Jeepys - without reference to Jims linked documents, I can tell you that on average Chivenor managed circa 300 jobs per year.
During peak times that could vary from none during a shift to 7 on the bounce which is the most I saw.
Within that scope it could be several 20 minuters or a few short followed by a long night job - you never knew what you would get when you started your shift.
WE always called in the new crew early if we had a night job so that the readiness state at 0800 was always RS 15 - the civsar flights do their changeover at 1200 rather than 1000 and don't call the new crew in early - that means that following a night job, the RS state in the morning is variable depending on when they went to bed.
Progress????????