VolkerStevin was the principal contractor for the Defence Infrastructure Organisation (DIO) on the £34m Queen Elizabeth Class (QEC) Base Porting Infrastructure Project at Portsmouth Naval Base. Boskalis Westminster also worked directly for the DIO undertaking the capital dredging contract associated with the scheme. HMNB Portsmouth is home to two new aircraft carriers – HMS Queen Elizabeth and HMS Prince Of Wales – the biggest ships ever built for the Royal Navy.
VolkerStevin’s design and build contract included the refurbishment and upgrade of the existing jetty and berthing facilities, including the upgrade of the shore side infrastructure, which principally consisted of:
- Demolition and replacement of the 1920s and 1970s sections of the Middle Slip Jetty
- Addition of two new bespoke fender spacer units
- Installation of new navigation aids
- Reconfiguration of the jetty to provide a potable water supply and other vessel support services
- Modifications to the jetty face to accommodate other types of vessels
- Provision of a dedicated high voltage electrical supply
Boskalis Westminster’s contract for dredging the approach channel had a value of approximately £30m.
The dredging activities were related to the deepening and widening of the 4-5 mile long approach channel, including removal of obstructions and unexploded ordnance. A total volume of approximately 3 million cubic metres of hard clay, sand and gravel was removed.
For this project, medium-sized trailing suction hopper dredgers and backhoe dredgers were deployed. Customised working methods and continuous monitoring were applied in order to meet the stringent environmental requirements.
Both offshore and onshore works progressed well, despite the stormy weather encountered in December and January. Work is now complete on the project, with all upgrade work delivered successfully for the client.