Department of Energy (DOE) OSH Technical Reference

Chapter 7 - Mobile Work Platforms

Part 4 - Work Practices

Table of Contents

• 4.1 Clearances
• 4.2 Inspection and Test Procedures
• 4.3 Operations
• 4.4 Maintenance and Repair
• 4.5 Manually Propelled Work Platforms and Scaffolds

4.1 - Clearances

4.1.1 Electrical

When operating aerial lifts near electric power lines, the following clearances must be maintained:

• For lines rated to 50 kilovolts, or less, the minimum clearance between the lines and any part of the aerial lift must be at least 10 feet (3 meters).

• For lines rated in excess of 50 kilovolts the minimum clearance between the lines and any part of the aerial lift must be at least 10 feet (3 meters) plus 0.4 inch (1 centimeter) for each kilovolt in excess of 50 kilovolts or twice the length of the line insulator, but never less than 10 feet (3 meters).

4.1.2 Exceptions to Electrical

• Where the work is performed from an aerial device insulated for the work, and the work is performed by trained communications personnel, outside plant workers, line clearance and tree-trimming employees, or exterior electric linemen.

• Where the electric power transmission or distribution lines have been deenergized and visibly grounded at the point of work or where insulating barriers not a part of or an attachment to the aerial lift have been erected to prevent physical contact with the lines.

4.1.3 RF Radiation

Whenever work is to be performed from elevated platforms in the vicinity of communication and radar equipment, prior clearance must be obtained from the installation's safety office.

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4.2 - Inspection and Test Procedures

4.2.1 Aerial Ladders

Aerial ladders must be inspected and tested annually or immediately following any activity when it is known or suspected that the ladder may have been loaded beyond the manufacturer's maximum load capacity. Ladders should also be inspected immediately following any repair of a structural or mechanical component of the ladder assembly. The procedures in Appendices A and B are the joint responsibility of the principal operator of the vehicle and a mechanic qualified to perform the annual vehicle safety inspection. A record of the inspection and test must be recorded on the vehicle historical record.

4.2.2 Articulating and Extendible Boom Platforms

These platforms must be inspected and tested annually. Special inspections and tests must be conducted immediately following any work where the platform may have been loaded beyond the manufacturer's rated capacity or immediately following any repair of a structural or mechanical component of the boom or platform assembly. The inspection and test procedures in Appendix C must be carried out jointly by the principal operator and a vehicle mechanic qualified to perform the annual safety inspection of the vehicle. A record of the inspection and test must be recorded on the vehicle historical record. When the personnel platform is an attachment to a telescoping derrick or crane with a rated capacity higher than that of the work platform, test procedures contained herein do not apply and testing must be accomplished in accordance with the standards on cranes.

4.2.3 Visual Inspections

The unit should be visually inspected and the lift controls tested prior to each shift or day's work to determine that the unit and controls are in safe working condition. The override feature explained in paragraph 4.3.4 should be tested at this time. A record of this test should be noted on the Operator's Inspection Guide and Trouble Report.

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4.3 - Operations

4.3.1 Operator's Manuals

A manufacturer of aerial devices is required by ANSI Standard 92.2 to publish a manual(s) and to provide for the distribution of the manual(s) to dealers and direct sale purchasers. The manual(s) must be procured by the DOE user of this equipment and must be readily available for use by workers and contain:

• Description, specification, and capacity of the aerial device.

• Instructions for installing or mounting the aerial devices.

• An expression of the operating pressure of any hydraulic or pneumatic system that is part of the aerial device.

• Instructions regarding operation and maintenance.

• Replacement part information.

4.3.2 Nameplates

The manufacturer is also required to attach to each aerial device a plate(s) located in a readily accessible area, clearly visible, stating:

• Make, model, and manufacturer's serial number.

• Rated capacity.

• Platform height.

• Maximum recommended operating pressures of hydraulic or pneumatic system(s) or both.

• Cautions or restrictions.

• Operating instructions.

Where alternative configurations are possible, the plate must show by chart, schematic, or scale, the capacities of all combinations in their operating positions and cautions or restrictions or both for operation of all alternate or combinations of alternate configurations. These plates must not be removed from the device, painted over, or otherwise made unavailable for reference by the operator.

4.3.3 Traveling

Before a mobile unit is moved for travel, the aerial device must be secured in the specified lower traveling position (to prevent rotation) by the use of cradles or locking devices in accordance with the manufacturer's instructions.

