Why is the Class 69 not a subclass of the Class 56?

[071]

I'm a bit puzzled as to why the Class 69 is not simply classed as a variant of the Class 56, such as a Class 56/4 or 56/9 or whatever.

I accept that the guts have been entirely replaced, new engine and controls, etc. However, this isn't the first time that a new powerplant has been put into a type without complete reclassification.

For example:

• Class 31 - originally Mirlees, refitted with English Electric without any renumbering
• Class 37 - units refitted with Mirlees or Ruston powerplants became the 37/9 subclass, not even consistent fitment with the subclass
• Class 47 - 47046 refitted with a 16-cyl Ruston engine became 47/6 and subsequently the same loco became a 47/9 when fitted with a 12-cyl Ruston

The Class 69 is never going to be built in huge numbers. Does it really need a whole class to itself? It seems to me that a subclass of the 56 could have been used. Are there reasons why it wasn't? Why did it need a whole new class designation?

 

[xotGD]

Class 31s were originally Class 30 when they had the original engine, so they were renumbered.

Class 57 became a new class.

Class 69 follows the pattern of these two.

The 37/9 and 47/6, 47/9 examples were essentially engine testbeds rather than roll-out of a 'new' locomotive fleet, so that may the rationale for the difference.

 

[Speed43125]

Personally, I'd have favoured the use of a class 56 subclass purely on the basis of the relatively low number of classes left available in the locomotive category (compared with virtually all of 7xx being free for EMUs for example).

 

[birchesgreen]

Because its much better marketing to give it a new class number.

 

[Mollman]

Same reason that rebuilt 47s became 57s

 

[XAM2175]

They've been modified to use AAR multiple working, so there's no longer any operational compatibility with 56s.

Personally, I'd have favoured the use of a class 56 subclass purely on the basis of the relatively low number of classes left available in the locomotive category (compared with virtually all of 7xx being free for EMUs for example).

The locomotive class numbers are taken from the vehicle numbering range, which is separate to the class numbers used for multiple units.

In any case, how many new classes of diesel locomotive are we really expecting to designate in future?

 

[Trackman]

Personally, I'd have favoured the use of a class 56 subclass purely on the basis of the relatively low number of classes left available in the locomotive category (compared with virtually all of 7xx being free for EMUs for example).

I was thinking that too.
One day something has to give with the class numbering... maybe for another thread.

 

[adc82140]

The 73/9s are very much removed from their original form. But we are trying to put logic in to the TOPS system, which as we know is not really possible.

 

[sd0733]

Personally, I'd have favoured the use of a class 56 subclass purely on the basis of the relatively low number of classes left available in the locomotive category (compared with virtually all of 7xx being free for EMUs for example).

There arent that many free 56xxx numbers either with them being used in numbering 170 centre cars.

 

[D365]

Because the 69s, electrically, are completely new. They’re essentially a 66-56 hybrid.

the question should be, why were the rebuilt 73s not reclassified?

 

[Cowley]

Because the 69s, electrically, are completely new. They’re essentially a 66-56 hybrid.

the question should be, why were the rebuilt 73s not reclassified?

I’d say this too actually. As @xotGD said, the 37/9s and 47/9 were test beds, but the 73/9s are heavily rebuilt (especially the Network Rail ones) and have been turned into Type 3s while running on diesel.

 

[xotGD]

I’d say this too actually. As @xotGD said, the 37/9s and 47/9 were test beds, but the 73/9s are heavily rebuilt (especially the Network Rail ones) and have been turned into Type 3s while running on diesel.

Yes, the 73/9s could legitimately have been renumbered as a new class. Class 75? Or 38? Then again they aren't all the same so do we need multiple new classes?

 

[Cowley]

Yes, the 73/9s could legitimately have been renumbered as a new class. Class 75? Or 38? Then again they aren't all the same so do we need multiple new classes?

I know that we’re applying logic to a system that isn’t entirely logical here, but what about class 75 for the GBRF ones and. Actually, maybe I’ll just leave it there before my head explodes.

 

[XAM2175]

I’d say this too actually. As @xotGD said, the 37/9s and 47/9 were test beds, but the 73/9s are heavily rebuilt (especially the Network Rail ones) and have been turned into Type 3s while running on diesel.

The inverse no-logic-in-TOPS argument could apply here: the numbering standard holds that "existing electro-diesel locomotives" should be placed in Class 73 so that's exactly where they were put

 

[birchesgreen]

There was some talk of renumbering the 73/9s to 75, i read somewhere. As it is the 73/9 subclass is nonsense as it contains two quite different rebuilds.

 

[randyrippley]

And just to stir the mix you have (or had.........) class 48

 

[D6975]

I was thinking that too.
One day something has to give with the class numbering... maybe for another thread

Why?
There are loads of class numbers available for use, far more than back in the 80s for example.
Note that preserved locos running on the mainline are all class 98s, so 40 for example is available.

