Missing DMU/EMU Classes

[Helvellyn]

I've been wondering about some of the gaps in BR second generation DMU and EMU classes: -

Class 152 - Missing
Class 153 - Originally missing, then converted 1-car 155 units
Class 157 - Proposed Hunslet DMU for Strathclyde PTE - never built

Class 167 - Why was the Class 168 not this?

Class 316 - Was this meant to be another PEP derivative?
Class 324 - Why the jump from Class 323 to Class 325?

Class 509 - After Class 508, Class 510 was the proposed classification for what became Class 455.

 

[starrymarkb]

I've been wondering about some of the gaps in BR second generation DMU and EMU classes: -

Class 152 - Missing
Class 153 - Originally missing, then converted 1-car 155 units
Class 157 - Proposed Hunslet DMU for Strathclyde PTE - never built

Class 167 - Why was the Class 168 not this?

Class 316 - Was this meant to be another PEP derivative?
Class 324 - Why the jump from Class 323 to Class 325?

Class 509 - After Class 508, Class 510 was the proposed classification for what became Class 455.

316 did exist for a while, it was a 455 with 313 trailer fitted with Asynchronous traction as a testbed for Networkers

 

[David Goddard]

This helps explain Cl316 and Cl457, with links to the fascinating Cl210 story:
http://en.wikipedia.org/wiki/British_Rail_Classes_316_and_457

 

[Waldgrun]

Seem to remember that at one stage, that for BR's Regional sector a class of new build single car units where proposed, with a stated class number of 161. these where never built and the class 155's where converted in 153's instead.

 

[ash39]

Loads of locos missing too - straight from 60 through to 66.

 

[Manchester77]

Class 152 was supposed to be a single car 156 but this job came to the 155s becoming 153s

 

[Darren R]

I always thought the "missing" classes were often due to the numbering of individual units/carriages/locos. If there was a class sub-divided into different sub-classes sometimes it resulted in the numbers going over into what would be the next class up so to speak. Say there was a class 400 loco sub-divided into 25 individual class 400/1 these would be numbered 400100 - 400124, which would mean the next sub-class would have to be 400/3 in order to avoid confusion and that this effect sometimes happened with entire classes.

In regard to multiple units I thought it was a similar effect but caused by the numbering of individual carriages in batches according to the vast number of vehicle types that proliferated with first gen dmus/emus. The need to give all Class 104 DMBS carriages a different batch of numbers to differentiate them from the TS/DMS/etc etc meant that some classes were skipped because the numbers had already been allocated to 'lower' class fleets. (If you get my drift!)

Realised what I said about loco classes doesn't actually make any sense since it would require over 999 individual locos in a class for the next class to be skipped as a result! ()

However - here is the link to where I originally read about numbering on Wikipedia:
http://en.wikipedia.org/wiki/British_Rail_locomotive_and_multiple_unit_numbering_and_classification

It explains it better than I can!

 

[Helvellyn]

316 did exist for a while, it was a 455 with 313 trailer fitted with Asynchronous traction as a testbed for Networkers

But that was out of sequence - BR jumped from Class 315to Class 317 in the early 1980s for no reason I can see.

Class 152 was supposed to be a single car 156 but this job came to the 155s becoming 153s

Again, the jump from Class 151 to Class 155 was without an obvious reason. The Class 154 prototype, then the Class 153 conversions, came later.

 

[telstarbox]

What is the difference between the 300, 400 and 500 classes?

 

[O L Leigh]

I seem to recall that Cl152 and Cl153 were originally reserved for other builds of 20 metre Sprinter DMUs with the 23 metre classes of "Super Sprinters" starting with Cl155. The conversion of Cl155s to single car units for local services removed the immediate need for any further 20 metre Sprinters and so were allocated the classification Cl153.

Cl316 was later used for Networker prototypes, but I would imagine that the classification was originally kept aside in the event of further builds of inner-suburban AC units.

But then TOPS classifications have never followed a logical sequence.

