Infrastructure Management 2019

Asset renewals ASSET MAINTENANCE AND RENEWAL LESSONS Engineers and experts on track and asset renewal gathered in Nottingham for the latest LRT Excellence Day – here are some of the lessons they shared.

esigned to improve the sharing of best practice and innovation between operators, infrastructure managers and the wide network of product and service providers Dwho help us all to keep our respective systems running smoothly, the latest LRT Excellence Day was attended by around 70 delegates – all keen to learn and share their experiences.

Challenges and innovation Craig O’Brien, the recently-appointed Engineering Manager for industry body UKTram, began with an overview of recent The creation of new tramway assets for the extension of Dublin’s Luas Green line, also known as the rail replacement projects in Sheffield. Cross-City line, involved extensive remodelling of the historic centre of the Irish capital. TII His opening remarks summed up the sentiments of many engineers in the room: (5.5%) and Scout Hut (8.5%) (2017); and forewarned is forearmed. He then outlined “We need to focus on the the latest projects at Shipstone Street (three five simple principles to success: understand horizontal curves – 20m, 60m and 50m, the effect on stakeholders and employees; lifecycle picture and inclines of 4.5-8.5%) and Gregory Boulevard/ data capture and analysis is key; identify understand the The Forest (interlaced track and both manual critical challenge areas early; preventative points and powered switches). maintenance is a must; and finally, renewals requirements of both now It was emphasised by Mr Cundy that are inevitable so they must be properly wherever possible it is important to not planned for. and the future.” only look at like-for-like renewals, but for Mr O’Brien also beseeched delegates improvements that could either remedy to share their knowledge: “While we all When choosing contractors and suppliers, possible design issues with the original accept that our tramways are unique, they he suggested, it can be a tricky balance as installation, or incorporate upgrades made also share fundamental similarities. So do those with a proven reputation may not possible by new technology. In Nottingham’s not ignore lessons from the past, and do always focus on innovation: “Do we go with case these included improved points drainage share information as, chances are, someone the tried and tested, which keeps the market and track lubrication systems. somewhere will have already experienced small, or take the risk of going with a more Due to differences between the similar problems and may have a solution.” unknown quantity? original documentation and the installed The importance of planning works “Also plan as far ahead as you can as, for specification, the team has had to learn effectively and considerately was a theme example, the amount of rail required may be as they go along in some cases, but this that would run through the day. No-one likes beyond the amount held in stock by suppliers, has helped inform a new set of optimum replacing assets, Mr O’Brien said, but it is and other components may be needed so principles that should see longer life and important not to get ‘caught out’ by deferring there may be a substantial lead time on easier maintenance. These include raising the maintenance or not communicating effectively procurement. The UK is hardly flooded with track foundation slightly and increasing the with passengers, residents and businesses who embedded rail experts, so do not assume they base and side supporting structure to give a depend on reliable tram services. will be available when you need them – look more stable base to avoid side roll. And while laboratory data can be very at what other systems may be doing to see if The latest renewals have installed useful, he argued, there is no substitute there are ways of working together.” heat-treated grooved rails, seen very much as for real-world experience. This is why a ‘put in and forget’ solution. Improvements benchmarking is vitally important: “Often Improvements and upgrades in materials composition include enhanced we recognise the importance of analysis The next case study came from Neil Cundy polyurethane embedding systems, where based on maintenance costs, but we focus and Marek Szwej of Nottingham Trams, the profile and density of the material can be on the short-term. We need to focus on who explained their recent track renewal adjusted to provide an optimal combination the lifecycle picture and understand the programmes (2016-18); Nottingham Trams of lateral support with lower vertical stiffness requirements of both now and the future.” Ltd is contracted as the operations and to improve noise and vibration mitigation. Referencing the practice of gauge weld maintenance concessionaire for the tramway During such works, maintaining and restoration, he explained that while it is a in the East Midlands city until 2034. stabling trams on the ‘dark side’ has also very useful tool in the shorter-term, it would Planning was again the focus of the first raised particular challenges. As Nottingham ultimately never prevent renewals. He further section of their presentation, detailing the only has one depot, Wilkinson Street, there showed how effective groove grinding had various challenges of five projects that posed have been times where the network has been prolonged rail life in Sheffield by two to three individual challenges: tight 20m horizontal “cut in half”. This has seen the establishment years, combatting flange running without curves at Lace Market (2016), tight horizontal of a “flying squad” of Alstom engineers who the need for full renewals. curves with steep inclines at Radford Road can respond to vehicle issues anywhere on

www.tautonline.com . www.lrta.org AUGUST 2019 / 301 Asset renewals

LEFT: Engineers and suppliers from across the industry gathered for the lively day of discussion in April. TAUT

