Coach lettering conventions

[FrankBNG]

Hi all,

I've noticed that on 4-car DMUs I go on, mainly the class 158, the coaches are always A, C, D and F. A guard once explained the meaning of this to me, however I cannot remember what it is.

I believe C and F stand for 'cycle' and 'four-cycle'? Does anyone know how the coaches work?

 

[Domh245]

I think it's largely down to the individual TOCs. As far as I'm aware, East Midlands Trains' 158s run as coaches A, B, C, and D when in 4 car formation so I can't imagine there being much precedent for C and F standing for anything in particular.

 

[Julia]

A/C/D/F is so that if the TOC has a mixture of 2- and 3-car units, a 3-car unit can be substituted for a 2-car and vice-versa without upsetting the system - the centre car of the 3 being B or E depending where in the formation it is.

 

[dp21]

A good friend of mine at XC explained to me that they have a dodgy lettering convention that is purely down to the fact that the Voyagers were designed to be able to be 6-car units.

Had they ever been extended, they would have had the full suite of A-F.

 

[Bletchleyite]

A/C/D/F is so that if the TOC has a mixture of 2- and 3-car units, a 3-car unit can be substituted for a 2-car and vice-versa without upsetting the system - the centre car of the 3 being B or E depending where in the formation it is.

It also means, where you've got units like Voyagers and Pendolinos, a given letter always has the same seating layout. Makes things like seating plans easier.

One thing I have noticed, though, is a trend on the London commuter operators to number coaches rather than lettering them...does this confuse people, or is it fairly transparent because it is for a different reason?

 

[43096]

One thing I have noticed, though, is a trend on the London commuter operators to number coaches rather than lettering them...does this confuse people, or is it fairly transparent because it is for a different reason?

It is transparent, primarily for use with SDO/short platforms or splitting trains. So if SDO is “front 7” and announced as such, and the coaches are numbered 1-10, it is easy to know if you are in the right place (doesn’t stop normals getting it wrong though!). Coach numbering is also always from the leading cab, which is different to the lettering, which is more for seat reservations etc.

 

[SEClass375]

On loco hauled stock, why do they skip the letter G, unlike letters I, X or Z or Q, it isn't ambiguous or abnormal?

 

[Bletchleyite]

On loco hauled stock, why do they skip the letter G, unlike letters I, X or Z or Q, it isn't ambiguous or abnormal?

A bit similar to C at a glance maybe?

 

[swt_passenger]

On loco hauled stock, why do they skip the letter G, unlike letters I, X or Z or Q, it isn't ambiguous or abnormal?

Perhaps G is where they could add a notional extra coach, which would mean H & J would retain their existing letters for reservations purposes. G does get used in some stock doesn’t it?

 

[Bletchleyite]

Perhaps G is where they could add a notional extra coach, which would mean H & J would retain their existing letters for reservations purposes. G does get used in some stock doesn’t it?

It's used on 11 car Pendolinos for a first class coach which is missing from 9 car sets.

 

[swt_passenger]

It's used on 11 car Pendolinos for a first class coach which is missing from 9 car sets.

Also on the second set of doubled XC Voyagers. So no systematic avoidance.

 

[TwistedMentat]

It also means, where you've got units like Voyagers and Pendolinos, a given letter always has the same seating layout. Makes things like seating plans easier.

One thing I have noticed, though, is a trend on the London commuter operators to number coaches rather than lettering them...does this confuse people, or is it fairly transparent because it is for a different reason?

My guess is it's more a platform length thing when they can only open so many doors. It's easier to say "You must be in the first 6 coaches" than "You must be in coaches A, B, C, D, E, F, etc" So you can just look at the internal passenger display and know if you need to move or not.

Note that's just a guess.

 

[swt_passenger]

There’s always exceptions - SWT’s 458/5 conversions still use letters for coach identification internally. Don’t know what appears on station and onboard announcements though, I’ve only used them at ten car stations...

 

[xotGD]

TPE use A, B, C on the 185s. However, they are incapable of telling you whether A or C is at the front.

 

[43096]

There’s always exceptions - SWT’s 458/5 conversions still use letters for coach identification internally. Don’t know what appears on station and onboard announcements though, I’ve only used them at ten car stations...

They are different because the internal screens don't/can't display "Coach 1 of 10" or whatever. Presume either the Alstom TMS can't do this or the mod was too costly.

 

[TEW]

There’s always exceptions - SWT’s 458/5 conversions still use letters for coach identification internally. Don’t know what appears on station and onboard announcements though, I’ve only used them at ten car stations...

They gave up on the letters inside pretty quickly. Passengers are pretty much just left to guess which carriage they are in now. Announcements refer to the need to be in the front x coaches both at stations and onboard, but it isn't especially useful without any numbering to passengers.

 

[swt_passenger]

They gave up on the letters inside pretty quickly. Passengers are pretty much just left to guess which carriage they are in now. Announcements refer to the need to be in the front x coaches both at stations and onboard, but it isn't especially useful without any numbering to passengers.

Oh thanks for the update. They did lead to some complicated announcements and I guess they mean another ten advertising spaces can be rented out again...

 

[swt_passenger]

They are different because the internal screens don't/can't display "Coach 1 of 10" or whatever. Presume either the Alstom TMS can't do this or the mod was too costly.

That’s right, in fact from previous discussions the 458 ASDO is not part of the TMS, and is fairly limited in that it doesn’t work on coach numbers as such, each coach has its own system and the doors are opened if that coach has passed over the platform entry beacon.

 

[GW43125]

That’s right, in fact from previous discussions the 458 ASDO is not part of the TMS, and is fairly limited in that it doesn’t work on coach numbers as such, each coach has its own system and the doors are opened if that coach has passed over the platform entry beacon.

Often leads to people asking, though.
However I prefer the 458 system as it protects against a stop-short.

 

[jopsuk]

Coach G is a standard class coach on East Coast HSTs.
On the EC sets:
A: the guards van/bike store (the latter bit why it has a carriage letter for reservations) on an HST
B-E: standard class both types
F: Accessible standard class both types
G: Standard class HST
H: Buffet standard electric
J: Buffet 1st HST
K: 1st electric
L: Accessible 1st both types
M: 1st both types
P: DVT bike store electrics

All that's skipped:
I: looks too much like a 1
N: Sounds too much like M
O: looks too much like a 0

Meanwhile, when the Pendolinos were originally set up, clearly extension to 10 carriages was catered for but not 11, thus the insertion of U...