Simple and cost effective marina plan

The fact that it sat on clay meant it got off to a good start.

The designs, by UK based Opus International Consultants, included digging to form the marina basin and associated clay core embankment. This was not so easy, as the field which formed the main marina footprint sloped away down across the site, requiring a cut and fill balance.

However, the clay enabled the marina bund to be formed in the excavated material without the need for a lining. Prior to the start of works, soakage tests were carried out to establish the properties of the clay. So, although there was a need for additional material for the bund, this was obtained by the creation of a borrow pit in the centre.

The key theme of keeping it straightforward and cost effective underlies some interesting aspects of the design. The water depth being a fixed 1.4m meant the access ways could be formed as a fixed structure, not needing pontoons or other added extras. The quay wall was in part constructed from spare box culvert units, recycling material from previous projects. This provided a vertical concrete wall, the middles being filled with as dug material and a concrete capping forming the top edge.

Another part of the project involved the creation of a farm access bridge across the marina entrance along the tow path. In keeping with the inland waterways theme a bascule bridge was designed to allow access for tractors and farm plant to the adjacent field. This was designed as a steel structure but followed the classic concept of the overhead frame and ballast box.

There was also the concrete entrance, allowing access from the canal to the marina and lift bridge and associated highway improvements. The development also meant keeping it easy for the extra traffic as the entrance needed better sight lines: the original access was on a blind corner.