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A and B ends on trains: facing and numbering
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Do you mean sections of a station platform? If so, a random sample of Leeds, Birmingham NS and Cardiff Central suggests "a" is at the Up (London) end, but I don't know if that's universal.
If you're meaning a locomotive or multiple unit, then I don't think there's a general answer.
The example that springs to mind is certain designs of LT underground train which had "A" and "D" (not "B") end cars and - theoretically at least - always worked one way round
http://en.wikipedia.org/wiki/London_Underground_1938_Stock. You may find similar examples via Google
If you're meaning a locomotive or multiple unit, then I don't think there's a general answer.
The example that springs to mind is certain designs of LT underground train which had "A" and "D" (not "B") end cars and - theoretically at least - always worked one way round
http://en.wikipedia.org/wiki/London_Underground_1938_Stock. You may find similar examples via Google
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If you are talking about an EMU then the DMOS-A and DMOS-B are exactly the same in terms of equipment except the numbering denotes the A and B ends and therefore the formation of the EMU. In the case of an LO 378 4 car formation this would be DMOS-A, MOS, (P)TOS, DMOS-B. Individual car numbers denote what is what so 0= DMOS-A, 1=DMOS-B, 2=MOS, 3= (P)TOS - so the formation might be 38022 (DMOS-A), 38222 (MOS), 38322 ((P)TOS), 38122 (DMOS-B). In the case of the East London Line at least the A end is in fact usually at the London end with the B at the country end, however there are one or two exceptions to the rule, so it is not a given. The most recognisable way to spot the exceptions (other than by the numbering) is if you notice the (P)TOS on the 'up' is the second carriage rather than the third.
I hope this is what you meant by your question?!
I hope this is what you meant by your question?!
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On Bombardier multiple units equipped with MITRAC-based systems, the brains of the set are located in just one driving car with the other driving position being just a remote terminal controlling the systems at the other end.
This is also true for Siemens multiple units based on the Modular Metro platform, but I have no close-up experience with the Desiro platform (whether full-sized, UK or UK City variants) to know whether they have one computer or duplicated at each end.
Alstom units based on the X'Trapolis platform work the other way around, their computers are fully duplicated in both driving cars for redundancy.
This is also true for Siemens multiple units based on the Modular Metro platform, but I have no close-up experience with the Desiro platform (whether full-sized, UK or UK City variants) to know whether they have one computer or duplicated at each end.
Alstom units based on the X'Trapolis platform work the other way around, their computers are fully duplicated in both driving cars for redundancy.
hairyhandedfool
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The 'A' end or 'B' end of a unit are primarily to identify which end of the train is which when they have identical vehicles in the train. On a locomotive or other single piece of rolling stock (coach or wagon for example), the ends would normally be referred to as 'number 1 end' or 'number 2 end', to aid identification for fault reporting, etc. In some cases the train will always be same way round, like the Pendolinos on the West Coast Mainline, but quite a few units run on 'loop' lines, like FCCs 319s, or triangular routes which means they could be either way round.
It may be true that the ends are the same for many EMUs, but some do have differences. The original 317s, I believe, were built virtually identical, however, each DTS had a main air res tank which was later agreed to be too much and the one tank was removed (can't remember which one though). On all NSE Mk3 based EMUs, the 'B' end had a parcels compartment and the associated isolating switch and indicator, many of which, I presume, have now been removed.
It may be true that the ends are the same for many EMUs, but some do have differences. The original 317s, I believe, were built virtually identical, however, each DTS had a main air res tank which was later agreed to be too much and the one tank was removed (can't remember which one though). On all NSE Mk3 based EMUs, the 'B' end had a parcels compartment and the associated isolating switch and indicator, many of which, I presume, have now been removed.
UK trains don't have an A or B end, unless you mean a 2-coach DMU, where the coaches might be lettered A and B
There's no way you could ever say the "A" end would face a particular direction, because trains get turned regularly!I guess you are referring to the platform lettering and numbering at UK stations? So I have moved this thread to the appropriate forum, and clarified the thread title. If I am wrong, then let me know and I'll move it to Traction & Rolling stock, and amend the title accordingly (or you can edit the title yourself by clicking Edit and then Advanced)
The answer will vary depending on what station it is. I think you'd need to give some example stations to be answered, as there is no universal answer.
You can look up any station here: http://www.nationalrail.co.uk/stations_destinations/
At Leeds, most platforms go up to C, and some even to D. So in these cases B is at neither end.
Meanwhile York doesn't have any A, B, C or D distinction. The longest platform face is assigned two seperate platform numbers (3 & 4).
How about point ends ? Where two or more work in conjunction with each other, they're.normally sufficed A, B etc. - the A end usually being nearest to the controlling box, in mechanical areas at least (not sure whether they tend to follow a different convention in other areas.
