Class number categories

[D365]

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.

Because rolling stock engineers treat bi-modes as electro-diesels, rather than diesel-electric.

 

[150249]

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?

What type of train do the Tyne and Wear metro units actually come under exactly? To me they've always been electric Pacers but that isn't very technical.

 

[norbitonflyer]

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.

Bimodes and diesels can go anywhere. Only straight electrics are tied to the wires.

However, bimode Classes 73, 74, 88 and 99 are/were/will be classified as electric locomotives, despite being able to operate off the juice.

Likewise bimode 755, 756 etc are classified in the 7xx series when a range in the 6xx series would better reflect their capabilities. (and the 777s, which have no diesel capability, are already in that series)

 

[D365]

Bimodes and diesels can go anywhere. Only straight electrics are tied to the wires.

However, bimode Classes 73, 74, 88 and 99 are/were/will be classified as electric locomotives, despite being able to operate off the juice.

Likewise bimode 755, 756 etc are classified in the 7xx series when a range in the 6xx series would better reflect their capabilities. (and the 777s, which have no diesel capability, are already in that series)

All of the examples that you have listed are, by design, primarily electric vehicles.

 

[swt_passenger]

What type of train do the Tyne and Wear metro units actually come under exactly? To me they've always been electric Pacers but that isn't very technical.

They’re fairly ordinary DC EMU traction tech. I suppose 5xx is quite appropriate for the existing stock. Although their power comes from 1500 V DC OHLE, on each articulated unit there are two traction packages at 750V DC connected in series...

 

[DanNCL]

I could be mistaken, but my understanding of the numbering for Tyne & Wear Metro units was that 599xxx were unit numbers introduced with the Sunderland extension, and 994xxx were vehicle numbers originally for delivery in 1979-1981 over the national network but retained beyond that in case any further movement over the national network was required. I’m happy to be corrected if I’m mistaken.

What type of train do the Tyne and Wear metro units actually come under exactly? To me they've always been electric Pacers but that isn't very technical.

They’re fairly ordinary DC EMU traction tech. I suppose 5xx is quite appropriate for the existing stock. Although their power comes from 1500 V DC OHLE, on each articulated unit there are two traction packages at 750V DC connected in series...

The closest relation to the Tyne & Wear Metro units would be German Stadtbahn vehicles, although there are a significant number of differences and the Metro units were built in the UK to a British design.

 

[XAM2175]

Bimodes and diesels can go anywhere. Only straight electrics are tied to the wires.

Okay, but distinguishing those abilities isn't actually a stated objective of the classification scheme.

Likewise bimode 755, 756 etc are classified in the 7xx series when a range in the 6xx series would better reflect their capabilities. (and the 777s, which have no diesel capability, are already in that series)

Wait, what? You want to put fleets that meet the exact criteria for Classes 750-799 into the range for single-mode units? You've lost me completely.

I remind you that the current definition for 600-699 is "multiple-unit sets powered by diesel and/or other fuels", while 750-799 is "multi-mode multiple-unit sets" with multi-mode being defined as having two or more sources of traction power, at least one of which is external.

What type of train do the Tyne and Wear metro units actually come under exactly? To me they've always been electric Pacers but that isn't very technical.

They’re fairly ordinary DC EMU traction tech. I suppose 5xx is quite appropriate for the existing stock. Although their power comes from 1500 V DC OHLE, on each articulated unit there are two traction packages at 750V DC connected in series...

Neither of the 400-499 or 500-599 ranges have ever included a stipulation on voltage or current delivery; they've always been for all EMUs taking a DC supply.

 

[swt_passenger]

Neither of the 400-499 or 500-599 ranges have ever included a stipulation on voltage or current delivery; they've always been for all EMUs taking a DC supply.

I was only trying to quickly explain how their traction was arranged, in response to the earlier poster’s question, rather than trying to justify a particular class number.

 

[YorksLad12]

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

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.

 

[antharro]

Wasn't expecting two pages of replies. Much more involved than I had thought! Seems I have some reading up to do. Thanks!

 

[Flying Scott]

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?

I could be mistaken, but my understanding of the numbering for Tyne & Wear Metro units was that 599xxx were unit numbers introduced with the Sunderland extension, and 994xxx were vehicle numbers originally for delivery in 1979-1981 over the national network but retained beyond that in case any further movement over the national network was required. I’m happy to be corrected if I’m mistaken.

Thank you @swt_passenger and @DanNCL for your replies. What you have suggested makes sense, in that they were Class 994 for delivery purposes and later reclassified as Class 599, or given vehicle numbers in the 994xxx range.

On a similar theme, I recall reading in an industry publication that the Parry People Mover vehicles were originally allocated Class 999 for testing purposes, before being reclassified as Class 139 at a later date. I don't know if this is the same case as above.

 

[Western Sunset]

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

Dewey is a pain when it comes to classifying transport material. Regards from another MCLIP.

 

[Tester]

Dewey is a pain when it comes to classifying transport material. Regards from another MCLIP.

387, 625 and 656 for railways. I never worked out why but just went to all three!

 

[Glaswegian]

As to duplication, have there ever been clashes between 08xxx locomotives and 8xxx carriages?

 

[themiller]

387, 625 and 656 for railways. I never worked out why but just went to all three!

It’s a long time ago but is one engineering whilst another is transport?


Edit: checked in my local library and confirmed on Wikipedia.

