89,000 tonnes of rock armour delivered to Sea Defence Improvement Scheme

Aiming to enhance coastal defences and protect critical infrastructure along the Humber Estuary, between the ports of Immingham and Grimsby, this ambitious project required 70,000 tonnes of granite to be shipped from Aggregate Industries’ renowned Glensanda superquarry in Western Scotland via Immingham Dock.

The granite, with each piece weighing between 0.3 to 1.0 tonnes, made its two-day sea voyage aboard the 90-meter-long Hagland Saga. Each of the 17 shipments carried approximately 4,500 tonnes. Upon arrival at Immingham, the cargo was swiftly offloaded and transported by road to the Stallingborough project site. Additionally, 19,000 tonnes of smaller grade rock armour, ranging from 60kg to 300kg, were sourced from the firm’s Bardon Hill quarry in Leicestershire and delivered in approximately 700-tonne loads.In collaboration with Jackson Civil Engineering, Aggregate Industries ensured a seamless delivery, overcoming challenges such as unpredictable docking times and the migration of vital bird species which limit works within the designated Humber Estuary site between April and September every year.

Nick Gilbert, business development manager for Aggregate Industries, adds: "We are proud to have played a crucial role in in protecting Stallingborough and its surrounding areas. Our comprehensive network and methods enabled us to meet the logistical challenges of this complex and reactive project which effectively saw the equivalent of a quarter of the Humber Bridge’s tonnage seamlessly delivered and discharged, directly contributing to the safety and resilience of the local community."

The Stallingborough Sea Defence Improvement Scheme is the third phase of ongoing coastal improvements and is designed to provide a further 25-year design life to the current flood defence embankments. This project will see the repair and fortification of a 4.5km stretch – including some 3km of rock armour – with the works comprising resealing and improvements of existing revetments, some of which date back to the 1953 North Sea flood. This effort will safeguard 2,300 homes, vital infrastructure and industry, as well as precious habitats in the Stallingborough area.

Nigel Priestley, Senior Project Manager for the Environment Agency, said: “Aggregate Industries have provided a great service to Jackson and the Environment Agency by supplying the smaller rock to allow installation to commence in 2023, and then the larger rock from Oban, through the winter, impacted by numerous storms, in time for a March 2024 start.

“The option to deliver by boat from the UK has also saved a significant amount of carbon too and minimised transportation by road.”

The granite used in this project, known for its durability and longevity, is an ideal material for modern sea defences. With a lifespan exceeding 100 years, these specialist aggregates are designed to withstand harsh weather conditions and dissipate wave energy, mitigating soil erosion and maintaining the natural integrity of the landscape.

Beyond its protective capabilities, the rock armour also promotes vegetation growth and facilitates habitat creation, aligning with Aggregate Industries' commitment to environmental sustainability. This project will not only fortify the coastline but also nurture a harmonious balance between environmental protection and preservation.

Visit Aggregate Industries’ website for further information about its Stallingborough coastal defence project or to view its extensive range of flood and sea defence aggregates, including Rip Rap, Gabion stone and Basalton Quattroblock.