4.3.4 Upper/Lower Controls

Articulating and extendible boom platforms must have both upper and lower controls. Upper controls must be in or beside the platform within easy reach of the operator. Lower controls must provide for overriding the upper controls. Controls must be plainly marked as to their function. Lower level controls must not be operated unless permission has been obtained from the employee in the lift, except in case of emergency. Whenever a worker is in or on an elevated work platform, at least one person qualified to operate the equipment must be stationed near the lower-level control panel.

4.3.5 Load Limits

Boom and basket load limits specified by the manufacturer must not be exceeded. An aerial lift truck must not be moved when the boom is elevated in a working position with men in the basket, except for equipment that is specifically designed for this type of operation. In all cases, the manufacturer's operating instructions must be followed.

4.3.6 Brakes and Chocks

The brakes must be set and outriggers positioned on pads or a solid surface. Wheel chocks must be installed before using an aerial lift on an incline.

4.3.7 Electrical Conductors

Aerial devices including insulated aerial devices, must not be brought into contact with an electrical conductor. Workers should not rely on the dielectric capabilities of aerial devices.

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4.4 - Maintenance and Repair

4.4.1 Maintenance

Manufacturer's recommended maintenance procedures must be strictly followed. If deficiencies that affect the safe operation of the equipment are discovered during the daily operator inspection or during use, the equipment must immediately be removed from service until repairs can he made.

4.4.2 Repair

All repairs must be done by qualified personnel. Workers must always stand firmly on the floor of the basket, must not sit or climb on the edge of the basket, or use planks ladders or other devices for a work position. Climbers must not be worn while performing work from an aerial lift.

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4.5 - Manually Propelled Work Platforms and Scaffolds

4.5.1 Safety Rules

• Scaffolds must be provided with a climbing ladder or stairway for access and egress and either be affixed or built into the scaffold. It must be located so that its use will not have a tendency to tip the scaffold. A landing platform must be provided at intervals not to exceed 30 feet (9.1 meters).

• Personnel must not ride on mobile units while they are being moved. If equipment is left on the work level, it must rest securely on the platform protected by the rail or toeboard.

• Scaffold casters must have a positive wheel and/or swivel lock to prevent movement. Ladder stands must have at least two of the four casters lockable and be the swivel type.

• A minimum of two brakes, wheel locks, or permanently installed jacks, must be operable on all mobile work platforms.

• The erection of a scaffold exceeding 50 feet (15.2 meters) in height above the base must be done in accordance with manufacturer's instructions under the supervision of a qualified professional engineer. Plant engineering is the authorizing agency for scaffold erection.

• The minimum base width of mobile work platforms must not be less than 20 inches. (50.8 centimeters)

• Steps must be uniformly spaced, with a rise of not less than 9 inches (22.9 centimeters) or more than 10 inches (25.4 centimeters) and a depth of not less than 7 inches (17.8 centimeters). The slope of the steps section must be a minimum of 55 degrees and a maximum of 60 degrees measured from the horizontal.

• Mobile work platforms having more than four steps or 60 inches (1.5 meters) vertical height to the top step must be equipped with handrails.

4.5.2 Work Level Height Requirements

• The maximum work level height must not be more than four times the minimum or least base dimension (width) of any mobile ladder stand or scaffold. Where the basic mobile unit does not meet this requirement, suitable outrigger frames must be used to obtain this least base dimension or the unit must be tied with guy wires or braced to keep the unit from tipping.

• The minimum platform width for any work level must not be less than 20 inches (50.8 centimeters) for mobile scaffolds (towers). Ladder stands must have a minimum step width of 16 inches (40.6 centimeters).

• The steps of ladder stands must be built fabricated with slip resistant treads.

• Scaffold work platforms at work levels of 10 feet (3 meters) or higher above the ground or floor must have a standard 4-inch (10.2-centimeter) nominal toeboard.

• Scaffold work platforms at work levels of 10 feet (3 meters) or higher above the ground or floor must have a guardrail of 2- by 4-inch (5.1- by 10.2-centimeter) nominal lumber or the equivalent installed no less than 36 inches (91.4 centimeters), or more than 42 inches (106.7 centimeters) high, with a midrail when required of 1- by 4-inch (2.5- by 10.2-centimeter) nominal lumber or equivalent.

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