ExoSphere Testing at Brightlingsea

Following the Living Windfarms Project workshop, Exo Engineering carried out a day of ExoReef strength testing. The project targets the use of conventional scour protection vessel loading and mass deployment methods which involve large impacts and stresses. Therefore, testing is needed to mimic the impact that will likely be exerted on the ExoSpheres during the loading and deployment phases. This test day forms part of the Living Wind Farms programme which also includes lab tests, measuring the reinforcing strength of the GeoBlock® materials used to manufacture the units, as well as computer modelling of the inherent survivability of the ExoReef units. During the test day we examined the real-life durability of the ExoSpheres by conducting a variety of drop tests to compare this against computer modelling and lab testing. These tests were conducted at the Port of Brightlingsea in Essex and a total of 100 ExoSpheres were used.

Tests included variable velocity impact testing, single sphere drop tests, multiple simultaneous spheres drop tests as well as trialing loading and handling of the ExoSpheres using front loaders and grabs. The test day provided an opportunity to compare different high strength and reinforcing materials to improve the strength of the ExoSpheres to meet the survivability requirements of the loading and deployment methods. A high-speed camera was used to record these tests, which were later analysed. The use of a high-speed camera allowed us to determine the velocity of each ExoSphere upon impact and therefore examine the effect of different strength reinforcing methods. These “real world” tests help us to understand if the modelling and lab tests reflected the real maximum survivable impacts and inform ExoReef designs and suitable deployment methods to be used in the project.