For the construction of a new oil refinery, Jan De Nul Group were contracted by Dangote Group to backfill a 2,400-hectare site on the Lekki peninsula, 70 km east of Lagos.
The challenge of initially dredging 30 million m³ in only 9.5 months (later extended to 50 million m³) could only be achieved by the largest trailing hopper dredgers on the planet. Jan De Nul Group deployed mega-hoppers Leiv Eiriksson and Cristóbal Colón, each with a hopper capacity of 46,000 m³. To prepare for this massive reclamation job, the trailing hopper dredger Gerardus Mercator created a 5 km long access channel to size for both mega-hoppers.
Because of the sensitivity of the lagoon area, we absolutely had to prevent saltwater to flow into neighbouring waters. To pump the salty process water back to the Atlantic Ocean, a battery of 5 specialised pumps ran day and night. With their high-performance pumping capacity, both mega-hoppers bridged a discharge distance of more than 7.5 km to cover the whole site. In total, more than 50 million m³ sand was extracted and compacted in accordance with the client’s wishes.
Over 7 km of sinker pipes, 30 km of land pipes and more than 130 dump trucks and other pieces of heavy equipment were transported to Nigeria for this project. This mobilisation was achieved in a record time of 2.5 months. A real tour de force for the project team and the support services at the office.