? Where two or more work in conjunction with each other, they're.normally sufficed A, B etc. - the A end usually being nearest to the controlling box, in mechanical areas at least (not sure whether they tend to follow a different convention in other areas.Question: Aren't both ends of the ELL the 'London end'?
It is a bit confusing without the line ending at a main London terminus in some respects and I guess people might suggest that Shoreditch High St is geographically nearest to central London, however in terms of signalling the numbering runs from north to south. Therefore even if at Dalston Junction the signaller would know that if we refer to an issue at the country end we are referring to the end nearest to Shoreditch High St. The up and down directions hold true for the entire length from north of the river until we meet the London Bridge lines and I guess at it's southern extent (W Croydon and Crystal Palace) these places would certainly be considered the country end of what is a metro line. That's about as 'country' as we get!
The only thing we have to be careful of is that heading down from H&I to CLJ we stay on the down ELL, the down Silwood, the down South London but then we are on the UP Atlantic before switching back to the down Ludgate. Although the signaller should know our direction it would be all to easy to communicate that you are on the down Atlantic when in fact we are on the up.
http://en.wikipedia.org/wiki/British_Rail_Class_377
That's how I found out about them. There seems to be DMCO(A) and DMCO(B).
What's the difference and how are they numbered?
sprinterguy
Veteran Member
On all multiple units that have similar driving vehicles (For example, both are Driving Motor Standards), they are identified as having "A" and "B" ends of the unit to differentiate between vehicles. Looking at the class 150 traction manuals, this even applies to these units which are formed DMSL - DMS.
Naturally the class 153 units, with two cabs in a single carriage, also have "A" and "B" ends to differentiate which is which, also referred to the "No. 1" and "No.2" ends.
Spagnoletti
Member
Just to muddy the water further on diesel electric locos (not sure about AC electrics) the cabs would be designated 1 and 2 and often the sides of the vehicle would be referred to as A and B, due to the larger diesel power units having A and B cylinder banks.
For example when describing a position on a Cl37 you might say faulty <whatever> No.1 end A side.
For example when describing a position on a Cl37 you might say faulty <whatever> No.1 end A side.
Refer to post 3 above with examples of how units are numbered in sequence (at least on class 378).
So have I! The class 455 has something different in the A and B ends, because you're supposed to tell the signalman is the A or B cab faulty. Can't mean different cabs on a single vehicle.
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On diesel locos no1 end is the radiator end, if you are looking at the side and the radiators are on the left then that is the B side.
Great Eastern 360s and 321 can end up turned at Colchester. I think they can also be turned if needed (as can West Anglia 317s and 379s) at Stratford. I don' use the line, so I'm not sure if they try to orient them a particular way (eg 1st class end towards London). On the West Anglia route GA do seem to be keeping the 379s with 1st class towards London, but the 317s are very much assorted (not that it matters so much with the /5 and /8 where 1st class is in the 2nd or 3rd carriage) in direction.
MCR247
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It depends which way round the train is :roll: 'A' and 'B' are given to the individual vehicles, so if the set get turned, 'A' could be facing London or away from London
What if the PTSO is the 3rd car?
On a Bombardier EMU the A end driving car has the computer control systems, the B end just has a remote terminal linked back to the computer in the A car. The A and B driving cars are not interchangeable.
This is pretty well only used for maintenance and troubleshooting, and when letters are also used to describe the arrangement of the cars for passengers it is understandable that the A/B ends are not displayed prominently for fear of causing confusion.
Assuming there is no difference between the ends (e.g. first class at one end only) there is no need for the A/B end to be required to run facing a particular way.
No one would care, nor should they, surely? The only trains where 'which end faces London' are long distance InterCity services, where 1st class is normally at the London end, to save 1st class passengers a longer platform walk. What way round a multiple unit is makes no difference, where the pantograph car is in an EMU matters even less, though it is rather helpful if each unit has one!
The pantograph is useless on a third-rail EMU. Anyway, do you guys know Train Simulator 2014?
What do you expect the signalman to do, even if he does know whether the problem is at A or the B end? Other than for passing messages on to Control, that sort of information is only useful in terms of leading or trailing cabs, and then only really if the train can't be driven or assisted from that end. This thread gets even more bizarre - why can't a single vehicle have two ends?
Basically, you can make your own scenarios for routes, I'm doing the 1F09 right now and I need help with train placements. Can a 360 run this service? How many cars are there usually? And which end faces London: A or B? Note that the last question is about the 11th of December service.
sprinterguy
Veteran Member
If by 1F09 you mean the 06:40 Braintree to Liverpool Street, then it is typically formed of 3 x class 321 units (12 carriages).
Ok, but CAN a 360 run it? I've heard they don't run to Southend. Don't know why.
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Anyway, how are the 360s and 377s numbered? Is there any difference between A and B ends there?
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