Sailing through the surf zone near a beach during an amphibious landing can be a dangerous operation, particularly because sailing with a landing craft through following breaking waves can pose challenges to the course keeping ability and/or surf riding that can lead to large uncontrolled roll and/or pitch motions.
Model tests are the only viable option to assess the safety of an amphibious operation for now. At the same time, a model test of an amphibious operation is very different from an ordinary seakeeping test, due to the changing bathymetry and changing waves over the run and the influence of the operator during each approach.
Navies are currently modernising their amphibious forces, leading to high performance landing craft, which have much higher speeds than traditional landing craft. These more advanced vessels may have different behaviour while travelling through the surf zone. This potentially leads to a higher need for model testing these operations.
Given their specifics, MARIN has never developed a standard for these tests. To enable MARIN to offer technically sound and cost-effective amphibious testing capabilities to its clients, we decided to perform a testing campaign to develop a new approach. The objectives of these tests were to:
- Develop a cost-effective, removable beach structure that could be built in either the Offshore Basin or the Shallow Water Basin.
- Get a better understanding of the relevant aspects of sailing through the surf near a beach.
- Develop a standard approach for amphibious tests.
A removable beach was designed and constructed in the Offshore Basin at MARIN. A large beach structure is needed to obtain a beach slope that is still somewhat steeper than many beaches around the North Sea. With this beach, we tested different aspects to assess the safety of these operations. The results form the basis of a new standard that is being developed. This standard will be finetuned, based on the experiences of future test campaigns.
Eelco Harmsen | firstname.lastname@example.org