The effectiveness of the double hull tanker design is limited to what type of casualties?

The double hull tanker design primarily enhances safety and spill prevention in the event of a casualty. It consists of an inner and an outer hull, with a space between them that serves as a barrier. This design is specifically effective in scenarios where the energy involved in the impact or puncture is relatively low.

Low energy casualties refer to situations like minor collisions or grounding incidents where the structural integrity of the hull may not be severely compromised. In these cases, the double hull can absorb some of the impact and prevent the inner hull from being breached, which in turn helps to contain any potential oil spill.

In contrast, high energy casualties, such as collisions at high speeds or significant structural failures, can lead to greater deformation and damage to the hull, potentially breaching both the inner and outer hulls. This means that while double hull designs provide substantial benefits, their effectiveness diminishes under high energy impacts where the protective capacity of the double hull may be overwhelmed.

Thus, the answer focuses on the scenarios in which double hulls are primarily designed to function effectively, specifically during low energy incidents where the protection against oil spill and environmental impact is maximized.