Dave wrote:
Andrew writes
I was always under the impression that you are entitled to
15 minutes break after working four hours, and legally can
not be forced to work longer than four hours without a
break.

That's not the case.

As stated elsewhere, if you work more than six hours, you
are entitled to a break of 20mins. For the majority of
workers, that means the lunch break - there is no legal
entitlement to any additional tea-break. Of course
contractual arrangements may allow for more generous
breaks.

http://www.legislation.hmso.gov.uk/s...9981833.htm#12
http://www.dti.gov.uk/er/work_time_r...6.htm#section6

This isn't specifically railway work, but almost every job
I've done has adhered to this.

You've had some good employers. Many people have the legal
minimum and no more.

I once (very briefly) had a permanant night job where the breaks were
limited to 2 x 15 minutes.