TECHNICAL ARTICLE

AS PUBLISHED IN The Journal January 2018 Volume 136 Part 1

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Alison Stansfield MARKETING DIRECTOR Permanent Way Institution [email protected]

PLEASE NOTE THE OPINIONS EXPRESSED IN THIS JOURNAL ARE NOT NECESSARILY THOSE OF THE EDITOR OR OF THE INSTITUTION AS A BODY. TECHNICAL

DEVELOPMENTS AND PROGRESS ON TRACK RENEWALS ON

LONDON UNDERGROUND HALF DAY TECHNICAL SEMINAR OCTOBER & NOVEMBER 2017

AUTHOR: Chris Parker - Fellow, PWI

This seminar was presented identically on two quieter and safer. New methods of concrete occasions, this report is based upon that at the mixing and delivery have also been developed LT Museum, Covent Garden on 29th November and implemented. Some of these new ideas 2017. were to be covered in more detail in later presentations. On that occasion the seminar was chaired by David Packer, CEO, PWI. David welcomed In fact, the face of LU has been changed, delegates and introduced the session before meaning an unparalleled period of track handing over to Stephen Barber, LU, who gave safety, a 75% reduction in track asset lost the keynote address. customer hours over 10 years, and meaning that as of 2016 track is “on track” to meet its performance objectives. This has been KEYNOTE accompanied by reductions in whole life costs through, for example, reduced inspection & ADDRESS maintenance requirements. LU Track is now looking at how to further capitalise upon the robustness of the new track forms and the Keynote Address - Stephen Barber STEPHEN BARBER associated reduction in failures. LONDON UNDERGROUND What has been learned in all this? Firstly the order or the wrong way round. Stephen referred to the “trials and tribulations importance of strategic planning. With the Failing to provide enough of a particular of the past 9 years”, then described the positive increasing complexity of our work, the ever resource such as specialised tools, trying to achievements of LU in the last decade. 39 km greater pressure to allow traffic to run for use labour with insufficient experience of the of ballasted track renewal (BTR) and 21 km of longer each day (and every day) and the need task, all these are examples of the myriad deep tube track renewal (DTR) headed his list, to work around sporting events and so on, details that can trip up a plan and lead to together with the renewal of 66 P&C units. planning has to be right. trouble.

At the same time the organisation has Teamwork came next in Stephen’s view, Finally, stakeholders must not be overlooked. developed new track forms for optimal whole and this means the whole LU team and They need to be borne in mind right from life cost, including FB ballasted concrete their suppliers, not just the immediate track the initial planning stages to completion bearer P&C with under bearer pads. The last team. Collaboration with LU colleagues in and afterwards. They must be consulted LU bull head (BH) P&C relay was at Upney operations, line service management and appropriately and their views must be taken in 2012. A closer sleeper spacing has been access management is essential. All need to into account. selected for ballasted plain line renewals, understand the plan and why it is as it is, to using under sleeper pads (USP), and for DTR recognise that its success is as vital to the If, despite all this, things do go wrong, they works the selected track form utilises resilient organisation and its customers as the daily need to be informed as soon as this becomes baseplates and booted blocks. The expected operation of the network. apparent on site. It is too late to advise them benefits are an increase in ballast life of when the job is already significantly in trouble, between 50 & 100% and extended life for the Contingency planning and management they need time to plan their own responses and deep tube track. is equally crucial. The cost and effort of deal with the consequences of the problem in contingencies must be recognised, and the most effective way possible. Techniques and methods have been every detail of the work plan must be got revolutionised too, resulting in renewals without right in order to minimise the risks. Stephen Continued at the bottom of page 47... speed restrictions, weekend reballasting and gave some examples, such as trying to fit an modular P&C installations. Concrete is now engineer’s train into too small a space, leaving broken out using bursting methods rather things off the train or loading it in the wrong than breakers, making the operation quicker,