O L Leigh

 

[Manchester77]

Again, the jump from Class 151 to Class 155 was without an obvious reason. The Class 154 prototype, then the Class 153 conversions, came later.

Wasn't it to differentiate from Sprinters and Super Sprinters

 

[Crossover]

What is the difference between the 300, 400 and 500 classes?

To go from the start:

1xx are DMU's
2xx are DEMU's
3xx are intended as OHLE pickup EMU's (but not always the case)
4xx are intended as 3rd rail pickup EMU's
5xx - not too sure

 

[Manchester77]

3XX - have AC overhead but can also have DC 3rd rail
4XX - have DC 3rd rail only, operate within the London Area
5XX - have DC 3rd rail only, operate outside the London Are

 

[Michael.Y]

What is the difference between the 300, 400 and 500 classes?

Broadly speaking:
300 - AC EMUs and dual voltage
400 - DC EMUs - Southern Region
500 - DC EMUs - non Southern Region

 

[Eng274]

The individual vehicle numbering system doesn't always follow a rational pattern. On 170s, DMOSA, MOS, and DMOSB are 50xxx, 56xxx and 79xxx respectively. But on older EMUs this didn't always happen, ie 314 DMOS are numbered consecutively after each other so that all A end were even, and odd for B end.

The majority of the EMU numbering from the late 70s and 80s followed no apparent or logical pattern at all AFAICS.

 

[BelleIsle]

But that was out of sequence - BR jumped from Class 315to Class 317 in the early 1980s for no reason I can see.

Back in the 80s, I asked the same question of a high up during an "incident" whereby loads of foreign stock had to be borrowed. Forget if it were due to ASLEF blacking the 317s or the smoothing chokes failing in the bad weather . Anyway, the answer was straightforward - the Bedpan electrification was to be based on the GN pattern. i.e. two fleets of trains. An express unit for the outer suburban work and a metro unit for inner suburban work including the tricky tunnelled section. Instead of the GN's 312s and 313s the Bedpan was to have 317s and 316s. The latter effectively being a dual voltage 315.

So what changed?

It was assumed that the requirements for the Bedpan route were similar to the GN one but when they were revisited a different tale emerged:

- The GN had a requirement for first class on its outer suburban routes but not its inner suburban ones. The Bedpan did not. In fact, the change was so late that the 317s were built with 1st class saloons which were just declassified.

- The stations on the GN inner suburban route are numerous and close together. This means a unit with lower top speed but better acceleration would give quicker journey times. The Bedpan stations are just more spaced out thus negating most of the advantage.

- The short (6 car) platforms on the GN&C meant that inner suburban services were restricted to 3 car units. The Widened Lines used by the Bedpan route had no such problem.

- The space limitations in the GN&C tube necessitated end doors for evacuation. The Bedpan had the same requirement due to the single bores near Barbican. However, unlike the 312s, the 317s were gangwayed between units. Just add a suitable set of steps and you have your emergency exit.

- The clearances in the GN&C meant that OHLE was not an option. On the Widened Lines it was possible, albeit difficult.

Having a single, uniform fleet of single voltage trains is much cheaper than two differering types. Once it became clear that it was a possibility the LMR did everything they could to shoehorn the knitting into the Widened Lines. Of course, removing the possibility of "Drayton Park" incidents heped too

And then came Thamelink, dual voltage stock and an expensive new substation near Farringdon...

 

[jopsuk]

The individual vehicle numbering system doesn't always follow a rational pattern. On 170s, DMOSA, MOS, and DMOSB are 50xxx, 56xxx and 79xxx respectively. But on older EMUs this didn't always happen, ie 314 DMOS are numbered consecutively after each other so that all A end were even, and odd for B end.

The majority of the EMU numbering from the late 70s and 80s followed no apparent or logical pattern at all AFAICS.

Indeed- it would have been far better had TOPS allowed for longer carriage numbers- simply add 01, 02 etc to the unit number. But then the early DMUs (especially) were prone to be rearranged a lot.

