Odd Happening at London Bridge 22/01

[Minstral25]

On Thursday the 18:26 London Bridge to Reigate/Horsham apparently left the station some distance, stopped and then reversed back before leaving London Bridge again almost an hour late causing disruption all round. Any idea what happened?

 

[Bald Rick]

On Thursday the 18:26 London Bridge to Reigate/Horsham apparently left the station some distance, stopped and then reversed back before leaving London Bridge again almost an hour late causing disruption all round. Any idea what happened?

Wrongly routed at South Bermondsey, and driver didn't sign the route via Peckham.

 

[Minstral25]

Thank you

Interesting that would mean potentially stop at Norwood Junction could be missed depending on route taken.

Similar Happened to 7:40 Reigate to Victoria yesterday as well, incorrectly routed via Crystal Palace and arrival at Victoria was over an hour late.

Why does this happen.

 

[W230]

Similar Happened to 7:40 Reigate to Victoria yesterday as well, incorrectly routed via Crystal Palace and arrival at Victoria was over an hour late.

Why does this happen.

It shouldn't. But it sometimes does. Interestingly we had been told to accept a wrong route originally following the London Bridge resignalling due to it causing too much of a back log with services if it happened. But as you can see, if the driver doesn't sign the "wrong" route then it's not possible anyway.

 

[Bald Rick]

Signaller error, usually for one of three reasons:

1) An incorrect head code inserted for the train, signaller then routes according to that. Most often occurs at first junction after a terminal station, as per this example, or first junction on a new panel.

2) a head code oddity, eg all 'J' head codes normally get routed to line whatever, except for 2J78; or the head codes are changed for amended timetables caused by engineering works

3) 'reading back' - a signaller has, say, three trains approaching a diverging junction on one line, the first two going straight on, the third turning left. The signaller sees the headcode for the third train, but sets the divergent route for the second. Northbound trains from Ely were a favourite for this.

Note this is not to blame signallers. A typical signaller in a busy box will make over a thousand signalling actions, including several hundred routing decisions in a shift. He/she might make 1 or 2 mis-routings a year. That is a very good accuracy rate. Also note that under normal signalling, a mis routing is perfectly safe, as the integrity of the signalling system is held at all times.

 

[Yabbadabba]

Wrongly routed at South Bermondsey, and driver didn't sign the route via Peckham.

I thought it looked like a bit of a Mexican at South Bermondsey with that 5Uxx standing face to face with it.

 

[tsr]

Wrongly routed at South Bermondsey, and driver didn't sign the route via Peckham.

I'm not 100% sure, but I believe under usual circumstances the conductor taking that service from London Bridge wouldn't sign that route either. That's assuming crew changeovers happened as usual that day.

I thought it looked like a bit of a Mexican at South Bermondsey with that 5Uxx standing face to face with it.

That's how I understood it was initially recorded - stand off between services - but it then turned out it would have been unsafe for the passenger service to proceed anyway, due to route knowledge.

 

[southerner2174]

It wouldn't have made any difference if the conductor signed the route or not, if the driver had signed the route the train could have been made DOO between South Bermondsey and Norwood Junction and then gone as booked, as it happened the driver didn't sign it so back it went :roll:

 

[Minstral25]

I'm not 100% sure, but I believe under usual circumstances the conductor taking that service from London Bridge wouldn't sign that route either. That's assuming crew changeovers happened as usual that day.



That's how I understood it was initially recorded - stand off between services - but it then turned out it would have been unsafe for the passenger service to proceed anyway, due to route knowledge.

Erm - wouldn't a stand off between trains mean they were routed down same track in opposite directions. Presumably signals would not let them get close but not a good situation either?

 

[tsr]

It wouldn't have made any difference if the conductor signed the route or not, if the driver had signed the route the train could have been made DOO between South Bermondsey and Norwood Junction and then gone as booked, as it happened the driver didn't sign it so back it went :roll:

Southern conductors should be trained to challenge a route they don't sign as soon as they are aware they are set to take it, in practice usually by alerting the driver. You would then have to get Control's permission to run DOO with a service booked to have a conductor, which certainly doesn't always happen and I can think of instances where it hasn't. And the driver might not be happy either. Indeed, I am very reliably informed that some depots used to avoid the extra days needed for conductors to sign the South Bermondsey route during their initial training, with the result that some trains were unable to be diverted during one bout of particularly severe disruption and the resulting chaos meaning the route was hurriedly put back into certain depots' standard route knowledge.

Erm - wouldn't a stand off between trains mean they were routed down same track in opposite directions. Presumably signals would not let them get close but not a good situation either?

AFAIK, you are correct in that the phrase "stand off" meant something of that nature and that was initially thought to have been what happened. I can only quote what I was told as I was not viewing any live signalling output at the specific time this happened, nor was I in the London Bridge area.

 

[Bald Rick]

Erm - wouldn't a stand off between trains mean they were routed down same track in opposite directions. Presumably signals would not let them get close but not a good situation either?

Possibly, but not necessarily, and I don't know the facts in this case. What it means is that the route for train A is blocked by train B and vice versa. Happens a lot in the Stratford area with long freight trains even when they are on different lines.

But it is absolutely the case that the signalling system would prevent a collision at London Bridge - Even if it was both trains on the same line, AND both went passed the relevant protecting signals at danger, TPWS would have stopped them both in the respective overlaps. Conflicting routes set concurrently cannot share an overlap.