and that's not all - when they DO work...
Ah, how I don't miss platform 2 at Newcastle. The journey time from NCL to DUR (Durham) is 11 minutes, so if a Northbound train was, say, billed as being 6 minutes late you merely cursed a bit and waited, and waited. In the 11 minutes though, some form of dark matter took over, and just as 5 minutes had elapsed - so the train must be within a mile of Newcastle - almost in sight, it would mysteriously become 12 minutes late. More cursing. and again, and again.
The real pity is that if they just said 'It's going to be a half hour late' then there's time for a pints worth of delay at the handy bar behind platform 1 (through the barrier) - but 6 minutes - never enough to risk abandoning your spot next to the eventual carriage door.
...so many lost pints you could almost plot on the brewery sales figures...