Which part is specifically designed to prevent the beams of a wooden ladder from separating?

The tie rod is specifically designed to prevent the beams of a wooden ladder from separating. It acts as a stabilizing element that connects the two beams, ensuring they remain aligned and providing structural integrity to the ladder. This feature is crucial for maintaining safety and stability when the ladder is in use, as any separation of the beams could lead to a collapse or malfunction.

In wooden ladders, the beams bear the weight and stress during use, making the role of the tie rod essential in preserving the ladder's structural configuration. It effectively holds the beams together under load and reduces the risk of failure.

Other options refer to different components of the ladder that serve distinct purposes. The rungs, for example, are the horizontal steps where a firefighter places their feet, while the beam refers to the main structural parts of the ladder itself. The ledger is typically associated with the vertical supports or connections in ladder design, but it doesn’t serve the same function as a tie rod in preventing beam separation. Understanding these roles clarifies why the tie rod is the correct answer in this context.