RIGHT: The team from Robel and Plasser demonstrated a number of new products and tools for track maintenance. TAUT

BELOW RIGHT: The PCAT test track at Long Marston; further trials are due to be conducted later this summer. PCAT

the network, looking after a revised daily at junctions on the existing Red and Green finished in granite setts and is accompanied by maintenance and cleaning programme, for lines had shown premature damage, Mr Corsi additional ‘no entry’ and ‘trap warning’ signs. example. During such programmes, trams are explained), it was decided to increase rail and While pleased with the overall result, Mr stabled overnight on the bridge at the railway road stability at the rail edge by using concrete Haworth said that the UK’s attitude to risk station, for security purposes, and some infill laying over the structural slab, brought may make widespread adoption more tricky, exams are carried out early to minimise the up to minimum distance from the top of rail. but it is worth pursuing where appropriate: risk of any issues when vehicles are unable to “Getting the shoulders right is so “It is very popular, so be prepared that if you return to the depot. important,” he said. “As the wheel and rail do install it you will be asked for more!” wear, the wheels can run on the concrete. Two other innovative trackform approaches New-build projects in Dublin This is bad for stray current transmission, were presented at the LRT Excellence Day, Later in the day, Marcello Corsi from Transport it’s bad for the wheels and it causes cracks. both seeking to reduce both the cost and Infrastructure Ireland shared lessons from the Granite setts with concrete shoulders are build time for light rail infrastructure. creation of Luas’ new EUR360m Cross-City structural, long-lasting, easy to maintain and The first is a design featured inTAUT before route. The new 5.6km (3.5 miles) of double- support encapsulation. They look fantastic that is now making real progress as part of the track route installed through the heart of the and last longer than concrete or tarmac, but UKTram Low Impact Light Rail programme. Irish capital threw up a number of significant do come at a cost.” PCAT technology uses macro-synthetic engineering tasks, including new and polypropylene (MSF) fibre-reinforced slabs to strengthened bridges and major remodelling Lessons from alternative trackforms replace steel fibres; pioneered by Greenwich of O’Connell Street near the landmark GPO Amongst a number of sessions on alternative University in the 1990s, synthetic fibre- building, he explained. The project involved trackforms, Chris Haworth from Transport reinforced concrete offers dramatic weight six years of planning and design before the for West Midlands shared experience of reductions and improved thermal properties. two years of construction began. It opened to the installation and maintenance of the Five kilograms of synthetic fibre replace 30kg passengers in December 2017. short section of green track put in at Snow of steel, helping to reduce the construction Focusing on the embedded track sections Hill as part of the Birmingham City Centre depth by 25% and the carbon impact by 50%. of the project, Mr Corsi first outlined TII’s Extension in 2015. It can also be easily recycled. extensive European benchmarking exercise Used widely across Europe, examples of A patented dry joint system allows precise and how he had found a wide range of green track are few and far between in the location and curved connectors are inserted different approaches to embedded track UK, although the choice to install 150m of from the top of the slab and tensioned; this design and gauge control (some mechanical grass track (using the STRAILastic_R system) allows individual sections to be removed in and some fastening based). This helped to at Snow Hill came partly at the request of the two to three hours if required. Geopolymer inform the following requirements for the neighbouring property developer as a revision resin injection fills the gap under the slabs, Cross-City track design: to the initial design. It now complements providing a resilient material to cushion • Reinforced track slab construction for the ‘living wall’ and high-quality aesthetics pressure on subterranean utilities. With a track and road sections of the Snow Hill estate and is mowed and predicted lifetime of 120 years, the system is • Using sleepers for construction support, treated at night by the developer. made even more attractive in that any surface alignment and gauge control As well as the aesthetic improvements can be laid on top and utility ducting and • Continuous encapsulation to manage stray and better noise and vibration attenuation, manhole covers can be incorporated into currents and vibration control probably the most obvious benefit is the the design. Laboratory testing has indicated • A preference for no filler blocks for better attraction for passengers, Mr Haworth added, a 300-400% whole-life saving compared to stability on shared-running sections serving as a further visual demonstration of established ballasted track designs. • Learning lessons of rail shoulder and road the environmental credentials of light rail. A 100m test track has been installed at surface joint degradation. For others looking at such systems, location Long Marston and it is estimated that the The foundation is a continuously reinforced is key, he explained, with maintenance, concept’s simplified installation process jointless slab track with a design life of 60 drainage, long-term durability and potential would allow up to 100m to be installed in a years. This was chosen as the best arrangement vehicle incursions being other considerations. single day in an urban carriageway, with up for the eventual surface solution of granite There have been 66 incidents of road to 250m achievable when upgrading from setts on key city centre sections, without vehicles travelling over the tram-only grass ballasted track. Wireless monitors record the precluding the use of asphalt elsewhere. section since it opened in 2015, often causing stresses placed upon the connectors and track Various trials were subsequently carried out major damage. This has seen the addition of movement, so action can be taken before this on a section at Red Cow park-and-ride. anti-incursion methods such as a 150-170mm movement becomes so severe that it risks Learning from previous encapsulated vertical kerb at the entrance to the section, tram or train derailment. We await the results track design issues (around 60% of shoulders that also incorporates drainage. This has been of the next round of trials with interest.

