ECML South disruption - OLE down 09/12

[GRALISTAIR]

Things *seem* to be getting back to normal this morning. A few late departures owing to disrupted staff, but nothing out of the ordinary.

And I suppose Thameslink should as well, on the arguably more heavily trafficked section south of Peterborough?

Most of Peterborough - Doncaster (well, Grantham - Doncaster) is two-track with single-track cantilevers which don't bring the same level of chaos that headspans do when the wires go down (although there are some headspans here & there).
It would be a lot easier in terms of possessions to re-engineer the OLE north of P'boro as you have longer windows of time in which to do the work on Saturday nights; those full 10-hour possessions are a luxury the routes nearer London don't have.

10 year rolling plan to convert all headspans to portals?

 

[59CosG95]

10 year rolling plan to convert all headspans to portals?

I wish! Let's hope something of that ilk pops up in my lifetime...

 

[Nicholas Lewis]

10 year rolling plan to convert all headspans to portals?

Headspans aren't not ideal but nor is trying to replace all swathes of it. What is needed is to improve the resilience of what we have although of course we don't know what the cause of the recent failures have been but with so many train pans now incorporating pan videos there will be plenty of video to look at to get answers.

 

[Samzino]

Headspans aren't not ideal but nor is trying to replace all swathes of it. What is needed is to improve the resilience of what we have although of course we don't know what the cause of the recent failures have been but with so many train pans now incorporating pan videos there will be plenty of video to look at to get answers.

Headspans aren't fail safe and are a dated technology. If one wire falls it usually brings the whole span down which is what the newer versions prevent. Procrastinating imo is what has been leading to all these reoccurs.

Series one or two OHLE would ideally be a good approach to consider but it all costs money and time however that will need to be weighted against the cost of OHLE induced delays and cancellations.

 

[Nicholas Lewis]

Headspans aren't fail safe and are a dated technology. If one wire falls it usually brings the whole span down which is what the newer versions prevent. Procrastinating imo is what has been leading to all these reoccurs.

Not saying they aren't ideal but we don't know the root cause of the latest failure. BR used to run campaigns to change out components that were known problem areas does that still happen?

Series one or two OHLE would ideally be a good approach to consider but it all costs money and time however that will need to be weighted against the cost of OHLE induced delays and cancellations.

New electrification has become unaffordable trying to rebuild existing kit wont be any cheaper.

 

[Samzino]

Not saying they aren't ideal but we don't know the root cause of the latest failure. BR used to run campaigns to change out components that were known problem areas does that still happen?

New electrification has become unaffordable trying to rebuild existing kit wont be any cheaper.

Whilst we may not know the cause we know however the result of it and the fact that where the cause started was enough to cause multiple line issues instead of affecting the one area of line/ track. Series one or Portals are also relatively mature technology that's already on WCML and Certain bits of the GWML of which those areas hardly have the issues we see with dated headspan technology.

 

[zwk500]

I wish! Let's hope something of that ilk pops up in my lifetime...

There was definitely a trial Headspan to Portal conversion scheme pre.covid. not sure if it was MML or ECML.

 

[josh-j]

I just happened upon this article from 2019 which mentions a conversion at Connington on the ECML:

The Connington area, on the East Coast main line south of Peterborough, experiences relatively high windspeeds and, as such, is prone to dewirements, resulting in significant train delays over recent years. Network Rail identified this area for conversion to portals to help build resilience into the OLE system. Arup was commissioned to prepare a design study to look at replacing several headspans in the area

With the conversion of 30 headspans completed, Arup can look to the future. The next step is to convert a complete tension length, including all of the complex structures that were left out in this conversion project. Further evaluation of the complex structures will be required as part of a new feasibility study and the performance improvement gain is expected to be considerable.

There are photos of some of the converted structures

 

[Silver Cobra]

There was definitely a trial Headspan to Portal conversion scheme pre.covid. not sure if it was MML or ECML.

Some of the head spans between Huntingdon and Peterborough were converted to portal-like setups, alongside a very small number near Potters Bar.

 

[59CosG95]

There was definitely a trial Headspan to Portal conversion scheme pre.covid. not sure if it was MML or ECML.

I just happened upon this article from 2019 which mentions a conversion at Connington on the ECML:


There are photos of some of the converted structures

Some of the head spans between Huntingdon and Peterborough were converted to portal-like setups, alongside a very small number near Potters Bar.

As all of you have said, it was ECML - top marks for Conington!
One was indeed done at Potters Bar, using a different design of boom.

There have also been examples on the MML (one at Borehamwood Neutral Section, and one more recently at the new East Hyde Neutral Section), and several on the GWML (one near Westbourne Park, and 3 in the Acton Main Line area).

With the possible exception of the Western Route's work, all of these have been one-offs or trials. AFAIK there's been nothing solid to suggest full-scale replacement, even on the GWML where the numbers of total headspans are the smallest out of the 125mph main lines.