TOPS class numbers

[rodent279]

Following on from the recent discussion about why class 86/1's & 86/2's were not the other way round, this leads me to another question, piffling trivia if you will!

 

There were some gaps in the TOPS numbering scheme. There was a full house between class's 20 & 29, then there was class 30, the original designation for the Brush/Mirrlees type 2, and 31, the EE re-engined class 30's. Class 33's  I understand were originally going to be class 33 & 34, but this was changed to 33/0 & 33/1. Class 35 & 37 we all know about.

 

Why was there no class 32 or class 36? Why were 33's not class 32's? 35's not 34's or 33's? 37's not 36's or 35's?

 

Similarly, with type 5's, there was class 50, 52, 53 (Falcon), & 55-59. Why were 52's not class 51's, & 55's not class 54's?

 

There was class 70 (the Southern electric trio), 71, 72 (original designation for class 73/0), 73, 74, then 76 & 77. I can understand the gap between 3rd rail DC class 74 & 1500v DC o/h class 76 & 77, so again pretty much a full house.

 

With the AC electrics, there was again a full house between class 80-87. There were plans for a class 88 electric freight loco, which eventually seems to have become class 92, and they then went to class 89 for the solitary example of it's type, and class 90, which were originally going to be class 87/2.

 

Piffling trivia it may be, but there must have been a reason for it. Surely it wasn't BR allowing for future builds by leaving a gap in the number ranges. DMU's, EMU's & coaching stock did not go on TOPS until the early 80's so it can't have been because of a clash with those number ranges.

 

cheers N

Edited August 5, 2017 by rodent279

[EddieB]

I don't know whether you'd referred to it, but perhaps worth mentioning that the current issue (226) has a full listing of TOPS and pre-TOPS classifications for BR diesels and electrics. It includes class numbers allocated or proposed and not used.

 

As I understand it, ranges were allocated to power ranges, leaving gaps for future builds. So "type 1" began at 14, 2 at 21, 3 at 33, 4 at 40 and 5 at 55. This would explain gaps at the end of a power range sequence, while most gaps within a sequence can be explained by proposals not adopted. Not all, though, such as 19 with the type 1 range, or why there was a jump from 60 to 66 (albeit 62 and 65 allocated but not used).

[rodent279]

I don't know whether you'd referred to it, but perhaps worth mentioning that the current issue (226) has a full listing of TOPS and pre-TOPS classifications for BR diesels and electrics. It includes class numbers allocated or proposed and not used.

 

As I understand it, ranges were allocated to power ranges, leaving gaps for future builds. So "type 1" began at 14, 2 at 21, 3 at 33, 4 at 40 and 5 at 55. This would explain gaps at the end of a power range sequence, while most gaps within a sequence can be explained by proposals not adopted. Not all, though, such as 19 with the type 1 range, or why there was a jump from 60 to 66 (albeit 62 and 65 allocated but not used).

Must admit, I've always wondered why 30/31's, being type 2's, were not in the 20-29 range.

 

Another slight anomaly is that 45's and 46's were deemed worthy of their own separate class range, when the difference between them is electrical equipment supplier, one being Brush (45's) the other being GEC (46's). (Edit-or is one of them Crompton Parkinson? Haven't got a P5 book handy).

The same is true of HST power cars-there are varients with Brush traction motors & electrical equipment, and with GEC traction motors & electrical equipment. Why then were they not allocated separate classes? Class 42 could have been used for one & 43 for the other.

Edited August 6, 2017 by rodent279

[russ p]

Its a very speculative topic about the gaps but some can possibility be plugged.

Bearing in mind that the NBL A1A warships were supposedly 41 , DP2 was possibly 49 as both types were withdrawn in 1967

Some of the later gaps such as the jump between 60 to 66 is due to individual MU cars being numbered in the 6XXXX series

DTC DMUs were originally 56xxx but had to be renumbered to avoid conflict with class 56s

[Clive Mortimore]

David Percival wrote very informative article on TOPS classes for Traction many moons ago. From memory his conclusion of some of the abnormalities came from the fact the Derby drawing office drew the list up. Hence the three classes for the Peaks (Derby design) where other classes with similar small variations were grouped together. As for the Brush type 2s getting numbers in the low thirties which were allocated to the type 3s, there weren't any more room in the twenties series.

 

He did speculate about the missing numbers and what locos would/could have been allocated to them.

