SEACOMBE FERRY TERMINAL

NEARSHORE CONSTRUCTION OF SEACOMBE FERRY TERMINAL

The original Seacombe Ferry Terminal dated back to the 1870s. It had suffered in the elements, and the linkspan bridges had reached the end of their operational lifetime – they all needed to be removed and replaced. This was all part of a major investment to keep the services running at Seacombe for many years to come.

Cllr Liam Robinson, Transport and Air Quality Portfolio Holder for the Liverpool City Region Combined Authority: “The installation of these new linkspan bridges is a major milestone in this significant investment at Seacombe Ferry Terminal by the Combined Authority. The Mersey Ferries are an important part of our cultural identity and these works will make sure that they continue to run from Seacombe for many years to come.”

DETAILED PLANNING AND DELIVERY

Due to its age and a lack of original plans, there was very little to show how the linkspan bridge was built, or how it worked. We supported our client for 18 months with marine engineering, naval architecture and project management expertise, developing comprehensive method statements, lift plans, risk assessments and a detailed project schedule for everything within our scope.

This is where we excel. We have the marine, heavy lift and civil engineering expertise in-house, and experience in multiple sectors that let us deliver bespoke, turn-key solutions to our clients’ challenges.

• Co-ordinated heavy lifting and marine asset removal
• 18 months of expert, marine engineering support
• An adjustable mooring, coping with tidal flows
• Mooring studies supporting infrastructure removal
• Unique project solution with a floating crane barge

Before deconstruction began, we engineered and delivered an adjustable mooring system that would keep the ferry terminal pontoon in the same place, while the bridges and restraining booms were removed and reinstated. 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.

Deconstruction took place in July, as we did five coordinated 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 account, so our teams worked into the night for some of the operations. We then transported these oversized components away from the site, ready for disassembly or refurbishment.

Each bridge weighed more than 125 tonnes, and the refurbished north and south booms weighed 50 tonnes each. Over a four-day period, the new north and south linkspan bridges 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.

UNIQUE LIFT USING FLOATING CRANE BARGE

This marine lift involved using a floating crane barge to locate and install each bridge section, with a bespoke mooring system that aligned the pieces perfectly between the shoreside terminal and floating pontoon. We 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 the operation, 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 make sure 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.

Joe Wardle, Osprey – our Project Manager on the Seacombe Ferry Terminal project: “This project has shown what team work and having the right people with the right skills on the job can achieve. The Osprey team worked collaboratively with all involved to ensure the job was completed safely and successfully for our client.”

This project highlighted how valuable our team’s marine engineering and naval architects’ experience is, as we were able to help everyone else involved to find the safest, most practical solution in this challenging environment – site meetings with our client, end clients, pilots, vessel captains, partners and third parties… getting everyone’s input, making sure every aspect of the project was conducted as safely as possible. The new landing stage at the Seacombe Ferry terminal should have a sustainable operation window of least 25 years before any major future maintenance is needed again.