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The airport

Appropriately for a project the industry has fallen in love with, CM visited Heathrow鈥檚 Terminal 5 on Valentines Day, negotiating passport control and a maze-like access route in a quest to find Phil Wilbraham, BAA鈥檚 head of design, development, engineering and infrastructure on the project鈥檚 Leadership Team. We caught up with him in a busy site canteen and found that much like the signs dotted around the site that proclaim 鈥極ne day you鈥檒l be proud to say, I built T5鈥�, Wilbraham is evangelical about the project. 鈥榃ithout doubt this project has raised the bar in the appreciation of construction,鈥� he says.

He鈥檚 not joking: the scale of T5 鈥� a 拢4.3bn project to build a new terminal (T5A) and satellite (T5B) that will increase passenger numbers by 30 million 鈥� is mind boggling. It takes in a tube line extension, new train stations, new mainline railway tunnels, diverted rivers, a spur for the M25, a multi-storey car park, a hotel, an 87-metre-high control tower 鈥� plus two huge terminal buildings. One of them, T5A, measures 396 metres long by 176 metres wide and 40 metres high, making it the largest single-span structure in the UK. 鈥楾5A is enormous 鈥� one big floorplate, with no columns,鈥� explains Wilbraham. 鈥業t鈥檚 an incredible space. Just as railway stations were symbolic of travel in the 19th century, so T5 will be in the 21st century.鈥� Wilbraham says raising the roof was a major achievement for his team, using a strand-jacking technique perfected offsite.

What is perhaps more unbelievable than the scale of this project is the fact that it is on time and on budget. Wilbraham explains this is down to the integrated team approach that flows from the T5 Agreement, a unique contract that binds BAA closely to its key suppliers and means the airport operator carries all the risk. 鈥楢t T5 it鈥檚 not about, 鈥測ou do this, I do that鈥�. There鈥檚 more trust. Everyone buys into team targets and the delivery of the project rather than just their own programmes,鈥� says Wilbraham.

Construction started in September 2002 and is on track to be completed this autumn. There will then follow a six-month period of trials and tests to ensure operational readiness for a 2008 opening. Another smaller development phase will wind up in 2010 when a second satellite building (T5C) is completed.

T5 is actually a collection of projects that Wilbraham says run in sequence and parallel. 鈥榃e go through a fixed process of gateways. We get to a point called D-Day where design is complete, it鈥檚 been effectively priced and we know how long it will take to build. It鈥檇 be great to have one big D-Day for T5 but because of the scale and complexity, it鈥檚 just not possible.鈥�

Wilbraham is now concerned with accommodating the retail teams and British Airways, which are looking to start their fit-out programmes as the shell and core are ready for handover.

It鈥檚 also worth mentioning that the T5 team has hit the million man hours without a reportable accident target on six occasions and previous safety records were broken last July when two million man hours were clocked up. Wilbraham expects that to continue, even though the delivery team will be running flat out as it approaches the finishing line. 鈥淥ver the next nine months, there鈥檚 going to be much stretching of sinews,鈥� he says. 鈥淏ut it鈥檚 been a joy to work on what is one of the UK鈥檚 greatest ever construction projects.鈥�

The tower

The Burj Dubai is a statement. The world鈥檚 tallest building says prestige and power. And it鈥檚 not just the building which makes that statement: the engineering, resources and logistics employed to create the tower are awe-inspiring.

鈥楾he design and construction methods and techniques we are using to create the tower are pushing the envelope as to what is practical with existing technologies,鈥� says Greg Sang, assistant director, projects, for developer Emaar Properties.

The tower, designed by architect Skidmore Owings & Merrill, will be more than 800 metres high and it reached its 100th storey in January. And to fox rival developers its eventual height remains a closely guarded secret.

Sang explains that the build is fast-track, so design continues as construction proceeds. 鈥極ur designers are located worldwide and without the internet, the huge amount of co-ordination and the finalisation of design details, at the speed required, it would not be possible.鈥�

The concrete is delivered by the largest concrete pumps in the world and must remain pumpable while retaining the high early strength required for the three-day cycle of the jump form. The mix is a blend of Portland cement with silica fume, fly ash, and ground granulated slag.

The logistics, which will include moving 5,000 men at the peak, are aided by specially modified tower cranes and hoists which move at 100m a minute with a 3,200kg capacity. A specially developed GPS monitoring system ensures the tower鈥檚 accuracy.

South Korean contractor Samsung Corporation is still on track to complete it by the end of 2008. The development will also include a huge shopping mall and acres of water features.

鈥淲e are all fortunate be to able to participate in this historic project, but often we are so caught up in the business of doing what we are trained to do, we can forget to stand back and reflect on what is being achieved,鈥� says Sang.

