Archive for category: Water Management

Drain lining technology from Lanes Group plc is being used to rehabilitate highway drains while helping hard-pressed maintenance budgets stretch further.

Highway chiefs are switching from excavating and replacing defective drains to lining them because the no-dig approach is proving safer and less costly.

Effective maintenance of roadside drainage is a key priority for highway authorities to reduce the risk of flash flooding which can contribute to accidents and traffic disruption.

Working with one highway authority in South West England, Lanes Group’s sewer rehabilitation and lining division has, to date, completed schemes to line defective drains at four different locations.

Partnership working, with Lanes teams scoping high-risk sections of roads to allow the highway authority to make informed choices on maintenance approaches, has been key to the project’s success.

Melvyn Newman, the local authority’s site manager for highway maintenance, said: “Lining surface water drains is proving to be a very useful approach to highway maintenance.

“It’s especially helpful where drains are co-located with other services, such as gas and water mains and fibre-optic cabling.

“In these cases, excavation is more complicated to plan and carry out, adding to the costs and the time taken to tackle potentially-serious localised flooding problems.

“Where these issues arise, lining highway drains is proving to be significantly less expensive than excavation and can be carried out in days, rather than several weeks.

“Lining is also less disruptive for road users and safer, because often it needs less traffic management or none at all, and our maintenance teams do not have to work close to busy roads.”

Lanes has combined lining with the use of advanced remote access cutting technology to remove tree roots which had infested the drains, preventing the free-flow of water.

Pipes lined have ranged in diameter from 225mm to 450mm. The longest liner installed so far has been 160 metres.

Simon Bull, Lanes Group’s Sewer Rehabilitation and Lining Manager, said: “We have installed several liners in one village. Conventional excavation would have caused serious disruption for residents over weeks.

“We can rehabilitate the drains to the same standard in a fraction of the time, and local people would barely be aware we are working in their community.”

In one case, 60% of the volume of a 225mm-diameter clay pipe was filled with roots along its length.

These were removed using Lanes’ powerful ProKASRO electric robotic cutter, which can operate up to 110 metres from the entry manhole, allowing the pipe to then be lined.

Two lining techniques were used – hot cure lining and ultraviolet (UV) lining – to take account of differing layouts of each pipe.

Hot cured in place pipe (CIPP) liners are flexible tubes of resin-impregnated needle felt which are inverted into defective pipes using water.

The water, fed into the liner from height, presses the liner tight to the host pipe. The water is then heated to nearly 90 degrees Centigrade to cure, or harden, the resin.

With UV CIPP lining, compressed air is used to inflate the liner and UV light emitted from a UV light train pulled through the pipe is used to cure chemical catalysts in the liner.

Lateral pipe connections are then reopened using the robotic cutter, creating a new pipe within a pipe which has a design life of up to 50 years.

Hot CIPP lining can be used where drains curve and change direction along their run. However, the water used in the process needs to be disposed of at an authorised site because it has a taint from the resin.

UV CIPP lining can be used where there are straight runs between manholes. It uses less equipment, takes less time to complete, and does not create wastewater that needs authorised disposal.

Lanes Group: www.lanesfordrains.co.uk

The drainage system at one of Sheffield’s most iconic buildings has been rehabilitated with an extensive programme of remote structural repairs.

Sheffield City Council commissioned Lanes Group plc to carry out the planned drain maintenance work at the Grade I Listed Sheffield Town Hall.

Drainage engineers from the Lanes Sheffield depot have installed 64 structural liners in pipes beneath the 120-year-old civic building in the centre of the city.

The cure in place pipelining (CIPP) technique, often referred to as patch lining, allows drainage systems to be renewed without the need for extensive excavations.

Arnold Morton, Minor Works Supervisor for Sheffield City Council, said: “The way the Lanes team has gone about its work has been impressive. The town hall is a high-profile building in a prominent city-centre location, so setting the highest standards of health and safety and work-site management has been very important. Lanes has delivered on both.”

The patch lining programme has involved Lanes drainage teams working both inside and outside the building, late in the evening and at night to avoid inconvenience for its users and the general public.

Lanes, the UK’s largest independent drainage specialist, has extensive experience of surveying, repairing, and rehabilitating the drainage systems of historical buildings like Sheffield Town Hall.

David Cheesman, Area Development Manager for the Lanes Sheffield depot, said: “This was one of the largest number of patch liners installed in one go by our depot.

“The process is a highly effective way to rehabilitate drains. A patch liner extends the life of the section of pipe it’s installed in by up to 25 years. Effectively, it’s the equivalent of a new pipe.

“Many of the sections of pipe we were renewing under the town hall were in such hard-to-reach places that this no-dig drain repair solution was the only realistic option.

Pipe Lining “Patch lining is often more cost effective than excavating and replacing drain lines, and can be completed more quickly. In this case, the work was scheduled to take a month, but was completed it in less than three weeks.”

The work at Sheffield Town Hall was carried out by a three-person team, led by CCTV drainage survey engineer Scott Sorsby.

He said: “The work has gone very smoothly, despite the size of the project. We installed up to six patch liners a night, most of them a metre long.

“In some cases, we installed up to five liners sequentially, with each liner overlapping the other, to rehabilitate a longer section of pipe. And in one case we had to traverse the liner 30 metres along the pipe to where it needed to be placed.

“With patch lining, the worksite can be kept small, and can be set up and taken down very quickly. In a live environment, like the town hall, where we were working inside and outside the building, that’s a big advantage.”

Sheffield Town Hall, built over a seven-year period from 1890 to 1897, is the venue for most official meetings, and many civic events, held by Sheffield City Council.

It was designed by architect Edward William Mountford, who went on to design the Old Bailey law courts in London.

The need to rehabilitate the town hall’s drainage system, made up mainly of 150mm-diametre clay pipes, was established by a CCTV drainage survey, also carried out by Lanes Group.

Patch lining is one of a range of CIPP techniques used to rehabilitate sewers and drains.

A flexible glass-reinforced matting liner impregnated with resin is inserted into the pipe, where the resin cures, creating a durable pipe-within-a-pipe.

With CIPP drain rehabilitation, the resin can cure in ambient temperature, as was done with this point lining programme. Or the curing process can be accelerated with hot water or ultra-violet light.

Lanes Group: www.lanesfordrains.co.uk