Final answer:
A spreader bar is typically required to lift trusses if the span exceeds 35 feet. This device spreads load to ensure stability during the lifting process.
Step-by-step explanation:
In the context of trusses and their lifting mechanisms, a spreader bar is used to spread the load across a wider area, thus providing balance and stability during lifting operations. The precise span that necessitates a spreader bar can vary based on various factors, including the specifications set by the manufacturer and the particular safety protocols observed on a construction site. However, a general rule of thumb prevalent in numerous engineering practices is that a spreader bar is needed to lift trusses if the span exceeds 35 feet (Answer d). This requirement is primarily due to the need to prevent potential distortions and to afford appropriate control over the object being lifted.
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