The power plant

鈥業鈥檓 driving down a dark highway,鈥� says Timo Kallio when CM tracks him down on his mobile phone. He鈥檚 heading home after another long day on the site of Olkiluoto 3, the half-built nuclear rector on Finland鈥檚 west coast, commissioned by his employer, power generation company Teollisuuden Voima Oy (TVO). When he adds that the project is now 18 months behind schedule, his journey home seems like an apt metaphor for the senior construction manager鈥檚 task ahead.

But this isn鈥檛 a project you would choose to rush 鈥� there can be no corners cut here. On completion in 2010/11 it will be Europe鈥檚 first nuclear power station in a decade and, more important, its first Pressurised Water Reactor 鈥� a third generation design that will be both more economic and, crucially, safer.

Despite the setbacks 鈥� blamed on bureaucracy and detailed design coordination 鈥� Kallio says his team is making good progress on the terror-proof, double-shell concrete wall of the reactor, which is designed to withstand the impact of an aeroplane. 鈥業n the past week, we鈥檝e poured 4,000m3 to form the walls鈥� foundations,鈥� explains Kallio. It will need a whole lot more, as each is around 1.6m thick and will rise to a height of around 60 metres.

However, the next milestone will be the completion the turbine building cast and, once again, it鈥檚 a big operation. 鈥業t鈥檒l require a pour of around 4500m3 鈥� reinforcements are six metres thick,鈥� says Kallio.

It should be completed by May.

Kallio describes the Finnish health and safety regime in general as exacting, while at Okiluoto 3 it鈥檚 one of 鈥榸ero tolerance鈥�. But he says the foreign firms within the construction consortium 鈥� France鈥檚 Areva (now part of Bouygues) and Germany鈥檚 AG Seimens 鈥� have both welcomed the procedures and work well within its parameters.

鈥榃e have less accidents here, than in other parts of the construction sector,鈥� claims Kallio, who adds that last month, work was halted on site for 48 hours when a routine inspection revealed small cracks in the base of a crane (one of 17 on site) It was dismantled and access restrictions were removed.

With years of experience in reactor builds behind him, Kallio is preparing for a big push as he attempts to get the project鈥檚 schedule back on track. It means, he says, making a crucial sacrifice: 鈥榃e鈥檝e had so many visitors 鈥� scientists and tourists 鈥� but it鈥檚 no longer safe and it takes up too much time. So no more site visits!鈥�

The tunnel

Istanbul鈥檚 grand constructions and huge urban projects have come to define its history. Robust viaducts and immense city walls tell their own stories about the times in which they were built, while elegantly domed mosques and kilometre-long suspension bridges relate equally compelling narratives.

But in terms of sheer ambition, a new development 鈥� the Marmaray project 鈥� is set to trump them all. The multi-billion dollar rail infrastructure scheme will link Europe and Asia with an immersed tunnel, which at 58 metres will be the deepest in the world. Other aspects of the project involve 11km of bored tunnels cut trough solid rock to create a rail transport network aimed at easing the city鈥檚 nightmarish congestion problems.

The first section of the 1.4km tunnel is being placed in a precut trench in the Bosphorus, the busy waterway notorious for its unpredictable currents and frequent tectonic activity. With an earthquake of magnitude 7.5 on the Richter Scale predicted to hit the ancient city sometime in the next decade, the Marmaray tunnel has been designed to absorb it. One other aspect impacts upon every move the construction team makes: a rich seam of urban archaeology reaching back through seven millennia runs through the site.

A transcontinental tunnel was first considered in 1860 under the rule of the Ottoman Sultan Abd眉lmecid I. The idea was revisited over a century later when the Turkish government commissioned a feasibility study for a mass transit railway connection that would involve tunnelling under the water鈥檚 bed. The conclusion was positive, and in 2002, Avrasya Consult, a Turkish-Japanese joint venture in association with infrastructure expert Parsons Brinckerhoff (PB), won the contract for the design, tender, preparation, and construction supervision of the first railway crossing beneath the Bosphorus Straits.

Walter Grantz of PB, Marmaray鈥檚 immersed tube tunnel construction supervisor, was involved in the original feasibility study in 1985. 鈥楾hen, as now, my focus was on the immersed tunnel and its alignment is same as the sketch I did on an A3 bit of paper 20 years ago!鈥� he says.

