The Project

Further to the recent Asset Health Survey Programme carried out by Northern Gas Networks under the RIIO price control settlement, it was identified that the existing plant and equipment at Low Thornley PRS site was obsolete, approaching end of service life and in need of replacement.
The project comprised the demolition and rebuild of existing plant and equipment including the upgrade of the pre-heating to bring the site in line with current Northern Gas Networks standards and compliant with British and European legislation.
Working closely with the end user (Northern Gas Networks), Sonae (UK) was appointed as sub-contractor to MWC (Stanningley Engineering) to carry out the E&I Installation works associated with the site re-build and pre-heater upgrade.


A complete rewire of the electrical installation was required including the isolation, disconnection and removal of redundant electrical equipment in accordance with the G17 design. Rewire and relocation of the site electrical distribution to the existing generator room. Installation of new 300kVA 1:1 Isolation Transformer 400/400v. Installation of new 100kVA standby generator set, Auto Changeover and Bypass panel. Installation of new exterior lighting to the new boiler house, governor house and top store building. Rewire of all interior lighting, heating and small power to boiler house, workshop, mess, top store, WC, office, new instrument room, new electrical room, governor house and store. Inspection and testing of the complete installation to BS7671.


A complete rewire and replacement of all redundant instrumentation in accordance with the G17 design documentation including isolation, disconnection and removal of redundant, obsolete equipment. Rewire of existing slam shuts and bursting disks. Installation of new intruder alarm circuits. Manufacture and installation of new RTU, I.S barrier, Non-I.S and PSU control panels. Pneumatic hook-up and cabling of new I/P converter to remote pressure monitoring equipment. Installation of new outlet temperature surface mounted RTDs. Pneumatic hook-up and cabling of Inlet Pressure Transmitters IP1, HP2, HP3 and
Outlet Pressure Transmitters HP1 and ODP1. Installation of Boiler Interface and Boiler Control Panels. Pressure Testing of new small bore st.st impulse pipe and instrument loop checks to BS6739:2009

DSEAR Inspection

All ATEX certified equipment supplied and installed under the contract scope was subject to detailed inspection in accordance with DSEAR Regulations BS EN 60079-17.


Preparation and submission of Non-Routine Operation (NRO) document for Authorising Engineer approval prior to pre-commissioning checks.
Provision of SCO 4&5 competent persons to carry out the end to end checks and wet commissioning of the complete E&I installation under a controlled NRO procedure.


Test Records and red-line marked as-built drawings were produced and submitted at key stages as identified by Northern Gas Networks for pre-commissioning purposes in accordance with management procedure NGN/PM/RE/18.
Databook records were compiled in accordance with MPTF-001 Databook Framework document.
All final handover records were submitted to the Northern Gas Networks in both electronic format via A-site media document control system and hard copy format.

Health & Safety

All works were carried out under a controlled PTW in accordance with Northern Gas Networks SCO (Safe Control of Operations) management procedures.


The site was located adjacent to an SSSI (Site of Special Scientific Interest) with reports of Great Crested Newts in the area.

All site operatives received environmental awareness training provided by the MWC prior to the commencement of works on site informing them of the content of the environmental management plan and the response procedure to adopt in the event of newts being discovered in the work area.

The works were delivered to the satisfaction of both the MWC (Stanningley Engineering) and the end user (Northern Gas Networks) in accordance with the key delivery dates specified within the accepted programme.


October 2016
Northern Gas Networks
Low Thornley PRS