Extensive redevelopment has already been carried out in the west of the city, now Birmingham's developers are looking east. The existing Bull Ring has been demolished to make way for a larger, modern shopping centre. Now covering a 26 acre site, and providing 110 000 m2 of shopping space, the New Bull Ring will include over 130 retail units and be flanked at either end with flagship stores: Selfridges and Debenhams.
"This'll be the shopping centre of Birmingham, there's no doubt about it," comments John Shore, project director with electrical contractor Hills Electrical & Mechanical.
Hills won the £7 million electrical services contract for the £500 million project by competitive tender based on concept drawings. Its contract covers the design and installation of the electrical services, including landlord's lighting, small power, access control, and security systems. The firm is also responsible for the exterior floodlighting of two listed buildings at either end of the site: the Rotunda office block and the 19th-century St Martin's church, which will be a focal point of the final development.
The site slopes away from the adjacent Birmingham New Street Station towards the church. Inside the mall a management suite and two levels of underground car parks are topped by three double-height levels of retail units.
Due to the size of the project, Hills employed m&e consultant FaberMaunsell for the detailed design. "We took [the concept] designs and calculated the cable sizes and co-ordinated them with the latest architect's general arrangements," explains Paul Davies, Hills project engineer.
The design team was housed in an existing building adjacent to the site; this reduced design and planning times. "Rather than having to get on the phone to someone, you could just go next door, so in theory we could iron out problems easier," stresses Matt Jones, senior electrical engineer with FaberMaunsell. Another advantage was existing relationships between members of the Hills' team, Shore explains: "At the time we'd just completed the Hippodrome project, so it dropped nicely for us as a team to move across to the Bull Ring." Both Shore and Davies joined the project in October 2001 following the other scheme's finish.
All drawings were completed using AutoCAD, with three operators carrying out this task in the site design office. Co-ordination of services between the different trades was simplified by using the RSUK electronic system. Jones elaborates: "We can basically look at everybody else's drawings. Where there's co-ordination issues, such as containment track side by side with someone else's, we can call up their drawings and look at their levels or we can look at set architects' drawings and levels of the ceiling, so we always know that we're co-ordinating with what else is in the building and all the other services."
On site, the 86 Hills operatives were organised into smaller teams across the project. "We basically broke it down into about seven areas, with seven supervisors that report directly to our site agent," explains Shore. The firm installed all main bracketry, starting at Selfridges and following the building work to the opposite end. Other contractors then attached their containment to this bracketry.
Co-operation and co-ordination between the construction teams continued on site. Rather than hold progress meetings in an office off site, Hills joined other contractors in a weekly walkaround of the scheme with project manager Sir Robert McAlpine. During these sessions, the team covered all aspects of the project, from services areas to back-of-house corridors, and were able to target specific problems and liaise with each other to plan any programme changes needed for the following week.
"You can see what's going on this way; you might lose something if you're in an office elsewhere," says Shore. "It's a time that all the different contractors can use to co-ordinate certain things that are not going to plan and target areas, such as commissioning," adds Davies.
M&E services plant is generally split between the basement (electrical) and roof (mechanical). A dual hv electrical ring ensures continuity of supply, with automatic changeover should one ring fail. There are four lv substations, one each in the north, south, east and west areas of the development. From these, distribution is by busbars. Two busbars, from all but one of the panels, follow individual risers that run the height of the building. At each main level a connection is made to local distribution boards. This system allows every part of the building to be accessed and serviced.
The dual-busbar system is also part of the fire strategy. Each is of equal capacity, but the secondary riser supplies the rooftop extract fans via fire-rated cables, so if the main riser is compromised the supply will automatically change over.
The rooftop plant areas consist mainly of ahus, extract fans and associated ductwork. This is divided into six 'pods', partly because much of the roof is glazed and partly, says Shore, "to keep distribution to a compact format". Each pod serves the area directly below. A louvred screen around the roof edge conceals this plant and trunking follows this edge and feeds the external floodlighting and catenary lights in the mall's central street.
The external lighting was designed by specialist firm DPA. Energy efficient lighting has been used throughout the scheme, with gobos at high level in the mall, and projector lighting leading to St Martin's Square. On the Rotunda, lamps are positioned on arms around the top of the building. Colour cathode lamps and projectors around its base combine with these for controlled scene-setting.
The lighting system in the Bull Ring is controlled by bms in conjunction with daylight sensors on the roof. It is designed on a matrix system that controls how the light switches off. "Its designed as an alphabet lighting control, so reference A will be a certain group of fittings, and they can be switched off individually," explains Shore.
In the mall, natural light is fully utilised during daylight hours, topped up by high level lighting.
The basement car parks lack this natural light, and in peak hours the lighting is on full level. Part of the matrix control system, as the centre becomes quieter and reaches closing time, the lighting can be reduced by switching of certain banks of lights in sequence until a base security level is reached.
Hills is scheduled to complete the electrical installation by the end of October, with the fit out beginning in Spring 2003. The new Bull Ring is due to open in September 2003.
Providers
Project: The New Bull Ring Electrical suppliers
BMS: Robell
CCTV: Vicon
Cable: Delta and Pirelli
Electrical distribution: Bill Switchgear
Electrical accessories: MK Electric
Fire alarm/detection: Protec (RMC) HV switchgear: Done by SEC for RMC
LV switchgear: Bill Switchgear
Power busbar: MEM
Public address: Protec
Security equipment: Protec access/intruder
Voice and data equipment: Redstone (RMC)
Lighting suppliers
Emergency luminaires: Cooper
Lighting controls: Robell
Luminaires: Thorn; Wirefield; Whitecroft; Aurora; Coughtre
Prices
Total cost: £500 million
Electrical services cost: £7 million
Source
Electrical and Mechanical Contractor
Credits
Client Birmingham Alliance Project manager Sir Robert McAlpine Architect Chapman Taylor Architect McAlpines Benoy Architect Birmingham Alliance M&E consulting engineer WSP Birmingham (indicative design) M&E consulting engineer Faber Maunsell (detail design) Lighting designer WSP Birmingham Lighting designer DPA Edinburgh (exterior) Main contractor Sir Robert McAlpine Electrical contractor Hills Electrical & Mechanical Mechanical contractor Emcor Drake & Scull
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