Use of couplers on LU trains

[TwistedMentat]

To the best of my knowledge these days all Underground trains are essentially semi-permanently coupled units that are the full length of the platforms they serve.

This got me wondering yesterday travelling through London. Do Underground trains often couple with other trains? Or are the couplers largely there for shunting and rescue use?

Looking at the couplers they do not appear to get much use with no obvious bits that have been worn down or rubbed up against another coupler.

 

[bramling]

To the best of my knowledge these days all Underground trains are essentially semi-permanently coupled units that are the full length of the platforms they serve.

This got me wondering yesterday travelling through London. Do Underground trains often couple with other trains? Or are the couplers largely there for shunting and rescue use?

Looking at the couplers they do not appear to get much use with no obvious bits that have been worn down or rubbed up against another coupler.

Not necessarily.

Everything is still made up of units. Some lines (e.g. Bakerloo, Central, Jubilee, Piccadilly) do swap the units around on a pretty regular basis, whilst the rest generally leave them in their as-delivered pairs. The Northern for example has just a small handful of mis-formed trains which have occurred for various reasons, the Vic to my knowledge is all as delivered. It's very common for the trains to be uncoupled down to their individual units in depots.

The couplers on driving cabs are purely for emergency use on those cabs which can only be formed at the ends of train formations. As such basically the only use they see is during a 'pushout' situation (*very* rare), or during training for pushouts.

 

[Dstock7080]

Everything is still made up of units.

S Stock are not made up of units, they are block trains as they do not have auto-couplers in the 'middle'. Cars can only be uncoupled in a depot by engineering staff.
Victoria Line '09 Stock do have auto-couplers in the middle and can be uncoupled by a driver in certain circumstances.

 

[philthetube]

Although Sstock are not made up of units the two halves are identical.

 

[Domh245]

Although Sstock are not made up of units the two halves are identical.

Other than where one half has 3 cars and the other has 4

 

[bluegoblin7]

Other than where one half has 3 cars and the other has 4

And also the de-icing S8s.

 

[philthetube]

Other than where one half has 3 cars and the other has 4

And also the de-icing S8s.

Both points conceded.

 

[TwistedMentat]

Cheers folks.

So if I'm getting this right, there are still some lines with stock that can and is often decoupled into 2 independent units. While for the more recent stock that is built as a single full length unit (like the S-stock) the couplers at each end are intended more for emergency usage than routine couple and decoupling.

 

[bluegoblin7]

Cheers folks.

So if I'm getting this right, there are still some lines with stock that can and is often decoupled into 2 independent units. While for the more recent stock that is built as a single full length unit (like the S-stock) the couplers at each end are intended more for emergency usage than routine couple and decoupling.

All trains bar the S stock are capable of being decoupled into smaller units but won't* run in service as such. The outer couplers ("wedgelocks") are used solely for emergency use**, whilst the inner ends will only be separated in a depot. As stated already, however, the 2009TS, 1995TS and 1992TS on the W&C have broadly remained with their original counterparts.

Bit, of course, it's the Underground, so there's always exceptions:
*1973TS has a number of double-ended vehicles that are capable of operating as a single, three-car unit. Whilst this hasn't happened in service for many years, two 3-car units were used during leaffall as temporary Sandite units. The 1992TS is made up of two car units coupled together. It's possible to operate 4-, 6- and 8-car (the norm) trains; 4-car sets were trialled last year with a view to re-instating the Woodford-Hainault shuttle, but this idea has now been put on the back burner.

**In the case of double ended units obviously one end becomes the middle, so these couplers are used routinely for non-emergency use.

 

[rebmcr]

You can tell when 1973TS has been formed oddly, as the vertical fairings intended to streamline the middle of a train 'stick out' from the usually rounded cab end.

I've been unable to find an example image of this, however.

 

[DanNCL]

You can tell when 1973TS has been formed oddly, as the vertical fairings intended to streamline the middle of a train 'stick out' from the usually rounded cab end.

I've been unable to find an example image of this, however.

Is this what you're thinking of?

(not my image)

 

[Domh245]

That looks like the one, although it's worth noting that they aren't for streamlining, but for attaching intercar barriers.

 

[jopsuk]

The 1992TS is made up of two car units coupled together. It's possible to operate 4-, 6- and 8-car (the norm) trains; 4-car sets were trialled last year with a view to re-instating the Woodford-Hainault shuttle, but this idea has now been put on the back burner.

There are of course 5 trains formed of 4 cars of 1992TS in everyday use.

The Bakerloo 1972 stock has a DM on the inner end of the four car unit, coupled to the UNDM, but the cab is not fully operational- this is the one that isn't painted red. Presumably it is used in the depot?

 

[ChiefPlanner]

There are of course 5 trains formed of 4 cars of 1992TS in everyday use.

The Bakerloo 1972 stock has a DM on the inner end of the four car unit, coupled to the UNDM, but the cab is not fully operational- this is the one that isn't painted red. Presumably it is used in the depot?

Presume so , not an expert by any means , but a minimal shunting control in the "uncoupling non driving motor" - just a brake gauge, power handle and brake handle ? ....

 

[philthetube]

There are of course 5 trains formed of 4 cars of 1992TS in everyday use.

The Bakerloo 1972 stock has a DM on the inner end of the four car unit, coupled to the UNDM, but the cab is not fully operational- this is the one that isn't painted red. Presumably it is used in the depot?

It is operational but not kit out for service, additions such as door buttons and other upgrades done to the end cabs have not been done, they are basically in an as new condition, not aesthetically.

 

[Mojo]

You can tell when 1973TS has been formed oddly,

What do you mean by “formed oddly?” Both ends of double ended units are like this, for reasons stated above.

 

[rebmcr]

What do you mean by “formed oddly?” Both ends of double ended units are like this, for reasons stated above.

It's still much more uncommon to see that end on the outside, though.

 

[100andthirty]

There are roughly 20 double ended units. Both ends are fitted with the attachment points for the inter car barriers. So, roughly 20 trains are running with the inter car barrier attachment points at one end.

 

[Mojo]

It's still much more uncommon to see that end on the outside, though.

The ‘fins’ are on both ends of the unit, and one end of the unit would always be on the outside because trains are only formed of two units.

 

[rebmcr]

There are roughly 20 double ended units. Both ends are fitted with the attachment points for the inter car barriers. So, roughly 20 trains are running with the inter car barrier attachment points at one end.

The ‘fins’ are on both ends of the unit, and one end of the unit would always be on the outside because trains are only formed of two units.

Ahhh I see. Thanks for clarifying that!