Class number categories

[antharro]

I've been trying to figure out the categories for class numbers and could use a little help!

As far as I know (with examples):

Class 1xx: DMU (150, 153, 158)
Class 2xx: DEMU (221, 222, 230)
Class 3xx: EMU, OHLE (313, 315, 317)
Class 4xx: EMU, 3rd Rail (442, 444, 450)
Class 6xx: Hydrogen (600, 614)

Here's where my knowledge falls apart a bit.
Class 5xx: EMU, 3rd Rail (507, 508)
Class 7xx: EMU, 3rd Rail (701, 707)
Class 7xx: EMU, OHLE (720, 745)
Class 8xx: EMU (long distance), OHLE (800, 801, 802)

Given 507 and 508 are 3rd rail EMU commuter trains, why are they not classed in the 4xx category? Alternatively, why are 455s not 510s as they were at one point intended to be? Same for 7xx 3rd Rail, surely they should be 4xx, and 7xx OHLE should be 3xx?

If the aim is to separate trains by their intended use, then it would seem that a lot of renumbering would need to happen; for example, separating 450s and 455s from 444s.

Am I missing something or is the numbering system somewhat confusing?

 

[swt_passenger]

As I understand it:
3xx are dual voltage or AC EMU
4xx are DC EMU normally used in the former Southern Region.
It’s arguable that 450 and 444 could have been numbered in the 3xx range as they are just as AC ready as many Electrostars.
5xx originally meant DC EMU “not used in the former Southern Region”
6xx is an available but hardly used range, for any additional DMUs or other self powered units, eg Hydrogen.
700-749 are dual voltage or AC Emus.
Even 701 and 707 are built as dual voltage, they just don’t have pantographs fitted. There is no obligation to use these numbers, Crossrail stayed with 345, on the same basis I believe SWR could have put their new units in the 4xx range if they’d wanted to.
750-790 are for various bi-modes. It is thought 777s are not correct for this relatively recent split of the 7xx range.
8xx are defined as high speed, (125 mph), fixed formation trains, whether EMU, DEMU or Bi-mode. There hasn’t been a diesel only version, but it’s not impossible.

The 7xx range was not a replacement for 3xx and 4xx, it was to provide extra capacity and flexibility. There’s always been a time limit allowing class numbers to be recycled anyway, another argument is they could have just recycled old class numbers rather than starting new ranges.

 

[XAM2175]

I've been trying to figure out the categories for class numbers and could use a little help!

As I understand it:

The policy on numbering has changed quite a bit over time. This is a good place to start:

British Rail locomotive and multiple unit numbering and classification - Wikipedia

en.wikipedia.org

The current policy is contained in Rail Industry Standard RIS-2453-RST, which was issued in December 2017:

Section A.3.1 (Table 7) Multiple unit / fixed formation sets

Rail Vehicle Group	Class Identifier Range
Diesel-mechanical / diesel-hydraulic multiple-unit sets	100 - 199
Diesel-electric multiple-unit sets	200 - 299
Diesel and / or other fuels multiple-unit sets	600 - 699
DC electric multiple-unit sets	400 - 599
AC and AC / DC electric multiple-unit sets	300 - 399 and 700 - 749
Multi-mode multiple-unit sets (*1)	750 - 799
High-speed multiple-unit / fixed-formation sets (*2)	800 - 899
Infrastructure maintenance / non-passenger multiple-unit / fixed-formation sets	900 - 999

*1 = where a multi-mode unit is one with two or more sources of traction power, of which at least one is external to the unit
*2 = where a high-speed unit is one capable of operating at speeds above 190 km/h (120 mi/h)

If the aim is to separate trains by their intended use, then it would seem that a lot of renumbering would need to happen; for example, separating 450s and 455s from 444s.

Obviously, units already allocated class numbers did not have them changed to comply with the new standard.

Same for 7xx 3rd Rail, surely they should be 4xx, and 7xx OHLE should be 3xx?

700-749 is a valid range for AC-only multiple units, as well as those that are dual-voltage (even if only technically so, like the 701s and 707s).

5xx originally meant DC EMU “not used in the former Southern Region”

This distinction no longer officially exists, but fans of it will be glad to see that the new Tyne and Wear Metro units are going in to Class 555.

It is thought 777s are not correct for this relatively recent split of the 7xx range.

Regardless of how correct the assignment was or wasn't at the time, it is now technically suitable as the full fleet is being fitted with traction batteries.

Am I missing something or is the numbering system somewhat confusing?

