Trading places

It’s growth rate, amazingly, showed no signs of slowing down so the company began to look for more premises in the area. Most of the surrounding building footprints were already set in the Canary Wharf master plan, but despite the competition for space CSFB was able to earmark the 25 000 m² 20 Columbus Courtyard, a planned nine-storey structure adjacent to the existing building. (These buildings will be referred to in Canary Wharf language as B5 and FC1 respectively, as shown on figure 1.)

Initial concepts saw the buildings as two independent structures and construction began to this format. After ground level construction was completed, the involvement of CSFB prompted a rethink to the extent that joining the new building B5 to building FC1 could create a single building with much larger floor plates and trading floors.

Engineering consultant Hilson Moran was appointed to carry out the expansion. Its contract included extensive modifications to building FC1, including services and infrastructure upgrades, as well as the shell and core and fit-out of building B5. Hilson Moran project director Chris Plummer states an “integrated approach to the two buildings” was essential from the start of the project.

Before construction began thorough surveys were completed to identify exact floor and ceiling levels in building FC1. The plan was to build building B5 just 500 mm from FC1. Within building FC1 a temporary wall was constructed, consisting of sound-block plasterboard, a two-hour fire barrier and waterproofing materials. This effectively became the outer wall of FC1 and a 2 m “zipper zone” was thus created between the floorplates of FC1 and B5.

Once B5 was complete, the external cladding on FC1 was stripped and seismic joints used to join the two buildings. This allows for inevitable differences in movement between structures.

Financial trading in FC1 carried on throughout construction and the fit-out of B5 was completed before removal of the temporary wall, so final expansion of working areas effectively happened overnight.

The first area to be filled was a trading floor in July 1999, 13 months after the initial contract was signed with Canary Wharf. Other areas were finished on a rolling basis, with the final floor completed in December 1999.

The company acquired part of another banking organisation, BZW, in 1998, making the new structure too small before it was even complete. To accommodate this, Credit Suisse once again consulted the Canary Wharf master plan.

A second nine-storey building was chosen, the 18 500 m² 17 Columbus Courtyard (B4), for which Canary Wharf had begun shell and core construction. During the construction period Credit Suisse set to work planing the interior. This enabled fit-out to be completed “in record time” as it began immediately on completion.

The buildings

Building FC1 was constructed by Canary Wharf as part of the area’s initial redevelopment plan. It sits around 200 metres North-West of Canary Wharf Tower and backs onto West India Dock. The development of B5 and B4 curves round the dock’s corner onto the western end.

The exterior of FC1 is around 50% stone cladding and 50% glazing. Building B5 has slightly less stone cladding, and B4, around 5-10%.

The main entrance to the development is through building FC1. The opulence of the building is immediately striking. A vast reception area larger than most people’s homes greets visitors, and entry past this area requires magnetic credit card style swipe cards to operate electronic revolving gates.

Wide, winding corridors lead visitors through the building. The decor is consistent throughout the floors so it is almost impossible to detect when you leave building FC1 and enter building B5. The only evidence is the discreet six inch seismic joint which circles a cross-section of the corridors. This plays testament to the planning and organisation of the fit-out team.

This ‘joined’ building (FC1/B5) houses the trading floors, 50 meeting rooms, conference areas, plus a plethora of staff facilities including a restaurant, gym and shops. Services provided mean that staff have virtually no need to leave the building during the working day.

Building B4 is reached by a glass-sided walkway that connects the two buildings between ground and fifth floors. This ‘link bridge’ is wide enough to provide useful floor space in the form of individual offices and meeting rooms. At the time of visit these were unoccupied but fully fitted out. The main building area contains offices for ancillary staff, a ground-floor coffee shop and an IT suite.

Change of services

The joining of an entirely new building to an existing one had a profound effect on the services strategy. By removing the building facade, it was also necessary to remove and reroute air supply and exhaust paths that terminated there. Also, the joint runs across virtually the centre of the trading floors so if flexibility for movement was to be maintained, the IT and services systems had to be altered to cater for the entire area as one building.

Having two networks serving a single trading floor was not a practical option for several reasons, the first of which was the IT network – local area networks had to cover all traders equipment – the second was the level of flexibility required by the company.

