Making a splash to keep Severn Trent sewer works on the right course.

Thursday 19th January 2017

Severn Trent’s £60 million project in Newark went to new depths at the weekend after diving company DiveTech UK helped to prevent delays to works on Newark’s sewers.

You wouldn’t normally expect to see a scene from 20,000 leagues under the sea in Newark town centre, but a specialist diving company helped Severn Trent to investigate an obstruction at the bottom of a nine metre shaft that they are building on Queens Road. Just to complicate matters, the obstruction was below several meters of murky water.

Tim Sawyer from Severn Trent says: “When we build shafts in areas with wet ground, like here in Newark, the shafts are purposely built under water and then pumped dry when they are completed. Whilst we are working on them, the water is often murky and we are unable to see to the bottom, so from time to time we need to call in specialist divers to come and work underwater in the hole that we are digging. The divers can then help us to pinpoint and dig out areas of hard ground.”

“DiveTech sent out a five man team to our site to carry out the dive, and lowered an engineer to the base of the shaft in full diving gear. He found an area of hard rock that needed to be removed so DiveTech high pressure jetted, jack hammered and lifted the rock clear, allowing our team to then continue with work on the shaft from the surface."

Severn Trent is currently working in Newark to completely overhaul the waste and water network for the town, with work being carried out by BNM Alliance.

Dave James from BNM Alliance says: “Four divers from the team spent two days breaking out the harder rock, working in rotation for up to two hours under water. They used umbilical air lines to feed air to the diver which also allowed communication between the team.

“We needed to sink the shaft, so by clearing the rock we were able to get it to the required 12 metre level. The DiveTech team were great and did a smashing job, helping to make sure that we can keep our works on track!’

The shafts that Severn Trent are constructing will be entry points that allows BNM Alliance to lower its state-of-the-art tunnelling machine under the streets of Newark to form new, larger sewers.

Severn Trent’s work in Newark is due to be completed in 2020.