Post by stanmorek on Oct 3, 2009 11:11:28 GMT
Permanent Way Institution - London Section Meeting
Victoria Line Upgrade Project - Trackwork
At 55 Broadway St James’ Park 8 June 2009
Presented by John Hardy (London Underground Ltd)
Introduction
The Victoria line was constructed in 1967 and had life expired track assets at the commencement of the Public Private Partnership (PPP) Contract in 2003. Metronet Rail BCV (MRBCV) was required to replace the current rolling stock and the signalling system for the Victoria Line Upgrade (VLU) Project. The PPP requirements are to increase capacity measured through Journey Time Capability (JTC) on the Victoria line by 2012.
Track Programme
The PPP Contract requirements for the Victoria line track assets were to maintain track condition at Maintenance Standard as outlined in LUL track standards. This is a minimum maintainable standard. The condition of the track inherited by MRBCV was in a poor state such that 24-hourly patrolling was required between Seven Sisters and Kings Cross. As a consequence there was little time for track maintenance in this section and this would pose potential access problems for the planned line upgrade works. Considering this and other issues, MRBCV in order to deliver the full benefits of VLU, re-scoped its Track Programme to include renewal, rail-wheel interface and a track maintenance strategy.
Victoria Line Upgrade Project
MRBCV bore in mind the need for effective delivery of the VLU and to also integrate this with an effective maintenance strategy. For instance track renewed in 2006 will not realise the full benefits until all upgrade works are completed in 2012. Also in its contract with Bombardier, with respect to new rolling stock, there are minimum track geometry requirements. These include ride quality, rail corrugation and track gauge. Then there was also work required for gauge clearance surveys of line side equipment. Another feature is the power upgrade works with the replacement of standard 64kg/m conductor rails with composite conductor rail (CCR) to minimise power loss and reduce the number of sub-stations.
Track Quality
Early on in the life of VLU, the common faults to track quality included tight gauge, top and line, track twist and voiding under sleepers though track maintenance standard was maintained. To aid the VLU, the Track Programme was scoped to improve the condition of 55% of track assets up to an acceptable standard whilst taking into account maintenance needs. Track Quality Improvement Works (TQIW) will deliver the remainder. To date, track work has been carried out to 86% of the route with 66% converted to CCR on the 22 kilometre long railway.
A scope of works was developed for each section of track by examining the rail-wheel interface, contractual asset condition benchmarks, maintenance requirements and requirements of the VLU. For instance, these requirements include new sleeper layout at 650mm centres. The Victoria line has limited access with a single link for engineering trains via Finsbury Park making logistics difficult. New flat bottom rail is delivered in 90 metre long strings.
There is a marginal improvement in track alignment though tunnel clearances are still tight. However, it is better than the existing alignment on the Central line.
During design and installation phase, gate reviews were held to check that the project was still delivering the requirements with continuous information input from Westinghouse and Bombardier.
Work Bank
The VLU works were split into four stages or geographical zones on the line working from north to south. A re-railing programme to replace the original 1967 track was phased as such to eliminate the requirement for 24-hour maintenance patrolling thus allowing running of the Test Train following completion of Phase 1. The Test Train accesses the Victoria line via the link at Northumberland Park Depot.
Phase 1 – Seven Sisters to Highbury & Islington
Phase 2 - Kings Cross to Oxford Circus
Phase 3 – Green Park to Pimlico
Phase 4 – Vauxhall to Brixton
The standard full reconditioning of track in tube tunnels requires breakout of the existing concrete invert in which the sleepers are embedded in and resetting of new concrete. The track work programme was compressed by foregoing full reconditioning works. Balfour Beatty were able to save much time where the existing invert concrete was found to be good quality through strength testing. In this case, as much as possible of the concrete was preserved and only the existing sleepers cut out and replaced. This process is known as sleeper 'popping'.
Weekend Closures
Major track renewal prior to VLU was mainly done on ballasted track with little experience of this in tube tunnels.
During the first weekend possession for VLU track work, there was a murder in the vicinity of Highbury & Islington station, which was made a crime scene resulting in taking up the possession late. Work during this possession was poorly managed with no site control exercised by Balfour Beatty and too much rail had been taken up. There was a lengthy overrun as there was not enough time to reinstate the rails as the clips had been put in the wrong way.
The lessons learnt from the initial stages were preparation, to reinforce centralised control and use of multi-sites in possessions to maximise opportunities. It was a steep learning curve and regular closures were required to keep up with the programme. Over time, work sites became increasingly productive and coordinated with signals and platform works as well as track maintenance.
Extended Engineering Hours
London Underground had agreed to early closures of the line and extend available engineering hours for a 6 month period. Track works shared engineering hours shifts with the running of the Test Train on Tuesday and Thursday nights.
Scrap management on the line was a major issue with a 30 year legacy of redundant rail. Much was left in tunnel bolt holes making access difficult. With track renewal works included, 100km of scrap rail had to be cut and removed. A redundant 40m long spur tunnel in the Finsbury Park area is currently being used to store scrap. At the same time, maintenance of the track had to be kept up with patrolling, lubrication management and access for the rail grinding train maintained.
Crossing renewals are planned as separate works to plain line renewal with sites at Finsbury Park, Walthamstow and Brixton each carried out over 3 weekend possessions.