 

Remember class numbers or names are only a way of cataloging the stock you have. 

[SRman]

Another anomaly was the class 24 and 25 numbering, where the subclasses were not separated using the third digit of the numbers.

[DY444]

Must admit, I've always wondered why 30/31's, being type 2's, were not in the 20-29 range.

 

Another slight anomaly is that 45's and 46's were deemed worthy of their own separate class range, when the difference between them is electrical equipment supplier, one being Brush (45's) the other being GEC (46's). (Edit-or is one of them Crompton Parkinson? Haven't got a P5 book handy).

The same is true of HST power cars-there are varients with Brush traction motors & electrical equipment, and with GEC traction motors & electrical equipment. Why then were they not allocated separate classes? Class 42 could have been used for one & 43 for the other.

 

45s were CP and 46s Brush.  There were a large number of differences between the two hence the separate class numbers.  A 46 is much more like a 47 internally - in fact the early 47s used equipment ordered originally for more 46s.  This is also why 46s tended to be allocated to depots with 47 maintenance experience such as Laira and Gateshead when the 45s weren't.

 

The "West of England" batch of HST PCs had GEC motors.  Everything else is the same.  Far fewer differences than between say 47s with series-parallel and all parallel electrical equipment and yet they were a single class. 

 

I agree it is a bit of a lottery though.  BR seemed to manage ok pre-TOPs in dealing with 3 operationally very different variants of Class 33, classes where some locos had boilers or dual brakes or dual AWS, the various combinations of heat, brakes, SSC on 47s etc.

[Holmesfeldian]

With the peaks I always found it strange that random 45s were ETH fitted (as and when works overhauls came up) rather than just the entire Class 46 series (plus you got 6 extra ETH fitted machines!).

 

Perhaps even in the early 1970s the 45s were deemed to be "better" machines.  Anecdotal evidence suggests Crompton Parkinson electrics was more highly regarded than Brush.

 

Toton and Tinsley had 47 experience so maintenance shouldn't have been that much of an issue.

[Baby Deltic]

With the peaks I always found it strange that random 45s were ETH fitted (as and when works overhauls came up) rather than just the entire Class 46 series (plus you got 6 extra ETH fitted machines!).

 

Perhaps even in the early 1970s the 45s were deemed to be "better" machines.  Anecdotal evidence suggests Crompton Parkinson electrics was more highly regarded than Brush.

 

Toton and Tinsley had 47 experience so maintenance shouldn't have been that much of an issue.

BR had a lot of trouble with Crompton Parkinson electrical equipment in the 1960s. I believe that Crompton got so snowed under trying to repair damaged/burnt out electrical equipment returned by BR that they couldn't deliver the equipment for all of the class 45 builds, hence why BR dropped them in favour of Brush for classes 46 and 47. Quite a few class 45's were sent to Brush for refurbishment in the mid 60s. I think Crompton had either gone under or been acquired by then. I remember seeing Brook Crompton Parkinson motors in the 80s.

[cheesysmith]

As to the different class numbers for the 45/46. Axle load and RA and also crew training, the latter having totally different electrical systems. How much would the different TOPS classes be for different crew knowledge, operational differences, and maintenance differences?

[Zomboid]

With the peaks I always found it strange that random 45s were ETH fitted (as and when works overhauls came up) rather than just the entire Class 46 series (plus you got 6 extra ETH fitted machines!).

 

Perhaps even in the early 1970s the 45s were deemed to be "better" machines. Anecdotal evidence suggests Crompton Parkinson electrics was more highly regarded than Brush.

 

Toton and Tinsley had 47 experience so maintenance shouldn't have been that much of an issue.

The ETH alternator and other kit in the 45/1s was supplied by Brush.

Not sure what that tells you though. It could have been as simple as the CP Genny and control system was easier to modify than the Brush version. It's certainly very tight between the alternator and the control cubicle in a 45/1. If the Brush main generator is a just a little bigger you'd be looking at moving the whole cubicle to get it in whilst being able to get the doors open/ off.

Or it could be something else entirely.

[Clive Mortimore]

Does any of it really matter today, it is as daft as the Gresely v Thompson row that has lasted longer than both the LNER and BR did added together.

 

Let us accept this what happened no need to question why. 

 

To back up what Baby Deltic has stated. Years ago I use to work some guys who had been at Crompton's in Chelmsford and they said they spent more time repairing returned motors and generators than making new ones. Crompton works became Marconi Radar factory until they folded, it is now a housing estate and the front office a GP surgery.

