What do you need/where can you divide trains?

[mr williams]

Those of you who work in the industry will know this inside out but for us lay people what is needed to be able to divide/connect trains. (I'm talking primarily about multiple unit-types rather than engine+coaches)

Presumably most divisions/joinings are done at major stations or junctions but what limits it being done anywhere? Obviously signalling and routeing on single-track lines comes into it and no doubt those nice people at Health & Safety are involved.

In days of old you'd see workmen jump down onto the track at stations and physically attach huge metal coupling chains but in these days of DMUs is it all automated/electric?

As an example (apologies to those of you not familiar with the area) could a DMU train from Cardiff be joined to one from Gloucester at Severn Tunnel junction so the combined units can head to Bristol, and be divided again on the return journey?

 

[O L Leigh]

About the only thing you must have is a permissive platform.

The usual principle behind railway signalling is to make sure that there is no more than one train in any one signal section, but obviously you need to get two trains into the same section if you're going to attach. So the signalling system is a little different.

As well as the normal main aspect signal there will be an associated position light signal. If the signal section is empty the train will be signalled normally using the main aspect signal. However, if the section is already occupied by a train and you want to get a second train in there to attach, the second train will be signalled down to a red and then the associated position light signal will clear giving the driver authority to proceed into the platform and warning him/her to go at caution, being prepared to stop as the line ahead may be occupied.

The main reason why attaching/dividing is done in a platform is because it is more efficient to combine this with a station stop, especially if one portion is running late. Passengers don't like stopping out in the middle of nowhere at the best of times, even when a service is timetabled to wait. Plus having a handy platform means you have a safe working environment in which to go in and out of the train checking things.

Modern units have auto-couplers that give the physical connection between unit as well as having a connector block that contains all the air and electrical connections. In most cases you just drive one train into the other one and, once you've checked that you've got a good connection so the units won't come apart and everything else looks huny-dory, you press a button in the cab to make the air and electrical connections.

O L Leigh

 

[rail-britain]

The above assumes it is a passenger train, hence using a platform
However the same also applies to any and all other types of trains
In the event the loco needs to be removed then the handbrake needs to be applied before the loco is detached

I used to observe many of the join / splits at Carstairs
The challenge here is that the station is not level
In most cases one of the trains still has a loco attached
However the loco brakes on the main train would be applied throughout
As above, the joining train would receive a "call-on" to allow it to proceed into the occupied section
For splitting only one train would be signalled
A similar process is used at terminus stations, where another loco arrives and the original loco is trapped as the train leaves

The process is almost identical for non-passenger trains
In some cases the "call-on" signal can remain on at all times to allow the shunting loco access to a manually controlled yard

In general there has not been much change in the joining / splitting of DMUs and EMUs, it just a change in the mechanical method
In Scotland it was quite common to see units joining and splitting, especially at the terminus stations (Glasgow Central, Glasgow QS, Edinburgh, Aberdeen, Ayr)
However, this practice has almost ceased

Something that does not appear to have changed is the access of a second (or even third) train into an already occupied platform at a terminus
For example at Glasgow Central
The first train will receive a single amber and stop in the platform
The second train will also receive a single amber, rather than a "call-on" signal, on passing that signal the driver wil not be aware the platform is already occupied, but will be aware of this on approaching the platform
Hence why the speed limit is lower beyond the final signal

 

[Geezertronic]

Also, the units have to be compatibe to be able to join together. Due to the variations in electrical configuration, onboard computer, physical coupling mechanism, plus some others that someone with more experience than me can comment on, you cannot just connect any unit to any unit.