302 / AUGUST 2019 www.tautonline.com . www.lrta.org Much has been made of the ground- life therefore requires optimal selection of breaking lightweight vehicles being provided the profile and rail steel grade. for the Coventry Very Light Rail (VLR) Dr Jaiswal said that “networks should programme, but Dr Nick Mallinson from not be considered as a single linear asset as WMG outlined the initial requirements for different stretches will degrade differently. the equally innovative trackform for the The rate of degradation (and life) is never project, due to open to passengers in 2024. uniform throughout any rail network, so In 2017, Coventry City Council choosing a single rail grade is unrealistic.” commissioned WMG to lead the Instead, he argued, tailored solutions for development of a low-cost rail-based system sub-sections should be based upon with the aim of achieving a “whole-system knowledge of influencing factors such as cost of around GBP7m/km”. One of the areas curve radius, cant deficiency, gradient, and of focus is a new ‘ladder-form’ track design vehicle type and loading. that is quiet, cyclist-friendly and can be A methodology for segmentation and laid in 6-8m sections, requiring minimal determining susceptibility to degradation installation depth to reduce as far as possible has been established at the University of the requirement to relocate utilities. Early Huddersfield, but this needs to be extended consultation has been crucial, Dr Mallinson for all UK networks in the creation of an reported, with discussions with utility industry database of rail grades, lessons from providers to date being “very constructive”. their maintenance and where they are used An ‘innovation partner’ for the trackform to allow accurate comparators. Only once is due to be appointed in the coming months we have a comparative study can we develop ahead of the installation of a test track in ABOVE: The grass track section installed in guides for optimisation of maintenance and Dudley in 2020, for full-scale testing in 2021. Birmingham (UK) has become a new visual landmark design of future networks and the selection of as part of the stylish new Snow Hill development. TAUT rail steel grades, he argued. New thinking on rail grade selections R260 (shallow curves or tangential track) In a wide-ranging exploration of rail steels, “Grass track is very and R340 HB (curves susceptible to side wear) Dr Jay Jaiswal of ARR Rail Solutions – also account for 99% of European rail assets, Dr a Visiting Professor at the University of popular, so be prepared Jaiswal said, and hardened and heat-treated Huddersfield’s Institute of Railway Research rails are increasingly becoming the ‘standard’. – described the key rail degradation that if you do install it you Summing up, a total rethink is required mechanisms, their causes and some when considering rail grade selection, he considerations for both flat-bottom and will be asked for more!” suggested. For tangent track, authorities and grooved rails that can affect the choice of operators should consider the use of the most grades for renewals and new-build projects. wear-resistant grade – no weld restoration He started by explaining that while the will be required and the harder grade reduces wear of mating components is inevitable, rail corrugation growth. For shallow curves life – and consequent replacement – should (i.e. >250m radius), choices need to be based be dictated by safe wear limits being reached. upon avoidance of keeper wear before the Any other replacement should be regarded as vertical wear limit is reached; for tighter premature. Although acceptable wear limits curves, he suggested opting for the most vary from system to system, he added, how wear-resistant grade that can also be weld often are these mandated limits reviewed? restored. Experiences in Sheffield have While side wear can be restored on selected shown that this can significantly increase the steels, vertical wear cannot so grooved rail life before replacement is needed. life should only be dictated by the magnitude of vertical wear. As the threshold for vertical The latest LRT Excellence Day was organised wear is dictated primarily by the need to Gauge weld restoration in Sheffield (UK); this by Mainspring in partnership with UKTram avoid flange running (i.e. groove depth and technique has significantly increased the life of the and took place on 30 April in Nottingham – flange height), achieving the maximum rail South Yorkshire system’s rails . C. O’Brien/Supertram www.mainspring.co.uk/lrt-excellence-days/

ROLLING STOCK LRTEXCELLENCE Rotherham – 13 September 2019 LRT Excellence Days are designed to enhance understanding and co-operation between the teams responsible for the day-to-day operation and maintenance of light and urban rail systems, those with procurement responsibility, and the supply chain. Complimentary places are available for local authorities and rail operators.