1926.1426—Free fall and controlled load lowering.
(1)
The use of equipment in which the boom is designed to free fall (live boom) is prohibited in each of the following circumstances:
(iii)
The load or boom is directly over a power line, or over any part of the area extending the Table A of § 1926.1408 clearance distance to each side of the power line; or any part of the area extending the Table A clearance distance to each side of the power line is within the radius of vertical travel of the boom or the load.
(v)
The load is over a cofferdam, except where there are no employees in the fall zone of the boom or the load.
(2)
The use of equipment in which the boom is designed to free fall (live boom) is permitted only where none of the circumstances listed in paragraph (a)(1) of this section are present and:
(ii)
The equipment is a floating crane/derrick or a land crane/derrick on a vessel/flotation device.
(b) Preventing boom free fall.
Where the use of equipment with a boom that is designed to free fall (live boom) is prohibited, the boom hoist must have a secondary mechanism or device designed to prevent the boom from falling in the event the primary system used to hold or regulate the boom hoist fails, as follows:
(ii)
A secondary braking or locking device, which is manually or automatically engaged, to back-up the primary brake while the boom is held (such as a secondary friction brake or a ratchet and pawl device).
(2)
Hydraulic drums must have an integrally mounted holding device or internal static brake to prevent boom hoist movement in the event of hydraulic failure.
(3)
Neither clutches nor hydraulic motors must be considered brake or locking devices for purposes of this subpart.
(c) Preventing uncontrolled retraction.
Hydraulic telescoping booms must have an integrally mounted holding device to prevent the boom from retracting in the event of hydraulic failure.
(d) Load line free fall.
In each of the following circumstances, controlled load lowering is required and free fall of the load line hoist is prohibited:
(3)
The load is directly over a power line, or over any part of the area extending the Table A of § 1926.1408 clearance distance to each side of the power line; or any part of the area extending the Table A of § 1926.1408 clearance distance to each side of the power line is within the radius of vertical travel of the load.