The Project

As a result of the Asset Health Survey Programme carried out by Northern Gas Networks under the RIIO price control period, it was identified that the existing plant and equipment at Marton Crossroads PRS site was obsolete, approaching end of service life and in need of replacement.

The project comprised a full civil, mechanical, electrical and instrument rebuild to bring the site in line with current Northern Gas Networks standards and compliant with British and European legislation. Due to the compact footprint of the site, its location on a busy crossroads and the requirement to maintain supply through the site at all times the project presented many challenges.

Employed directly for Northern Gas Networks to carry out the E&I Installation works associated with the site re-build, SONAE worked closely with the MWC (Fastflow Group) to ensure key deliverables were achieved to the satisfaction of the end user (Northern Gas Networks).


A new E&I kiosk was constructed to house an all new electrical distribution system allowing the existing installation to continue to operate in parallel the new installation. A new electrical system was installed comprising incoming switchgear, overcurrent and earth leakage protection and small power distribution system servicing new interior and exterior site lighting, E&I room lighting and heating and telemetry power supply unit. The installation was delivered in accordance with the clients G17 detailed design documentation and inspected and tested to BS7671.


A new E&I kiosk was constructed to house an all new remote telemetered instrument monitoring and control system. The scope included the manufacture and installation of new RTU, I.S barrier, Non-I.S and PSU control panels. Pneumatic hook-up and cabling of Inlet Pressure Transmitter IP1, Outlet Pressure Transmitters MP1, LP1 and Filter Differential Pressure FLT-DP1, FLT-DP2, FLT-DP3 and FLT-DP4. Installation of switches and cabling associated with Slam Shut and Intruder Alarm equipment. Pneumatic Pressure Testing of new small bore stainless steel impulse pipe and instrument loop checks. Isolation, disconnection and removal of redundant, obsolete equipment following instrument changeover.

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.


SONAE were responsible for supplying both the NRO documentation and competent persons to control and execute the changeover in line with the networks SCO 5 requirements.

Commissioning was phased to allow the existing and new installations to operate in parallel before isolating and de-commissioning the old equipment ensuring continuity of supply throughout the 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

Sonae (UK) were appointed directly by the end user (Northern Gas Networks) to carry out the E&I installation works.

Sonae (UK) undertook the role of a contractor during the construction phase, working in co-ordination with the Principal Contractor (Fasflow Group).

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


September 2018
Northern Gas Networks