Bespoke engineering undertaken by Planned Maintenance Pennine (PMP Ltd) on Yorkshire Water’s distribution network running across the Tinsley Viaduct in Sheffield has delivered an estimated £80k in provisional cost savings.

Tinsley Viaduct is a multi-level bridge structure allowing the M1 and A631 to span the Sheffield and Tinsley canal and the River Don. It provides a vital link to the north of England and is deemed to be a strategic national infrastructure asset. In addition to facilitating traffic flows, it also houses a number of utility pipelines and other services.

The utility pipe-lines within the southern abutment of the viaduct include two 24” diameter water mains which form part of the water company’s Sheffield and Rotherham distribution network.

Access to viaduct is strictly controlled and work subject to very tight timescales

Access to the structure for effecting reactive and planned maintenance activities is strictly controlled and all work has to be pre authorised and then completed within very tight project timescales, including out of “normal hours” working.

Yorkshire Water was aware of leakage on this section of the network and instructed Planned Maintenance Pennine (PMP Ltd) to undertake an asset condition survey and report the findings. The survey undertaken by PMP’s confined space survey team identified that one of four 24” flow control/isolation valves required replacing and a section of complex cross connections were heavily corroded.

Following the survey, Yorkshire Water instructed PMP to formulate an outage plan to facilitate the repair of the cross connections, rather than facing a serious reactive challenge at a later date. The tee section to be changed was located within a valve chamber and the access cover had been constructed after the pipework had been installed. The size of the access was such that it was totally impractical to remove the corroded tee without removing a section from the top of the chamber. This was not considered to be a viable option as it would cause major disruption to local traffic and the cost of reinstatement would be prohibitive.The chamber lid was 600mm square and the tee to be removed from the chamber contained 3 flanges measuring 800mm on the outside edge. PMP offered a solution that required the off-site manufacture of a bespoke tee in which the centre flange could be separated from the tee body. This allowed all components to fit through the existing access arrangement.

An AMEX-10 seal was then used in the reassembly of the tee section and flanges when inside the chamber.

Provisional cost savings estimated at £80,000

The provisional cost savings were estimated at £80,000, which was influenced by the fact that no reinstatement or traffic management required as PMP adopted an innovative and flexible engineering approach to a complex issue. In-house workshop capacity enables PMP to undertake bespoke engineering projects and to manufacture constituent components for complex jobs such as this.

Originally founded in 1983, the company has an excellent reputation for fast response to emergency call-outs and for carrying out work safely, on-time and with a ‘can do’ attitude.

Providing bespoke engineering solutions and with over 30 years’ experience of safe working in high risk confined spaces, PMP Utilities has become renowned for its ability to generate new and innovative solutions to often complex and difficult, ‘one-off’ mechanical engineering problems.For more information contact PMP on 01282 855220 or email This e-mail address is being protected from spambots. You need JavaScript enabled to view it

www.pmp-utilities.co.uk