Grand designs

The challenges of planning and building an underground utilities superhighway for the Games were overcome through co-operation and the use of new design protocols, as Phillip Norman reports.

The most powerful symbol of Olympic and Paralympic endeavour is the Olympic Flame. It began its journey across the UK on 19 March and will tour the country before arriving at the opening ceremony on 27 July. Enabling this potent symbolism to keep burning as the athletes go into battle involves the rather humdrum fact that it must be constantly fed by a reliable fuel supply. But underlying this is something altogether more interesting and dizzying in its complexity.

Atkins has been scheme designer and site supervisor for a four-year design and build contract to create a subterranean world of power, telecommunications, water and gas. The project to design an underground utilities superhighway has gone relatively unheralded, but in terms of engineering challenge, it was one of the most complicated endeavours on the Olympic Park.

For starters, there was the sweeping scale of the 2.5km2 park. The numbers are huge: 100km of trenches, 300km of ducts, 20km of pipework, 140 electrical substations served by 100km of cabling, all in aid of servicing both the Games and, in legacy, an estimated 23,000 new homes on the Olympic Park site.

Then there were the physical restrictions of the site. Atkins engineers needed all their ingenuity to design a network that could avoid the many obstacles, connecting utilities underneath the waterways, roads and railway lines and around the major venues – and to achieve consensus among utilities as to where their assets would fit.

Finally, one of the biggest puzzles was how to design a system to cope with the demand of 250,000 visitors a day during summer 2012, but which could then efficiently supply a lower demand for several years afterwards.

We decided that an independent distribution network operation model would work well at the Olympic Park. Each utility would need to be a standalone system with minimal connections to the host utility network within which it sat, and which in effect supplied the independent network. This infrastructure had to be accommodated in tight spaces in unobtrusive areas. New thinking was needed to identify locations that made the masterplan work, and which also allowed proper maintenance and operation.

The system also needed to work effectively when demand dropped off for several years after the Games. It is not as simple as just shutting off supplies. With water and sewerage, for example, switching off can lead to problems in bigger pipes where, without sufficient flow, the water can become stagnant. Accordingly, Atkins worked with Thames Water to model the demand for the potable water network over a long period to find a size of pipe that would work for all scenarios.

There were also major cross-park utilities to factor in, such as water pipelines that fed Canary Wharf and other areas of north and east London. Retaining them on site would avoid the high costs of relocation as well as the great difficulty in finding suitable alternative locations. As a result, large portions of the existing primary drainage and potable water systems stayed, saving money and land.

Utilitarian though all this work may be, it has produced some eye-catching achievements. A key success has been in managing business relationships and communications, quite apart from the pure engineering acumen. Devising protocols that all parties could agree at the outset was a strategic success that may influence utilities design for years to come.

For example, the width of the service corridors at the Olympic Park had to be tightly constrained because of the large venues, watercourses, railways, roads, protected habitats and other environmental factors. The pits and trenches to take the pipes and cables had to be squeezed into a tighter space than normal. Yet utility companies have specific demands about where their services should be located, both in relation to other pipes and cables and what structures can sit above.

Atkins asked each operator what its ideal would be for the service corridor in terms of depth of service, using the National Joint Utilities Group standard as a starting point. Because this did not cover all scenarios, Atkins established a “vertical separation protocol”, which laid down the depth of each utility service and how the services would relate to one another. For example, it stated that there should be a minimum 300mm gap between a wet service and an electrical one. Having such a well-defined model in three dimensions gave clear criteria for design and made it easier for companies to see the bigger picture, and to compromise where necessary.

Above the ground, host utilities outlined their requirements for placement of assets in relation to curbs, drainage systems, lamp posts, benches and so forth. In an ideal world, each utility’s requirement to be a minimum distance away from such structures would be achievable, but that was not the reality at the Olympic Park. Atkins responded by establishing a “structures protocol” to define what was acceptable and what might be negotiable. This ultimately allowed around one-third of issues to be settled without the need to negotiate details individually.

These two protocols saved the Olympic Delivery Authority about six months in the planning and design stage and at least another six months on site by enabling contractors to proceed with construction, rather than pause while negotiations took place. Atkins could respond to individual contractors’ requests for information far quicker than the standard 14 days. The protocols already provided many of the answers, and when they did not, the host utility could provide one quickly because it was not swamped with requests for information.

At the end of the process this scheme design was adopted by the vast majority of host utility companies. This would not have been possible without the­ ­protocols.

Looking back, this hugely complex utilities project was delivered under budget and without disrupting the critical delivery deadlines for the London 2012 venues. This in itself provides a powerful testament of the major strides possible when all parties work together from the outset.

Or, to put it another way, utilities may appear to be all about joining up cables, pipes, and ducts. But in the end they are about people and joined-up thinking.

Phillip Norman, head of utilities, Atkins

This article first appeared in Utility Week’s print edition of 29 June 2012.

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