What term describes closely spaced beams designed to handle heavy loads?

The correct answer is grillage. This term refers to a system of closely spaced beams that is specifically designed to distribute heavy loads over a certain area. The configuration of these beams helps in effectively transferring loads to the foundation, minimizing the risk of structural failure. Grillage systems are commonly used in various types of construction, particularly where heavy equipment or materials are involved, allowing for a stable and secure base that can handle significant weight.

In contrast, the other terms—combustible beam, truss, and inquiry beam—refer to different structural concepts. A combustible beam typically pertains to wood or other materials that can ignite under fire conditions, not focusing on load distribution. A truss is a structural framework often consisting of triangular units designed to support roofs and other loads but does not specifically refer to closely spaced beams. Inquiry beam is not a standard term used in construction and lacks common relevance in this context. Understanding the specific definitions and applications of these terms is crucial for grasping foundational concepts in building construction and fire service operations.