if you've stopped at the correct mark or not)
- CSDE fitted everywhere which works flawlessly
- the culture regarding incidents on tfl infrastructure is more relaxed than it is on the mainline
- aggressive driving isn't 'encouraged' but it certainly isn't frowned upon
- stock & stations both designed for faster acceleration & braking (there's an incline into many underground platforms and a decline on the way out)
- no TPWS integration, even when driving over network rail infrastructure
Mainline:
- Many different train lengths (metro drivers can - and do - drive 2/3/4 different train lengths over the same route in one shift)
- CSDE only present on newer stock, commonly GPS based which isn't very reliable and it usually won't prevent you from releasing the doors if you stop short. Older stock has no safeguards at all
- in some places external monitors are mounted on the opposite side to the platform, almost like they're trying to catch you out
- any incidents which can compromise safety are of course taken extremely seriously
- TPWS grids fitted on the approach to most signals
Pausing before releasing doors (and covering up the opposite buttons) are drilled into every new driver from the start, because a wrong side release is pretty much the only error a trainee can make that can't be rectified by the DI from the secondman's side, at least without a heroic leap across the cab.
LU is able to significantly reduce the risks of these kind of incidents with it's 'closed shop' infrastructure, but it remains a very real problem on the mainline. At some TOCs they've had to implement rather extreme measures to try and prevent it - SE metro drivers MUST cross the cab and use the buttons adjacent to the cab door for a wrong side release, which is why the pause is often longer compared to many other TOCs (not sure what they do in the city beams though).
And my last point is just a personal experience but I found the braking of a '72 to be in a completely different league compared to my current (modern) stock. I could hit the platform at Wembley at nearly line speed, in fine rain, whack it into full service and still stop on the mark. If you ever overcooked it you could pop the handle or even dump the air and you'd magically unlock even more secret braking capability, regardless of the conditions. Really impressive when there's no WSP or sanding equipment
I was totally shocked when I started on the big railway, electrostars will slide all over the place if they so much as see a dark cloud, even below 10mph. The difference is stark.
