River Hamble Harbour Master’s Office

This project involved the refurbishment of the sea wall at the River Hamble Harbour Master’s Office. The jetty provides an amenity access to pontoons for leisure boating, and also supports the Harbour Master’s Office which functions to control marine activity on the estuary. Due to the location of the work that needed to take place, there were a few variables that made this a challenging environment to work in:

• The working area was very small
• It is a public amenity and therefore keeping disruption to a minimum is key
• The tide makes the window in which work can take place is much shorter

The first step was to install a temporary sheet pile cofferdam (a temporary watertight enclosure). This extends the tidal working window, aiding the jobs cost and program efficiency.It also provides a clean and dry working area which is essential when working with concrete. The permanent works involved casting an in-situ concrete face to the existing wall. Ecology is always central to construction activity around watercourses and shorelines and so the face featured a number of innovations to encourage biodiversity such as the use of a textured formliner and rockpools of various shapes and sizes to mimic a natural rockfaceas well as a series of smart chamfered pre-cast coping units.

We set the wall height and embedment with a balance of economical installation, and maximum benefit to the program for the follow-on activities. We were able to provide this, in a very congested and limited access environment through ownership of the UK’s only Movax-Lite side grip sheet piling attachment. In common with other plant used on site thisequipment featured hydraulic circuits with a low impact bio-oil.

The location of the job is on the Warsash waterfront, which presents an attractive and historical environment for tourism and leisure. Part of the remit was to manage and contain our effect on the public, marina users, Harbour Office staff and concession operators within the immediate vicinity. Which we achieved through good communitcation, sensitive programming and the use of modern techniques and equipment to minimise disruption.