 

[Peter Mugridge]

Loads of locos missing too - straight from 60 through to 66.

That's because the numbers would have clashed with a lot of EMU carriage numbers.

 

[MK Tom]

Broadly speaking:
300 - AC EMUs and dual voltage
400 - DC EMUs - Southern Region
500 - DC EMUs - non Southern Region

3XX - have AC overhead but can also have DC 3rd rail
4XX - have DC 3rd rail only, operate within the London Area
5XX - have DC 3rd rail only, operate outside the London Are

I've always thought of 500 as 'anything else'. The 508s did see use in the Southern Region originally and the 505s and 506s were overhead powered.

 

[Manchester77]

I've always thought of 500 as 'anything else'. The 508s did see use in the Southern Region originally and the 505s and 506s were overhead powered.

5XX - Alternative traction not intended for London use

 

[starrymarkb]

the 505s and 506s were overhead powered.

They were DC though

 

[Zoe]

5XX - Alternative traction not intended for London use

I'm not sure about that. The 501s were ordered by the LMR for use in the London area.

 

[ainsworth74]

I'm not sure about that. The 501s were ordered by the LMR for use in the London area.

I wonder if it isn't 4xx is DC units for the Southern Region (I can't think of any 4xx units that weren't at least originally ordered for the Southern even if they ended up elsewhere) whilst 5xx is DC units for all other regions. The 508 being used in the Southern Region isn't an anomaly as they were ordered for the North West before being diverted to work out of Waterloo.

 

[Helvellyn]

I wonder if it isn't 4xx is DC units for the Southern Region (I can't think of any 4xx units that weren't at least originally ordered for the Southern even if they ended up elsewhere) whilst 5xx is DC units for all other regions. The 508 being used in the Southern Region isn't an anomaly as they were ordered for the North West before being diverted to work out of Waterloo.

The Class 418s for Tyneside suburban services are the exception to the rule, basically a 2-EPB for use in the NorthEast.

 

[hairyhandedfool]

Anyone considered the Electrostars and the Desiros?

most 375, 376, most 377, 378/1, 444, 450 - DC
350/1, 375/6 377/2, 377/5, 377/7, 378/2 - Dual Voltage
350/2, 357, 360, 379, 380 - AC

 

[cjmillsnun]

Anyone considered the Electrostars and the Desiros?

most 375, 376, most 377, 378/1, 444, 450 - DC
350/1, 375/6 377/2, 377/5, 377/7, 378/2 - Dual Voltage
350/2, 357, 360, 379, 380 - AC

TBF 375, 376, 377 378, 444 and 450 are all dual voltage with the addition of a pan, transformer and HV cabling (as are 458 but not 460 which are DC only), whereas 450/2 457, 460, 379 and 380 are AC only. Of the dual voltage capable stock the ones that are misnumbered are the SWT Desiros and Junipers which should be in the 3XX range (to follow the example of 313 and 319)

 

[12CSVT]

One oddity with the class 501 to 506 units is that they weren't allocated unit numbers, apart from the 504s which were still in traffic in the late 1980s.

 

[southern442]

Just a question, what makes a fleet have to change sub class? For example, the 91's were all changed to 91/1's when they were refitted. Why did they have to change sub class though? the 378/0's all changed to 378/2's when an extra carriage was added, but the 455/7's still retained their sub class when they were added with a 508 TSO. Why?

 

[transmanche]

Just a question, what makes a fleet have to change sub class? For example, the 91's were all changed to 91/1's when they were refitted. Why did they have to change sub class though? the 378/0's all changed to 378/2's when an extra carriage was added, but the 455/7's still retained their sub class when they were added with a 508 TSO. Why?

And even more confusing to me; why the Southern 375s were reclassified as 377/3 when their Tightlock couplers were replaced with the Dellner type. But Southeastern's 375s were not reclassified after the same work.

 

[rebmcr]

6XX — New-build DMU/DEMUs
7XX — New-build EMUs
8XX — New-build Intercity