London Southend Airport railway station development project

By any measure, a new main line railway station is a rare commodity. There has been only a handful over the past 20 years, some linked to regional airports. But the south-east region in the UK now has its own, all-new, congestion-easing rail-air interchange at Southend Airport – the work of infrastructure engineers Stobart Rail. Situated just a few minutes up the line from Southend Victoria, the new station will play a key part in the airport’s evolution from a sleepy general aviation base into a busy east-of-London terminal, ready to service the influx of visitors expected for the 2012 Olympics. In an interview for Global Railway Review, Stobart Rail’s Managing Director Kirk Taylor and Project Manager Stephen Harker, explain the importance of this all-new interchange and the planning and construction involved.

The vision to develop Southend Airport came from the Stobart Group itself – better known as Britain’s most recognised truck operator but, in reality, a diversified transport company with a well-established rail division, Stobart Rail.

“We’ve been working with Network Rail and other rail engineering clients for some years,” says Stobart Rail Managing Director Kirk Taylor, “but Southend Airport Station is our biggest project yet – a complete design and build from the ground up, with very intricate working conditions on a busy commuter line into London.”

A 40-minute train ride from Stratford’s Olympic Stadium on the line into Liverpool Street, Southend Airport is expected to be handling one million passengers soon after opening in 2012, with that figure doubling by 2020. Hence the need for a new station to cope with the passenger numbers expected to take the train into the capital and the Games’ venues, making the station an integral function of the airport.

Planning navigation

Stobart Group took control of Southend Airport in December 2008, immediately developing ambitious expansion plans including the new rail station and car park, a new terminal building, a new air traffic control tower and a 300m runway extension. It has delivered rail infrastructure works through its Stobart Rail division since 1998, completing dozens of major schemes. Typical projects delivered have been bridge reconstructions and refurbishments including track-off, track-on permanent way works, slab track installations of both Rheda 2000 and Pandrol Viper systems, which reduce tolerance on the track construction and therefore enable the routes to cater for larger gauge rolling stock. These and many other projects are precision engineered and have been carried out on major routes throughout the United Kingdom.

“Stobart Rail specialises in time-critical works where minimising disruption to services and delivering a high quality job are vital,” says Kirk Taylor. The Southend Airport interchange falls into this category. “This project has enabled us to demonstrate Stobart Rail at its best, delivering a multi-disciplined scheme utilising in-house resource across a broad spectrum of activities.” Speed has certainly characterised the project, with designs commissioned by Atkins Global, smoothed through the planning process and built in just 23 months, all for £12.5 million.

The company plunged into the planning process with the local council as soon as it took control of the airport, knowing that seamlessly integrating the air and rail operations was vital. Hand luggage-only plane passengers should be on the station platform just 15 minutes after touchdown. A high quality design was agreed, featuring metal-clad buildings with an enclosed high-level walkway to link the west and eastbound platforms. “It’s a quality design that pleased the planners and we’ve carried that quality through into the build,” says Taylor.

Stobart consulted with the Southend line’s operator National Express to ensure the finished station would meet with the operational requirements of all the other stations along the route.

Stobart Rail additionally met with the Office of Rail Regulator as it was their intention to apply for a licence to operate a main line station. The Group Board decided it would prefer to operate the station in-house as it would give greater opportunity to control customer care and satisfaction.

To the casual observer, the bridge and platforms are the obvious signs that Southend Airport has a new station. But the invisible ground works and construction preparations absorbed a great deal of time, resources and planning.

Getting underway

All that started in January 2009 with multiple regulatory site surveys, including unexploded ordnance (none unearthed), archaeology (Iron Age fire pits logged and recorded) and wildlife (150 slow-worms, lizards and rare spiders found and relocated). “The whole of the site footprint had to be fenced off so that specialist contractors could check the wildlife over a threeweek period at the start of the build in early 2009,” says Project Manager Stephen Harker.

Then, before construction of the twin 250m platforms could begin, Stobart had to straighten and level the track to ensure the carriages and platforms lined-up correctly, and the platform surfaces were perfectly level to meet Network Rail standards. “It sounds like a simple job but one of our most complex engineering tasks was to realign the tracks to ensure they were coplanar,” recalls Harker.

Procurement of the plant (tamper) to align the track could not be made until after the platforms were constructed which differs from normal procedure. Inevitably this would have meant either a two-month delay or laser profiling to de-risk the chance of being out of tolerance. Given the tight project timeline, the company couldn’t afford any mistakes so they brought in a laser-levelling machine to perform a gauging analysis and check the kinematic envelope of trains as they passed through the station. “Expensive but essential if we wanted to stay on schedule,” insists Harker.

To get a parallel and co-planar track, Stobart moved the track 125mm in horizontal slew and lifted it 75mm.

Time pressures

Built to Network Rail’s latest standards and containing 6,000 building blocks, the coping stones that make up the safety-critical edge flush to the carriages are accurate to +5mm and -15mm. All the platform foundations, blockwork, oversailers and brickwork were constructed while trains were running at their usual 20- minute intervals, although much of the key work was scheduled for overnight periods when services stopped and possessions could be taken.

