I'd like to hear stories about when you've had to fail a train. I've heard from other drivers that control and maintenance have tried to get them to continue on (to avoid delay attribution fines) and the driver has either had to lay down the law (or got totally shafted along the way).
One that I can remember is a train which had no compressors, where the driver was put under some pressure to keep the train in service by control staff who didn't fully understand/appreciate what they were being told. Needless to say the train eventually ran out of air, and then sat down for two hours in a very inconvenient location, complete with passengers.
Generally speaking the driver *shouldn't* be put under pressure. He's in charge of the train, and providing he's complying with company policy and/or the Rule Book then there should never be any comeback. As long as the driver can justify their actions in a report if requested then that's normally the last they hear about it. This holds true most of the time, but occasionally some people (not just management but control staff too) will try it on, either through lack of knowledge or motivated by other reasons.
The difficulty is that *most* of the time, keeping a train in service with a defect where it shouldn't be in service probably won't result in a problem, either through luck or because other layers of safety keep things safe. However, as in the example described above, there are times when you're running on borrowed time which eventually runs out, and luck can never (and shouldn't) be relied on either. The ultimate reminder of the latter is, of course, the Southall accident.