 

As for 46 being allocated to depots where they had 47 experience the LMR Midland lines lost its class 46 allocation in the late 60s to the WR to replace the hydraulics.   

[luckymucklebackit]

I remember seeing a list of Eastern and North Eastern Region Diesel Locomotive classification numbers in an early Ian Allen ABC (can't find it on-line)  was there any link between that list and the TOPS list?

 

Jim

[The Stationmaster]

I remember seeing a list of Eastern and North Eastern Region Diesel Locomotive classification numbers in an early Ian Allen ABC (can't find it on-line)  was there any link between that list and the TOPS list?

 

Jim

 

No - apart from a similar(ish) idea being adopted by the BR CM&EE based at Derby and being reworked for the whole diesel fleet (and later electrics and multiple units).  The ER system worked on the base of the leading class identifier digits being the nominal horsepower of the engine - thus a Deltic was 33/3 (not sure what the /3 meant).

 

The WR Main Line Loco Diagram book used another system where classes were identified by Transmission type/Power type/individual class number - thus a Hymek was DH/3100/whatever (the whatever varying according to boiler fit etc).  Possibly this system was also centrally based but I can't establish that; incidentally it split the Class 45/46 into four sub-groups.

 

Neither of these other systems suited what was clearly Derby's aim when the two digit class designation system was devised - i.e. that it would eventually be used as part of the painted number system on locos (the introduction of TOPS some years later of course providing the excuse to do exactly that).  You might almost say that so called 'TOPS numbers' on BR locos were actually invented long before TOPS had even been considered for adoption by BR

[DY444]

With the peaks I always found it strange that random 45s were ETH fitted (as and when works overhauls came up) rather than just the entire Class 46 series (plus you got 6 extra ETH fitted machines!).

 

One reason I've heard is that the 45s were considered to be better than 46s at higher speeds and thus more suited to passenger work

[frobisher]

The same is true of HST power cars-there are varients with Brush traction motors & electrical equipment, and with GEC traction motors & electrical equipment. Why then were they not allocated separate classes? Class 42 could have been used for one & 43 for the other.

Remember that at the time they weren't classed as locomotives, they were coaching stock (the sets had the TOPS number in the 253/4 XXX range) and they (plus the prototype power cars) retrospectively got class numbers.

[frobisher]

Piffling trivia it may be, but there must have been a reason for it. Surely it wasn't BR allowing for future builds by leaving a gap in the number ranges. DMU's, EMU's & coaching stock did not go on TOPS until the early 80's so it can't have been because of a clash with those number ranges.

The simple answer is you're seeing a mixed set of regimes. The initial TOPS class allocations (but not numbers...) would be distinct from what actually happened as various classes were withdrawn before ever getting renumbered into TOPS.

 

Off the top of my head these would be 02, 04, 05, 10, 11, 12, 14, 15, 16, 17, 21, 22, 23, 28, 29, 30 (effectively), 35, 41, 42, 43, 48 (effectively), 52, 53, 77 and 80.

 

In and around the same time period, only classes 56 and 87 were introduced into that regime that never carried anything but TOPS numbers.

 

Thereafter, new classes follow on as withdrawals allow the absorption of EMU and DMU coaching stock into TOPS (notably 40, 44, 55, 76 (71 and 74 already gone)).

 

 

 

The 58 was the next loco class to be introduced but this happened as withdrawals had started within the TOPS numbered classes freeing up room for some coaching stock ranges (40, 44 (followed latterly by 45 and 46), 55, (71 and 74 already gone), 76). 59 and 60 followed, but 61-65 were used by EMU coaching stock I believe, hence the later gap to 66 et al.

[jim.snowdon]

Remember that at the time they weren't classed as locomotives, they were coaching stock (the sets had the TOPS number in the 253/4 XXX range) and they (plus the prototype power cars) retrospectively got class numbers.

Although, rather conveniently, the power cars were all given numbers in the 43/xxx range that neatly fitted in with their being classified as locomotives, which is of course exactly what they were. What the HSTs weren't, strictly, were diesel multiple units as there no facility for 2 HST sets to be coupled together and run in multiple; just a fixed formation coaching stock set with a pairs of locomotives, one on either end, running in multiple. Even if they are unit sets for operational purposes, the power cars are interchangeable units and more akin to locomotives in terms of their maintenance regimes.

