A bespoke cabling system will aid security at Gatwick Airport’s new Pier 3 project. EMC reports.

A critical set of requirements for a project at Pier 3, London Gatwick Airport, has resulted in the design, production and installation of a unique seven-pole armoured wiring system by Metway Electrical Industries. The constraints driving the strategy to extend from five or six-pole functionality are based on a range of factors specific to the secure and efficient running of one of the world’s busiest international airports – these are placing additional demands on the expertise of the project team.

With work nearing 70% completion, Metway has been successfully involved in an application that has demonstrated the quality of its bespoke design and manufacturing skills. The project has also provided the first opportunity for the company, located about 20 miles from Gatwick, to work airside at the airport.

Metway was contracted by Crown House Technologies on behalf of the client BAA. The Crown House engineers produced a design solution for the project in liaison with Metway. In line with BAA’s security policy to alter it’s airport piers to separate arriving and departing passengers, Pier 3 is being built to provide segregated access to Gatwick’s South Terminal satellite.

Around 70 airlines use Gatwick to fly to approximately 200 destinations worldwide. In the aftermath of 11 September, the rapid installation of effective security measures such as segregated piers is particularly important to protect passengers.

Modular construction

Crown House’s approach was to develop the project around a series of component modules that could be manufactured off site. The principal element is a fully functional arrivals and departures corridor with auto-walk, made up of a series of four-metre modules.

The Pier is approximately 500 metres long, with 58-metre, double-storey bridge structures carrying the corridor between a series of towers. These provide stability and allow for changes in direction of the corridor if required. The towers create open spaces to break up the journey for passengers to the arrivals hall and provide the location for emergency escape routes and a range of technical services.

Metway specialises in creating robust and cost-effective alternatives to hard-wiring. It has experience in producing flexible and armoured wiring systems for a wide range of applications. “A modular approach was required for the electrical services. This met the two key project requirements; speed of installation together with BAA’s requirements to limit security liabilities by restricting the numbers of personnel required to work airside,” explains Dave Morris, design manager for Crown House Technologies based at Gatwick Airport.

The Metway seven-pole wiring system was manufactured off-site at its factory. It requires a re-engineered armoured cabling that has increased the regular cable diameter from 32 to 40 mm. This incorporates three cores for power and two twisted pairs of data cabling linking to a Luxmate lighting control system and a Thorn Explorer self-test and monitoring system for the emergency lighting.

The system provides robust, metal-encased wiring in the ceiling void, with a plug-in facility to the primary distribution hub and nine seven-pole outputs. The twisted-pair configuration gives sufficient protection for data signals to be unscreened, with a resultant cost saving.

The primary components within the system are Metway’s GST connectors, Flexicon conduit and low smoke, zero halogen cabling, which means that no noxious fumes are produced in the event of fire breaking out.

Lighting controls

The Luxmate lighting control allows for dimming to 10% luminosity when the area is free of people, constituting a significant energy-saving measure. This can be boosted instantly to 100% operating capacity through a digital signal received via a switchable interface. The area involved includes 1000 light fittings. Most elements of the system are maintenance-free, which responds to the airport security situation and the need to minimise personnel going airside.

The emergency lighting system is self-contained and not subject to the dimming cycle: it operates continuously 24-h per day at 100% luminosity. With both seven-core and five-core being utilised, a strict system of colour-coding is established for the customised boxes to minimise the possibility of installation error.

The Thorn Explorer self-test facility constantly monitors mains and emergency operations, including lamps, batteries and chargers. In case of power failure, lamps can run for up to three hours on battery. Digital printouts of any problems relating to each emergency luminaire are available for the maintenance crew. This means that replacements are only made when needed, rather than as a matter of course as frequently occurs with maintenance procedures. This is yet another element of cost-saving inherent in the system.

Manufacture and testing

The system is assembled in the factory and is subject to minimal snagging because of the strictly controlled workplace environment in which it is manufactured. Tests carried out ensure full continuity, polarity, earth loop impedance and insulation resistance results are satisfactory.

Metway md Jonathan Vening says that the company’s bespoke product experience is underpinned by BS EN ISO 9001: 2000 accreditation, which strongly influences manufacturing and testing processes and procedures. He explains: “With the system being based on a seven-pole configuration, which is unique, and given the particular requirement of the airport environment for 100% reliability, the need for rigorous attention to quality controls is paramount.

“As well as providing the ability to exert complete control over production, the benefits of pre-manufactured modular wiring systems include savings on costs and time at point of use. For instance, installation at the airport takes less than one-third of the time you would expect if conducting a conventional electrical installation.” Setting up the electrical wiring at Pier 3 also required co-ordination with other services, including the pa system, fire alarms and air conditioning, which makes simplicity of installation all the more relevant.

The armoured system of flexible metal conduits was specified by Crown House because of the high level of protection it provides, for instance against vibration of the piers from aeroplanes, but most importantly for the added security of the cabling in the event of an explosion.

Metway’s core experience in the manufacture of armoured systems stood it in good stead for the demands and scale of the project. “Both Crown House and BAA are delighted with the results we have seen as the project nears completion,” comment Alex Best and Robert King of the Gatwick Pier 3 project team.