Class 508

[bramling]

I know the class 508s originally entered service on the South Western division, and were subsequently transferred to the Wirral Line after their first few years.

However, when ordered, was it the original intention these trains would transfer to Liverpool, or was this decision only taken after the trains entered service?

I've heard two conflicting theories, firstly they were always originally intended for Liverpool (but seems a lot of expense to build them as 4 cars when presumably it was always known Liverpool would require 3/6 car trains), but equally I've heard it said from reliable sources that they were intended for the South Western, but the Southern didn't like them because they were non-standard compared to the rest of the (then) Southern units (if intended for the Southern how come the class 5XX?). Always wondered as it's something that's never quite made sense.

Of course there were wasn't any other design on the table at the time, the MkIII designs didn't come until slightly later as I understand it. This does make me err more towards the stop-gap idea. It's noticeable the class 508s have different compressors to the 507s, sounding more akin to the contemporary Southern units.

 

[Islineclear3_1]

My understanding was that the 508s were a stop-gap to replace aging 4SUBs and the Class 455/7's were ordered as 3-cars so that when the 508s went north as 3-cars, the 4th car was inserted into the 455/7 build during their construction

 

[Mikey C]

Why did the Southern get a Mk3/317 derivative rather than a Pep derivative? The 455s were inner suburban trains, and this do a similar job to the 313s and 315s north of the river.

 

[Bletchleyite]

Why did the Southern get a Mk3/317 derivative rather than a Pep derivative? The 455s were inner suburban trains, and this do a similar job to the 313s and 315s north of the river.

Newer, and more similar to the new Mk3 standard, I guess.

Merseyside I think needed smaller units because they wouldn't fit the loading gauge, ISTR it isn't quite big enough to take Mk3s (even 20m ones) through the tunnels.

Neil

 

[Mikey C]

Newer, and more similar to the new Mk3 standard, I guess.

Merseyside I think needed smaller units because they wouldn't fit the loading gauge, ISTR it isn't quite big enough to take Mk3s (even 20m ones) through the tunnels.

Neil

I suppose it also gave the Southern the chance to do their usual trick and recycle some traction motors from the 4-SUBs!

 

[Islineclear3_1]

I suppose it also gave the Southern the chance to do their usual trick and recycle some traction motors from the 4-SUBs!

Didn't they recycle the compressors as well...?

 

[WarrenTManager]

Not just the SUBs......

One of the DH25s (compressors) is dated 1938. 4101 didn't appear until 1941.

 

[Helvellyn]

Oddly, Roger Butcher's BR Departmental Coaching Stock book shows the 508 fleet built under Lots 30942-30945 (Order made 30/12/1977; Completed 17/05/1980), but in 1983 a further three Lot No.s appear - 30979-30981 - which is for the vehicles transferred to Merseyside.

Also, I believe the Class 455 fleet was originally going to be known as Class 510.

 

[507 001]

Of course there were wasn't any other design on the table at the time, the MkIII designs didn't come until slightly later as I understand it. This does make me err more towards the stop-gap idea. It's noticeable the class 508s have different compressors to the 507s, sounding more akin to the contemporary Southern units.

508s actually have 2 compressors, one that sounds like a 507s and one that sounds like an old SR unit.

 

[prod_pep]

one that sounds like a 507s and one that sounds like an old SR unit.

I've corrected this a few times on here before - the two Class 508 compressors both sound like an old SR unit. They are identical.

 

[Peter Mugridge]

Also, I believe the Class 455 fleet was originally going to be known as Class 510.

That is correct and quite a few of the 455/8s did enter service with their internal stickers in the cabs reading "Class 510" so that change of classification must have occured at some point not long before the first units were delivered.

 

[Bletchleyite]

That is correct and quite a few of the 455/8s did enter service with their internal stickers in the cabs reading "Class 510" so that change of classification must have occured at some point not long before the first units were delivered.

Why were there two different ranges for third-rail EMUs, 4xx for Southern and 5xx for elsewhere? There aren't for any other type of MU or locomotive.

Neil

 

[Islineclear3_1]

Why were there two different ranges for third-rail EMUs, 4xx for Southern and 5xx for elsewhere? There aren't for any other type of MU or locomotive.

Neil

Merseyrail had Class 502 and 503; LMR had Class 504 (which were 3rd rail units); the old LMSR had Class 506 (which was overhead DC) and when the PEP derivatives came out; Class 507 went to Mersey, Class 508 to Southern (with the intent of moving north). I have no idea why they might have become Class 510 as '508 would have been the natural progression. And there wasn't a '509 to my knowledge

The SR always had 4xx starting from 401 - 499 (not all used however) whilst the ER had 3xx units (which of course were overhead)

Of course

 

[DoubleD55]

Having spent a day yesterday riding on the Northern and Wirral lines and seeing a mixture of both 507 & 508 I was wondering if there is any special diagramming or are they treated as one class in daily use

 

[Bletchleyite]

Pretty sure they are mixed up, as there is no practical difference.

 

[DoubleD55]

Thanks Neil

Just wondered and as you say they seem identical

 

[Bletchleyite]

Thanks Neil

Just wondered and as you say they seem identical

There are subtle differences, but nothing operational, and some of them were removed at the big early-2000s refurb, e.g. the 508s used to have blanked over door button panels and blanked-over space for handles on the doors themselves, the 507s had neither. I think half the door button panels from the 508s (the ones on the left) were fitted to the 507s to take the crew door control panels - or at least it looks like.

Neil

 

[8J]

In the early days, the 507's were intended for use on the Northern Lines and 508's on Wirral lines. Nowadays they're mixed up. However they did for a time recently keep one unit exclusively for use on the Northern Line (507015) and one for the Wirral line (508139). This was to compare wheel wear between the tight curves of the Wirral Loop Line and the Northern Line. However you can regularly see 507015 on the Wirral Line but I have not seen 508139 as many times on the Northern Line.

 

[headshot119]

You can tell the difference between the a 507/508 when going over a gap in the current rail.

507 the lights stay on, 508 the lights all go off apart from the emergency ones.

 

[Bletchleyite]

You can tell the difference between the a 507/508 when going over a gap in the current rail.

507 the lights stay on, 508 the lights all go off apart from the emergency ones.

Didn't the Merseyrail ones have the bus line reinstated (the removal of which would cause that effect)? I'm pretty sure they did, and I have certainly never seen that effect on Merseyrail.

Neil

 

[prod_pep]

The lights do indeed regularly go off to this day on the 508s when crossing points, but there are exceptions to the rule.

 

[Bletchleyite]

The lights do indeed regularly go off to this day on the 508s when crossing points, but there are exceptions to the rule.

Never noticed 508s behaving any differently to 507s in this regard, and I spent my entire childhood riding the things on a daily basis. They sometimes I think started to fade as the motor-alternator set spun down on certain pointwork (i.e. where both power cars were gapped) but I never noticed 507s being any different.

Neil