Revised plans to replace Heathrow airport’s first permanent passenger terminal were unveiled this week. Modularisation will be the key on the congested site.
Plans for an airport terminal to rival the elegance and ease of Heathrow airport’s Terminal 5 (T5) were launched this week − Heathrow’s Terminal 2A (T2A).
In structural form the two are not very different. Both are steel framed, glass clad buildings and both are huge rectangular boxes − T5 has a footprint of 396m by 176m while Terminal 2A will have a footprint of 300m by 200m.
The most striking difference is T2A’s rippling roof. Where T5 had a majestic arch across the shorter span of the footprint, T2A has a wavy truss. The truss has three peaks and two troughs corresponding to distinct points in the terminal.
“The waved ceiling acts as a guide. There are three key activities − check-in, security and departures. ”
Duncan Pickard, BAA
“The waved ceiling acts as a guide,” BAA head of T2A delivery Duncan Pickard tells NCE. “There are three key activities happening on the top floor of the terminal − check-in, security and departures.
“At check in, the roof rises. After check in, it dips down to the exit. As you’re coming into security, it opens out again, then dips down again at the exit and then rises up again into the integrated departure lounge.”
Secondary trusses span between the wavy trusses. They run from the lower flange on one main truss to the upper flange on the adjacent truss, creating a sloping roof between each wavy truss. The vertical face on this sawtooth profile offers the opportunity to get light into the terminal, but avoids the greenhouse effect produced by a large amount of glazing.
“The roof helps us to get enough light in without the solar gain,” says BAA Eastern Campus programme director Phil Wilbraham. “The roof lights are northfacing 4m high windows.” The 6m floor-to-floor height will add to the feeling of airiness inside the four-storey building.
At ground level, there are back of house facilities like ramp storage and offices, followed by arrivals at first floor level, departure gates at second floor level and check in and security on the top floor. The composite floors of the building are held up by steel columns on a 9m by 9m grid.
Being shoehorned in
T5 had the luxury of being built on open land on the west side of the airport whereas T2A is being shoehorned onto the site of the existing Terminal 2 (T2).
The site is constrained by London Underground lines running beneath it, runways and existing terminals to the side of it and sightlines to the control tower over it.
“It’s not dissimilar to T5. The different thing is that it has to be phased. It’s being built on a site that is being used.”
Phil Wilbraham, BAA
“It’s not dissimilar to T5,” says Wilbraham. “The different thing is that it has to be phased. It’s being built on a site that is being used.”
The first steps towards the new terminal are already being taken for a 2013 opening.
The adjacent Queens building, previously used for office space. The buildings are being emptied to make way for the new terminal.
“The Queens building is now vacant and we’re starting to asbestos strip,” says Wilbraham. “We’ll see physical demolition of Queens by September and T2 will be empty before Christmas.”
- 2006 Pier 6 in T3 opens for the Airbus A380 “superjumbo”
- 2007 Air traffic control tower opens T3 redeveloped with new modern forecourt
- March 2008 T5 opens Personal rapid transport system trialled
- Throughout 2009 Refurbishment of T4 begins; Work on T2B satellite pier continues
- Sept 2009 Demolition starts on Queens Building Christmas 2009 T2A target price contract to be let; Existing Terminal 2 emptied
- 2010 T5c, a second satellite building for T5 opens
- Jan 2010 Construction starts on T2A; First three stands to open on T2B satellite building
- August 2010 T2A module installation to start
- October 2010 Three further stands to open on T2B satellite building
- 2013 Phase one of T2 opens, accommodating 20M passengers
- 2019 Phase two, a second satellite building for T2 opens, increasing passenger capacity to 30M annually
Making sure that the construction work does not impact on the busy airport is a constant concern.
To make sure demolition of the buildings can occur safely, services that run through T2 have been diverted in front of the building. “There are gantries in front full of services − power, IT, water and wastewater,” says Wilbraham.
“They have been taken out of T2 and the Queens building and brought forward to safely demolish the buildings. Water was commissioned this week and all services are now diverted.”
In addition to the T2A building, work is already underway on the northern section of the terminal’s new pier, 2B. Three out of six new stands will be open by January next year. By making those three stands available, some of the existing stands that are under the new terminal’s footprint can be demolished, leading to the completion of three new stands by October next year.
The elegant design of the new terminal has been heavily influenced by how it will be constructed, to try and make the process easier on this constrained site. “The design has been led by the way it’s being built,” says Pickard.
“We’ve worked it backwards and the design has been influenced by the construction. Normally it’s the other way round, a building is designed and then you look how to build it.”
Hetco, the consortium of Ferrovial Agroman and Laing O’Rourke that will, subject to price, eventually build the terminal, took over design in March last year, procuring designers to work with them.
“The design has been influenced by the construction. Normally it’s the other way round.”
Duncan Pickard, BAA
Architect Foster & Partners produced the initial concept design and is still involved, but Amey and Ferrovial’s technical office have taken over detailed design from concept designer Arup. first tier suppliers,” adds Wilbraham.
“Siemens for the baggage control, Siemens for the information systems and Hetco. “We are now working with them to ensure competition in their subcontracts.
“Hetco has worked well managing the design process and is now working on the procurement. “We will be letting the actual construction contract to Hetco around Christmas, setting a target price. We need to get to a point of certainty on programme and cost.”
Modularisation and repetition
Modularisation is to be used extensively at T2A, with 1,483 off site modules planned.
“There has been a big push on designing for manufacturing and assembly − for things to be the same,” says Pickard.
“For example we will be using 12m long sections of pipe tray [with all pipe work attached] in the floor rather than individual pipes. It takes pipe work off site which gives us better quality control and better safety as it will minimise the amount of working at height.”
Modularisation and repetition will also help BAA overcome one of the major problems it had with T5 − the commissioning. The 200m by 300m floor plate is broken down into 12 zones. Each of these zones has its own core which supplies services to its zone.
“There has been a big push on designing for manufacturing and assembly − for things to be the same.”
Duncan Pickard, BAA
Therefore the building can be commissioned on a zone by zone basis, rather than waiting until the whole building is finished “How we commission the building and the build sequence has informed the design,” says Pickard.
“We have learnt from T5. The building centres around 12 cores. Each core is a 9m by 9m box, 18m tall. You can split the cores into modules 2.5m by 2.5m by 9m long − to transport by road − so you have a number of plug and play boxes manufactured off site. We can commission in zones and reduce the length of time in build.”
Once construction is underway, progress on site will be rapid. Manufacturing of the modules needs to start next year so that when the site is ready for installation to start in August 2010, the right amount of modules can be delivered when they are needed.
- Client BAA
- Architect Foster
- Principal Contractor Hetco consortium comprising Ferrovial Agroman and Laing O’Rourke
- Concept structural engineer Arup
- Structural Engineer Amey
- Services engineer Hoare Lea