The key lesson is that the standard has never been perfectly observed. People who demand unwavering logic are advised to not look too closely

 

[150249]

If the aim is to separate trains by their intended use, then it would seem that a lot of renumbering would need to happen; for example, separating 450s and 455s from 444s.

We can't renumber them!
Everyone loves 444044!

 

[Razorblades]

There is an additional reason why many 3xx xxx can't be used for units, which is that several wagon series already occupy the range. Hence why the 700 series for units was started.

 

[Flying Scott]

I've been trying to figure out the categories for class numbers and could use a little help!

As far as I know (with examples):

...

Am I missing something or is the numbering system somewhat confusing?

The Class 9xx range has been allocated to departmental multiple units, infrastructure maintenance vehicles such as Network Rail's test trains, along with on track plant and other associated vehicles.

This distinction no longer officially exists, but fans of it will be glad to see that the new Tyne and Wear Metro units are going in to Class 555.

For completeness, the existing units have been given the TOPS allocation Class 599. I have also seen reports that the units are also in Class 994, but I cannot find anything to confirm this.

 

[XAM2175]

There is an additional reason why many 3xx xxx can't be used for units, which is that several wagon series already occupy the range. Hence why the 700 series for units was started.

No, multiple-unit numbers are separate from vehicle numbers. Case in point - Class 385/0 units have DMSL vehicles numbered 444001 to 444046!

It's locomotives, wagons, passenger coaches, and multiple-unit vehicles that come from the same numbering series and thus can't repeat. For example, you wouldn't be able to number a locomotive 68801 because that's already used for a Class 390 trailer.

For completeness, the existing units have been given the TOPS allocation Class 599. I have also seen reports that the units are also in Class 994, but I cannot find anything to confirm this.

Oh really? I wonder if we can find anybody to have a peek in the Rolling Stock Library for us...

 

[Ken H]

So I order some new trains. who gives me a class number for them?

is there any impediment why they cant use old class numbers? Could we have a new class 101, for instance?

 

[themiller]

It's locomotives, wagons, passenger coaches, and multiple-unit vehicles that come from the same numbering series and thus can't repeat. For example, you wouldn't be able to number a locomotive 68801 because that's already used for a Class 390 trailer.

But their EVNumbers would be different.

 

[XAM2175]

But their EVNumbers would be different.

Correct, but any domestic system that relies only on the GB vehicle number wouldn't be able to handle the duplication unless it also checked the TOPS carkind or something similar.

 

[315801]

If I may add here, the 5xx series also included the 504, 505 & 506 units aswell.

The class 504s were 1,200 volts dc side contact 3rd rail whereas the class 505 & 506 units were 1,500 volts dc overhead powered.

 

[norbitonflyer]

For completeness, the existing units have been given the TOPS allocation Class 599. I have also seen reports that the units are also in Class 994, but I cannot find anything to confirm this.

That would be consistent with them carrying numbers in the 4xxx range (anyone know why?) The new ones, being class 555, might be expected to be numbered in the 5xxx range.

 

[Western Sunset]

For completeness, I suppose you could include locos as 0xx.

 

[TT-ONR-NRN]

At some point they’ll need to start the Class 1000s as more units are introduced.

 

[zwk500]

At some point they’ll need to start the Class 1000s as more units are introduced.

Or re-issue the older numbers. If there's preserved units blocking them they could be given a different TOPS number in the same way heritage steam and pre-TOPS diesel locos are.

 

[TT-ONR-NRN]

Or re-issue the older numbers. If there's preserved units blocking them they could be given a different TOPS number in the same way heritage steam and pre-TOPS diesel locos are.

I just think that would be enormously confusing.

 

[zwk500]

I just think that would be enormously confusing.

1. You've rather missed the bus with trying to Keep TOPS numbering from being enormously confusing and 2. We've had classes re-assigned before, mostly of prototypes or limited numbers but the two class 43s were in full service (warships and HSTs).

 

[Western Sunset]

Class 70 - ex-SR DC electric locos
Class 70 - Type 5 Freightliner and Colas diesel locos

 

[D365]

At some point they’ll need to start the Class 1000s as more units are introduced.

Adding an extra digit will cause far more problems than it fixes.

 

[150249]

At some point they’ll need to start the Class 1000s as more units are introduced.

They could bring in more 5xxxxx units

 

[TT-ONR-NRN]

They could bring in more 5xxxxx units

Or 9xx. They have to realise reserving 100 class numbers for departmental use, almost all of which are conversions anyway, isn't practical.
Anyway, I thought Class 900 would be perfect for the HS2 series. 800 is for the new generation of high speed stock - 125mph as always, and HS2 is something entirely ground-breaking and new - so going 100 up from 800 seems fair enough.