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PRESENTATION 1 RENEWALS WITH SLAB TRACK; BAKER STREET TO FINCHLEY

DAVID SLOANE LONDON UNDERGROUND

ALLAN HENDERSON LONDON UNDERGROUND

David and Allan presented their excellent project, which is reported in the Network Rail Winter Track Engineering Conference 2017 on page 57. Full house

PRESENTATION 2 OVERNIGHT BALLASTED TRACK RENEWALS

DAVID SLOANE LONDON UNDERGROUND

ALLAN HENDERSON LONDON UNDERGROUND

David Sloane & Allan Henderson

The presenters began by recounting the slab track renewals, the re-railing is done an adapted wagon on in an engineering train background to this innovative project. Night on the existing track. The reballasting and was used to bring in two mini excavators, tube and other pressures on track were making resleepering is undertaken beneath the new allowing the renewal of two 8m sections in a 2 BTR more challenging. Additionally, there was rails. Sues and vertical geometry changes hour 10 minute window. Robel hand tampers an increasing number of high priority renewals are restricted to the minimum to try to avoid were used to consolidate the new ballast. To that were in awkward locations that were not the need for re-stressing. Between November date some 6 sites have been successfully readily accessible commercially. In 2013 a 2013 and January 2014 a 220m trial renewal treated on a variety of sites, with up to 100m team began working on ways to tackle this was undertaken on the Central Line between being renewed per week. situation. Buckhurst Hill and Woodford. Ballast removal was by DISAB vacuum excavation. Up to After this presentation there was a Q&A A methodology was developed that is 10m was renewed in each 4 hour occupation session involving the speakers from the earlier phased thus: re-rail, stress, core renewal, without using engineering trains. Next a presentations taking questions from the floor. tamp, re-stress, follow-up tamp. As with the renewal on the was done, where

cont... up after that, but will not resume earlier levels Consequently there will always be space for Lastly Stephen reminded that you are only as even then. Securing future track investment is new ideas, since greater productivity and lower good as your last job! Looking to the future, going to require stronger business cases than costs will always be required of us. he predicted that the pressures on us will not ever before. lessen. Financially LU’s world is tightening. The “The challenges make our work interesting and budget for track renewals in 2018/19 is going to Efficiency is still the key. Engineers must work more worthwhile, and there will be plenty more be the lowest in a decade. It is expected to pick with the asset managers to deliver this. of those” was Stephen’s parting comment!

47 TECHNICAL

PRESENTATION 3 DEVELOPMENTS IN NEW TUBE TRACK FORM

ANDREA SMITH LONDON UNDERGROUND

Andrea Smith

The original track consists of timber sleepers Like the other speakers, Andrea said that in the When the time comes to lower the track, the and BH rail with a shingle filled channel. In deep tubes it is normal to relay “bottom up” in shims are removed and the baseplates are platforms there are concrete pit with timber pit short sections (3 to 4m) in the limited access permanently fastened down. Thus it has been blocks. This track is life expired. windows available. In order to facilitate the possible to lower track by up to 25mm. aim of eliminating timber completely, a direct Various attempts had been made in the past fixing conductor rail support plate has been Future developments include the introduction to introduce improved track forms. These developed. of a lightweight gauge to hold the rails to included trying concrete sleepers, using track gauge during pit renewals, instead of “hedgehog” concrete sleepers in platform Andrea went on to talk about some of the having to insert one sleeper in four for the areas, or using trapezoidal pit blocks. Rubber process improvements over the years. Included same purpose. Lightweight access steps have boots around pit blocks were also tried. were better management of the risks of buried been introduced to permit safe entry to and Concrete supports set into rapid setting services, the introduction of concrete bursting exit from platform pits without obstruction to concrete were also tried in place of pit blocks, as a safer and more efficient alternative to trolleys, stair climbers are being tried to carry and trapezoidal pit blocks were another breaking, the development of a reusable heavy loads on station stairs & escalators, alternative tried. Finally direct fastening into modular formwork, the use of “Hippo” mixers, and a mechanised rail vehicle (MRV) is to be concrete using Hilti anchors was tried. and trials of lightweight battery power packs as developed that will be able to carry to and from stand-by power instead of generators. Shims a worksite all the required resources. Andrea In early 2014 deep tube began using Delkor under the Delkor baseplates have been used had a long list of other small improvements that direct fastening resilient baseplates and NTF45 during relaying, meaning that the sleepers go have been introduced or are to be so. concrete sleepers, and later Delkor check rail in lower than the originals being replaced. blocks were also introduced. Several Delkor variants have been tried, but now the 195 is the normal choice.

