At London Waterloo station, more than most other places, timing is everything.
Every weekday at six o’clock a long line of commuters stretches in front of the 19 operational platforms, looking up at departure boards, greeting even the smallest delay with sharp huffs and muttered expletives. The station is the busiest in the UK with 99M passengers a year, and as such it runs to the minute if not the second – or rather, most of it does.
Waterloo International Terminal (WIT) is the newest part of the station. Finished in 1993, the station won the European Union Prize for Contemporary Architecture. All of the five platforms (20-24) are covered by a 400m long glass and steel vault and, despite the 72 year age gap, it looks comfortable next to the main station roof.
After the Eurostar moved to St Pancras in 2007, the terminal has seen very little action. Platform 20 was briefly brought back into regular use in 2014 but the others have been largely untouched, save a critically acclaimed performance of The Railway Children in 2011. In a station where trains can depart as often as every minute, nine years feels an awfully long time.
The wait will soon be over, as an £800M investment by Network Rail will bring the WIT back into regular use. The ambitious and complex project will see the largest capacity increase at Waterloo in decades, with capacity increasing by 30% at peak times.
The project, which also includes the lengthening of platforms 1-4 to accommodate 10-car trains, is due to be completed by December 2018. Ensuring the timely completion of such a large scheme requires precise work across numerous disciplines.
That, says Wessex Capacity Alliance (WCA) deputy manager David Barnes, is why collaboration is so important. The alliance is made up of two contractors [Colas Rail and Skanska], a couple of designers [Mott MacDonald and Aecom] and Network Rail. “It’s a large scale project, it’s complex, it’s multi-disciplined. The alliance was the only real vehicle to deliver a project like this one.”
The alliance’s job is complicated by the logistical difficulties of carrying out work within a live railway station. Platforms 1-9 will close in August 2017 with the WIT opening temporarily to take up the slack, meaning that there will be a reduced service for 23 days, but other than that the alliance is keen to ensure that as little disruption is caused as possible.
View from the middle of platform 21
The job of ensuring that all of the pieces fit together on time falls to WCA delivery lead Derek Van Rensburg. “Going in when the actual railway is shut is crucial for our works,” says Van Rensburg, “so that we don’t disturb the running of the trains. The work almost requires the brain [of the railways] to be shut off. That is why Christmas this year is really crucial for us.”
The ageing signalling at Waterloo is not yet ready to be updated, meaning that operating that “brain” is a very specific skill indeed. “There is only one specialist in the country that can work on this brain, and very few people who know how to work on TEML41 as it is an analogue, not a digital system,” says Van Rensburg.
From 8pm on Christmas Eve until early 27 December, Waterloo and the lines connected to it will shut down, and Van Rensburg and his team will have to work around the clock. It is simply not an option for Waterloo to close again. The delivery leader says that he feels suitably prepared, and is only nervous about the weather and other unforeseeable circumstances.
Rail road excavator
There is plenty of work that can be done while the station is in use. The WIT is currently cordoned off from the main concourse with the work most necessary to the platforms’ basic operations being carried out.
The most important work on the WIT platforms is the shortening of the platform. While elongation at one end of the station and shortening at the other may sound counterintuitive, 50m is being taken off the station end to allow for the creation of a new concourse. The WIT platforms will serve the Windsor lines, which won’t require the 400m of platform length for Eurostar trains.
Though separated from the main part of the station, the demolition still needs to be carefully controlled. The noise level must be kept under a certain limit and the demolition technique can not involve any breaking, meaning that the structures have to be dismantled piece by piece (pictured below) and through hydrodemolition.
Despite the precautions taken to assure that the works do not affect the day to day running of the station, Van Rensburg’s team still have to be vigilant: “We often have spotters up at Yo Sushi [restaurant that overlooks the site], who are just there to make sure there are no dust or fumes coming toward the concourse that could create concern. If there are then we immediately stop work.”
The difficulties that a large job like this presents can also offer opportunities for engineers to innovate and, as WCA lead engineer David Otohwo terms it, “to demonstrate efficiencies”. The shortening of the platforms is a good example of such an opportunity.
“The way that the WIT structure works is that under the track it is load bearing for rail, whereas the platform is not,” explains Otohwo “So the track modelling meant that we were cutting across load bearing structures against non-load bearing structures.”
Though a challenging task, Otohwo says the engineering team came up with a design innovation that reduces the number of piles by 65 for the WIT approaches. “For the project, this meant that we saved about 17 weeks and roughly £5M. There were good sustainability numbers as well, 1480t of embodied carbon was saved.”
Load bearing is a problem in other areas of the job also, particularly in the installation of a roof to bridge the 14M gap between the WIT roof and that of the main station. As Van Rensburg explains, “we wanted to put a tower crane there, but the foundations for the tower crane would require a huge raft because of the load we were going to put on top of the Waterloo and City line.”
Minding the gap
This meant that Otohwo and his team had to design a roof 65m long, with no foundations, instead using existing foundations. “We have taken a lot of load out of the existing structure, instead of adding more load on, and we were able to demonstrate that the existing load bearing capacity was able to support the new roof,” Otohwo says.
Many of the challenges for WCA are to do with the fact that Waterloo simply cannot stop for any length of time, but there are also advantages to doing major works at a live railway station. The morning we are shown around the site, a fresh delivery of materials turns up in the form of a 12-carriage long freight train. Additionally, the excavators and other plant are all designed to run on road as well as rail.
Though long overdue, the project is clearly moving on apace. Even more intense work will have to be done in August to ensure that platforms 1-4 are extended in the three week time period. Van Rensburg will lead a 300-strong team, working around the clock to deliver the longer platforms, as well as the slight shortening of platforms 5 and 6.
WIT is finally starting to feel more like the rest of the station. Its idleness used to stick out like a sore thumb, but now it is the busiest part of the station.