Extra 317/7's for FCC

[bramling]

A number of the peak hour fast services that start/terminate at Royston are usually 365s. I have noticed that a couple of these services are currently 321s when I have used them since the timetable change - they were usually 8 car 365s until December.

Through the day the diagrams interwork between the different services. On M-F it's basically arranged so that during the midday period and after the evening peak, all of the faster services are 365, and some of the stopping services are also 365. For the stopping services the particular services which are 365 seems to change with each new timetable.

Generally many of the peak 'extras' are 317 or 321, which may go on to form other services depending on where the diagrams take them.

There is at least one 2x365 diagram which stays as a pair all day and starts & finishes at Hornsey Depot, this is the obvious one to go 2x317, which it currently often does if there's a shortage of 365s. This diagram includes fast Peterboroughs and Cambridge services. There's also a regular diagram which is often 321s instead of 365s which takes 321s to Ely.

In summary, it's more to do with how the diagrams are arranged, rather than putting particular trains on particular service types.