By Alison Luke
In a city that loves to shop, residents are eagerly awaiting the completion of the Dubai Mall. As the first areas are handed over for tenant fit-out, Alison Luke finds out how this entertainment giant is being serviced.
While all eyes are focussed on the Burj Dubai, another major project is quietly progressing alongside it on the same city centre site. Although a more sedate four-storeys high the Dubai Mall is no less challenging than it’s neighbour, with immense quantities of MEP services required to meet the demands of the facilities being included.
Around three times larger than the city’s existing Mall of the Emirates, when complete it will be the largest shopping mall in the world. And a world away from the region’s traditional souks, it’s not only shopping fans that will gain from the project, for as well as the 1160 shopping ‘anchors’, hidden away in the vast project are roller coasters, a hydraulically-operated fashion catwalk, Olympic-sized ice hockey rink and one of the largest walk-through aquarium tunnels in the world.
Catering for this mix of activities is a closely co-ordinated MEP services installation that includes pipes of over 1700mm in diameter; ductwork over 4.5 m wide and Dubai’s first ice thermal storage system.
“We don’t have difficult systems here, it’s only the massive quantities that are really scary and the integration of the systems,” stresses Ziad Taleb, MEP manager for Dutco Balfour Beatty (DBB) – Al Ghandi & Consolidated Contractors Corporation (AGCCC) joint venture partnership. “We’ve done much more difficult jobs than this,” he adds.
DBB and AGCCC are acting as the main contractor for the project following a joint tender to client EMAAR. It is a fully integrated joint venture, with the firms on a 50:50 basis and DBB acting as the joint venture leader.
Singapore-based consultancy Meindhart was responsible for the initial design of the MEP services, with the main contractor developing the final design and creating shop drawings. The main contractor has carried out areas of the MEP installation that are directly related to the structure, such as earthing and underground stormwater and drainage networks, and is overseeing the remainder of the works.
The main MEP installation within the mall is being carried out under a joint venture between Juma Al Majid and Mapco. Other sections of work such as the lifts and escalators and district cooling plant have been divided into separate packages and awarded to nominated subcontractors. “Each package is awarded to a subcontractor and we manage, as the joint venture, all of these packages,” explains Taleb. On site the project has been divided into small areas, with a different engineer in charge of each.
This approach was taken to cope with the scale of the project. “The electro-mechanical works in the Dubai Mall’s budget is 1.2 billion Dirhams – I think it’s one of the largest building electro-mechanical works in the world,” states Taleb.
Aside from the physical scale of the project, over 13,000 operatives are currently working on the site, with this peak expected to last a further six to eight months. Ensuring that everyone is carrying out their task correctly and at the right time to enable build programmes to be met has required close co-ordination and a tight logistics plan.
“It’s like a big cake, you have to slice it into small pieces. It takes a lot of effort to organise and plan – and we’re doing it,” assures Taleb. “It’s a big co-ordination job between the different packages, different subcontractors and the architectural aspects. We are in charge of the co-ordination, execution, workmanship and the timely execution of the project,” he adds.
To ease the process, a dedicated logistics department has been created on site and all project teams have been site-based throughout. “Every main subcontractor is based next to us [in the site offices] otherwise we would lose control,” stresses Taleb, “This includes their engineering staff and supervisory and management staff.
“This is not a small project, it is treated like a big factory,” he adds. Communication is by e-mail or “face-to-face”, with the six on-site meeting rooms reported to be permanently fully occupied. And on a weekly basis the main contractor’s management staff walk around the entire site to check on progress: “If we don’t do this we will lose control. We must be kept updated,” stresses Taleb.
The MEP contractors were among the first on site, which was necessary as many distribution routes are integrated with the mall’s concrete structure. Prior to starting installation, the drawings for all individual elements of the build were co-ordinated. “This is one of the engineering difficulties; the most difficult task is to get everything really harmonic together,” states Taleb.
The mall structure is being completed by beginning at one end and following through, so some areas are now ready to hand over to tenants, while construction is continuing in the areas furthest from these. The MEP installation has generally followed the build pattern, with work also being prioritised according to programme demands. “We jump by priority areas that open up work for different subcontractors,” explains Taleb. Around 50% of the MEP scope of works is based between the lower ground and roof levels, the balance being the linking of these two areas via the risers and general distribution routes.
The 120MW electrical load is being met by a new 132kV substation built by the client at the edge of the site to serve the mall, Burj Dubai and Burj Dubai Lake Hotel.
Within the mall, the main supply feeds ten internal substations where the 11kV supply is stepped down to 380V for local distribution via around 500 riser rooms and 47 main electrical risers.
The project is zoned according to the location of the substations, but the inclusion of a ring main unit between the primary and secondary substations mean that should one fail, power can be redistributed to this zone from another substation. Three 1.75MW diesel generators have been installed to provide back-up to the essential life safety systems in the event of a total power failure.
A 43,000TR district cooling plant will provide chilled water for the mall’s air conditioning systems; this will also serve the adjacent hotel, business park and Burj Dubai. For cooling purposes the mall is divided into three zones, with a main secondary chilled water pumping station serving each individually and supplying the final air handling units and fan coil units via heat exchangers.
In a bid to follow through the energy efficient operation of the air conditioning system provided by the district cooling system, the back-up to this is being provided by an ice thermal storage system. In addition to providing security of supply in the event of a power failure, to reduce noise and for energy efficiency it will be used during the night to pre-cool the chilled water.
It is planned that the air conditioning system will be operational from Spring 2007, with wild air being used to ease the working conditions and provide suitable environments for the mall’s finishings to be applied. “Wild air does not require the systems to be commissioned, only pre-commissioned,” explains Taleb. “We aim to start commissioning in April. That will take about a year, which is normal for this size – again it’s a big cake, we have to slice it up into pieces and eat it one slice at a time,” he adds.
One area in which temporary air conditioning is already operational is the aquarium. “Because of the special bonding on the acrylic, it requires a maximum temperature of 25°C to be maintained [throughout the installation process] for the panels to bond together properly,” explains Taleb.
With ductwork weighing up to half a tonne for a metre length and internal pipework of up to 900mm diameter, the installation techniques being used involve special lifting gear and the MEP contractor has had to install substantial support brackets for the products.
Despite their scale the products used are themselves standard, reports Taleb, but more often used in the oil and gas industry than in a shopping mall.
Prefabricated ductwork has been used where possible to reduce time and risk on site. “Because we have quite large sized ducts here – some of it is 4 x 1.5m or 3 x 1m – anything that can save time is good,” states Taleb. “[It was also chosen] because of the quantity – the quantity is the issue here.”
Catering for these vast quantities meant ordering a large percentage of the materials early in the project. “We order a percentage, say 50-60%, as soon as [materials] get the approval and then finalise the quantities and order the balance later,” Taleb explains. “We will have about 80% of the materials and the equipment on site by the end of this year,” he states.
With some tenants areas in the mall ready for handover ahead of schedule, the project team is well on target to meet the completion date of December 2007, something that Taleb says the whole team should be proud of. “It’s going to be an achievement for everybody who has contributed,” he concludes.