 

[norbitonflyer]

Class 31s were originally Class 30 when they had the original engine, so they were renumbered.

They were not renumbered when the engines were changed, as they kept their original numbers in the D5500 series. Likewise the handful of Brush Type 4s that were built with V-form engines retained their D17xx numbers when converted to standard spec.

When TOPS classes were allocated in the late 1960s, both versions still existed and were allocated different class numbers (30/31,47/48), but as the conversion programmes were completed before TOPS numbers were introduced in the early 1970s, no loco ever carried a 30xxx or 48xxx TOPS number.

A similar situation arose with the handful of NBL D61xx locos that had their MAN engines replaced by Valentas. Again both types existed when TOPS classes were introduced, classified 21 and 29, but in this case both versions were extinct before actual renumbering started.

Fairly minor engine differences have justified different TOPS classes in the past - see classes 24/25, 26/27, and 44/45, in each case the latter merely being an uprated version of the former. Other classes with different engines in otherwise similar locos include 08/10 and classes 42/43 (but not the Rolls-Royce engined class 17s)

There are counter examples of locos which did receive new D/E numbers after conversion - Gas Turbine engine 18100 was converted to straight electric and became E1000 (and later E2001). And some of the E5000 (later Class 71) Bo-Bos were converted to electro-diesels and renumbered in the E61xx series (later class 74)

 

[Alanko]

The 73/9s are very much removed from their original form. But we are trying to put logic in to the TOPS system, which as we know is not really possible.

Plus, the GBRf 73/9s and the yellow 'Minion' 73/9s are different internally, so it is two different locos sharing the same subclass.

 

[071]

So it seems there is plenty of precedent for allocating a new class number. Seems a waste though when there will be very few of them built.

 

[Trackman]

Why?
There are loads of class numbers available for use, far more than back in the 80s for example.
Note that preserved locos running on the mainline are all class 98s, so 40 for example is available.

I thinking more of the power-rating/electric/diesel classing as originally TOPS.

As for class 89's (98's are Steam) quite a few have now reverted back to their original TOPS numbers as I assume the duplicate numbers has been removed, vehicle scrapped or whatever. I know 40145 is one as when it was renumbered they had to remind drivers of the new (well old) TOPS number.

From the RCTS website:

TOPS Class 89​

INTRODUCTION
The following numbers have been issued by the Rolling Stock Library (RSL) for privately owned diesel and electric locomotives for situations where the original TOPS number has been reused. The third digit represents the power classification and the last two digits are the final two digits of the pre-TOPS number, except where duplication occurs. The only exception is 89212 LUL 12 Sarah Siddons. Not all the preserved/privately owned locomotives are included in the series.

RSL	POOL	FORMER TOPS NUMBER	PRE TOPS NUMBER	NOTES
89100	MBDL	20050	D8000
89101	..	20001	D8001	Renumbered back to original TOPS number
89104	MBDL	01566	D9504
89110	MBDL	20110	D8110
89127	..	20227	D8327	Renumbered back to original TOPS number
89142	..	20142	D8142	Renumbered back to original TOPS number
89151	MBDL	..	D9551	Registered on TOPS March 2019
89166	..	20166	D8166	Renumbered back to original TOPS number
89188	..	20188	D8188	Renumbered back to original TOPS number
89200	MBDL	31018	D5500
89204	..	26004	D5304	Renumbered back to original TOPS number
89210	..	27059	D5410	Renumbered back to original TOPS number
89212	MBEL	..	12	LUL Loco
89223	MBDL	25173	D7523
89233	MBDL	25904	D7633
89247	..	27001	D5347	Renumbered back to original TOPS number
89254	MBDL	24054	D5054
89259	MBDL	25909	D7659
89261	MBDL	24061	D5061
89262	MBDL	25901	D7612
89280	..	31162	D5580	Renumbered back to original TOPS number
89287	..	20087	D8087	Renumbered back to original TOPS number
89317	MBDL	..	D7017
89320	..	76020	26020	De-registered
89376	MBDL	..	D7076
89400	MBEL	..	27000
89401	MBDL	47401	D1500
89402	..	50002	D402	Renumbered back to original TOPS number
89403	MBEL	71001	E5001
89404	MBDL	44004	D4
89405	..	47117	D1705	Renumbered back to original TOPS number
89406	MBDL	40106	D306	Re-registered on TOPS April 2011
89407	..	50007	D407	Renumbered back to original TOPS number
89408	..	50008	D408	Renumbered back to original TOPS number
89408	MBDL	44008	D8	Re-registered on TOPS September 2014
89410	MBDL	46010	D147	Re-registered on TOPS May 2019
89412	MBDL	40012	D212
89413	MBDL	..	D1013
89415	..	50015	D415	Renumbered back to original TOPS number
89416	MBDL	..	D1015
89417	..	50017	D417	Renumbered back to original TOPS number
89420	MBDL	45108	D120
89421	MBDL	..	D821
89422	..	50021	D421	Renumbered back to original TOPS number
89423	MBDL	45125	D123
89424	MBDL	..	D1023
89426	..	50026	D426	Renumbered back to original TOPS number
89427	MBDL	50027	D427
89431	..	50031	D431	Renumbered back to original TOPS number
89432	MBDL	..	D832
89433	..	50033	D433	Renumbered back to original TOPS number
89435	ELRD	40135	D335
89437	MBDL	..	D1010
89440	MBDL	45133	D40
89441	MBDL	..	D1041
89442	..	47192	D1842	Renumbered back to original TOPS number
89443	MBDL	50042	D442
89444	..	50044	D444	Renumbered back to original TOPS number
89445	..	40145	D345	Renumbered back to original TOPS number
89448	..	..	D1048	De-registered
89449	..	50049	D449	Renumbered back to original TOPS number
89453	MBDL	45041	D53
89460	MBDL	45060	D100
89462	MBDL	..	D1062
89466	MBDL	47449	D1566
89472	MBDL	46035	D172
89500	LSLS	55022	D9000	Transferred from Pool MBDL October 2018
89501	..	89001	..	Renumbered back to original TOPS number
89502	..	84001	E3036	Renumbered back to original TOPS number
89509	DBLX	55009	D9009
89515	DBLX	55015	D9015
89516	LSLS	55016	D9016	Transferred from Pool MBDL October 2018
89519	DBLX	55019	D9019
89520	DBLX	55002	D9002
89523	DBLX	..	DELTIC
89535	..	83012	E3035	Renumbered back to original TOPS number
89561	..	85101	E3061	Renumbered back to original TOPS number

