Which hose loads are not suitable for large-diameter hose (LDH)?

The horseshoe and accordion hose loads are not suitable for large-diameter hose (LDH) primarily due to the physical characteristics and operational requirements of LDH. Large-diameter hose is typically larger and heavier, which makes certain types of hose loads less practical for deployment and management during fire operations.

The horseshoe load, which requires careful handling and manipulation, may prove cumbersome with the weight of LDH, thus making it challenging to deploy quickly in emergency situations. Similarly, the accordion load, which involves folding the hose back upon itself in layers, can create awkward handling and deployment issues as the size and bulk of LDH lead to complications in maneuvering.

In contrast, the other options listed—such as stacked load, flat load, triple load, donut load, single load, and cross load—are more adaptable to the attributes of large-diameter hose. These types of loads can often provide better control, stability, and ease of deployment, which are crucial in firefighting scenarios involving larger volumes of water and maintaining sufficient flow rates.