 

Jim

[Clive Mortimore]

No - apart from a similar(ish) idea being adopted by the BR CM&EE based at Derby and being reworked for the whole diesel fleet (and later electrics and multiple units).  The ER system worked on the base of the leading class identifier digits being the nominal horsepower of the engine - thus a Deltic was 33/3 (not sure what the /3 meant).

 

The WR Main Line Loco Diagram book used another system where classes were identified by Transmission type/Power type/individual class number - thus a Hymek was DH/3100/whatever (the whatever varying according to boiler fit etc).  Possibly this system was also centrally based but I can't establish that; incidentally it split the Class 45/46 into four sub-groups.

 

Neither of these other systems suited what was clearly Derby's aim when the two digit class designation system was devised - i.e. that it would eventually be used as part of the painted number system on locos (the introduction of TOPS some years later of course providing the excuse to do exactly that).  You might almost say that so called 'TOPS numbers' on BR locos were actually invented long before TOPS had even been considered for adoption by BR

Hi Mike

 

Detics were 33/3, yes the 33 was for its power, /3 being its manufacturer English Electric.

 

Other manufacturers/works were

 

1, BR

2, Brush

3, English Electric

4, North British

5, British Thompson Huston and Metropolitan-Vickers (don't know why both had the same number)

6, BRCW

7, Beyer Peacock

8, LMS

9, SR

10, LNER

11, G*R

12, Barclay

13, Drewry

14, Hudswell Clarke

15, Hunslet

16, Ruston

17, Yorkshire Engine

18, Clayton

 

A letter was used for some variations within classes or to identify a different class.

 

A 15/6 was a BRCW type 3 and a 15/6A is a BRCW type 3, Hastings gauge.

 

A 11/4 was a NBL type 2 (diesel electric, class 21) and a 11/4A was a NBL type 2 (diesel hydraulic, class 22)

[frobisher]

Although, rather conveniently, the power cars were all given numbers in the 43/xxx range that neatly fitted in with their being classified as locomotives, which is of course exactly what they were.

There does seem to have been some forward planning there by someone there (also the HST coaching stock in the 40 XXX, 41 XXX 42 XXX and 44 XXX ranges). In the midst of all this, the prototype DMBs went from class 41 to coaching stock and eventually to class 43 - 41001/43000 is a 43/9 officially.

[russ p]

The simple answer is you're seeing a mixed set of regimes. The initial TOPS class allocations (but not numbers...) would be distinct from what actually happened as various classes were withdrawn before ever getting renumbered into TOPS.Off the top of my head these would be 02, 04, 05, 10, 11, 12, 14, 15, 16, 17, 21, 22, 23, 28, 29, 30 (effectively), 35, 41, 42, 43, 48 (effectively), 52, 53, 77 and 80.In and around the same time period, only classes 56 and 87 were introduced into that regime that never carried anything but TOPS numbers.Thereafter, new classes follow on as withdrawals allow the absorption of EMU and DMU coaching stock into TOPS (notably 40, 44, 55, 76 (71 and 74 already gone)).The 58 was the next loco class to be introduced but this happened as withdrawals had started within the TOPS numbered classes freeing up room for some coaching stock ranges (40, 44 (followed latterly by 45 and 46), 55, (71 and 74 already gone), 76). 59 and 60 followed, but 61-65 were used by EMU coaching stock I believe, hence the later gap to 66 et al.

A few 02s and one 05 got TOPS numbers

[pete_mcfarlane]

As I understand it, ranges were allocated to power ranges, leaving gaps for future builds. So "type 1" began at 14, 2 at 21, 3 at 33, 4 at 40 and 5 at 55. This would explain gaps at the end of a power range sequence, while most gaps within a sequence can be explained by proposals not adopted. Not all, though, such as 19 with the type 1 range, or why there was a jump from 60 to 66 (albeit 62 and 65 allocated but not used).

 

I believe that TOPS has a single number space for everything, so some parts of the 01001 to 99999 range have been taken up with coaches (and at one point ships), which is is why some of the 6xxxx numbers weren't used for locos (hence the jump from class 60 to 66). 

 

Numbering the HST power cars in the 43xxx range fitted in with the other number ranges for HST vehicles, which (I think) were in the 41xxx and 42xxx blocks. I've read elsewhere on here that they were originally coaches, and then somebody changed their mind (or, more likely, changed roles and the new person had other ideas....)

