Abeko UK, specialist marine and coastal engineering contractor, in partnership with Team Van Oord, is currently working on the latest Environment Agency contract to replace old sea defences at Sea Palling, on the Norfolk coast.
Abeko is working on an 18 km long stretch of beach between Happisburgh and Winterton, replacing groynes and construction a new revetment, while Team Van Oord is providing technical support and doing beach replenishment works.
Quantities involved include 35,000 t of fresh granite rock, an estimated 25,000 m³ of rock which has, over the years become buried in the sand as well as 280,000 m³ of dredged sand for beach replenishment. The rock for the groynes is sourced from waste material and is brought in on high tide by sea going barge from Norway. Bringing in 32,000 t. of rock from Norway is the simplest and most environmentally beneficial solution.
The rocks are unloaded by a Cat 988 wheel loader working from the barge. Once the load of 13,500 tonnes of rock is unloaded, the barge is taken back out to sea before the retreating tide leaves it stranded on the beach.
With all the rock on the beach, a 78 t. O&K RH25.5 heavy-duty tracked excavator, with extra counter weight and heavy-duty cylinders begins recovery work. The excavator is equipped with a large grab, weighing 6.7 t. and manufactured by Flynn Welding Services. The work is shared with a Hitachi Zaxis 470LCH, which has also been fitted with extra counterweight.
To avoid damaging the body and the suspension of the Cat 740 and Volvo A35D articulated dump trucks, the rocks are gently placed in the dump-body and moved clear of the high water line, where they can be easily redistributed for construction of the groynes.
The Environment Agency and environmentalist are watching the works very closely to see that the contactors do not disturb the existing sand dunes, contaminate the beach or endanger the local habitat. Some of the work is also undertaken under the watchful glare of seals that populate part of the beach. As it is the breeding season, part of the beach is closed to the public but the construction works continue although under the watchful eye of an ecologist.
Work is ongoing and scheduled for completion by the end of Spring 2009, depending on weather.