For trusses longer than 30 feet, what device should be used for mechanical hoisting?

When dealing with the hoisting of trusses longer than 30 feet, the use of a spreader bar or stiffback is essential to ensure safe and effective handling. A spreader bar is designed to distribute the load evenly across multiple points, which helps to prevent any potential bending or twisting of the truss during lifting. This is particularly important for longer trusses, as uneven lifting can lead to structural damage or instability.

Using a spreader bar or stiffback also enhances the overall safety of the hoisting operation. By providing better control over the load and reducing the risk of tipping or swaying, these devices directly contribute to the safety of the crew and equipment on site.

In contrast, the other options, while useful in certain contexts, do not offer the same level of load distribution and stability necessary for longer spans. Simple hoisting straps may not provide adequate support, whereas a winch or chain block generally serves different purposes and lacks the specific design needed for safely hoisting larger trusses.