Netherlands-owned UK construction company VolkerStevin has delivered the Queen Elizabeth Class (QEC) Base Porting Infrastructure Project in Portsmouth Harbour on budget and two months ahead of schedule. The infrastructure was officially handed over to the naval base on Tuesday 7th March 2017.

Aerial view of ‘The Princess Royal Jetty’ under construction

Aerial view of ‘The Princess Royal Jetty’ under construction

VolkerStevin was appointed by UK MoD offshoot, the Defence Infrastructure Organisation (DIO) as the principal contractor on the project back in 2014 along with BAE Systems.

The design and build contract, worth £34.4m, was to reconstruct the secure tidal berth on the Middle Slip Jetty at Her Majesty's Naval Base Portsmouth (HMNB Portsmouth), which will house the two new Queen Elizabeth Class Aircraft Carriers HMS Queen Elizabeth and HMS Prince Of Wales – the biggest ships ever built for the Royal Navy.

National press, including Maritime Journal, were invited on March 10th to view an exercise in a programme of trials, known as a FIT programme (Familiarisation, Integration and Testing), in which it was planned for 200 personnel, lorry transits, emergency response teams, and security disembarking from the USNS Robert E. Peary. The weather unfortunately conspired against these well laid plans, and the US Navy warship was left on a mooring out on the Solent while a thick mist descended.

Familiarisation has included legions of people outside of the expected MoD staff. For instance, Hampshire Fire and Rescue, who have a responsibility for firefighting incidents when the vessel is berthed, have already travelled up to Rosyth to begin exercises on accessing and dealing with incidents on the (still very much under construction) HMS Queen Elizabeth.

The infrastructure work included the demolition and replacement of the 1920s and 1970s sections of the Middle Slip Jetty, the addition of two new fender spacer units, installation of navaids (as previously reported in MJ), refurbishment and upgrade of the existing jetty and berthing facilities, including the upgrade of the shore side infrastructure, reconfiguration of the jetty, modifications to the jetty face to accommodate other types of vessels and provision of a dedicated high voltage electrical supply.

The main apron of the jetty, which is due to be Christened ‘The Princess Royal Jetty’ sits on 220 steel piles, and while vibration piling could take place around the clock, traditional piling techniques had to be conducted between 7am and 7pm, and could not take place at all on Sundays due to planning constraints.

The very specific task of berthing an aircraft carrier, according to Philip Wise, DIO Project Lead, required some vessel-specific infrastructure, such as the fender spacer units, which are effectively large steel tanks which rise and fall with the tide within bearing tracks on the quay: “The carriers have 20m of hull flare from waterline to deck level, so these spacers were required to keep the vessels at the correct distance from the apron”, said Philip.

At berth the vessels will use an 11,000 volt shorepower supply, so the vessels will not rely on burning generator fuel at berth. The cable however, is of 5 inch diameter containing plenty of copper as the berthed ship could have similar power demands to a small town. Due to this and the 20m hull flare, a Cavotec boom is in place to pass the cable when the ship comes to her berth.

The dredging of the turning circle area for the carriers is still ongoing, and has to allow 2m clearance beneath the keel at high water neaps, as well as springs. The dredging has to account for the increasing draft of the vessels throughout their lives, as it is a little known fact that naval vessels, due to new equipment and technology being fitted, get significantly heavier throughout their life spans. The 65,000t HMS Queen Elizabeth and HMS Prince Of Wales are expected to put on up to 10,000 tons before their active service comes to an end.

By Jake Frith