The U.K. railway station in Reading, west of London, is in the midst of a massive expansion, including a redesigned station, expanded tracks and platforms, and a new viaduct to relieve congestion. Jim Stephenson
Engineers and builders are separating freight from passenger rail and significantly expanding the capacity of the Reading station, west of London—all on a very tight schedule.
June 11, 2013—With 14 million passengers a year, the Reading railway station, 40 mi west of London, is the busiest in the United Kingdom outside of London. The station, which is the main commuter rail gateway into the capital from the west, has seen traffic become ever more congested.
“If you were coming from London and going west to Reading, you’d generally have to wait outside the Reading station for a free platform to become available,” says Bill Henry, a principal vice president of San Francisco–based Bechtel and the project director for the firm, which is overseeing an ambitious scheme to modernize the station’s infrastructure and track system. “If you were coming from the west country toward London, then you’d generally have to wait even longer because you [would have] crossing freight trains on the same plane—on the main line—and local branch lines that were also congesting the area.”
The nation’s iconic Great Western Main Line, which is based on the Great Western Railway and connects the capital to the west and south of England, runs through Reading; about 800 trains pass through the station every day on only four tracks. Passenger volume is expected to double by 2030, but the layout of the station hasn’t changed in 100 years. “It was a bottleneck of services that’s [quickly] become a bottleneck of passengers,” Henry says.
So the United Kingdom’s national railway operator, Network Rail, is undertaking the £850-million (U.S.$1.28-billion) renovation. In addition to a new station with a significant increase in the number of tracks and platforms, the project will involve a viaduct west of the station that will separate the main lines from the freight and branch lines.
Soaring canopies at the new Reading railway station help unify
the design and connect the station to the surrounding city.
In 2010 Bechtel, which is formally the project’s integrated delivery partner, began the “enabling” work that would set the stage for the major expansion to come, Henry says. Crews had to raze the main line’s signaling control center and widen a bridge just west of the new station. In a 10-day span this year that included the Easter holiday, engineers and builders completed what Henry describes as “the largest commissioning of new infrastructure ever done in Network Rail’s history. It is the largest transformation of the Great Western Railway ever undertaken in over 100 years.”
Between March 28 and April 9 the company completed the most ambitious part of the program: the installation of 6 mi of tracks, new signaling, six new platforms (bringing the total to nine), two new concourses, and a new passenger transfer deck that will bring people down to the platforms. Typically that work would have required 20 weekends.
The new station also features a pedestrian underpass that will enable residents to pass through the station from one side of central Reading to the other. Engineers also added new relief lines to ease passenger bottlenecks, as well as new switches and crossing installations on the London side of the Reading rail infrastructure. “We really enhanced the whole scheme,” says Henry, “and then debottlenecked the railway at the same time.”
Spurred by government concerns that such big infrastructure projects are too expensive, Network Rail challenged Bechtel to find the least costly solution. To minimize disruptions to train service, Bechtel proposed compressing the work schedule rather than doing bits of work on the weekends. The engineering firm pushed Network Rail to allow crews to operate for longer periods over the Christmas and Easter holidays.
The canopies leading to the platform are fitted with metallic blue
soffits, creating a cathedral-like space that helps passengers get
their bearings. Jim Stephenson
This approach enabled Bechtel to shorten the timetable by a full year, from 2016 to 2015. “If you look [at it] in railway terms, I don’t know of any other project that has done that,” says Henry.
Bechtel also incorporated some time-saving construction methods. For example, the new transfer deck that spans the tracks, which is 30 m wide and 135 m long, was built in stages just north of the site and then “launched” into place above the working rail lines. To ensure that the deck would hold up as it was cantilevered over the rail lines, its walls are trusses of full height formed from hollow steel sections. And to offer views of the trains to the east and west, no diagonal members were used.
The signature design element is a set of canopies that swoop down above the escalators that connect the transfer deck to the platforms, creating a distinct visual identity for the new station. Tania Dee, an associate with London-based Grimshaw Architects, the station’s designers, says many through stations have an awkward interface as platform canopies connect with other elements of the stations. Grimshaw sought a more cohesive solution. “Our main objective was [to] create an intuitive station environment that was more permeable and better connected to its surrounding townscape,” says Dee. “Stations typically struggle with platform environments that feel cluttered and are difficult to maintain. We wanted to address this using a single unifying canopy element, simple and fluid in its form.”
The canopies are also fitted with metallic blue soffits. “By creating canopies that are purpose built off-site and that introduce color and conceal services, we were able to concentrate on refining the single most important design element for the station,” Dee continues. “The soaring canopies that fly up above the transfer deck provide cathedral-like spaces where people gather and make key decisions.”
The platform canopies are supported by large hollow steel
sections, which proved less expensive than faceted sections
welded in place. The hollow beams are supported by V-shaped
columns. Jim Stephenson
The canopies are supported by large hollow steel sections, the curved members having cross-sectional dimensions of 650 by 450 mm and the straight ones dimensions of 750 by 750 mm. These pieces turned out to be less expensive than faceted sections welded in place. The hollow beams are supported by V columns that connect to the canopy beams at only two points, reducing the length of the spans and the depth of the steel involved.
Work continues on a new, 1.24 mi viaduct west of the station that will take the main lines over freight and branch lines and further reduce delays. All told, the viaduct, including new embankments, will stretch about 2 mi.
London-based Atkins was brought on in the middle of last year to conduct a value engineering study of the viaduct. “No one normally does value engineering this late,” says Russell Jackson, CEng, a regional rail director for Atkins. “People do value engineering when they’re doing the optioneering. That’s why this was a real challenge.”
The timetable was tight; the value engineering study last year ran from July through September and was followed by six months of detailed design work that ended in March. “We had to be a little bit smart about this,” Jackson says. “We had to spread design delivery across milestones and get it right the first time because we didn’t have enough time. Obviously, if you’ve got a short program, you might rush, which increases your risk of error.”
Most projects like this, he explains, have a fixed milestone for delivery. The client receives hundreds of drawings, specifications, and risk assessments—all at once. Add to that a technically knowledgeable client, such as Network Rail, whose in-house engineers can easily take a few months more reviewing all the information, squeezing the timetable even further.
Atkins proposed to “jam spread” the delivery of the design. The firm submitted general details ahead of schedule while saving fine details that were unlikely to change until the end. That gave both parties sufficient time to hammer out the major points of the design.
Atkins also found a way to save Network Rail roughly £20 million (U.S.$31.4 million) by reconfiguring the foundations for the viaduct. “When we talk about a long viaduct, track-structure interaction is tricky,” says Nicolae Bidiga, an engineering manager for Atkins. The braking force of the trains can put a lot of horizontal pressure on the foundations, so Atkins developed a more integrated foundation structure to reduce load. The engineers originally planned a series of 15 m simply supported spans that would transfer the full horizontal load to the foundations. But the bearings normally used in such a structure could have created long-term durability problems. Instead, Bidiga opted for longer (25 m) spans, every second pier being an integral pier with no bearings.
Steelwork has been put in place to eventually electrify the Great Western Main Line, which currently runs on diesel. (See “Crossrail Electrification Plan Moves Forward,” on Civil Engineering online.) Work on the platforms will be completed by June 2014, and the entire project will wrap up in 2015. “Station terminals are more than transport infrastructure,” Dee notes. “They can be public buildings in their own right.”