Why must the bottom pins be removed first when dismantling a lattice boom?

When dismantling a lattice boom, removing the bottom pins first is essential to avoid a sudden collapse of boom sections. This practice is crucial for maintaining control over the structure as it is being disassembled. By starting at the bottom, the integrity of the upper sections is preserved until the appropriate time, thus preventing any unintended failure or tipping that could occur if the top sections were to fall unexpectedly.

This procedure ensures that the load from the upper sections is gradually released, maintaining stability throughout the dismantling process. Adhering to this method enhances safety for crew members and minimizes the risk of damage to the equipment itself, as well as surrounding structures. While facilitating easier handling and compliance with industry standards are important considerations, the primary reason for this specific order of dismantling is to prevent a potentially hazardous situation from arising.