Last updated: 18th August 2019

 

[Ribbleman]

There are currently three different versions of Class 230 registered for use on NR. Despite the differences between them they have not received separate designations such as 230/0, 230/1 etc.

 

[D365]

So it seems there is plenty of precedent for allocating a new class number. Seems a waste though when there will be very few of them built.

How many more diesel locomotives are you expecting to be built in the next ten years?

 

[birchesgreen]

How many more diesel locomotives are you expecting to be built in the next ten years?

Indeed, and there are enough gaps to suffice i'd have thought.

 

[Taunton]

Other classes with different engines in otherwise similar locos include ... 42/43

Although they looked the same in the bodywork, the Warships from Swindon (42) and North British (43) were completely different inside, not just engines and transmissions but all the subsidiary items as well, because North British had been allowed to do their own thing. If you were cataloging spares you needed two completely different sets for the two types. Not only that, but North British designed and built a significant number of the auxiliary items themselves instead of going to established suppliers, only to go bankrupt at the end of construction. The bodywork was designed by Swindon, and the drawings sent up to Glasgow, but not the internal layout. It was rather a shame, the WR view was the best design NB did was the initial D600, then all the competent technical team saw the writing on the wall and left. There are drawings around of NB's own first pass at a Class 43 bodyshell, sort of a blend of the D600 and D6300, very sad looking at the front, which must have caused apoplexy at Swindon and an instruction to "send them ours".

 

[Towers]

Have we had these yet??

(Image shows a Network Rail Class 97, a renumbered Class 37).

 

[Speed43125]

Have we had these yet??

(Image shows a Network Rail Class 97, a renumbered Class 37).

Incidentally, where do those work? I've only come across colas or drs (or herritage livery) operated test trains.

 

[Towers]

Incidentally, where do those work? I've only come across colas or drs (or herritage livery) operated test trains.

Weren't the 97s modified for ERTMS testing on the Cambrian? I think one/some of them have since made it into preservation, as I'm sure it was one of these that ran away and belted a preserved mail carriage at one of the heritage lines.

If you're talking 37s in general, pretty much anywhere on the front of NR test trains, or frequently on new/old train delivery and scrap runs at the moment!

 

[61653 HTAFC]

The 37s numbered in the 973xx series were the ERTMS test bed, and now work infrastructure trains both on the Cambrian and elsewhere.

Going back further, many different locomotives of an assortment of classes were given 97xxx numbers when part of the BR Departmental/RTC fleet.

Another inconsistency in numbering conventions is the Network Rail 153s, which one could argue should become 953s.

 

[D365]

Weren't the 97s modified for ERTMS testing on the Cambrian? I think one/some of them have since made it into preservation, as I'm sure it was one of these that ran away and belted a preserved mail carriage at one of the heritage lines.

Indeed.

The 97s were specifically modified with Ansaldo kit, but similarly converted 37s since then (Hitachi, and soon Siemens) have not been renumbered.