Was there a system to BR's original diesel numbering?

[Karl]

Never used that but class 50s were D400ers to us.

Yes I was going to mention the very same as a young Preston spotter when they were first introduced in the late 60's.

 

[Snow1964]

"Original" diesel numbering was actually in the steam loco series - 1xxxx was diesels and 2xxxx was electrics. It was given up as the first pilot scheme main line diesels came in but there were a lot of diesel shunters by then, some of which then were not repainted/renumbered for years afterwards. The regular "Class 08" at the goods depot at the east end of Bristol TM, still painted black, was something like 13137 well into the 1960s I recall.

I think you will probably smile when I say that for some of us the reverse is true - what do I know this "Class 29" as?

Many years ago someone told me the reason why the big locos (type 4) came first with numbers D1-D1999 then shunters, then the mid sized locos was a hangover from the steam numbering scheme. They simply replaced original 1 with D so if had a shunter numbered 12345 It became D2345 etc. The mainline diesels started at 10000, the diesel shunters at 12000, bigger shunters at 13000

Quite simply there was a handful of prototypes mainline locos, then lots of shunting locos ordered before the general move to diesel following the modernisation plan. The mid size diesels didn’t exist before 1957 so no one had needed to use the 14000-19999 number ranges upto then, which is why D4000-D9999 could be used for new diesel classes
EDIT (just remembered the Bulleid shunters we’re numbered 150xx so some of 14000-19999 sequence had been used)

The nationalisation number scheme kept GWR numbers (as the were cast not painted), allocated 1xxxx to diesel locos, 2xxxx to electric locos, 3xxxx to Southern by adding 30000 (with the Bulleid alpha-numeric made numeric), then LMS with 40000 added, LNER with 60000 added and BR standard classes starting 70000

The one part I have never understood is what happened to the low 2xxxx numbers, we know the new electric locos ended up 26xxx and 27xxx (years before the ac locos started with E prefix), but why 26xxx and not say 21xxx onwards (Southern railway had built 3 electric locos in 1940s which became 20001-3)

 

[xotGD]

One thing that has puzzled me is why for classes 25 and 26 the sub-classes are just numbered in one sequence, unlike other classes. I.e. why didn't 26/1s start at 26101?

 

[Taunton]

Many years ago someone told me the reason why the big locos (type 4) came first with numbers D1-D1999 then shunters, then the mid sized locos was a hangover from the steam numbering scheme. They simply replaced original 1 with D so if had a shunter numbered 12345 It became D2345 etc. The mainline diesels started at 10000, the diesel shunters at 12000, bigger shunters at 13000

It was actually pretty random. The small shunters, of which a good proportion of the total were built quite early on and had these original numbers, were completely renumbered and the sequence changed. Some of the older larger shunters were never renumbered until withdrawal and ran right into the early 1970s as such.

 

[Fleetwood Boy]

I was wondering if we could work out when the list of classes was first created as that might help us work out which odd locos were still around to explain the odd number gaps?

I’d say the clues are: Firstly, the re-engining of Classes 21 and 30 was underway but not completed (hence a need for both 30 and 31). Secondly, some - but not all - of the various EE shunter designs were still in service, hence Classes 10, 11 and 12 but with some of the variants of the 08 having already gone, along with the GW and LNER ordered shunters? And thirdly (assuming DMUs we’re classified at the same time) the Derby and Metro Cammell lightweights didn’t get class numbers.

If we can date the list then we might be able to better explain the gaps, which as well as affecting the Type 3s also seem to affect the Type 1s (which seems even harder to explain)?

Slightly off topic, but class 100 has always puzzled me. The DMU numbering is otherwise quite neat and explicable but no other MU numbering sequence started at x00. Did the just forget the Gloucester units or perhaps expected them to be withdrawn early?

 

[gg1]

The one part I have never understood is what happened to the low 2xxxx numbers, we know the new electric locos ended up 26xxx and 27xxx (years before the ac locos started with E prefix), but why 26xxx and not say 21xxx onwards (Southern railway had built 3 electric locos in 1940s which became 20001-3)

The prototype EM1's LNER number was 6000 so it's BR numbering followed the same principle as steam loco renumbering of adding an extra digit at the start.