 

[rail-britain]

Also, the units have to be compatibe to be able to join together

Not in all cases
They may be able to join, but one may not be able to control the other

For example a Class 314 can couple up to a Class 334, but only to remove it from the line

Equally, there are drawbars available so that locos can haul units
The brakes on the units being hauled are then disabled, typically restricting the train to 25mph
There is then the HST drawbar again so that a loco can haul the entire train, to which there is a 80mph speed restriction

 

[12CSVT]

It usually helps if there is a straight platform. When the class 156s first started running in Scotland in 1988 two units were diagrammed to be coupled together in the platform at Carlisle to form a 4 car service to Stranraer. More often than not delays would occur here and it was later found that curvature of the platform was the main problem.

In BR days loco hauled services frequently joined / split at Preston, Carstairs and Georgemas Junction (in fact some trains with Manchester and Liverpool portions would join at Preston and divide again at Carstairs for Glasgow and Edinburgh). At numerous locations individual coaches were attached to sleeper services (class 08 haulage in some cases) and only ceased at Plymouth in 2006.

 

[Tomnick]

For example at Glasgow Central
The first train will receive a single amber and stop in the platform
The second train will also receive a single amber, rather than a "call-on" signal, on passing that signal the driver wil not be aware the platform is already occupied, but will be aware of this on approaching the platform
Hence why the speed limit is lower beyond the final signal

I very much doubt that's the case, unless Glasgow Central's a horrendously non-standard installation (which I also doubt). Firstly, amber does not feature in aspect sequences - yellow is the aspect to which you refer. Secondly, anything signalled into an occupied platform can't be signalled in on a main aspect, regardless of whether it's the second, third or seventh movement - though there's one exception that I'm aware of (Skegness - mechanically signalled). If Glasgow is an exception to that, it's certainly close to being unique.

In some cases the "call-on" signal can remain on at all times to allow the shunting loco access to a manually controlled yard

It's certainly possible for the opposing locking to be omitted between a pair of shunt or subsidiary signals, to allow movements between, say, a yard and its headshunt without continually bothering the Signalman. I don't think this is permitted onto or off a passenger line though; it wouldn't normally be much use if a running line was involved in any case.

 

[GB]

The brakes on the units being hauled are then disabled, typically restricting the train to 25mph

More like 5mph surely!?

 

[The Barlow Boy]

Those of you who work in the industry will know this inside out but for us lay people what is needed to be able to divide/connect trains. (I'm talking primarily about multiple unit-types rather than engine+coaches)

Presumably most divisions/joinings are done at major stations or junctions but what limits it being done anywhere? Obviously signalling and routeing on single-track lines comes into it and no doubt those nice people at Health & Safety are involved.

In days of old you'd see workmen jump down onto the track at stations and physically attach huge metal coupling chains but in these days of DMUs is it all automated/electric?

As an example (apologies to those of you not familiar with the area) could a DMU train from Cardiff be joined to one from Gloucester at Severn Tunnel junction so the combined units can head to Bristol, and be divided again on the return journey?

All you need is a Driver to couple modern multiple unit trains to-gether. All modern trains are now fitted with auto-couplers of varying designs - and compatabilities - which will couple everything to-gether mechanically, electrically and pneumatically. The indications to show a successful coupling are in the driving cab. There's no more need of Sammi the Shunter or Colin the Coupler slinging a coupling on to a hook and joining pipes and cables and/or checking the vertical pins on a "Buckeye" coupler. As to location, where it's a regular occurance then provisions will be made in the signalling system at that location with a "calling-on" signal provided to indicate to a driver of the second - and subsequent train(s) - that the section ahead of the signal is occupied. If not, then the driver will be contacted by the signaller to give the driver permission to pass the signal at danger for the purposes of coupling to another train in the signal section ahead.
Mind you, having said that it now takes three times as long. A good coupler could get two '63 sets to-gether at Haywards Heath in less than a minute whilst the punters were getting on and off.

 

[jopsuk]

Coupling the 365s at Cambridge always looks a horrendously violent operation- the stationary set gets quite spectacularly rocked forward. Must be joyful the occasions when it doesn't quite work first time, especially for passngers already in the rear coach of the front unit (or middle unit, when a four is being added to an eight).

