OSHA Guide – Cranes and Derricks in Construction

Section 1436 – Derricks

Operator Qualifications

Derrick operators need not meet the operator qualification/certification requirement of section 1427. However, you must train each derrick operator on how to operate the equipment safely.

Load Charts

For permanently installed derricks with fixed lengths of boom, guy, and mast, a load chart must be posted where it is visible to personnel responsible for the operation of the equipment. For derricks that are not permanently installed, the load chart must be readily available at the job site to personnel responsible for operating the equipment. Load charts must contain at least the following information:

  • Rated capacity at corresponding ranges of boom angle or operating radii
  • Specific lengths of components to which the rated capacities apply
  • Required parts for hoist reeving
  • Size and construction of rope must be included on the load chart or in the operating manual

Construction

Derricks must be constructed to meet all stresses imposed on members and components when installed and operated in accord with the manufacturer’s/ builder’s procedures and within its rated capacity. Load anchoring data developed by the manufacturer or a qualified person must be used.

Specific additional construction requirements are specified for:

  • Guy derricks
  • Stiffleg derricks
  • Gin pole derricks
  • Chicago boom derricks

Swingers and Hoists

The boom, swinger mechanisms, and hoists must be suitable for the derrick work intended and must be anchored to prevent displacement from the imposed loads.

Hoists must meet the following requirements:

  • Base mounted drum hoists must meet certain specified requirements of ASME 7-2001 (“Base-Mounted Drum Hoists”)
  • New hoists must be load tested to a minimum of 110% of rated capacity, but not more than 125% of rated capacity, unless otherwise recommended by the manufacturer. This requirement is met where the manufacturer has conducted the testing
  • Hoists that have had repairs, modifications, or additions affecting their capacity or safe operation must be evaluated by a qualified person to determine if a load test is necessary. If it is, load testing must be conducted in the manner specified in the standard

Operational Aids

The operational aids requirements listed in section 1416 apply to derricks except (1) a boom hoist limiting device (required by section 1416 for other equipment) is not required for derricks, and (2) alternative requirements to those in section 1416 are specified for the following two operational aids:

Boom angle or radius indicator

Such a device is not required, but if the derrick is not equipped with a functioning one, the employer must ensure that either:

  • The boom hoist cable is marked with caution and stop marks. The stop marks must correspond to maximum and minimum allowable boom angles. The caution and stop marks must be in view of the operator or a spotter who is in direct communication with the operator; or
  • An electronic or other device that signals the operator in time to prevent the boom from moving past its maximum and minimum angles, or automatically prevents such movement, is used

Load weight/capacity device. Derricks manufactured after November 8, 2011 with a maximum rated capacity over 6,000 pounds must have at least one of the following: load weighing device, load moment indicator, rated capacity indicator, or rated capacity limiter.

Post-Assembly Approval and Testing

The following requirements apply to new or reinstalled derricks:

  • Anchorages. Anchorages, including the structure to which the derrick is attached (if applicable), must be approved by a qualified person
  • Functional test. Prior to initial use, new or reinstalled derricks must be tested by a competent person with no hook load to verify proper operation. This test must include:
    • Lifting and lowering the hook(s) through the full range of hook travel
    • Raising and lowering the boom through the full range of boom travel
    • Swinging in each direction through the full range of swing
    • Actuating the anti two-block and boom hoist limit devices (if provided)
    • Actuating locking, limiting, and indicating devices (if provided)
  • Load test. Prior to initial use, new or reinstalled derricks must pass a load test conducted by a competent person. Test loads must be at least 100% and no more than 110% of the rated capacity, unless otherwise recommended by the manufacturer or qualified person, but in no event must the test load be less than the maximum anticipated load. The test must consist of:
    • Hoisting the test load a few inches and holding to verify that the load is supported by the derrick and held by the hoist brake(s)
    • Swinging the derrick, if applicable, the full range of its swing, at the maximum allowable working radius for the test load
    • Booming the derrick up and down within the allowable working radius for the test load.
    • Lowering, stopping, and holding the load with the brake(s)
  • Test documentation. The functional and load tests must be documented. The document must contain the date, test results, and name of the tester. The document must be retained until the derrick is retested or dismantled, whichever occurs first. All such documents must be available during the applicable document retention period to all persons who conduct required inspections (see section 1412)

Load Testing Repaired or Modified Derricks

Derricks that have had repairs, modifications, or additions affecting the derrick’s capacity or safe operation must be evaluated by a qualified person to determine if a load test is necessary. If it is, load testing must be conducted and documented.

Power Failure Procedures

If power fails during operations, the derrick operator must safely stop operations. This must include setting all brakes or locking devices and moving all clutch and other power controls to the off position.

Jumping

The process of jumping a derrick must be supervised by the Assembly/Disassembly (A/D) director.