Linkspan replacement in weekend window

The £5m marine civil engineering project to install the 41m long metal and glass structure on the Gosport side of Portsmouth Harbour followed months of meticulous planning. It took place over a weekend to reduce travelling disruption to a minimum for some of the service’s 3.6 million annual passengers. he facility was reopened to the public on the Monday morning following what is thought to be the largest replacement works on site since 1921.

Southampton based civil engineering and construction specialist Trant was appointed by Gosport Borough Council as the main contractor for the works, which culminated with the linkspan, being eased into position following 10 months of groundwork preparation and a clear weather window. A few hours before, the new 60m pontoon had also been placed.

Six piles had been driven 18m into the shore, with a further three 610mm diameter piles driven 28m into the seabed, with the facility secured onto the fixed supporting structure with pinpoint accuracy.

Fabricated by the Ravestein shipyard and construction company in Deest, Holland, the covered linkspan and pontoon were transported across the English Channel by crane barge.

The facility, allowing ferries to berth alongside, was constructed with a gentle linkspan incline to make it easier for wheelchair users, cyclists and people pushing buggies.

Keith Edwards, Gosport Ferry’s general manager, said, “We’ve been impressed by what Trant Construction has achieved, with liaison on a daily basis with Trant Construction’s project manager.

“The installation operation, which was logistically demanding and delayed several times due to inclement weather and tidal conditions, went exceptionally well.”

Mark Blackler, Trant Construction’s project manager said, “This design and build contract has demonstrated yet again the diversity of contracts that Trant Construction is capable of delivering. Works on site have been carried out in difficult conditions with many tasks having to be planned around peak passenger flow periods.”

The removal of the existing structure and installation/commissioning of the new one took place over a single weekend possession, with the ferry service between Gosport and Portsmouth operated from nearby Endeavour Quay during the changeover period. Installation of new piles into the harbour bed was assisted by local company Baker Trayte Marine, which supplied the floating plant.

The former pontoon, which suffered age fatigue, was floated away for recycling before the new one was lifted into place.

It is the second major shoreside project Trant has been involved with recently, having refurbished many of the listed building structures of Ryde Pier on the Isle of Wight.