The Southern's high brake pipes and jumper cables was to make coupling safer, wasn't it?

 

[NSE]

Actually the 365's coupling together arn't too bad to be honest. I've been in the rear coach when its happened and was no more violent than the 377's coupling up at Haywards Heath.

 

[The Barlow Boy]

Coupling the 365s at Cambridge always looks a horrendously violent operation- the stationary set gets quite spectacularly rocked forward. Must be joyful the occasions when it doesn't quite work first time, especially for passngers already in the rear coach of the front unit (or middle unit, when a four is being added to an eight).

The Southern's high brake pipes and jumper cables was to make coupling safer, wasn't it?

It was actually to make it easier to couple/uncouple at platform level for the shunter. He didn't have to get down to track level. The Buckeyes fitted to S.R. stock were unique in that a tell-tale pin was fitted to the upper side of the coupling and the release chain was operated by a handle above the buffers. So as well as making things easier the system was indeed safer.
Now, you mention Cambridge. A few years ago I visited that fine seat of learning and upon my return went to join the four car train sitting in platform one which was advertised as the whatever to Kings Cross. I couldn't get in because all the doors were locked. I found a railperson type person on the platform and asked why the doors were locked. "Health and Safety, we're not allowed to have anyone in the train whilst an attachment is being made". (I ascertained it was waiting for another four to come up from Lynn). I was speechless - which was more than the guy inside the train was. He'd come down from Kings Cross, fallen asleep and was still asleep when the front was detached and the rear portion (which he was in) was locked.
Health and Safety my 4r5e!

 

[rail-britain]

More like 5mph surely!?

That is possible, please refer to the original text
typically restricting the speed to 25mph
It depends on the coupling type
The drawbar for the Class 15x sprinter allows short journeys at 5mph and in exceptional circumstances at speeds of up to 25mph

I remember a Class 156 vehicle that failed in Aberdeen and it was agreed to move it to Inverness on a Sunday
Initially the shunting in Aberdeen was done using a Class 156, limited to 5mph
The Class 47 was then attached on a drawbar
This combination was then moved at 5mph to Platform 7
The train then proceeded from Aberdeen to Inverness at 25mph

The same 25mph speed limit applies to one failed HST power car being hauled by a loco, but not an entire set so long as the brakes are correctly operating

 

[heart-of-wessex]

I remember when 442s I was on at Bournemouth used to get rammed on by the rear 442 coming on from the siding!

For locos, I don't know if this applies to the mainline but on the preserved line I worked on, drivers had to come to a stop before making contact with the coaches and then slowly buffer up to the coaches. Some drivers didn't do so.

I noticed when I was at Edinburgh watching the 67s come on to the sleeper stock. They didn't stop but simply rolled on to the set at around 5mph (maybe a bit more), and simply bang on to the coach, which made it jump and jolt!! I wouldn't have liked to be in the front berth!

 

[rail-britain]

For locos, I don't know if this applies to the mainline but on the preserved line I worked on, drivers had to come to a stop before making contact with the coaches and then slowly buffer up to the coaches. Some drivers didn't do so.

I noticed when I was at Edinburgh watching the 67s come on to the sleeper stock. They didn't stop but simply rolled on to the set at around 5mph (maybe a bit more), and simply bang on to the coach, which made it jump and jolt!! I wouldn't have liked to be in the front berth!

It depends on where the shunter is and in what position the buckeye coupling is
If this person is nearby then it is good manners to stop short and await their instruction to draw up to the coach
If the buckeye coupling is in the raised position then there is no point in drawing up to the coach
However, with the sleepers the outer coaches rarely have their buckeye couplings raised and the shunter will have confirmed that it is lowered so that the driver can draw up

 

[Crossover]

Have been on a coupling 185 before now (where we were going onto the front one) - not a rough experience as such but sent a jolt down the train (no lateral suspension!)