According to Chris Plummer, “due to the dynamic nature of the financial services industry” business needs are frequently changing. These changes to the work structure induce around 5000 moves each year. A permanent team is employed by the company to plan these movements so they occur with minimal disruption. External contractors work with the client’s own personnel to carry this out.

Early changes centred on upgrading the IT infrastructure of building FC1. Two suites covering an area of 2000 m² were formed on floors 5 and 14, housing over 1000 voice and data cabinets and ancillary equipment. In addition, numerous satellite equipment rooms are dotted throughout the buildings.

In these areas FM200 fire suppression systems are used, with the heptafluoropropane distributed via nozzles at high level throughout the rooms. When two smoke detectors are activated simultaneously, the system starts.

To keep the equipment within operational conditions a 400 W/m² cooling load was required. To meet this, nineteen 50 kW dual-source close-control downflow air conditioning units were installed. These are fed by three 650 kW packaged air cooling chillers sited on the roof of building FC1/B5. A separate condenser water system using four 550 kW dry air coolers has been installed on the roof simply as back-up.

The plant used was installed on an N+1 basis “to ensure a high degree of resilience and ensure uninterrupted operation”. To further guarantee resilience, two separate routes carry the risers from the IT suites to the roof, so if one is damaged, operation should not stop.

Keeping cool while trading

There are three trading floors in the building, each with a staff capacity of 900. Two are currently occupied by traders, the third is available for future expansion but is now being used for other purposes.

One major investment by the company in this area was the computer screens. LCD flat screens were chosen to completely replace all existing monitors, both for their energy efficient properties and versatility for ‘stacking’ on the traders’ desks.

As traders desks house multiple processors and have from one to eight screens active simultaneously, the arrangement of these is crucial to ensure optimum working conditions for both equipment and staff.

Extensive analysis of comfort levels was carried out by the BSRIA. Four typical trading desks were set up in a room designed to replicate live conditions. Temperatures and average air velocity were then measured at over 600 points and the resulting comfort levels were analysed.

Particular detail was paid to the temperatures around the computer equipment and below the traders desks. In this area it was found that strong thermal currents are produced due to the amount of electrical equipment, and attention was focussed on where specific problems may lie and how to prevent them.

Further tests were carried out in conjunction with air distribution equipment manufacturer Trox to optimise the positioning of supply air diffusers and thus remove areas of poor airflow.

The final set-up allows hot air to rise by natural stack effect from below the desks, flowing towards the rear and rising through the centre of two back-to-back desks to be removed at ceiling level. Fans were avoided due to the maintenance and noise levels they would generate.

The electrical design load for each trading desk is 435 W, with the facility to increase to 595 W, a significant energy saving on using traditional cathode ray tube monitors that would have required a standard 600 W/desk with an upgrade capacity of 920 W/desk.

In addition to the energy savings made by using the lcd screens, floor space was also saved. The reduced bulk of the screens enabled smaller desks to be used by the traders, and a final occupation density of one person/7 m² has been applied.

Air conditioning

Air conditioning throughout buildings FC1 and B5 is provided by a fan-powered variable air volume system fed by roof-mounted outside air plant. To ensure future flexibility various enhancements have been incorporated, including the use of six 930 kW air-cooled chillers in the central cooling plant.

Again to ensure resilience, the units were installed on an N+1 basis and can maintain the full load with one chiller out of the system.

As this plant is housed on the roof of the nine-storey building B5, plumes from evaporative cooling towers would have a negative effect on the taller facade of building FC1. This was one of the main reasons for selecting air cooled plant. To further ensure a “clean roof line” and to maintain planning restrictions, this plant was concealed within wells on the 9th floor of building B5.

A 40 W/m² design load was set for the air conditioning system by the client. Hilson Moran was, perhaps unsurprisingly, “sceptical” about the need for this capacity. However, extensive testing within building FC1 showed that these levels did occur in areas of high staff density and computer use. To meet the client’s demand for flexibility it was necessary to ensure these levels were available throughout the entire floor area.

Two on-floor air handling units connected to a ring duct and the fan-assisted variable air volume units provide additional resilience to the cooling capabilities of the system and the 14 litres/s occupant outside air supply. Units are fitted in ceiling voids, a method predetermined by the deep voids in building FC1.

Lighting on the trading floors is provided by Category 1 luminaires fitted with dimmable controls. Additional luminaries “wash” vertical surfaces. The use of daylighting is minimal in this area due mainly to the deep plan of the rooms, but also to avoid problems of glare.