Grantz (pictured below) explains that the tunnel consists of 11 elements, each one 135 metres long and weighing 18,000 tonnes. 鈥榃e build the steel-reinforced concrete box sections in dry docks 40km away in the Sea of Marmara,鈥� he says. A bid to secure space at the city鈥檚 busy shipyards failed. It has meant dealing with strange water currents when the elements are floated to site. An upper flow of fresh water heads south from the Black Sea, meeting a counter-current beneath of salt water heading north from the Sea of Marmara. 鈥楾hey range up to six knots at the surface and when you consider that 50,000 major ships use the straits every year, it makes placing the elements in the trench a very challenging proposition.鈥�

Grantz鈥檚 colleague, project manager Daniel Horgan, has been on site for the past two-and-a-half years and has found other distractions. 鈥楾he city has such a rich history that you can find something new for every few metres you dig,鈥� he says, recalling the spectacular uncovering of the ancient sea port of Theodosius. It was found in 2005 when clearing a site for one of Marmaray鈥檚 railway stations on the Asian side of Istanbul. Eight sunken ships were unearthed as well as the stone remains of the harbour itself along with 4th century bric-a-brac such as leather sandals and hair brushes. Grantz鈥檚 immersed tunnel team, meanwhile, was isolated from archaeological findings 鈥� although they did find one pot. 鈥榃e thought for a while that we might have to dredge the Bosphorus with a spoon!鈥� he says with a chuckle.

A more pressing concern for the waterborne team is ensuring the tunnel copes with earthquake activity, which is sadly a certainty in this geologically volatile region. Immersion within the seabed is part of the solution but the weak point is the joint between the two tunnel types, where the underwater section joins with the rock-bored sections of the link. Flexible, thick rubber rings reinforced by steel plates will act like gaskets in the event of a tremor, allowing sections either side of the joint to move.

鈥楾ouch wood there鈥檚 been no tremors so far,鈥� says Grantz, adding that the ground conditions are important too. 鈥楲iquefaction can occur on the sandy bed during tremors so we鈥檝e extended the tunnel foundation 16 metres below the bed and stabilised nine metres of soil below that with mortar.鈥�

An Irishmen himself, Horgan highlights the international nature of the project where the challenge is integrating the various different work cultures: Turkish, Japanese, British and American. 鈥業t can be frustrating at times and requires extra and careful communication. But working in a multi-cultural environment on a project that links two continents, well, we鈥檙e making history here.鈥�

The swimming pool

A swimming pool clad inside and out in bubble-wrap around a steel structure based on the complex pattern of soap bubbles. Now surely only an architect could come up with something like that?

Not so in the case of the National Swimming Centre in Beijing, currently under construction for the 2008 Olympics. Known as the Cube, the building is the result of a unique collaboration between PTW Architects, structural engineer Arup and contractor China State Construction Engineering Corporation who won an international competition to design and build the centre.

鈥業t was a highly unusual way of working,鈥� says Tristram Carfrae, director of Arup. 鈥榃e sat down at the first meeting and said what we thought a swimming centre should be like from an engineering point of view.鈥�

The engineers came up with an insulated greenhouse to aid the year-round heating required and provide natural light. ETFE, acoustically transparent, would be a good alternative to glass which only adds to the noise reflecting from tiles and water.

The architects thought otherwise. 鈥楢ll our ideas were ignored at first,鈥� says Carfrae. 鈥楩or four weeks they explored lots of different shapes and philosophies. The Chinese and Australian teams were looking in different directions. Then, in a period of weeks, everything came together.鈥�

The catalysing moment was the discovery that Herzog de Meuron鈥檚 bird鈥檚 nest was to be the pool鈥檚 neighbour. 鈥業t鈥檚 probably just how I remember it. But we said 鈥渢heir鈥檚 is red and round so we will have a square blue one鈥�. Everybody agreed.鈥�

With only the structure of the steelwork to be resolved, Arup came up with an unique solution after an internet search. The structure, based on a mathematical theory developed in 1993 by professors Weaire and Phelan, would mimic the pattern formed by soap bubbles squashed together.

The design of the steel, formed in tubular sections, was a mammoth task, requiring new software to model it. Arup fully designed the package before it was handed over to the contractor and for the first time Arup handed over the model in both 3D and 2D.

Arup proposed welding the nodes where the tubes meet in the factory with joints mid-length in the tubes done on site. But the Chinese contractor elected to do the welding in situ, due to the availability of labour and scaffold. 鈥業n their economy and their situation, it was the cheapest most effective way to do it,鈥� explains Carfrae.

To date the steelwork is up and the external cladding complete. Inside, work on the cladding is still ongoing and the pool should be complete by the end of 2007.

Everything has been sourced from China, except the ETFE which comes from British firm Vector Foiltec. Unusally the cladding contract, shared with a local firm, includes the maintenance and operation of the cladding since it must be pumped to maintain its cushion-like form.

鈥楩rom the outside it looks fantastic,鈥� says Carfrae. 鈥業 can鈥檛 wait to see what it looks like from the inside.鈥