by Richard Lemon » Mon Aug 21, 2017 3:26 pm
A simple question, but the answer is not!
This is for each railway to decide by risk assessment (which must be documented) and the outcome - process - must be defined as part of the SMS (Safety Management System) as required by ROGS. This applies to all "Safety Critical" tasks - so Driver, Fireman, Guard etc., must also have specified number of turns. For a signalman, it could be two turns in each box twice a year, or six turns in one box. And, work in each box must be assessed on an ongoing basis. Then there is the thought of the task being very different at a Gala to a one train service in November! For drivers, it may apply to different classes of locomotive.
Heritage Railway Association (HRA) Guidance Notes may help.
I hope that this is of some use to you!
Richard