In office areas, Category 2 luminaires are used, arranged on a 750 x 750 mm grid to provide flexibility for moving dividing partitions.

Electrical supplies

Electrical infrastructure upgrades to building FC1 included the addition of a second (and independent) incoming electrical supply from a separate substation. An auto-changeover facility enables the building to be supported from either source.

Two 1600 kVA diesel generators were added to the original electrical generation system. Three of the four fitted are capable of supporting the entire building load for at least 48 h. These were roof-mounted in acoustic pods to meet set local authority noise levels.

Additional ups power was provided by four 800 kVA static systems (again with a redundancy of one unit). These upgrades meant the introduction of a new substation and switchgear on the top floor of the building. This contains two transformers and associated switchboards. All switchgear was constructed so any future additional circuits required can be added without disruption.

In order to accommodate this increase in equipment, the existing boiler plant housed in the top floor of the building was replaced and relocated to the roof. The new plant was prefabricated off-site and installed by crane. This saved considerable on-site time.

In addition to two incoming electrical supplies, building B5 has a disaster recovery link to building FC1. Four 2000 kVA transformers are provided, with each able to supply 50% of the total load. Thermostatically-controlled fans increase the output of each unit by up to 40%.

Three of the ups’ supply power to desks via diversely routed rising busbars. Isolating transformers have been installed throughout to minimise the harmonic disturbance passed to the lv infrastructure.

Electrical distribution to desks is via underfloor plug-in busbars sited between rows to simplify maintenance. Two busbar tracks serve alternate desks on the trading floors to minimise disruption should one circuit fail. The system has also been designed to enable the movement of plug-in floor boxes.

Static switches have been extensively used. These provide switches between primary and secondary power sources in only 4-5 msecs, so any computer equipment is not affected and does not even register the break in power supply. This has increased the operational resilience and provided greater flexibility of supply options during the phased completion stages.

Chris Plummer states that the extent of use of this technology is “unprecedented in the UK” and the client has received much outside interest over the details and reliability of the switches.

In building B4, further duplicate incoming supplies were established and four 1400 kVA diesel generators were installed to support the building in the event of power failure. Three 800 kVA ups units were installed with static switches, as in building FC1/B5, to give added protection to the IT suite and satellite equipment rooms.

Mission control

The entire services system is controlled from a single control centre within the main building. Looking more like the flight deck of an airport control tower than a bems, this centre was constructed as part of the expansion project and covers all three buildings.

Engineers monitor all systems 24 h/day from this point. Details of entire areas or single units can be displayed on flat panel monitors suspended from the ceiling. On these, the real time conditions are displayed, allowing any problems to be spotted and alterations to be made.

A full bems has been installed throughout the buildings and a separate electrical monitoring system for the transformers, electrical supply, ups and standby generators, power distribution points and static switches.

As this development is central to the company’s worldwide corporate services department, the bems and electrical monitoring systems have been supplemented by a facilities management system. This system is integrated with the client’s external IT network, enabling systems to be monitored from any of CSFB’s other buildings.

Energy efficiency measures

Care was taken to recover energy where possible. Research into conservation options was carried out and various measures implemented.

For example reject heat from the chillers is being used to preheat the 50 m³/s of outside air supply as well as some of the restaurant’s daily 27 500 litre hot water needs. Heat recovery condensers were incorporated in three chillers and a control sequence developed to ensure optimum use.

Research showed it would be uneconomic to apply this technology to all six chillers. Testing in the manufacturer’s climatic chamber found that up to 68% of the cooling capacity could be recovered as waste heat, this reducing to 55% with minus ambient temperatures.

Constant volume regulators have been applied to both fresh air and extract ductwork systems on all floors. These, coupled with variable speed inverter drives on the main supply and extract fans, enable individual floors to be shut out of the system when not in use.

A building which fits the bill?

The complex certainly seems to provide a comfortable and pleasant workplace, while providing the client with the flexibility and resilience required in the banking industry.

It could be questioned whether the facilities could be provided with slightly less resilience or if the economics of the industry disallow this stray from safety. The banking world in general sees redundancy and security of supply as essential and this necessity was highlighted by the crash of the Stock Exchange’s systems on the final day of the 1999-2000 tax year.