Redbridge - Southampton

Reactive scour works at the confluence of the River Test and Southampton Water required a significant mobilisation effort from the team. Scour protection measures involved installing Soluform bagged concrete ballast bags at multiple locations around the stone bridge abutments and piers. The operation necessitated three trucks and two trailers with six operatives; one large trailer was designated for transporting pontoon sections, edge protection panels, and additional equipment, while the crane trailer was utilised to lower further pontoon sections over an adjacent wall. A walkway pontoon measuring twenty-two metres by two metres was constructed to provide safe access, incorporating a landing dock extending into the river to accommodate tidal restrictions. Additionally, a seven-metre by four-metre spud leg pontoon, supported by one of our six-metre aluminium workboats and a two-man crew, facilitated the transport and precise placement of equipment using anchors and buoys. Lines secured to the bridge served as a multi-point mooring system, allowing for controlled positioning via veering and ferry gliding techniques using the very strong current. The scour holes could only be reached at low water on the spring tide which meant strong currents and extreme high and low waters heights. This meant continuous monitoring of the pontoon on the falling tide to do the works over low water, then leave when there was still enough water underneath the pontoon and workboat. Our six-metre workboat was delivered by water from our yard and then brought by water to and from site each day within the tidal work windows. Overall, the job was completed over 6 shifts including mobilisation and demob.