 

As an example of this, the mainline registered Hastings power cars had to be renumbered when they were re-registered on TOPS, as their original 60xxx numbers had been reallocated to class 60 locos. http://www.hastingsdiesels.co.uk/news/articles/2002a06/

[Peter Kazmierczak]

WR working timetables also mention some of their hydraulics as D6XX, D8XX, D10XX etc., with diesel-electrics  such as Brush 4s as D15XX.

[rodent279]

Does any of it really matter today, it is as daft as the Gresely v Thompson row that has lasted longer than both the LNER and BR did added together.

 

Let us accept this what happened no need to question why. 

 

To back up what Baby Deltic has stated. Years ago I use to work some guys who had been at Crompton's in Chelmsford and they said they spent more time repairing returned motors and generators than making new ones. Crompton works became Marconi Radar factory until they folded, it is now a housing estate and the front office a GP surgery.

 

As for 46 being allocated to depots where they had 47 experience the LMR Midland lines lost its class 46 allocation in the late 60s to the WR to replace the hydraulics. 

 

Oh none of it matters now, it's all piffling trivia, and largely irrelevant to today's world, but it just stimulates my curiosity.

 

 

Although, rather conveniently, the power cars were all given numbers in the 43/xxx range that neatly fitted in with their being classified as locomotives, which is of course exactly what they were. What the HSTs weren't, strictly, were diesel multiple units as there no facility for 2 HST sets to be coupled together and run in multiple; just a fixed formation coaching stock set with a pairs of locomotives, one on either end, running in multiple. Even if they are unit sets for operational purposes, the power cars are interchangeable units and more akin to locomotives in terms of their maintenance regimes.

 

Jim

 

I've always viewed HST's as effectively a double headed fixed rake of coaching stock, but with the locos on each end. Really HST's are two locos working in multiple top & tail.

 

 

No - apart from a similar(ish) idea being adopted by the BR CM&EE based at Derby and being reworked for the whole diesel fleet (and later electrics and multiple units).  The ER system worked on the base of the leading class identifier digits being the nominal horsepower of the engine - thus a Deltic was 33/3 (not sure what the /3 meant).

 

The WR Main Line Loco Diagram book used another system where classes were identified by Transmission type/Power type/individual class number - thus a Hymek was DH/3100/whatever (the whatever varying according to boiler fit etc).  Possibly this system was also centrally based but I can't establish that; incidentally it split the Class 45/46 into four sub-groups.

 

Neither of these other systems suited what was clearly Derby's aim when the two digit class designation system was devised - i.e. that it would eventually be used as part of the painted number system on locos (the introduction of TOPS some years later of course providing the excuse to do exactly that).  You might almost say that so called 'TOPS numbers' on BR locos were actually invented long before TOPS had even been considered for adoption by BR

 

I stand to be corrected, but I thought TOPS had been around since about 1965, when it first started to be used for recording & controlling wagon movements. I assume therefore that wagons were the first vehicles to go on to TOPS?

 

Another anomaly is that class 21's were rebuilt into class 29's, and 30's into 31's, yet were not renumbered out of their respective D61xx & D5xxx ranges. I know that 29's would have ended up being 29xxx had they lasted long enough, but it's intriguing that no one thought it necessary to renumber them into a different range after rebuilding.

[pete_mcfarlane]

Wikipedia and various other sources give the early 70s as the go-live date for TOPS in BR.

 

https://en.wikipedia.org/wiki/TOPS#Adoption_by_British_Rail

 

(The S/360 purchase needing cabinet approval story always amused me - I've heard it from ex-BR mainframe people to it's almost certainly true...)

 

This is from the New Scientist.

 

https://books.google.co.uk/books?id=r7IuKdt2iCkC&pg=PA160&lpg=PA160&dq=%22tops%22+software+%22british+rail%22&source=bl&ots=8sYx7ooqdO&sig=bZ3VNNmsccu7GhPtO68wXoIk0Qc&hl=en&ei=VN2eTZmcK86HhQe2mu2FBQ&sa=X&oi=book_result&ct=result#v=onepage&q=%22tops%22%20software%20%22british%20rail%22&f=false

 

Having now read it, the AAR quote 'The information is useful, but is it worth the cost?' amused me, with the hindsight of progress.. As is the idea that a (then) 10 year old computer system is outmoded. 

Edited August 7, 2017 by pete_mcfarlane