300 is Social Sciences, 380 is Commerce, Communications and Transportation, 385 is Railway Transportation.
600 is Technology, 620 is Engineering, 625 is Engineering of Railways.
656 isn’t used for railways.

 

[norbitonflyer]

As to duplication, have there ever been clashes between 08xxx locomotives and 8xxx carriages?

No, because the 8xxx series was never used in the BR series. (Although some SR emu vehicles were numbered in the S8xxxS series)

(Carriages built to pre-nationalisation designs kept their original numbers (or were added to the respective company's numbering sequence), but with a suffix. They also had regional prefixes. So SC1234M would be an ex LMS vehicle allocatedto the Scottish Region.

When renumbering of coaching stock was done in the 1980s to remove duplication - e.g 50xxx dmus renumbered as 53xxx because of the Class 50s - carriages in the 14xxx, 15xxx and 16xxx series were also renumbered, into the 17xxx and 7xxx series, as some SR EPB carriages were still extant in the S1xxxxS etc series.

== Doublepost prevention - post automatically merged: 22 Aug 2022 ==

Wait, what? You want to put fleets that meet the exact criteria for Classes 750-799 into the range for single-mode units? You've lost me completely.

No. I'm suggesting that the entire 7xx range should have been allocated to strauight electrics, and bimodes should have been allocated the 650-699 range.

You will note that 8% of the new range 700-749 allocated to straight electrics has already been used, (classes 700, 701, 707, 710, 717, 720, 730, 745), not counting the anomalous Class 777, whereas the 6xx range allocated to self-powered units, which is twice as big, has to date, a single unit, No 614209.

(Note also that only half the 3xx range was ever used: the fifty unused classes are:
300, 324, 327-330, 335-344, 346-349, 351-356, 358,359, 361-364, 366-369, 371, 372, 381-384, 386, 388, 389, 391-394, 396.
(Technically 301 was never used either, as the AM1 Lancaster-Morecambe units were withdrawn in 1966, before TOPs existed)


Putting the bimodes between the diesels and the straight electrics would have also had a sort of logic to it.

 

[krus_aragon]

You will note that 8% of the new range 700-749 allocated to straight electrics has already been used

With the 8 classes listed, I make that 8% of the 700-799 range, or 16% of 700-749.

 

[Glaswegian]

No, because the 8xxx series was never used in the BR series. (Although some SR emu vehicles were numbered in the S8xxxS series)

(Carriages built to pre-nationalisation designs kept their original numbers (or were added to the respective company's numbering sequence), but with a suffix. They also had regional prefixes. So SC1234M would be an ex LMS vehicle allocatedto the Scottish Region.

When renumbering of coaching stock was done in the 1980s to remove duplication - e.g 50xxx dmus renumbered as 53xxx because of the Class 50s - carriages in the 14xxx, 15xxx and 16xxx series were also renumbered, into the 17xxx and 7xxx series, as some SR EPB carriages were still extant in the S1xxxxS etc series.

== Doublepost prevention - post automatically merged: 22 Aug 2022 ==


No. I'm suggesting that the entire 7xx range should have been allocated to strauight electrics, and bimodes should have been allocated the 650-699 range.

You will note that 8% of the new range 700-749 allocated to straight electrics has already been used, (classes 700, 701, 707, 710, 717, 720, 730, 745), not counting the anomalous Class 777, whereas the 6xx range allocated to self-powered units, which is twice as big, has to date, a single unit, No 614209.

(Note also that only half the 3xx range was ever used: the fifty unused classes are:
300, 324, 327-330, 335-344, 346-349, 351-356, 358,359, 361-364, 366-369, 371, 372, 381-384, 386, 388, 389, 391-394, 396.
(Technically 301 was never used either, as the AM1 Lancaster-Morecambe units were withdrawn in 1966, before TOPs existed)


Putting the bimodes between the diesels and the straight electrics would have also had a sort of logic to it.

Thank you for pointing out that there were no 8xxx carriages. I should have checked.
However, in Locomotives and Coaching Stock 1985 there are a locomotive 03063 and a carriage 3063. This appears to show that it is permissible for two vehicle numbers to differ only by the presence or absence of a leading zero.

 

[David Goddard]

Fascinating thread, great for any of us who thrive on anything to do with numbers, and stimuation for anyone with OCD, or who thinks deeply into "what should have happened, what could have happened, and what should now happen".
There was a post on another platform a few months ago about what could have been different and brought up some interesting comments. Then we get into subclasses and thats another realm all together!

 

[GusB]

I thought there was a long-standing agreement that TOPS classes would never ever make sense and that it is utterly pointless to try!

Don't get me wrong, I like things to be in proper sequences as much as anyone else, but there does come a time when you have to admit defeat.

 

[D365]

I thought there was a long-standing agreement that TOPS classes would never ever make sense and that it is utterly pointless to try!

Don't get me wrong, I like things to be in proper sequences as much as anyone else, but there does come a time when you have to admit defeat.

And I’ve realised it doesn’t matter anyway. Other than diagramming, the only use for TOPS classes is for ops and engineering staff to identify vehicles. It doesn’t really matter what category, as long as each number is unique and distinct.

 

[norbitonflyer]

With the 8 classes listed, I make that 8% of the 700-799 range, or 16% of 700-749.

Oops, yes of course. Which re-inforces my argument