New trains help Metronet set track renewal record

Metronet’s track renewal programme, which exceeded its annual asset management plan (AAMP) for ballasted track replacements, will be further boosted with the introduction of the first rail and sleeper delivery train (RSDT).

Being used for the first time on the London Underground network Tube Lines’ innovative RSDT is similar to ‘Slinger’ trains in use on Network Rail but is designed to carry and deliver up to ten 216 metre-long ‘strings’ of long welded rail and up to 1,470 concrete sleepers, enough for a kilometre of track renewal in one load. It has never before been possible to deliver this amount of material using one train.

Three hundred metres in length, the RSDT delivers a much-improved capability over comparable equipment used on Network Rail. It comprises 13 specially modified FEA donor wagons supplied by FirstGBRf as part of its 10-year, £80 million contract with Metronet.

Supplied by Tube Lines, whose Trans Plant division project managed its design and build, this highly specialised train made its debut on the Underground network in April when it was put to work delivering sleepers, directly to their required positions and correctly spaced, during 780m of track renewals on the Metropolitan line at Pinner.

The RSDT joins a fleet of new heavy-duty, national rail engineering trains, hauled by Class 66 locomotives, being used for the first time on the London Underground infrastructure.

Supported by this impressive stable of state-of-the-art machinery, Metronet is set to increase its track replacement capacity on the sub-surface lines of the Metropolitan, District, Circle, Hammersmith & City lines from 15 weekend worksites per year to a minimum of 50. Metronet will renew over 200 kilometres of track in the first seven-and-a-half years of its PPP contract, and is already more than 80 kilometres towards that target.

Using the enhanced capacity and increased efficiency provided by the new trains, Metronet set a new Underground infrastructure record of 1,008 metres of new track laid during a single 52-hour possession over the weekend of December 9/10 2006. Before all track renewal had taken place using Tube Lines’ traditional engineers trains. Being much smaller they could only support around 500–600 metres of track during the whole course of a 52-hour weekend possession.

As an added bonus the programme’s current performance has allowed us to extend a number of projects in length and design as well as put more track on the ground.

Owned and operated by FirstGBRf, the fleet’s first operational deployment took place in August 2006 during a weekend track replacement on the Metropolitan line at two sites near Amersham using six trains – the project was 100 per cent successful.

To achieve complete success nothing was left to chance. That August weekend was the acid test of more than 10 months’ intensive planning and preparation carried out in close co-operation with FirstGBRf and Balfour Beatty Rail Projects, which is Metronet’s principal track renewals contractor. The key element in the planning was that we would, for the very first time, be supporting track renewal by bringing mainline equipment onto the London Underground network. To enable this there was a safety case to prepare, both for London Underground and the Office of the Rail Regulator (ORR). Meticulous attention had to be paid to every detail, no matter how small, before the new trains could put one wheel on LU infrastructure.

It was a critical period. FirstGBRf signed the contract in October 2005 and had wanted 12 months to prepare the new fleet, depots and train crews for operations on the Metropolitan and District lines for full operations. In the end we had just ten months in which to satisfy ourselves and London Underground that the new fleet could operate safely on a network designed for trains just 137 metres in length. Trains up to 450 metres long and comprising a set of combined sleeper and rail ‘Slinger’ delivery wagons, hauled by Class 66 locomotives made a first appearance on LU metals.

The process included providing ‘assurance’ cases for each of the different vehicle types being introduced including 14 new FEA Salmon wagons, 90 Falcon wagons, eight Tench wagons, 25 side-tipping wagons and 10 new high output autoballaster wagons as well as the Class 66 locomotives, five of which are painted in Metronet livery.

Originally the plan had been to stable the engineering trains at Ferme Park, Tonbridge or Wellingborough.

Wellingborough was to be a train stabling sidings and contingency material supply depot. That changed when the FirstGBRf and Metronet teams considered the potential risks to track renewal delivery from the requirement for the rail and sleeper delivery train to operate nationwide each week collecting rails and sleepers.

It was realised if there had been any problem with access to suppliers’ rail terminals or with Network Rail train pathing we could have found ourselves at risk. To overcome this risk we funded the development of Wellingborough into a local distribution centre (LDC), allowing the train to remain stationary between track renewal weekends and to store the materials required alongside the train, for loading using a set of three portal cranes currently being erected and commissioned.

FirstGBRf will deliver rails and sleepers to Wellingborough in bulk to suit the timing of track renewal possessions, effectively reducing the overall number of train movements around the country.

During a typical weekend’s track renewal work the engineering trains leave Network Rail lines for the London Underground. The first trains out are panel and spoil removal trains followed by bottom ballast wagons and the sleeper and rail delivery unit, which can lay and accurately position up to 28 sleepers at a time. A further train then delivers top ballast after which the new rail will be ‘thimbled in’ by road / rail machines if the RSDT has not delivered rail directly to the delivered sleepers. The new track is then tamped followed by the autoballasters topping up ballast levels where required.

Limestone ballast is being replaced with granite, bullhead rail with flat-bottomed rail and wooden sleepers with concrete.

We chose Class 66 locomotives because, as well as their availability, they are the most reliable traction currently operating in the UK. Built by EMD in Ontario, Canada, these Class 66s are powered by ‘leaner-burn’ diesel engines that comply with the Euro 11 lower emissions standard. The larger size of the 126-tonne Class 66 also meant we had to undertake safety assessments to demonstrate the vehicles were compatible with the routes we wanted them to access and work over before our new vehicles could put a wheel onto the LU infrastructure. This comprised a mix of theoretical studies including physical measuring of structures and computer modelling and later included gauging runs using LU’s existing engineering trains to confirm clearances.

LU’s standards are generally written around passenger train operation so in some cases we had to identify appropriate mitigating actions to show we wouldn’t in any way compromise the LU infrastructure. With LU’s help we developed a satisfactory assurance case, which included an assurance that our trains would never operate above 15mph. We also identified certain under bridges on the west end of the District line that required strengthening work to cope with the heavier axle loads of the FirstGBRf fleet.

Additionally, in parallel with the engineering activity, we were required to draft an operational safety plan to provide assurance that the new trains could be operated safely on the LU infrastructure, a particular challenge as the new trains would not be fitted with LU’s standard automatic train protection system requiring operation in ‘possession’ only. Because our new trains would be entering LU infrastructure directly from Network Rail infrastructure innovative hybrid possession procedures had to be developed in conjunction with Network Rail. It took several months to develop and agree these but, thanks to a determination to succeed and through excellent teamwork, a workable solution emerged.

From April this year we estimate the new fleet will be mobilised around 35 times per year. Currently the major thrust of the work is on the Metropolitan line, although two weekends in June will focus on the western end of the District line and in 2008 the track renewal programme is planned to move from the Metropolitan line to the west and east ends of the District line.

One of the key elements in the attainment of the improved rate of renewals is the level of team-work and co-operation reached during the ten-month planning process and the build-up to the engineering fleet’s maiden outing when the focus was on how we all could deliver more efficiently and effectively, tackling and overcoming problems and bring all our different expertise to the table. That continues to pay dividends.