Lanes solves basement drainage blockages at iconic skyscraper

Drainage engineers at Lanes Group faced significant access challenges when called in to clean a basement drainage system at an iconic skyscraper.

Wastewater service pipes beneath the Grade II-listed CIS Tower in Manchester, the tallest office block outside London, were becoming blocked.

A team from the Lanes depot in Eccles, Greater Manchester, was commissioned by facilities management specialist Interserve FS (UK) to investigate the problem and find a solution.

The 378-ft-high CIS Tower, opened in 1962, is Manchester’s second tallest building, and is now part of Manchester’s 20-acre NOMA office and urban living scheme.

The building’s design and location presented the Lanes with key challenges throughout the drainage survey and blockage cleaning work.

Carl Barlow, Engineering Supervisor for Interserve FS (UK), said: “The Lanes personnel were impressive. They stuck to the task until every scrap of material that could block the drains was removed. They really went the extra mile.”

Lanes Manchester Area Development Manager Simon Roberts said: “Instead of being buried underground, the drainage system for the CIS Tower is suspended within an undercroft between two of the building’s three basements.

“When the blockages occurred, overflowing wastewater was affecting a staff social club and gymnasium, containing very expensive fitness equipment, so it was important to solve this problem as soon as possible.”

The undercroft was little more than a metre high, creating cramped working conditions. Despite this, it was well lit and ventilated. This meant a risk assessment found it did not need to be treated as a confined space.

Jetting and vacuumation hoses had to be run 150 metres from the jet vac tanker, then down two storeys, to reach the undercroft. Pipework was accessed, not through manholes, but by unbolting pipe hatches.

Additional staff were deployed to ensure health and safety hazards relating to access difficulties were effectively managed.

A CCTV drainage survey of 600 metres of pipe, ranging in diameter from 100mm to 300mm, was carried out over one weekend.

This revealed the blockages were being caused by a build-up of scale and debris, combined with grease from kitchens directly above the undercroft.

The Lanes drainage team then meticulously jetted clean the pipework in a four-day programme spread over two further weekends.

During the work, they also cleared the outfall pipe, six metres down the external manhole, which had become blocked with asphalt and rubble from recent road construction in the area.

Their work left the drainage system at the CIS Tower free-flowing, and cured the wastewater leaks. Interserve is now putting in place a plan to prevent further drainage problems.