Capacity enhancements are the name of the game these days. Rail Engineer has recently been full of articles on longer trains, platform extensions to accommodate them, new signalling to let them run closer together and even infrastructure improvements so they can run more quickly for longer lengths of the route.
But all this comes at a cost. Longer trains mean more powerful trains while increasing the number of trains on a route also requires more power to run them.
If the line is electrified, all of that extra power has to come out of the overhead wire or the third rail. And it won’t be long before the existing substations can’t cope. That’s why most capacity upgrade projects on electrified routes have a power supply upgrade running alongside them.
Reading station has also been much in the news recently, completely redeveloped as part of both the Crossrail and Great Western Electrification programmes. Indeed, some of the earliest Great Western overhead electrification structures were installed at Reading while it was being rebuilt.
But that’s a new electrification project, so new power supplies will be installed to energise it. No need for any upgrade here.
DC to Reading
Actually, that’s not correct. Alongside the shiny new Class 802 IEP trains to Bristol, South Wales and the West Country, South Western Railway uses Platforms 4,5 and 6 for services to Waterloo. This service was run using Class 458 four-car units, coupled together in pairs to give eight-car trains.
However, those Class 458 units are now being lengthened to five-car, with the addition of a car from former Gatwick Express Class 460 trains. Two new Class 458/5 units will form ten car trains, and the intermediate stations are having platforms extended to accommodate them. So, once again, more trains, and longer trains, need more power. The majority of the resulting Reading 10-Car Power Upgrade works, which consisted of the installation and commissioning of three new substations and the enhancement of the DC traction system at two existing ones, was awarded to Lowery.
Since the Lowery management buyout in 2015, the company had been looking to grow the business in a sustainable and natural manner. With experience in high-voltage (HV) feeder renewals, DC-cabling enhancements and civil works supporting power companies in the delivery of electrification projects, the senior management team decided to enhance the existing expertise within Lowery by bringing in industry-known and respected engineers, project managers and construction managers. This new team was in place ready for the start of the Reading project.
Lowery was awarded the contract in January 2017. Timescales were tight, as Network Rail had to achieve an Office of Rail Regulation (ORR) milestone by the end of May.
The first task was to identify the possessions and sequencing of works. This involved the Lowery team working closely with both its client, Osborne, and with Network Rail to establish a common goal.
These discussions identified that the existing designs were lacking in detail, so Lowery was asked to utilise its in-house design team to update the designs and ensure that the programme was met.
Two of the new substations, at Sunningdale and Emmbrook, required all of the civil enabling works and civil bases including troughing to be undertaken, prior to the equipment modules being delivered using cranes over weekend possessions.
Another new substation, at Whitmoor, was nearly completed by a previous supplier. However, Lowery had to take responsibility for completing the installation of interconnecting wiring, as well as HV and DC cabling, within three weeks of contract award to ensure the first stage of the energisation was successful.
With a large power upgrade project such as this, particularly one being undertaken to such a tight timetable, sequencing the works is essential for successful delivery. Once set, this sequencing could not be altered as, otherwise, all the designs, as well as the SCADA (supervisory control and data acquisition) implementation, would have had to be changed and then the milestone would not have been met.
It quickly became apparent that, in order to complete this asset upgrade on time, specialist turnkey power contractor Lowery was faced with re-engineering and sequencing its complete scope of works. Meticulous pre-planning allowed Lowery to take the lead throughout the project, calling upon its significant in-house resource pool to successfully deliver the works.
Access issues and possession availability proved to be difficult. Some possessions had already been booked for significant DC cabling works, DC traction section proving and signal works testing, all of which required wheels-free access. Negotiations took place to utilise other contractor’s possessions, although Lowery’s work required the track to be energised and de-energised, which didn’t always fit in with the possession owner’s plans.
Signal testing took place over three weekends, with one weekend covering three sites (Whitmoor, Sunningdale and Emmbrook) which both challenged the Lowery testing resource and its S&T supplier’s testing resources.
Once Whitmoor had been commissioned, Emmbrook and Sunningdale soon followed. The major achievement for these was that both sites were completely installed and commissioned, including ll civil works, within 12 weeks of starting on site. Both sites were completed by the same installation and commissioning teams.
The other substations, at Winnersh and Ash Vale, received transformer-rectifier upgrades and ten track-isolating switches were installed.
The successful delivery of this project was down to the collaboration between all three parties – contractor Lowery, client Osborne and Network Rail. Having both civils and power teams in-house, Lowery was able to design, install and commission, not only the actual power upgrades, but the civils, power, telecoms and signalling elements as well.
Success breeds success
Following the Reading 10 Car project, Lowery was awarded a contract in May 2017 as part of the early works at Euston station which will later enable HS2 to make modifications to the London terminus. This called for the diversion of two HV feeders and the installation and commissioning of a new 11kV/433V auxiliary transformer with a mounted ring-main unit.
In detail, the works consisted of relocating the 11kV ring, which supplies Euston station and the Euston Power Box. These 11kV feeders are critical supplies to the station and, as a result, were programmed to be commissioned on the August Bank Holiday weekend during a complete shutdown of the Euston main line station. Lowery worked in collaboration with both principal contractor Skanska and Network Rail to ensure the works were delivered on time and safely.
A four-track UTX (under-track crossing) was installed, along with over 1km of troughing, both of the concrete and GRP types. Points-heating supplies were relocated and a new low-voltage (LV) cubicle installed to supply critical installations, including a GSM-R repeater.
The new three-core 150mm2 HV cable had to be jointed to the existing ring-main cable. This had a history of failing and had been repaired at multiple locations. Its condition was a risk to the project should it fail under test or while re-energising the HV ring. With this in mind, the Lowery engineering team developed the commissioning sequence to ensure that the HV ring was maintained throughout the works and that power to the station was not interrupted during the works.
Due to the re-engineering of the proposed design to minimise the disruption and to improve the sequencing of the works, the project was completed 12 hours ahead of schedule. As the works affected signalling, telecoms and both HV and LV disciplines, the Lowery group had the in-house resources to ensure each discipline was covered with the correct competences and cover over the weekend.
Prior to the major ring-main works commencing, an unrelated major electrical trackside fire occurred at South Hampstead in April 2017, damaging four HV feeder cables and closing Euston station for an evening. Lowery, in collaboration with Network Rail, undertook the repair works which included a new cable route, new cable insertions being installed and jointed and the four HV feeders commissioned back into service within 24 hours.
Lowery was highly commended by Network Rail for its speedy repair works to the fire-damaged cables. This collaborative team effort has now further been recognised by Network Rail IP in the form of the Aspire Awards.
With over six decades of providing engineering solutions in the rail sector, Lowery’s in-house civils and power capability has enabled the company to provide innovative solutions and to complete a large number of successful projects as a power and civil engineering contractor.
The company has a long and enviable track record of delivering projects on time, on budget, safely and to customer requirements. It is able to quickly integrate its expertise into each client’s structure, working collaboratively with excellent results. A sustainable approach is fundamental to its success and allows the business to align with its client’s requirements.”
This article was written and published by Rail Engineer on 5 December 2017.