In 2010, Brenwal won the contract to install a major upgrade of the salt water firefighting main at la Collette. This project, prompted by the Buncefield incident involved the installation of some 2km of ductile iron pressure pipework and the construction of a new pumping station.
The main operates at a pressure of 16 Bar, and is capable of supplying a flow of 300 litres per second. It sits with a background pressure of 5 Bar so that a pressure drop, initiated by opening a hydrant on any part of the system, causes the pumping station to start to satisfy the firefighting demand.
As a result of their familiarity with the firefighting infrastructure, Brenwal were appointed by Rubis to install a new connection from the ring main to their fuel farm at La Collette. Working closely with designers, Atkins, the infrastructure owners, DfI and Jersey Fire and Rescue Service, the project involved the installation of a 400mm diameter Tee, valve chamber and interconnecting pipework into the Rubis fuel farm.
A section of the ring main was isolated whilst the works were carried out, the primary objective being to complete the connection works within one day in order to minimise the length of time that the main was out of commission and that temporary firefighting cover was needed for Rubis and Jersey Gas.
The alignment of the new pipework was determined by the presence of existing services, which resulted in a relatively deep excavation and complex pipe geometry. The existing main was cut by means of a specialist pneumatic Keel cutter to expedite the cutting process and to ensure accuracy of fit for the Tee. Most of the new pipework was prefabricated, again to minimise fitting time during the outage. Working from two fixed ends, accuracy was paramount.
Works commenced at 0600 and were pressure tested and completed by 1200 when the main was re-pressurised and returned to normal working condition.