How many centre cars in a 158/159

[BlueLeanie]

What's the technical maximum number of centre cars (actual centre cars rather than reconfigured driving units) that can operate within a 158 unit, and the maximum that have operated either in service or part of a stock manoeuvre?

 

[norbitonflyer]

As far as I am aware no 158 or 159 unit has operated with more than one centre car, although of course a complete train (of more than one unit) may have two or even three. Some SWR formations are 9-car (3x3) or even ten (2x3 + 2x2). Whether there are any technical impediments to coupling two or more centre cars together, I know not.

 

[Wilts Wanderer]

https://www.reddit.com/r/uktrains/comments/1hpnc03/a_4_car_158_two_brandnew_intermediate_vehicles_on/?rdt=34104

This is the only time I’ve ever seen evidence of a unit operating with more than one centre car.

 

[BlueLeanie]

https://www.reddit.com/r/uktrains/comments/1hpnc03/a_4_car_158_two_brandnew_intermediate_vehicles_on/?rdt=34104

This is the only time I’ve ever seen evidence of a unit operating with more than one centre car.

Somehow that looks quite beautiful.

 

[Wilts Wanderer]

Somehow that looks quite beautiful.

Its certainly the best livery they’ve ever carried, although I must admit I liked the Northern Spirit version of WYPTE colours which only one or two examples ever wore.

 

[sprinterguy]

...although I must admit I liked the Northern Spirit version of WYPTE colours which only one or two examples ever wore.

Just the one, 158909.

== Doublepost prevention - post automatically merged: 10 Apr 2025 ==

What's the technical maximum number of centre cars (actual centre cars rather than reconfigured driving units) that can operate within a 158 unit, and the maximum that have operated either in service or part of a stock manoeuvre?

If I recall rightly, each centre car counts as a "cab", and 158s can operate up to a maximum of twelve cabs in a formation, so you could in theory have a 12 car 158 unit with ten intermediate cars. As noted above, though, I think the maximum is two intermediates on delivery runs.

 

[CR165022]

https://www.reddit.com/r/uktrains/comments/1hpnc03/a_4_car_158_two_brandnew_intermediate_vehicles_on/?rdt=34104

This is the only time I’ve ever seen evidence of a unit operating with more than one centre car.

I seem to remember this also happened with a SWT 159 a while back.

 

[Bigfoot]

There's something to do with the control voltage drop that limits the length of memory serves.

 

[D365]

There's something to do with the control voltage drop that limits the length of memory serves.

That in itself doesn’t limit the number of centre cars. Would I be right in saying that nine car 159s are timetabled out of Waterloo?

 

[JonathanH]

That in itself doesn’t limit the number of centre cars. Would I be right in saying that nine car 159s are timetabled out of Waterloo?

Yes, 0920, 1620 and 1823 on RTT today. There was a time prior to 2020 when there was a 10 car working (2 158s and 2 159s)

 

[Sun Chariot]

....you could in theory have a 12 car 158 unit with ten intermediate cars.

When the 158s were first introduced, BR ran a staff special (I think across the Hope Valley) consisting of six 2-car 158s. Photos of it were in the railway magazines of the day.

 

[sprinterguy]

When the 158s were first introduced, BR ran a staff special (I think across the Hope Valley) consisting of six 2-car 158s. Photos of it were in the railway magazines of the day.

Yeah, a round trip from Derby on 13 October 1990, there's a photo reproduced in 'The Regional Railways Story', published 2015.

 

[BlueLeanie]

As the time draws ever closer, say 5 years or so, to the withdrawal of 158 from day to day duties, would they make a good purchase for a Charter company to acquire say half a dozen driving units, and 12 centre coaches?

A late 1980s version of the Hastings set for spot hire.

 

[Bigfoot]

That in itself doesn’t limit the number of centre cars. Would I be right in saying that nine car 159s are timetabled out of Waterloo?

It limits the total overall length, which in turn limits the center car maximum.

My understanding is that each centre car is not different mechanically compared to a coach with a cab.

 

[lewisf]

They don’t even have to be centre cars. GWR have a number of 3 car units that are made of 3 driving cars with a cab in the middle

 

[TheHovisKid]

Was there not something to do with the number of brakes controllers in the formation? I'm sure that was given as a reason why cabs buried in a 3 car set used to lose them.

 

[Big Jumby 74]

In SWT days both 9 car and 10 car formations were in the base plan, and I suspect 9 cars still are, but were/are formed of set units, ie: 3 x 159, or 2 x 159 + 2 x 158. Whilst the centre car of a 159 may well have been removed on odd occasions for out of course maintenance reasons (this was never part of 'planned' maintenance regime), AFAIK no SWT unit was ever formed up with more than its booked number of centre cars.

