BR multiple unit numbering conventions

[Wilts Wanderer]

Sorry for being a pain in the proverbial, has anyone got a summary list of coach/vehicle numbers of 1st Generation Modernisation Plan DMUs in numerical order of class type please? I don't think I've seen one on here before!

Chris Williams

https://www.railcar.co.uk/numbering/vehicles/

This site may be of use to you? It’s a wealth of info / photos / history.

 

[frankmoh]

According to Wikipedia (I know, I know!) class 300 was reserved for a proposed parcels conversion of some class 307s. It doesn't say when this was proposed.

Would that not be the Propelling Control Vehicle? Or would that not get a TOPS class in the same way the DVT doesn't get one?

 

[norbitonflyer]

I seem to recall something about it being "improper" to have a Southern Region train have a double zero at the start of its 4-digit number. For instance, the 4BEPs had the TOPS class of 410 but had numbers starting from 70xx instead of 00xxx. There was also the Class 480 8VAB (VEP reformation), and the 430 (one of the TOPS classifications for the 4REP).

The 7xxx (and 6xxx) series were first used in the 1950s, a good ten years before TOPS started and 25 before SR units carried them. (And severak SR classes originally had TOPS classes ending in zero)
By chance, the 6S, 2HALs, 5BELs and 4EPBs had 4 digit numbers whise first digit corresponded with the last digit of the TOPs class (201, 402, 403 and 415) and only the last of those were around long enough to get TOPS numbers. Everything else had to be renumbered, eg the 4VEPs (423) went from 77xx to 30xx.
In addition, the buffet units (classes 410, 420, 430) were reclassified 412, 422, 432 to allow them to carry 4digit numbers without the need for a leading zero.

 

[43096]

Would that not be the Propelling Control Vehicle? Or would that not get a TOPS class in the same way the DVT doesn't get one?

I think the proposal was for a full conversion of 307s to parcels units, not the PCV conversion. Presumably overtaken by events (wisely!) with the Class 325 build and the PCV conversion (which didn't have a EMU TOPS class - they were NPCCS* like DVTs, BGs, GUVs etc).

* Non-Passenger Carrying Coaching Stock

 

[norbitonflyer]

Sorry for being a pain in the proverbial, has anyone got a summary list of coach/vehicle numbers of 1st Generation Modernisation Plan DMUs in numerical order of class type please? I don't think I've seen one on here before!

Chris Williams

I took those data from Hugh Longworth's "British Railways First generation DMUs" which does list the DMUs in their individual classes, complete with original unit forrmations

 

[Falcon1200]

The GE units didn't touch the WCML, and in turn were not connected to Glasgow, thus it didn't matter that there was an 001 on all three.

I got my first Ian Allan Combined Volume and was initially confused by the EMUs that looked like mine with similar numbers, of course they were the AM5 units whereas “mine” were AM4.

Getting into conversation with another spotter at Bletchley in the mid-1970s, I realised that he was confusing the LMR AM10/310 set numbers with the ER AM6/306 sets; And marking his Electric Locos and Units book accordingly! I quickly put him right.

 

[Sun Chariot]

Getting into conversation with another spotter at Bletchley in the mid-1970s, I realised that he was confusing the LMR AM10/310 set numbers with the ER AM6/306 sets; And marking his Electric Locos and Units book accordingly! I quickly put him right.

That's quite a "miss"! I admit my 1970s youthfulness initially thought the LMR 312 quartet were a subclass of the 31Os.

Totally OT - the "hiss .. sigh" of 310 and 312 brakes, then the "tatta-tatta-tatta" of driving trailer air compressor - those two sounds to me are the most distinctive and memorable of my latter 1970 and 1980s.

 

[Helvellyn]

What I found fascinating was the way that the Southern Region retained four digit unit numbers for the EMU fleet as part of TOPS but in a very logical way linked to the Classes and unit use. Buffet units had been Class 4x0, but because this wouldn't support a four digit unit number they became 4x2.

This we got:

• 4x1 - Express units
• 4x2 - Express units with Buffet
• 4x3 - 4-car Outer Suburban
• 4x4 - 2-car Outer Suburban
• 4x5 - 4-car Inner Suburban
• 4x6 - 2-car Inner Suburban
• 4x7 - miscellaneous
• 4x8 - Trailer units
• 4x9 - Luggage Vans

To then give an example:

• 11xx - Unrefurbished Phase 1 4-CIG (421)
• 12xx - Unrefurbished Phase 2 4-CIG (421)
• 13xx - Refurbished Phase 2 4-CIG (421) with modified field weakening ('Greyhound' units)
• 14xx - 3-CEP (reduced from 4-cars)
• 15xx/16xx - Refurbished 4-CEP (411, though in hindsight using 15xx for Phase 1 units and 16xx for Phase 2 units might have been better)
• 17xx - Refurbished Phase 1 4-CIG (421)
• 18xx - Refurbished Phase 2 4-CIG (421)
• 19xx - Refurbished 4-REP, later 6-REP (Class 431); then reused for Phase 1 4-CIGs fitted with Mk 6 Motor bogies recovered from the REPs when they were withdrawn.

 

[norbitonflyer]

What I found fascinating was the way that the Southern Region retained four digit unit numbers for the EMU fleet as part of TOPS but in a very logical way linked to the Classes and unit use. Buffet units had been Class 4x0, but because this wouldn't support a four digit unit number they became 4x2.

Indeed, but every slam door unit except the 413s and 415s had to be renumbered to achieve this. (The 413s were given approraite 3xxx numbers when concverted from 414s, and the 455s were numbered in the 5xxx series from the start)

The third digits were generally chosen to avoid duplication between old and new numbers, but there were for a while two 5705s in circulation (a 416 and a 455)

4xx (4TC) to 80xx
3xxx (4REP) to 2xxx
56xx, 57xx (2EPB) to 6xxx
6xxx (2HAP) to 4xxx
70xx (4BEP, 4 BIG) to 2xxx
71xx-74xx (4CEP, 4BIG) to 1xxx
77xx,78xx (4VEP) to 3xxx

== Doublepost prevention - post automatically merged: 6 Oct 2025 ==

When these were new, the GN units were 312001-026 and the GE units were 312101-119. These later became 312701-726 and 312781-799.

Although steps were taken to avoid the last three digist of the GN 312s duplicating other Eastern Region units, the 313s did duplicate the 306s.

Fortuitiously the 312/2s last three digits did not duplicate any other LMR units, which were in the 0xx range (classes 304, 310) and 1xx range (class 501). the 1xx range was not reused even when classes 317, 321 and 323 appeared (317/3, 321/4, 3232xx), even though the 501s were long gone by then