Class 900 - the first of the 9xx "Very High Speed" series and the first for HS2. Hopefully soon to be followed by a captive double decker 901, but that's another discussion

 

[Speed43125]

Or 9xx. They have to realise reserving 100 class numbers for departmental use, almost all of which are conversions anyway, isn't practical.
Anyway, I thought Class 900 would be perfect for the HS2 series. 800 is for the new generation of high speed stock - 125mph as always, and HS2 is something entirely ground-breaking and new - so going 100 up from 800 seems fair enough.

Class 900 - the first of the 9xx "Very High Speed" series and the first for HS2. Hopefully soon to be followed by a captive double decker 901, but that's another discussion

My understanding was that the 850-899 range was reserved for HSR trains.

 

[32625]

You also have the Sheffield tram-train as class 399 and the TFW ones in build as class 398.

 

[150249]

You also have the Sheffield tram-train as class 399 and the TFW ones in build as class 398.

You can't go any further though with a class 397 as they already exist

 

[norbitonflyer]

At some point they’ll need to start the Class 1000s as more units are introduced.

There are plenty of gaps in the lower series. And some numbers have been re-used, e.g 22, 41, 43, 70, 140-144, 150.

It seems odd to me that bimodes, which can go anywhere, are not classified in the same series as diesels, which can also go anywhere, but with straight electrics, which can't.

 

[YorksLad12]

Speaking as a Chartered Librarian (really)... TOPS is no worse than Dewey Decimal, in many ways.

More relevantly, class 139 was assigned a long time after the 14x and 15x sets were, and there are plenty of gaps in the sequence that could be filled. Also, the new class 331s about 20 years after the 332/333/334 units.

I wouldn't put it past some idiot to say that the HS2 sets should be class 900/901, but 85x should cover them. I've mentioned before that there's an almost perfect numbering sequence in the 80x series, with bi-modes being even and electric-only being odd. But then someone broke the sequence...

 

[XAM2175]

At some point they’ll need to start the Class 1000s as more units are introduced.

There are plenty of gaps in the lower series. And some numbers have been re-used, e.g 22, 41, 43, 70, 140-144, 150.

Yes, there's really no need what with the gaps all over the place. It might not be so easy to group related fleets into the most perfectly logical range in future, but that's only really a problem for enthusiasts.

It seems odd to me that bimodes, which can go anywhere, are not classified in the same series as diesels, which can also go anywhere, but with straight electrics, which can't.

How do you figure this? Bi-modes that include an external source of traction power (so diesel plus AC overhead, for example) have their own range of 750-799, where as bi-modes with two internal sources (such as diesel plus battery) would be numbered into the 100-199 or 200-299 based on their powertrain configuration. Hydrogen plus battery would similarly end up in 600-699.

EDIT: I've just realised you're presumably referring to the bi-mode AT300s, in which case yes it does appear that the high-speed designation takes precedence over the multi-mode designation. I'd be inclined to argue that this is fair given that those classes are clearly intended to use the overhead as the primary traction power, but at the moment though we can't be entirely sure that isn't just a stylistic choice for Class 800 derivatives.

My understanding was that the 850-899 range was reserved for HSR trains.

I wouldn't put it past some idiot to say that the HS2 sets should be class 900/901, but 85x should cover them.

The current standard defines the entire 800-899 range as being for high-speed units, unless something's changed recently?

 

[swt_passenger]

The Class 9xx range has been allocated to departmental multiple units, infrastructure maintenance vehicles such as Network Rail's test trains, along with on track plant and other associated vehicles.



For completeness, the existing units have been given the TOPS allocation Class 599. I have also seen reports that the units are also in Class 994, but I cannot find anything to confirm this.

Nobody has ever found any hard evidence for “Class 994”. I’ve just searched back through a few old threads and I’d describe it as highly doubtful. Then there’s a post from 2015 stating quite firmly that they were initially 599, but subsequently changed to 994. I suspect it was a pseudo class used only to enter the consists into TOPS for their original delivery runs, (hauled over BR), but it was never a real class number in the rolling stock library. I think everyone is in agreement that they don’t carry painted 6 digit numbers, inside or outside.

Didn’t they do something similar with a temporary class number for the main line delivery moves of stuff like the LU S stock?

 

[YorksLad12]

The current standard defines the entire 800-899 range as being for high-speed units, unless something's changed recently?

Nothing's changed. Until it changes, because someone didn't get the memo or read the manual

 

[XAM2175]

Nothing's changed. Until it changes, because someone didn't get the memo or read the manual

So where'd the 850-899 thing come from?