On Friday I was on the train up to Cambridge and we were held outside Hitchin for a few minutes. As is often the case when this happens, the guard made an announcement to apologise for the delay. Expecting your normal "We've been held at a signal" reason, I was somewhat amused when he came out with the following:

"Apologies for the delay to this service, this is due to the application of the breaks"

Well, yes, you would hope that would make you stop (or at least slow down).