Anglian completes ‘keyhole’ mains connection

Anglian has connected a live water main using a “keyhole” method adopted from the gas sector which improves safety and reduces disruption.

It carried out the live connection using an innovative coring technique, which the company claimed is a UK first for the water sector.

The work was part of a trial of new methods for open excavations with Tracto-Technik UK and Kier in Suffolk.

The coring method involves removing the top layer of a highway before excavating. This reduces the risk of striking other utility assets in the ground and means the original top layer can be replaced after the work is complete to make it faster to have the road in use again.

The excavation was cut using a 600mm coring rig and excavated using Air-Vac units before being connected by specialist long-handled tooling.

The technique is in use in the gas sector but adapted and developed for water, which Anglian said will improve safety, lower costs and reduce time spent on excavations.

Keith Childs, planned works and asset health co-creation delivery manager, said the trial achieved what was, until recently, only an aspiration, to complete a connection without anybody in the open excavation.

“Now, the challenge is to continue developing the technology so it can also be used for other activities across Anglian Water”.

Tracto-Technik is working to develop a coring rig that suits Anglian’s needs to use the process across the business.

Childs said the collaboration will continue to further develop the technology.