In October 2018, Landmarc were contracted by South Hams District Council to undertake the demolition and rebuilding of approximately 60 meters of the old quay wall at Kingsbridge. Due to the nature of the site being tidal, this created implications for periods of work. However, Landmarc designed a temporary work system of sheet piles which gave an extra hour either side of the tide. This enabled work to continue for longer periods. New foundations were cast up to 1.5 meters deep below the bed level of the estuary and foundations were poured in 4 sections. Timings were critical and tolerances were minimal. On completion of the foundations, approximately 300 cubic meters of concrete had been poured, with a tolerance of 6mm. Precast concrete units were then placed and fixed on the foundations, which enabled a new concrete wall to be faced with natural stone. This was then backfilled and compacted to the engineering specification. Finally, copings were fitted, new footpaths and dwarf walls were constructed. In addition, an area of car park was removed and re-laid to complete the work to the quay wall. The site was reopened in time for Easter 2019.
This is the second restoring quay wall project that Landmarc has completed in the South Hams. See below for Greenway Quay.
This project was undertaken for South Hams District Council in 2016 after coastal damage from exposure to severe winter storms 2014/2015 had caused the existing rock armour to fail, so the local village green which is situated behind this section of defences was exposed and being eroded. As well as reinstalling and re-profiling the original rock armour, in response to the council’s request for alternative solutions we designed a new innovative low-profile solution, which is both robust and aesthetically pleasing. During the winter of 2016/2017 our new design was put under test with several storms hitting this section of the coast. Under observation, it performed as expected, dissipating the impact of each wave and preventing further erosion of the village green behind.
A private landowner had a dream of building a cliff top home, but one of the planning conditions was to ensure that the cliff beneath the land was strengthened with concrete and rock armour to allow the build to happen. The main challenges were access and changing tides. The issue of gaining access was overcome by sourcing a landing craft from MTS in Falmouth, which would be able to carry a 22-ton excavator and land it on the beach. To combat the high tide, we were dropped off on an outgoing tide and had to race against time to build a platform on which to store the excavator above high tide level. Work was then started to build the rock armour required and to pump concrete into the cavities of the cliff. Working hours were restricted to tide times meaning that the Landmarc team were often working during night hours. The job was successfully completed, and the excavator was able to make its return journey on the landing craft back to Falmouth.
Landmarc was approached by the National Trust to work with a local engineering company to develop a design to restore the failing quay at Greenway on the River Dart. This example demonstrates Landmarc’s engineering skill and ability to work within an area of extreme environmental sensitivity. It also shows our ability to manage a project that has many different elements to the method. Challenges presented by this project included working in a high-profile site in close proximity to a watercourse and members of the public. In addition to this, Landmarc was given a very tight deadline for completion as the quay is used for parking and docking of ferries. The most efficient and environmentally friendly way to achieve the goal of restoring the quay was for the works to take place from the quay itself. This was made possible by using a long reach excavator working from the quay and was used at every stage of the project, for excavation, driving/removing sheet piles, placement of large rock, filling of mattresses with stone, laying of geogrid and concreting. Tidal constraints governed every element of the works. Landmarc came up with the solution of using interlocking sheet piles to construct a coffer dam which would maximise working hours at low tide. The project was completed in budget and on time.