Outstanding level of knowledge and experience and the enthusiasm, clarity and dedication of the speakers.

Excellent delivery by the younger engineers who had been involved with the projects.

Excellent timekeeping and efficient organisation.

Great Q&A sessions with a good rapport between delegates and speakers.

As always at PWI seminars - brilliant networking opportunities and knowledge exchange.

Feedback from our delegates.

48 TECHNICAL

PRESENTATION 4 RISK MINIMISATION AND WORKS OPTIMISATION

PETER JOHNSON LONDON UNDERGROUND

PAUL COLEMAN LONDON UNDERGROUND Paul Coleman Peter Johnson

Peter described the T-minus planning the JV lead to the loss from the programme Paul took over the presentation at this point, process that is used by the JV, how it links of the 2 hour float. The work was delayed describing works optimisation by referring to the stagegate process at T-8, and how at right from the start by a faulty locomotive at two example projects. T-2 a detailed plan is reviewed with key Ruislip Depot and things did not improve. The stakeholders. At T+2 a delivery improvement outcome was an overrun of 203 minutes and The first was Kings Cross Platform 2, forum reviews any issues and checks that as- ongoing service disruption over the following a 1400 m site in the inner and outer Circle built information is handed over appropriately. three days. Lines. As the platforms are on an island, there are two single lines here. In addition there were Delivery monitoring is critically important The team are due to return to Earls Court to be major worksites for other works on either during delivery, so 4 hourly reports have to be this Christmas, and Peter outlined some of side of the site during the line closures. Further produced and delivered to the business. Status the measures that have been taken to avoid challenges included difficult track geometry, is indicated by green/amber/red flags. Amber a repetition of this sort of problem. Three drainage issues, and of course the sub-surface indicates a risk of overrun if the programme linked crossovers are due for renewal, and location. Risk mitigation measures had to be float is exceeded. At such a point a revised loose relaying is the only viable method this planned in from the very first. programme and milestones must be submitted time. The JV has successfully argued for, and to the business. Red indicates that things obtained, 7 days for the work instead of 6. The second site was a BTR at Finchley Central are worse even than that, at which point the in September 2016. By good planning and service control has to be informed. Peter described various works that have innovative working the JV was able to relay been undertaken by his team, including loose 605m rather than the originally planned 430m, There is an escalation process for reporting relaying on surface lines and P&C renewal in saving a line closure. Snagging and follow- above site manager level to Level 1 and Level deep tube. On the latter a gantry crane was up tamping works for other jobs were also 2. The Level 2 Manager has the responsibility installed over the site, and has been left in achieved. for instigating and chairing conference calls as situ for future works. He spoke of a number required by events. of innovations like concrete bursting that Crucial to this success was the decision to have been mentioned by other speakers, and install a satellite depot close to the worksite, Robust mitigation plans are created in advance described the use of thermal nodes, sacrificial reducing greatly the time taken to get to/from for each programme of works. A float of at least temperature sensors set into concrete. These site. 2 hours is included in works planned to take allow the remote monitoring of the strength up to 52 hours, and for longer works this is achieved by the concrete as it goes off, A second Q&A session followed after which increased proportionately. using algorithms that deduce this from the David Packer closed the event by thanking temperature of the material. Another method the speakers and organisers for an excellent These precautions delivered an almost perfect being used now is phasing works by, for seminar. record until the works at Earls Court. There a example, laying in a crossover in two separate number of late changes outwith the control of halves in different access windows.

Presentations from all of our seminars can be downloaded from the PWI Technical Hub.

www.thepwi.org/technical_hub/ presentations_seminars_conferences

49 thepwi.org

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