A major factor in this regard being the maintenance shed at Salisbury can only accommodate 3 cars (a single 159) on each of its four roads. But also operationally, any out of course (longer than booked, ie 4 car 159 as a single unit) would have the potential of causing more problems than its worth, when it comes to platform occupancy etc, splitting/joining with other diagrams during the course of any given day etc. It wouldn't be entertained, unless it was for specific test/trial purposes, in which case a host of special instructions, revised unit/crew diagram detail etc etc, would need to be in place.

 

[norbitonflyer]

I would expect even if two 3-car sets each lost a driving car (collision damage or fault in the cabs) you would probably use three of the remaining cars to make one good 3-car set, and the remaining non-driving car to make up a 2-car to a second 3-car, rather than have a lone 4-car.

 

[D365]

It limits the total overall length, which in turn limits the center car maximum.

My understanding is that each centre car is not different mechanically compared to a coach with a cab.

My point was that, when considering 15x units specifically (other than 153), the composition of driving vs centre cars makes no difference to the maximum permissible train length. In either case, 12 car units are not permissible in regular passenger service due to the voltage drop affecting the operation of door control relays.

 

[JN114]

For 158s (and I assume therefore 159s), they are treated exactly the same as driving vehicles; as with all Sprinter types 12 vehicles maximum in formation, with each single 153 counting double.

So on paper, in theory, I guess you could probably run a 12 car 158/159 with 2x driving coaches and 10x intermediate coaches - but it would be impractically long for most things such as maintenance, station working and so forth.

The driving cabs really don’t “waste” much useful space on a 158/159, I would have thought for a hypothetical future charter operation you would have a fleet of 2 car units that you could multi together to make the required length of train to meet demand.

 

[BlueLeanie]

For 158s (and I assume therefore 159s), they are treated exactly the same as driving vehicles; as with all Sprinter types 12 vehicles maximum in formation, with each single 153 counting double.

So on paper, in theory, I guess you could probably run a 12 car 158/159 with 2x driving coaches and 10x intermediate coaches - but it would be impractically long for most things such as maintenance, station working and so forth.

The driving cabs really don’t “waste” much useful space on a 158/159, I would have thought for a hypothetical future charter operation you would have a fleet of 2 car units that you could multi together to make the required length of train to meet demand.

The passenger experience is quite different going between units and theough a unit with centre cars though.

 

[david1212]

As the time draws ever closer, say 5 years or so, to the withdrawal of 158 from day to day duties, would they make a good purchase for a Charter company to acquire say half a dozen driving units, and 12 centre coaches?

A late 1980s version of the Hastings set for spot hire.

Certainly they would be suitable for additional services to various events ( see the discussion regarding Chiltern today ( 13/04/25 )) here.
They are 23m so presumably some route limitations.
However in reality by the time they are released by a TOC / lease company will they need so much work both mechanically and structurally as to be unviable. I expect a few to turn up on a preserved line but then only a relatively low mileage at no more than 25mph.

 

[Steddenm]

Slightly off topic, but still in the 15x fleet, could a 155 or 156 be extended to a 3-car set by plonking a 153 in the middle of it?

 

[Efini92]

There's something to do with the control voltage drop that limits the length of memory serves.

That’s what we were taught, something about the voltage weakens as it goes through all the bsi couplers.
Though the centre cars use jumper cables so theoretically I guess you could have more than 12 if they didn’t weaken the voltage.

 

[sprinterguy]

Slightly off topic, but still in the 15x fleet, could a 155 or 156 be extended to a 3-car set by plonking a 153 in the middle of it?

I would imagine so, given that 2-car 156/153 hybrids have operated in the past when a 156 vehicle in a set has suffered damage.

 

[norbitonflyer]

I would imagine so, given that 2-car 156/153 hybrids have operated in the past when a 156 vehicle in a set has suffered damage.

You could, but why not put it at one end of the train?

 

[sprinterguy]

You could, but why not put it at one end of the train?

That'd certainly be the simplest option, as per the Scotrail units on the West Highland line now.

 

[Killingworth]

That'd certainly be the simplest option, as per the Scotrail units on the West Highland line now.

153s and 156s were substituted for 158s on Liverpool-Norwich until EMR got rid of both. Limited to 75 against the 158's 90 they were just about adequate but had no margin to recover any lost time. I understand the 153's braking efficiency may also be less than a 156 so that can also impede performance. But adding a unit to top or tail is by far the simplest option.

 

[Helvellyn]

I think the original Provincial/Regional Railways plan for the 158s looked at 4-car units for both ScotRail and TransPennine. I remember some Platform 5 books showing speculative formations/allocations before build began. The transfer of 66 vehicles to Network SouthEast (aka the original 22 3-car 159s) probably put paid to that. Plus I wonder if someone realised 2 x 2-car to run as a 4-car might offer more resilience in that if you had a fault you could still run a 2-car at least rather than cancel a whole train.