When the EM2s came along it's logical they'd have a higher number than EM1s being of a similar design but newer and more powerful, hence 27xxx (this bit is just a theory but it fits the facts).

The SR had adopted an alpha numeric classification for their electric locos so a completely new number was necessary, although even here the last digit was retained, CC1 became 20001 and CC2 became 20002.

 

[delt1c]

Most interesting thing I find is that The SR Electrics were class 70 (never carried) , however the classification was reused later for the current class 70's

 

[randyrippley]

Most interesting thing I find is that The SR Electrics were class 70 (never carried) , however the classification was reused later for the current class 70's

I believe the rule was a class had to be totally extinct (with none in preservation) for 10 years before a class number could be reused.
Thats why 41 and 43 were reused for the HST fleet, but not 42 as there are still some left

 

[hexagon789]

Slightly off topic, but class 100 has always puzzled me. The DMU numbering is otherwise quite neat and explicable but no other MU numbering sequence started at x00. Did the just forget the Gloucest

There are the Class 700 and Class 800 units , but I agree it's certainly a bit more unusual given the fact the other number ranges start at x01. There is no reason why they can't start at x00 though.

 

[Helvellyn]

Most interesting thing I find is that The SR Electrics were class 70 (never carried) , however the classification was reused later for the current class 70's

Class 80 was allocated to the prototype AC loco converted from Gas Turbine prototype 18100.

I was wondering if we could work out when the list of classes was first created as that might help us work out which odd locos were still around to explain the odd number gaps?

I’d say the clues are: Firstly, the re-engining of Classes 21 and 30 was underway but not completed (hence a need for both 30 and 31). Secondly, some - but not all - of the various EE shunter designs were still in service, hence Classes 10, 11 and 12 but with some of the variants of the 08 having already gone, along with the GW and LNER ordered shunters? And thirdly (assuming DMUs we’re classified at the same time) the Derby and Metro Cammell lightweights didn’t get class numbers.

If we can date the list then we might be able to better explain the gaps, which as well as affecting the Type 3s also seem to affect the Type 1s (which seems even harder to explain)?

Well the Class 80 mentioned above was withdrawn in 1968.

The AM1 EMUs used on the Lancaster-Morecambe route would have been Class 301, but were withdrawn in 1966. It's not clear if they actually were allocated that number given that switching AM2-AM11 to Class 302-311 was probably the simplest way of reclassifying the AC EMUs.

Now for a seemingly messy classification look at the London Midland Region DC EMUs in the 50x series:

• Class 501 - 1955-56 built units for use on LMR DC Lines services (Richmond/Watford - Broad Street; Watford - Euston; and Watfor - Croxley Green).
• Class 502 - 1939-41 built units for use on Liverpool Exchange - Ormskirk/Southport services.
• Class 503 - 1938/1956 built units for use on Liverpool Central - West Kirkby/New Brighton/Rock Ferry services.
• Class 504 - 1959 built 1200 V DC units for use on the Manchester Victoria - Bury route.
• Class 505 - 1931 built 1500 V DC units for use on the Manchester Picadilly - Altrincham route.
• Class 506 - 1950 built (1938 ordered) 1500 V DC units for use on the Manchester - Glossop - Hadfield route.

Logic seem to be lowest to highest voltage, working North to South, with third rail then overhead units.

The Class 50x series makes no allowance for the Tyneside EMUs. Services between Newcastle Central and South Shields switched to DMU operation in 1963, so the fact the 15 1953-54 built 2-EPBs that became 5781-5795 as part of Class 416 (after the 79 SR units of 5701-5779) suggests that reclassifications weren't planned that far back. (There was also MLV 68000, that didn't have a battery but which was withdrawn on Tyneside)

However, the 64 1938 LNER built units lasted on Tyneside until 1967 and also didn't get a classification in the 50x series. So that is what makes me doubt if the AM1s were ever officially Class 301 given that they were withdrawn in 1966.

 

[randyrippley]

Well the Class 80 mentioned above was withdrawn in 1968.

stored 1961, withdrawn 1968, scrapped 1972 - before the renumberings. Adds credence to the theory that the pioneer diesels were given class numbers