Chiltern Mainline problems 9/5/13

[ChilternHenry]

Does anyone have any news on what is causing all the disruption on the Chiltern Mainline today, took a good while longer for me to get home today. Thanks in advance

 

[Bald Rick]

Tree on the line Harrow and train problem Princes Risboro' at roughly the same time this eve.

 

[Daniel]

I don't know specifically about problems on the Mainline, but there was (half) a rather large tree on the line just south of Harrow-on-the-Hill. As it was on the NR side of the boundry LU staff could only attend in relation to signalling equipment, so I don't really have much information about the incident response.

 

[MK Tom]

Given the limited capacity of the throat between Marylebone and the junction where the main and Aylesbury lines split, serious delays on one would begin to affect the other.

 

[TDK]

Given the limited capacity of the throat between Marylebone and the junction where the main and Aylesbury lines split, serious delays on one would begin to affect the other.

Not necessarily as Neasden Junction is a fair way from Harrow, the only delays this would cause would be the extra services needed to go mainline to Aylesbury via High Wycombe

 

[Cherry_Picker]

There are only a couple of stop signals between Neasden Junction and Harrow though. It could get backed up pretty quickly given the lack of places you can hold trains.

 

[barrykas]

Biggest queue I can recall in recent years was a train at every signal from ME10 back to Sudbury Hill...

 

[Cherry_Picker]

Ouch. That has got to be getting on for ten miles. You don't really get to see these things as a driver, though there is an odd satisfaction is running out on greens while every peg on the other road has a train standing at it.
I suppose it is akin to when you are driving in free flowing traffic on the motorway while the other carriageway is at a standstill.

 

[Daniel]

Not necessarily as Neasden Junction is a fair way from Harrow, the only delays this would cause would be the extra services needed to go mainline to Aylesbury via High Wycombe

As far as I am aware, the only signals past Neasden Junction (to Harrow) on the Down line are ME27 and JB1, and on the Up are ME25 and JB40. With that in mind, there is very little capacity between the Neasden and Harrow South junctions. As JB1 is quite close to Harrow itself, in this particular incident, only a single train on the Down road could have been accommodated, with the route being blocked, at ME27. Once the first train had been sent towards Harrow, anything else would have had to have been diverted via the main line.
This is also considering I am unaware how quickly the situation was relayed to Chiltern Railways control and Network Rail's signallers. I had a relatively brief points failure at Harrow South the other afternoon, and almost immediately had Chiltern asking for an update, as their services were being held at Marylebone. With such a tight throat at this location, a small delay to any service can affect other services in the area.

Ouch. That has got to be getting on for ten miles. You don't really get to see these things as a driver, though there is an odd satisfaction is running out on greens while every peg on the other road has a train standing at it.
I suppose it is akin to when you are driving in free flowing traffic on the motorway while the other carriageway is at a standstill.

It's absolutely lovely, hammering up the Northbound Met between Finchley Road and Wembley Park, counting the Jubilee Line trains stuck in section owing to a failure. Not that it happens often on the Jubilee line, of course...