Lessons Learnt
Victoria Line Upgrade Project - Trackwork
At 55 Broadway St James’ Park 8 June 2009
Presented by John Hardy (London Underground Ltd)
Introduction
The Victoria line was constructed in 1967 and had life expired track assets at the commencement of the Public Private Partnership (PPP) Contract in 2003. Metronet Rail BCV (MRBCV) was required to replace the current rolling stock and the signalling system for the Victoria Line Upgrade (VLU) Project. The PPP requirements are to increase capacity measured through Journey Time Capability (JTC) on the Victoria line by 2012.
Track Programme
The PPP Contract requirements for the Victoria line track assets were to maintain track condition at Maintenance Standard as outlined in LUL track standards. This is a minimum maintainable standard. The condition of the track inherited by MRBCV was in a poor state such that 24-hourly patrolling was required between Seven Sisters and Kings Cross. As a consequence there was little time for track maintenance in this section and this would pose potential access problems for the planned line upgrade works. Considering this and other issues, MRBCV in order to deliver the full benefits of VLU, re-scoped its Track Programme to include renewal, rail-wheel interface and a track maintenance strategy.
Victoria Line Upgrade Project
MRBCV bore in mind the need for effective delivery of the VLU and to also integrate this with an effective maintenance strategy. For instance track renewed in 2006 will not realise the full benefits until all upgrade works are completed in 2012. Also in its contract with Bombardier, with respect to new rolling stock, there are minimum track geometry requirements. These include ride quality, rail corrugation and track gauge. Then there was also work required for gauge clearance surveys of line side equipment. Another feature is the power upgrade works with the replacement of standard 64kg/m conductor rails with composite conductor rail (CCR) to minimise power loss and reduce the number of sub-stations.
Track Quality
Early on in the life of VLU, the common faults to track quality included tight gauge, top and line, track twist and voiding under sleepers though track maintenance standard was maintained. To aid the VLU, the Track Programme was scoped to improve the condition of 55% of track assets up to an acceptable standard whilst taking into account maintenance needs. Track Quality Improvement Works (TQIW) will deliver the remainder. To date, track work has been carried out to 86% of the route with 66% converted to CCR on the 22 kilometre long railway.
A scope of works was developed for each section of track by examining the rail-wheel interface, contractual asset condition benchmarks, maintenance requirements and requirements of the VLU. For instance, these requirements include new sleeper layout at 650mm centres. The Victoria line has limited access with a single link for engineering trains via Finsbury Park making logistics difficult. New flat bottom rail is delivered in 90 metre long strings.
There is a marginal improvement in track alignment though tunnel clearances are still tight. However, it is better than the existing alignment on the Central line.
During design and installation phase, gate reviews were held to check that the project was still delivering the requirements with continuous information input from Westinghouse and Bombardier.
Work Bank
The VLU works were split into four stages or geographical zones on the line working from north to south. A re-railing programme to replace the original 1967 track was phased as such to eliminate the requirement for 24-hour maintenance patrolling thus allowing running of the Test Train following completion of Phase 1. The Test Train accesses the Victoria line via the link at Northumberland Park Depot.
Phase 1 – Seven Sisters to Highbury & Islington
Phase 2 - Kings Cross to Oxford Circus
Phase 3 – Green Park to Pimlico
Phase 4 – Vauxhall to Brixton
The standard full reconditioning of track in tube tunnels requires breakout of the existing concrete invert in which the sleepers are embedded in and resetting of new concrete. The track work programme was compressed by foregoing full reconditioning works. Balfour Beatty were able to save much time where the existing invert concrete was found to be good quality through strength testing. In this case, as much as possible of the concrete was preserved and only the existing sleepers cut out and replaced. This process is known as sleeper 'popping'.
Weekend Closures
Major track renewal prior to VLU was mainly done on ballasted track with little experience of this in tube tunnels.
During the first weekend possession for VLU track work, there was a murder in the vicinity of Highbury & Islington station, which was made a crime scene resulting in taking up the possession late. Work during this possession was poorly managed with no site control exercised by Balfour Beatty and too much rail had been taken up. There was a lengthy overrun as there was not enough time to reinstate the rails as the clips had been put in the wrong way.
The lessons learnt from the initial stages were preparation, to reinforce centralised control and use of multi-sites in possessions to maximise opportunities. It was a steep learning curve and regular closures were required to keep up with the programme. Over time, work sites became increasingly productive and coordinated with signals and platform works as well as track maintenance.
Extended Engineering Hours
London Underground had agreed to early closures of the line and extend available engineering hours for a 6 month period. Track works shared engineering hours shifts with the running of the Test Train on Tuesday and Thursday nights.
Scrap management on the line was a major issue with a 30 year legacy of redundant rail. Much was left in tunnel bolt holes making access difficult. With track renewal works included, 100km of scrap rail had to be cut and removed. A redundant 40m long spur tunnel in the Finsbury Park area is currently being used to store scrap. At the same time, maintenance of the track had to be kept up with patrolling, lubrication management and access for the rail grinding train maintained.
Crossing renewals are planned as separate works to plain line renewal with sites at Finsbury Park, Walthamstow and Brixton each carried out over 3 weekend possessions.
Lessons Learnt
- Initially there was not much thought given to track quality and a potential late start to the VLU Project;
- The time required for preparation was underestimated;
- There was a loss of 60% of booked engineering trains due to difficulties in logistics;
- There were problems with works access clashes during Phase 1 - MRBCV internal track gangs, Metronet Rail Infrastructure Services (MRIS) and Balfour Beatty Rail personnel were falling over each other;
- Technical Officers were a scarce resource;
- Scrap management problems – rails could only be dropped in one tunnel while the remaining tunnel had to be kept clear for walking routes in case of emergency detrainments;