Also seem them been uncoupled by a fitter at Manchester on a couple of occasions too. From my understanding, there are many MU's (Desiros such as 185's been one of them) where the door interlocks have to be engaged in order for the movement to take place, otherwise the onboard systems throw a hissy fit and won't release the brakes or such

Have been on others through (such as the 375's uncoupling at Faversham) where the doors have been open when it is has taken place

 

[TGV]

There's usually a limit on the curve radius along with some alignment geometry limits that need to be observed.

 

[route101]

Interesting stuff. Has there been a time when the train splits while on the move ? come apart.

 

[TGV]

Interesting stuff. Has there been a time when the train splits while on the move ? come apart.

Happened to a 365 a couple of years ago. It's a rare event, but every now and then you'll hear a story of a train splitting in service. Not such a problem on a 365 - brake pipe splits, train comes to a halt no worries, but I'd not like to be in a train that has a gangway between sets if that happened. Sure the brakes would come on but that wouldn't help a poor sod with one foot on each unit at the time!

 

[Lee_Again]

I've never understood why 180's can't run as a pair from Kings Cross to Doncaster, then split and go of to Hull/Bradford/Sunderland, or where ever.

This would free a path from Kings Cross for other uses. Then Open Access operators could create more services if they combined some on the busy southern section.

Does anyone know if a 15 car 180 is allowed? Also, could a train split in the sidings south of Doncaster or does it have to be in a platform?

 

[142094]

I've never understood why 180's can't run as a pair from Kings Cross to Doncaster, then split and go of to Hull/Bradford/Sunderland, or where ever.

More than likely due to what it used to cover the Sunderland - KX workings - no point in doing it when it might be a HST. Also would mean that it would have to stop at Doncaster, when the Sunderland trains don't at present.

 

[O L Leigh]

Now, you mention Cambridge. A few years ago I visited that fine seat of learning and upon my return went to join the four car train sitting in platform one which was advertised as the whatever to Kings Cross. I couldn't get in because all the doors were locked. I found a railperson type person on the platform and asked why the doors were locked. "Health and Safety, we're not allowed to have anyone in the train whilst an attachment is being made". (I ascertained it was waiting for another four to come up from Lynn). I was speechless - which was more than the guy inside the train was. He'd come down from Kings Cross, fallen asleep and was still asleep when the front was detached and the rear portion (which he was in) was locked.
Health and Safety my 4r5e!

Normally the front unit would be left open until the rear unit arrives, but the doors MUST be closed on both units during the coupling operation for two very good reason.

The first is that with Tightlocks you sometimes have to give the units a bit of a belt which can cause quite a noticeable jolt along the entire train. If someone is just stepping on or off at that precise moment there is a risk that they might lose their footing due to the sudden and unexpected movement of the train relative to the platform.

The second reason is that these units (along with most modern unit) send a constant "Door Close" signal down the door control wires. If you couple to a unit with doors open, the instant that you press the couple button all the doors on that unit will slam shut without warning.

But once the units are coupled there will be another door release given for the entire train, so no-one misses out.

O L Leigh

 

[Lampshade]

I've never understood why 180's can't run as a pair from Kings Cross to Doncaster, then split and go of to Hull/Bradford/Sunderland, or where ever.

This would free a path from Kings Cross for other uses. Then Open Access operators could create more services if they combined some on the busy southern section.

Does anyone know if a 15 car 180 is allowed? Also, could a train split in the sidings south of Doncaster or does it have to be in a platform?

GC tried that the other week, the 180s refused to talk to each other at Kings Cross so one portion was cancelled. They were going to try again a week later but they didn't even attempt it and started the Bradford portion from Doncaster.

 

[route101]

Happened to a 365 a couple of years ago. It's a rare event, but every now and then you'll hear a story of a train splitting in service. Not such a problem on a 365 - brake pipe splits, train comes to a halt no worries, but I'd not like to be in a train that has a gangway between sets if that happened. Sure the brakes would come on but that wouldn't help a poor sod with one foot on each unit at the time!

