Sub class or new class?

[gazthomas]

Apologies if a similar thread has come up in he past; I've searched and I haven't been able to find one though.

So my question - how do the people at the rolling stock library determine whether new rolling stock is a new class or a sub class?

Why is a 150/2 not a different class altogether?

Yet why is a 159 not a 158? I know the engine is slightly more powerful, but there are 158's with the same engine.

171's have a different coupler so I can see a slight justification over a 170, but class 66's have lots of variations such as low pollution, different gearing so why couldn't subclasses been used for 170/171/172?

All a bit of a mess in my view!

 

[route:oxford]

Apologies if a similar thread has come up in he past; I've searched and I haven't been able to find one though.

So my question - how do the people at the rolling stock library determine whether new rolling stock is a new class or a sub class?

Why is a 150/2 not a different class altogether?

Yet why is a 159 not a 158? I know the engine is slightly more powerful, but there are 158's with the same engine.

171's have a different coupler so I can see a slight justification over a 170, but class 66's have lots of variations such as low pollution, different gearing so why couldn't subclasses been used for 170/171/172?

All a bit of a mess in my view!

It was to appease the "empires"

Not so easy now that the numbers are running out.

 

[Rhydgaled]

And why were class 91s permanently renumbered into 91/1 subclass on refubishment, but the duplex pantograph 91 is still a 91/1? Personally, I think they should all go through a life-extension+duplex pan programme and have their orriginal (91/0) numbers restored as they go through the process.

Is 158 numbering subclassed for the three different types of engine and two different set lengths used? Also some of the more recent class 159s, converted by SWT I believe, have the lower-power engines anyhow.

 

[theblackwatch]

I don't think it's down to the Rolling Stock Library any more - more the owner or TOC operating the vehicles. The original 159s (159001-22) were originally built as Class 158s and went to Babcock Rail at Rosyth for modifications, but I can't remember exactly what.

I do agree it is a bit of a mess, but it's nothing new. The Class 90s were originally going to be Class 87/2, and in the 1980s someone decided that 197 DEMU power cars built in the 70s should now be classified as locos!

 

[jopsuk]

The 375s that were converted from tightlock couplers and sent to Southern were reclassified as 377, but when the rest of the Southeastern fleet were also converted, they were left as 375. The new 377/6s meanwhile are more like 379s than the the rest of the 377s.

At one time, there might have been an effort to keep ranges for certain types of class- but now the 37x range has the (withdrawn) 370 high speed tilting train, the International high speed 373 and the commuter and metro 375-379 Electrostars.

Most organised was the Southern Region 4xx numbering- but if that numbering scheme had been followed, the 450 and 377/375 might have received the same class number, which would have been confusing, both being four car units (mainly) designed for the same purpose!

 

[notadriver]

Surely the classifications are more to assist those who maintain and work with them rather than for anything else ?

 

[g4mby]

All a bit of a mess in my view!

The policy of allocating numbers has changed over the years to suit the needs of today's operators.

The allocation of 43 000, even though not carried, to prototype HST power car 41 001 which was 43000 when numbered in the coaching stock series is of course unique.

 

[455driver]

I don't think it's down to the Rolling Stock Library any more - more the owner or TOC operating the vehicles. The original 159s (159001-22) were originally built as Class 158s and went to Babcock Rail at Rosyth for modifications, but I can't remember exactly what.

First class was fitted!

Other 158s had FC fitted later but kept their original numbers.

 

[LE Greys]

T'was always so. The idea of sub-classes or 'parts' comes from the LNER, but they could be a bit inconsistent. To quote from P. Ransome-Wallis' Last Steam Locomotives of British Railways:

Many of the classes were divided into Parts signified by an oblique after the class number. Thus S1/1 was Robinson's 3-cylinder 0-8-4 tank engine and S1/2 was the same engine, but fitted with a booster. The division of classes into parts, however, was by no means consistent and depended a lot on local requirement. A different tender, different types of springs, different chimney heights were made into Parts but in other cases considerable differences were ignored and no division into Parts was made. An example of this, Class D40 consisted of non-superheater 4-4-0's of 1899 and also of superheated engines built in 1920.

I usually extend the system by classing Tornado as an A1/3 because of the roller bearings and other differences.

 

[jopsuk]

as far as I understand, the 322s were only classed as such so that Stansted Express had a "unique" fleet- they are simply 321s as far as I understand it.

 

[34D]

First class was fitted!

Other 158s had FC fitted later but kept their original numbers.

Erm yes and no. The braking system was changed - I think the original 158 was 3 step and the modified 159/0 was four step (or vice versa). One sort can lead the other sort but not vice versa. Hopefully 455driver can give us chapter and verse here? Other technical changes too.

Were the scottish 158s (the early ones) fitted with First Class before the 159s were even built?

Surely 150/0 150/1 and 150/2 are logical? Agree that 375/377 is bizarre.

 

[starrymarkb]

That was the original plan, and if followed through they would have be incompatible with 158s. IIRC they are standard now, not sure if any mods were done by SWT or by NSE pre privatisation

 

[Sapphire Blue]

It was to appease the "empires"

Not so easy now that the numbers are running out.

Seeing as there are lots of obsolete Class numbers, why could a new class of DMU not be numbered Class 101 (for example)?

 

[starrymarkb]

I believe new stock is going into a new series, IEP will be in the 800 series and new standard EMUs in the 700 series. I'm pretty sure there is also going to be a switch to 7 digit vehicle numbers and UIc (keyboard broken so can't cap the c) numbering.

 

[notadriver]

Regarding 375/377 - the 377s have Driver Only Operation cameras which 375s will not be fitted with.

 

[LE Greys]

Seeing as there are lots of obsolete Class numbers, why could a new class of DMU not be numbered Class 101 (for example)?

They've already re-used Classes 21 and 70, so I don't really see why not, provided the class is totally extinct, including preservation.

 

[455driver]

I think the original 158 was 3 step and the modified 159/0 was four step (or vice versa).

Oh yeah forgot about that bit.

One sort can lead the other sort but not vice versa.

Not sure on that, I am sure there have been occasions where a Wales and West (remember them?) 158 was coupled to a SWT 159 for the run from Basingstoke into Waterloo (via Hounslow because of engineering work) where the W&W driver drove up to Waterloo (conducted by a SWT driver) and the SWT driver drove back down, ensuring that each companies train was driven by their own drivers.

Hopefully 455driver can give us chapter and verse here? Other technical changes too.

Couldnt even give you the first sentence never mind the full chapter, never signed them (and dont intend to either)!

 

[WatcherZero]

I believe new stock is going into a new series, IEP will be in the 800 series and new standard EMUs in the 700 series. I'm pretty sure there is also going to be a switch to 7 digit vehicle numbers and UIc (keyboard broken so can't cap the c) numbering.

Arent they already all put into the European numbering system, they just only have to display it if crossing the Channel?