When the boom is being held in a fixed position, dogs, pawls, or other positive holding mechanisms on the boom hoist must be engaged.
When taken out of service for 30 days or more, the boom must be secured by one of the following methods:
For guy derricks, lifted to a vertical position and secured to the mast.
For stiffleg derricks, secured against the stiffleg.
Secured to a stationary member, as nearly under the head as possible, by attachment of a sling to the load block.