Mmm so the second pair is out of control

 

[O L Leigh]

Happened to a 365 a couple of years ago. It's a rare event, but every now and then you'll hear a story of a train splitting in service. Not such a problem on a 365 - brake pipe splits, train comes to a halt no worries, but I'd not like to be in a train that has a gangway between sets if that happened. Sure the brakes would come on but that wouldn't help a poor sod with one foot on each unit at the time!

There is no brake pipe to split. What happens instead is that the brake continuity wire would be broken initiating a simultaneous emergency brake application on both portions.

Even where a unit has a gangway, because both portions go into an emergency stop simultaneously they generally come to a stand no more than a few feet apart, though often significantly less. There have been occasions where a driver has not been aware of a train dividing because the two portions have come to a stand still touching each other, though just not sufficiently to maintain brake continuity. Therefore, while it is possible for someone to disappear through the gangway, the gap between the units is likely to be modest and not open suddenly. However, the first actions in such a situation would be to secure the gangways and ascertain if anyone is missing from the train.

O L Leigh

 

[The Barlow Boy]

Interesting stuff. Has there been a time when the train splits while on the move ? come apart.

One of the original Gatwick Express sets parted whilst leaving Victoria a few years ago and a few of the then newly allocated 455s on the Central division parted whilst pulling away from stations where they'd been (supposedly) coupled. More recently, didn't a Eurostar power car go walkabout?
--- old post above --- --- new post below ---

It depends on where the shunter is and in what position the buckeye coupling is
If this person is nearby then it is good manners to stop short and await their instruction to draw up to the coach
If the buckeye coupling is in the raised position then there is no point in drawing up to the coach
However, with the sleepers the outer coaches rarely have their buckeye couplings raised and the shunter will have confirmed that it is lowered so that the driver can draw up

There used to be an instruction that the driver stopped 6-8 feet short, then drew forward to couple.

 

[jopsuk]

Now, you mention Cambridge. A few years ago I visited that fine seat of learning and upon my return went to join the four car train sitting in platform one which was advertised as the whatever to Kings Cross. I couldn't get in because all the doors were locked. I found a railperson type person on the platform and asked why the doors were locked. "Health and Safety, we're not allowed to have anyone in the train whilst an attachment is being made". (I ascertained it was waiting for another four to come up from Lynn). I was speechless - which was more than the guy inside the train was. He'd come down from Kings Cross, fallen asleep and was still asleep when the front was detached and the rear portion (which he was in) was locked.
Health and Safety my 4r5e!

Very odd response, given that in the three and a half years I've been in Cambridge, almost everytime I've seen the trains being coupled there's been people in the front unit. They have to shut the doors, yes, but that's because even the "stationary" unit moves quite a bit- if a passenger wasn't paying attention at the crucial moment they WOULD get seriously hurt. The morning 12 car trains have their front eight cars pretty much full by the time the rear four arrive from Kings Lynn.

 

[O L Leigh]

It does also have the effect of distributing the punters more evenly along the entire train, though that is just incidental.

O L Leigh

 

[12CSVT]

Interesting stuff. Has there been a time when the train splits while on the move ? come apart.

It did happen in Penge Tunnel (Victoria - Bromley South line) about 2 years ago involving class 465 or 466 networker stock. Evening peak - caused chaos for the rest of the day.

 

[Lee_Again]

GC tried that the other week, the 180s refused to talk to each other at Kings Cross so one portion was cancelled. They were going to try again a week later but they didn't even attempt it and started the Bradford portion from Doncaster.

Didn't these things run in pairs on the GW. I'm sure I've been on a 10 coach 180. Maybe my mind's playing tricks again.

Also, why don't these companies 'play trains' in the privacy of a depot. Why do it in a station and worse, on a scheduled train. Surely you'd learn that on day one of even the most basic managerial course.