SYNOPSIS COLUMN: Sky dangers
By Bill Smith06 September 2018
There’s no getting around it: power lines are deadly for crane operators. Through electrocution, power lines have caused a third or more of all crane-related fatalities. Which is why this month we’re reintroducing you to some of the most important aspects of the OSHA standard pertaining to power line safety for cranes and derricks in construction.
For starters, you should assume that all power lines you come across are energized unless you have confirmed with the utility owner/operator that the power line has been de-energized. If the power line hasn’t been de-energized – and before you can begin operations – you need to identify the work zone in one of two ways:
By demarcating boundaries (such as with flags, or a device such as a range limit device or range control warning device) and prohibiting the operator from operating the equipment past those boundaries; or,
By defining the work zone as the area 360 degrees around the equipment, up to the equipment’s maximum working radius.
After determining the appropriate work zone, you must also determine if any part of the equipment, load line or load (including rigging and lifting accessories) could, at the equipment’s maximum working radius, get closer than 20 feet to a power line within the determined work zone. If not, you’re good to go and no further action needs to be taken. However, if equipment will indeed get within 20 feet of a power line, then you (or the employer) must meet the following requirements:
- Deenergize and ground. Confirm from the utility owner/operator that the power line has been deenergized and visibly grounded at the worksite.
- 20-foot clearance. Ensure that no part of the equipment, load line, or load (including rigging and lifting accessories), gets closer than 20 feet to the power line by implementing at least one of the measures specified in paragraph (b) of that particular section.
- Table A clearance. Determine the line’s voltage and the minimum clearance distance permitted under Table A (see § 1926.1408). (ii) Determine if any part of the equipment, load line or load (including rigging and lifting accessories), could get closer than the minimum clearance distance to the power line permitted under Table A (see § 1926.1408). If so, then the employer must follow the requirements in paragraph (b) of this particular section to ensure that no part of the equipment, load line or load (including rigging and lifting accessories), gets closer to the line than the minimum clearance distance.
If the worst-case scenario happens and contact is made between a crane and an energized line, the crane operator should stay inside the cab and try to remove the crane from contact by moving it in the reverse direction. If the crane cannot be moved away from contact, the operator should stay inside the cab until the lines have been de-energized. All other personnel should keep away from the crane, ropes and load, since it’s possible the ground around the crane could be energized.
There is, of course, a lot to think about when it comes to power line safety, but here are three takeaways to remember:
- Any time it’s possible, deenergize the power line.
- While power line safety is indeed the responsibility of everyone on the job site, it’s specifically the responsibility of the employer.
- Staying outside of the 20-foot distance from an energized power line is a good general rule of thumb. However, there are some instances where a crane should be even farther away than 20 feet.
It’s always best to consult the OSHA rule for yourself, so be sure to spend a little time refreshing yourself on what you can and cannot do. You’ll be happy you did.