'No-dig' tech could end traffic jams

Digging up roads causes frustrating jams

Traffic jams caused by roads being dug up to fix underground pipes could soon be a thing of the past.

Engineers are turning to "no-dig" or "trenchless" technologies to inspect, fix and replace pipes without digging up the road.

"We're putting cameras onto small wheeled or track vehicles that can move up a pipe," Ian Naysmith, Business Manager at the UK Water Research Centre for Underground Assets, told BBC World Service's One Planet programme.

"They've even got to the stage now of having little robotic side-arms on these things, so you can peer up the lateral pipes that come from buildings down to sewers."

Fix and replace

Without the cameras simply examining a pipe often requires roads to be dug up. Fixing and replacing the conduits could take days or even weeks.

Pipes suffer damage from chemicals which rot them from the inside, tree roots can crush and pierce them and the shifting found can squeeze and bend them creating leaks.

The time for some repairs has been slashed to just 30 minutes

During Britain's 1995 drought, one third of the water in some regions was lost through leaky pipes.

Formerly pipe repair works caused congestion on Britain's already snarled-up urban roads.

The development of remote-control technology means that entire sections of pipe can now be fixed in just half an hour.

Subterra, a company that specialises in the new technology, have come up with innovative ways to fix some of London's ageing pipes.

One method involves a fibreglass bag being glued into place.

First the bag is positioned at the point where damage has occurred and is inflated until it fits the pipe and irons out any dents.

Steam is then pumped in to glue the new lining to the walls of the pipe, which usually takes around two hours.

By using ultra-violet light to dry the glue this fix time has been cut to just 30 minutes.

Sharp objects or obstructions which cannot be removed with the bag are dealt with using remotely-operated high-pressure water jets.

New services

As well as making such "local repairs," existing pipes can also be replaced with "no-dig" methods.

"You can burst the existing pipe, and drag a new pipe of the same diameter through the hole that you've made," Mr Naysmith said.

"You can eat the existing pipe up using a device, and drag a new pipe in."

Engineers can now also install new pipes by tunnelling, forcing the pipe through the ground.

Combined with these developments, new technologies will also allow other services to be installed in sewers, meaning they too could be serviced without the need for roadworks.

Mr Naysmith said that optic fibres could be fitted to the walls of sewers, as well as numerous other cable types.

This would cut down the disruption caused by the installation of cable television, for example.

'Supertrench'?

However, Mr Naysmith added that this approach would not yet work with all services.

"Of course you have to be a bit careful with sewers because you can get explosive gases down there, so there's issues to do with mixing electricity and certain services," he warned.

Sewer pipes may soon carry much more than just waste

"Also you wouldn't want to mix water and electricity."

The eventual hope is that by developing these ideas, a simple but effective strategy for cities and new suburbs of the future can be produced.

Developers hope these technologies might make the creation of a "supertrench" possible, running alongside of every road.

They would contain all the main services, with room to add any that might be developed in the future, ending the problem of pipe-based road works.

However, this would mean designers and planners would be faced with the task of getting all utilities to agree to share the space.

That could prove more frustrating than any traffic jam.