Its because everybody is over complicating it. The format for the headcode is pretty much universal and that everyone who needs to know it will almost immediately understand it. On my patch I can look at the headcode and identify its route.
Hopefully a Signaler can confirm as it is more for them than us. I had a box visit and the Sig on the panel identifies the train by its route code and signals it accordingly. Once its left their panel then all is good and they continue with their day.
Spot on. Not only is the headcode (or train description, for the more pedantic!) importantly to uniquely identify a specific train in a signalman's area of control, the routing information and service patterns that are conveyed within are essential to assist the signalman in running the job efficiently, without having to look up every single schedule. Consistency is everything in that respect!
All we need to learn is the format. It is the simplicity of the system that makes it so useful.
I pulled this of the interweb.
E - London and North Eastern
I - European
L - Anglia
M - London Midland / North Western
O - Southern / European
S - Scotland
V - Western
X - Out of gauge trains, extra long trains, etc.
Z - Special trains
We will never have routing for Scotland but we do use everything else (not seen an X before) However it is still simply the route code part.
As others have said, many inter-regional trains still follow that convention. In some regions, those letters are used for 'internal' passenger services (1Lxx for Swansea services on FGW, for example), presumably acceptable (to give a wider range of letters) because there's no conflict with any inter-regional passenger services using the same letter (I can only think of one regular booked passenger service from the Western Region to Anglia!). Conversely, some busy inter-regional corridors (e.g. some TPE services) use other letters because they'd quickly run out otherwise!
The same seems to apply, to a much greater extent, with class 2 services - since relatively few of these cross regional boundaries, it's more likely to be acceptable to use those letters as there's little chance of a conflict. Looking back through old WTTs, it was common for the allocation of destination/route letters to be outlined for all trains, except class 2s which often used a completely different system.
Zulu is used a lot and is a fast way to change the headcode when thing go a bit messy out there. The Signaler will also flip out the class and keep the rest the same when your cancelled etc. They still see the route code and the running order and signal the train accordingly. It is also possible to use 99 as the running order number part but I'm not 100% sure when that it is used but again by recognizing the pattern you instantly know what the train is.
I know of at least one (TOC) train planning department that has tried to use 1Z99 for an STP'd passenger working - I'm not sure at which stage it was thrown out, but I suspect (and hope) that it was quite early in the process. For the uninitiated, 1Z99 is one of a small number of 'reserved' train descriptions, in this case for an assisting loco, breakdown train etc. going to clear the line.
More generally, a train running as xZxx stands out as something worthy of a closer look, so I'd certainly encourage its use for anything that's been amended to run outside the normal pattern.
A really rare one (at least for us) and probably no longer in use due to GSMR was the Sig would put your departure time as a temp headcode.
It's still done in quite a few areas. You can put anything (up to four characters) in a TD berth - "*T3*", "-LB-", "NOGO", "TREE" and "BROK" are all examples that I've seen, as well as some imaginative farewell messages when boxes close. I don't know whether there's any impact on the information systems on stations if this is done in the wrong berths though.
Because if we used "S" for Scotland and then "S" for a local route then the guy with his slippers on in the box might get a bit confused. I dont think the list I posted is in use any more as I pulled it off something about BR headcodes. Maybe an Historian can chip in about "headcodes" as I distinctly remember my local train was always number "70"
The Skegness HSTs give an excellent example of potentially confusing train descriptions - 1S01 and 1S02 at present, leaving its origin less than ten minutes after a train that actually does go to Scotland. Two years ago, when they were diverted via Peterborough all summer, there'd have been even more opportunity to get it wrong at Grantham. Yes, it fits in with all the class 2 services to/from Skegness, but - as above - there's no potential for confusion with those. I do think that there's an increasing problem with train planners allocating train descriptions on an apparently arbitrary basis, or something simple like the first letter of the destination, without considering or understanding the consequences for those of us who have to work with them.
