Osprey Delivers on Seacombe Ferry Terminal Construction Project – Video
The Osprey Marine Engineering, Logistics, and Heavy Lift teams are proud of their work in support of the Seacombe Ferry Terminal project.
The original structure at the Seacombe Ferry Terminal dates back to the 1870s. Over time, the infrastructure itself had suffered in the elements, and the linkspan bridges had now reached the end of their operational lifetime. They all needed to be removed and replaced. At the same time, our client was tasked with executing major refurbishment works on the landing stage, including upgrading the mooring bollards and installing new powered gangways. This is all part of a major investment to keep the services running at Seacombe for many years to come.
Due to the age of the structures and the limited availability of historical documents showing how they were built, and how they worked, Osprey supported their client for 18 months in the lead up to the project with marine engineering, naval architecture and project management expertise, developing comprehensive method statements, lift plans, risk assessments and a detailed project schedule for the execution of all tasks within our scope.
This is Osprey’s advantage: we have the marine, heavy lift and civil engineering expertise in-house, combined, with experience from multiple sectors allowing us to provide bespoke, turn-key solutions to our clients’ challenges.
Prior to commencing the deconstruct phase of the project, Osprey engineered and delivered an adjustable mooring system that would maintain the position of the ferry terminal pontoon in the River Mersey, for the duration between removal and reinstatement of the bridges and restraining booms. A mooring study explored how the pontoon would behave when we removed sections of the bridge, and what would need implementing to keep our vessels in place and provide moorings for our vessels. We had to contend with limited space, shallow water, vessels transiting the river, tides, and a significant swell.
The deconstruction phase took place in July, as we carried out five co-ordinated lifts over five days, lifting out the restraining booms and old linkspans. This narrow window had to take the Mersey’s significant tidal flow into consideration, meaning our teams worked into the night for some of the operation. We then transported these over-sized components away from the site, ready for disassembly or refurbishment.
Over a four-day period, the new north and south linkspan bridges – weighing in excess of 125 tonnes each and refurbished north and south booms – 50 tonnes each, were moved into place on the quayside using a small fleet of SPMTs and loaded to the barge with our LG1550 Crane. The barge was then towed to site in readiness for the marine lifting operations to take place. This marine lift was unique: it involved using a floating crane barge, “Lara 1” from Hapo International Barges B.V., to locate and install each bridge section, using a bespoke mooring system to align the pieces perfectly in position between the shoreside terminal and floating pontoon. We also consulted on the temporary locating structure that was needed to guide those bridge sections into place.
The tidal phases here only provided short windows for operations, and it was essential to plan everything down to the last detail: the timing for every phase of the work was critical. The River Mersey has a fast current and the second-highest tidal range in the UK, and the strong swell made for a challenging first lift of the bridge sections in the dark. Even for our crew transfers and safety boats, the swell and the current presented an interesting challenge.
We wanted to ensure our lift work supported the project team’s aspirations for minimum disruption, as much as possible. The installation of new sections for the reconstruction element of the project was completed in October 2021.