What is a common tool used to ensure proper alignment during the installation of beams?

A plumb bob is a common tool used in construction, particularly for ensuring vertical alignment. When installing beams, it is essential to ensure that they are not only level horizontally but also properly aligned vertically. A plumb bob, which consists of a weight on the end of a string, provides a direct downward reference line. By allowing the plumb bob to hang freely, workers can determine if the beam is vertical, making it easier to achieve accurate alignment.

Using a plumb bob is especially helpful in situations where precise vertical alignment is crucial, such as when erecting structural elements that must interact with other components of a building. The other tools mentioned serve different purposes in the alignment process. A level is primarily used to check horizontal planes, a measuring tape helps in determining lengths and distances, and a square is useful for checking right angles. While all these tools are important in construction, the plumb bob specifically addresses the need for vertical accuracy during beam installation.