I’d be interested to know what the rationale is behind Avanti headcodes as it doesn’t seem obvious why they are the way they are. As I see it they appear to follow the following pattern…
In the Up direction -
From the first train of the day (1R00 from Wolverhampton), all arrivals into Euston has a ‘1Rxx’ headcode regardless of origin. This continues for every arrival until 1R28 at just before 10am (although generally just counting up there are few numbers missing - totalling around the first twenty or so arrivals on a weekday morning).
After 10am they settle into a pattern of -
1Bxx (ex Birmingham)
1/9Sxx (ex Edinburgh/Glasgow)
1/9Axx (ex pretty much everywhere else)
I am aware that the distinction between the class 1s and class 9s in both directions is to show if trains are to be regulated via Birmingham or the Trent Valley. I would assume that’s for the benefit of the signallers?
In the Down direction the headcodes seem a lot more consistent and specific in terms of indicating a train’s destination.
Why then on the Up is there is change in pattern before and after 10am?
Also would be interested to know why most of the Voyager journeys to the likes of Holyhead (1Dxx) also have a 1Zxx ‘runs as required’ in the same path… is there any reason these might be turned short as opposed to any other services?
Are there any other oddities that I’ve missed?
In the Up direction -
From the first train of the day (1R00 from Wolverhampton), all arrivals into Euston has a ‘1Rxx’ headcode regardless of origin. This continues for every arrival until 1R28 at just before 10am (although generally just counting up there are few numbers missing - totalling around the first twenty or so arrivals on a weekday morning).
After 10am they settle into a pattern of -
1Bxx (ex Birmingham)
1/9Sxx (ex Edinburgh/Glasgow)
1/9Axx (ex pretty much everywhere else)
I am aware that the distinction between the class 1s and class 9s in both directions is to show if trains are to be regulated via Birmingham or the Trent Valley. I would assume that’s for the benefit of the signallers?
In the Down direction the headcodes seem a lot more consistent and specific in terms of indicating a train’s destination.
Why then on the Up is there is change in pattern before and after 10am?
Also would be interested to know why most of the Voyager journeys to the likes of Holyhead (1Dxx) also have a 1Zxx ‘runs as required’ in the same path… is there any reason these might be turned short as opposed to any other services?
Are there any other oddities that I’ve missed?