Construction gangs worked a 12-hour day shift, with safety enhanced by an Automatic Track Warning System which gave a 30-second warning of an approaching train. The night shift was shorter at eight hours, but was uninterrupted by the passenger service. “The platform build is traditional but the pressure on time when given limited windows of opportunity always presents a challenge,” says Harker.

Speedy action was needed on both the realignment and platform build because Stobart’s timetable had no slack in it for booking service disruptions with Network Rail and the lines operator National Express. “If we’d booked disruptive possessions, the lead time would probably have pushed the project back 12 months and affected the whole redevelopment plan for the airport,” asserts Taylor. So Stobart piggy-backed on other contractors’ possessions which required steely discipline to finish tasks on time. Even the replacement of overhead line equipment (OLE) was completed without booking a disruptive possession. “It piled on the pressure but we got it done,” Harker recollects.

As well as these precision activities, there was much earth-moving to be done, with new embankments constructed for each platform requiring 10,000 tonnes of hardcore and earth. Around half of that material came from waste concrete already on site – this was reused to keep local truck movements to a minimum. “Hardly any material has gone off site,” says Taylor proudly. “We’ve really minimised waste to landfill.”

When the track was realigned, the OLE also had to be repositioned to match the track and fit around the platforms. Sensibly, Stobart retained the existing catenary wiring where possible, but installed seven new steel portal structures, complete with concrete foundations, stove pipes, contact and catenary supports with associated wiring and registration equipment. As part of the works, nine existing structures were removed. Among the technical challenges was the electrification equipment’s unusual configuration which is unique to the Southend–Liverpool Street line – a legacy of being one of the first in the UK to be electrified.

Bridge installation

Once the platforms, track and OLE hardware were in place, Stobart turned its attention to the station, installing the overhead walkway linking the eastbound platform to the entrance and concourse on the other side of the railway. To simplify the task, all the services to and from the platform were routed under the tracks. That kept the footbridge free of electrical wiring and plumbing etc, therefore there was no reliance on any service feeds should the bridge installation fail. The bridge super structure was 90% clad before installation so there was no need for contractors to work above the line and therefore no safety-related service disruptions to slow down the construction process.

Steelwork for the walkway was supplied by a British firm and trucked to site as a kit of assemblies to be bolted into a finished structure. Once again, the installation programme left no room for mistakes or serious snags. “There was no Plan B for craning the footbridge into place,” grimaces Taylor. “We had a 6-hour possession window and no chance for anything to go wrong.” The next available opportunity would be at a minimum of 12 weeks later – a delay that once again would have put a major spanner in the redevelopment works for the airport. To minimise the risk, Stobart booked a 500 tonne lifting crane, twice the capacity required for the installation.

Steelwork arrived on site at the beginning of March. The footbridge slotted smoothly into position in the allotted time window and, in doing so, completed the major construction phases of Southend Airport Station. By the end of May, the bridge was fully-clad and waterproofed, with work moving onto the final fit-out.

Rail engineering expertise

But there were still dozens of other tasks to be completed including connecting the station to the line’s signalling system. As well as commissioning the driver only operation (DOO) equipment, 12 monitor banks containing up to six flat-screen TFT displays positioned at the 4, 8, and 12 car stops by-directionally – convenient to see from the driver’s cab. A communications room festooned with wiring, including broadband links into the BT network. To minimise installation time, all the cables were pre-cut off-site to a plan based on the station’s layout drawings.

“Stobart Rail is all about delivering solutions,” says a justifiably satisfied Taylor. “People have come to us for our expertise and this new station project is a clear demonstration of that. We’ve proven we can deliver a complete major project. Now we’re expecting more people to come to us in future for similar schemes.”

About the Authors

Kirk Taylor has a proven track record with over 20 years in the construction industry, the last 10 years involving work on the railway infrastructure, and he brings a wealth of knowledge and experience to the leadership of the company. Kirk joined Stobart Rail in 1998 as a foreman with his role expanding to involve estimating, programming and planning of projects through delivery to completion. He initiated and developed the logistics team enabling in-house capability to provide transport for all plant and materials as well as on-site management of delivery teams. In 2004, he assumed responsibility of the Plant Division and was a major influence in setting up the administration team which managed an annual turnover of £5 million. In 2007, Kirk was appointed Director of Stobart Rail and has been instrumental in producing a strategy to ensure the company’s continued success and maintain its position as market leader in this expertisedriven category. In 2009, Kirk took on the role of MD.

Stephen Harker has worked in construction for the past 12 years. Originally joining Stobart Rail in 2000 as a trainee engineer, he has covered most aspects of civil engineering projects. In 2008, Stephen rejoined the company after a 2 year break working as an engineer/site agent on road projects. Since rejoining as a Site Agent, he has progressed to Project Manager overseeing major civil engineering projects valued greater than £5 million across the UK rail network and more recently the London Southend Airport redevelopment.