22 January 2014

Two major pipework connections have been successfully completed at Costain’s £20million update of the Severn Trent Frankley Water Treatment Works.

New pipes are now connected to two of the original 120-year-old, 43-inch diameter cast iron gravity mains leaving what is Severn Trent’s largest treatment works.

The 52-hour operation was carried out in November without affecting a single Severn Trent customer. Jonathan Wagstaff, Severn Trent’s Programme Manager, hailed it as “an incredible achievement that is testament to the thorough planning, preparation, commitment and dedication of the whole team at Frankley.”

Jay Standen, Costain’s Delivery Manager, said: “These were particularly complex connections. We were dealing with pipes lying seven metres deep and nestled in existing services. The pipes were commissioned in 1894 and made of cast iron with lead joints and their condition was unknown. Our operation had to ensure that no damage was done to them or the surrounding infrastructure.

“We also had to make sure the water supply remained always on and good to drink, so we were working to very high standards of hygiene.”

Months of meticulous planning, preparation and enabling works went into the operation. Preparatory work included exercising existing valves to ensure they could be isolated to allow the connections to be made.

The operation began with a careful excavation. The team then used hydro-demolition to remove concrete from around the pipes, which revealed that they were in fact in good condition. This gave the design team the information they needed to finalise the pipe design, and decide on construction methodology and contingency planning. 

The team then worked round the clock to ensure the connections were successfully completed right first time, safely and on programme.

Added Jay: “This was a complex operation that involved the coordination of a multitude of trades and skill sets. But thanks to great collaboration between Severn Trent, Costain, MWH, Draper Civil Engineering, Freeflow Pipe Systems, Ainscough and Cemex, the work went without a hitch. Tests carried out after the work was completed showed that the water quality was spot on.”

These connections bring the total successfully completed during the treatment works update to nine. A further 20 connections of various sizes and complexities remain to be carried out.

 

Ends