Northern Line - unexpected route taken after Kennington (was 'wrong road')

[magd1272]

Standing on Platform 1 at Kennington on Sunday, I was surprised to see a "via Bank" train pull in. Not far into the tunnel, the driver made an announcement to say we'd been sent via Charing X without warning, and that those wanting Bank should return to Kennington. It caused no problem at all - we simply continued up the western branch and took the right road at Camden Town - but it made me wonder how often this sort of thing happens.

 

[Daniel]

'Wrong road' means a movement in the wrong direction, which this wasn't; it was a diversion via a different branch. This happens fairly often for a number of reasons on the Northern line, the most common of which is late running as the journey via the CHX branch is quicker than via Bank.
The on-train DMI is not directly linked to the signalling system and requires the driver's input to change, unlike the platform display which work directly off of the signalling data.

For the driver to say that s/he was diverted with no warning after leaving Kennington isn't technically true. Whilst s/he could have been diverted into Kennington 1 only after leaving the previous station, as soon as a diversion was inputted by the signaller an audible alarm would sound in the cab and a message would appear on the train operators display stating 'Destination Change' - the destination on the TOD would also change from, for example EDG-Y (Y = Bank) to EDG-X.

 

[magd1272]

Many thanks for your comprehensive reply, Daniel. That's interesting.

I was just intrigued because the driver sounded a bit surprised over the PA, saying something to effect of "We're now going via CHX; if you need stations to Bank then please alight at Waterloo and go back to Kennington." The platform indicators at Kennington were only displaying "Northbound trains", which probably didn't help, but the train was lightly loaded and I can't imagine too many people were inconvenienced.

 

[Busaholic]

'Wrong road' means a movement in the wrong direction, which this wasn't; it was a diversion via a different branch. This happens fairly often for a number of reasons on the Northern line, the most common of which is late running as the journey via the CHX branch is quicker than via Bank.
The on-train DMI is not directly linked to the signalling system and requires the driver's input to change, unlike the platform display which work directly off of the signalling data.

For the driver to say that s/he was diverted with no warning after leaving Kennington isn't technically true. Whilst s/he could have been diverted into Kennington 1 only after leaving the previous station, as soon as a diversion was inputted by the signaller an audible alarm would sound in the cab and a message would appear on the train operators display stating 'Destination Change' - the destination on the TOD would also change from, for example EDG-Y (Y = Bank) to EDG-X.

Any information yet as to whether this will still be feasible post-Battersea?

 

[Dstock7080]

Any information yet as to whether this will still be feasible post-Battersea?

There will still be the ability to hold 1 train in the Kennington loop while other trains continue to Battersea.

 

[Daniel]

Any information yet as to whether this will still be feasible post-Battersea?

Sorry, if what will be feasible? Diverting trains?

 

[berneyarms]

I would assume he means could a train from Morden take the Charing X branch after the extension to Battersea is added.

 

[swt_passenger]

I would assume he means could a train from Morden take the Charing X branch after the extension to Battersea is added.

As I understand it nothing changes with the existing layout in the vicinity of the platforms. The lines to/from Battersea are new junctions on the existing loop, which is retained because not all the CX branch service will run to Battersea.

 

[TheNewNo2]

Post-Battersea there's no reason they wouldn't get trains from Morden go via Charing Cross. It'll be when the line splits (into the Northern and Knorthern) that it may stop being an option, if only to avoid confusion of a "Northern" train on the "Knorthern" line.

 

[swt_passenger]

Post-Battersea there's no reason they wouldn't get trains from Morden go via Charing Cross. It'll be when the line splits (into the Northern and Knorthern) that it may stop being an option, if only to avoid confusion of a "Northern" train on the "Knorthern" line.

Yes, but even then the infrastructure wouldn't be likely to change. Isn't it likely that even when split into two lines some early and late trains will have to run from, and back to, Morden depot, whether empty or in service?

 

[Daniel]

Yes, but even then the infrastructure wouldn't be likely to change. Isn't it likely that even when split into two lines some early and late trains will have to run from, and back to, Morden depot, whether empty or in service?

Probably, as currently the depots have different equipment. Golders has a wheel lathe, Morden doesn't, Morden can address door faults, Golders can't.

 

[Busaholic]

Sorry, if what will be feasible? Diverting trains?

Apologies for my long delay in replying. Yes, I meant would it be physically possible for a train in service from Morden to be diverted onto the Charing Cross branch, either advertently or inadvertently? I gather the general consensus seems to be 'yes'.

 

[TheNewNo2]

Apologies for my long delay in replying. Yes, I meant would it be physically possible for a train in service from Morden to be diverted onto the Charing Cross branch, either advertently or inadvertently? I gather the general consensus seems to be 'yes'.

Unless they take away the points (which seems unlikely) or reprogram the TBTC software to be branch-specific (also unlikely) it would be possible.