Changing times

Media is changing, and fast. The once revered home of the Financial Times' printworks is testament to the fact that the Internet era is well and truly upon us.

In 1988, this Nicholas Grimshaw-designed building saw a high profile opening when the Financial Times moved to the east London site. Only a few years later the company moved on to Wapping, leaving the building empty until 'telehousing' company Global Switch took over, adapting the empty shell to service a new generation of media. The tenants now are internet service providers and telecommunications companies, dealing with airspace and the spoken rather than the printed word.

The opening this time has been low-key. Security and privacy are high priority and the building exterior does not even carry the owner's name, far less that of its tenants. This is media 21st century style, where £/m2 is second priority and power supply is everything. For these tenants, location desires end with the need for fibre optic and secure power supplies.

These types of buildings are sold on their electrical construction, and London Switch was no different. As Hills Electrical & Mechanical's Steve Collings noted on-site: "Three or four times a week a tour of prospective tenants would be led around the electrical installations, switchrooms, etc, examining systems which are usually in the background." An unusual sight with traditional developments, here the electrical supply was a major selling point.

Hills won the electrical contract for the refurbishment by tender and has been involved since May 1998, in the post-design stage. The company was employed initially by main contractor Bovis, then directly by the client for a further upgrade contract.

The building fitted the client's needs in several ways: it is sited close to the main fibre optic route in east London and the company was able to tap into this supply. It is also, as the company's blurb states, "metres from Britain's most established telecommunications and data centre". The building's physical attributes were also suited to a telehousing centre: floor to ceiling heights are large at 4 m, and floor loadings of 2000 kg/m2 are possible (see also "Power to the Internet" in this issue).

London Switch has individuality in the telehousing market. The buildings tend to be faceless, unglazed, metal sheds, but here a smoked glass facade spans the length of the building, breaking the monotony of the grey metal cladding.

This glazed face exists simply because the building is not purpose-built. The usual design is led partly by the need to reduce solar gains, as the buildings house highly temperature-sensitive equipment that may fail if critical temperatures are exceeded, making cooling of major importance and almost half the electrical load. This is provided here by five 288 kW Carrier chillers running at 80%.

Providing non-stop electricity
"The risks of an electricity outage [at London Switch] would be catastrophic," observes Collings. The supply must be consistent 24-hours, seven days a week, all year round, and there are no convenient times for annual maintenance shutdowns. To ensure this security of power, every supply has a back-up.

Two 11 kV mains supplies enter the building from two individual London Electricity Board substations. These feed an hv panel in the first floor switchroom that originates from the days of the FT.

Switchgear left by the FT was disguarded and the remainder of the switchroom stripped for reinstallation. This was due to the escalating capacity demands from tenants. Originally it was intended to use much of the existing switchgear, but as sale of the space progressed it became obvious that the capacity this could serve was too small.

This increase in demand brought several changes to the electrical installation as the scheme progressed but, tellingly, Collings talks of it as "an easy project to run". This was mainly due to pre-planning. Redesign work was carried out by m&e consultant RW Gregory and was planned well in advance of the alterations on-site.

Power is fed from the hv panel through step-down transformers into the tenants' switch panels. Originally one landlord's and two tenants' panels were installed, being fed from two transformers; a third, larger panel was added to cater for the increased loads. These were all initially fed from two transformers, but as tenants switched on-line, another transformer was added to feed the third tenants' panel.

This mains power supply is backed by six battery-started generators. All identical 1·25 MVA Broadcrown units, two were added at the upgrade stage, a soundproof enclosure being built adjacent to the building to house these. Tenants' switch panel three is linked to the two external units by 440 A and 2500 A busbars. Three generators feed the landlord's and tenants' switch panels one and two, the final generator exists incase one of the others fails. The entire system is automated. If there is a mains failure, the generators will start; should a generator fail to start three times in 4·5 minutes, the standby generator takes over.

Electrical fit-out of the individual areas was carried out by the relevant tenants. Global Switch provided a 415 V three-phase supply to each area and a guarantee that any power downtime will be limited to 15 minutes, enabling the tenants to size their ups capacities accordingly.

Upgrades aside, forward planning was essential for completing the electrical installation. "Around 95%" of the system was completed prior to full occupation, but for the remainder, work had to be completed in stages which lasted less than the 15 minutes downtime allowed.

For this, extremely accurate method statements were required. Hills worked on these with panel manufacturer ABB and RW Gregory. The sequence plant would be switched off, installed and reinstated had to be set out in detail to ensure the 15 minute time slots were not breached. With these tight timescales, Hills estimated that for this small part of the installation, a job that may normally take two days to complete, may well need a three week period.

Following the success of London Switch the client has added another building to its portfolio. Sited a few hundred yards away, a ten-storey unit is taking form, this due for completion in February 2001. Even this has grown from its original plans, starting life on the drawing board as a three-storey building. Yet another sign of the speed of change and expansion in the industry, and the need for centres to serve it.