Cranes & Power Lines
It's easy to prevent serious accidents involving cranes and power lines by complying with OSHA standards and applying some general safety techniques.
The OSHA Cranes in Construction Standard states that the crane operator must do the following:
- Identify the work zone by either:
- Demarcating boundaries (with flags, range limit device or range control warning device) and prohibit the operator from operating past those boundaries; or
- Define the work zone as the area 360 degrees around the equipment, up to the equipment’s maximum working radius.
- Determine if any part of the equipment, load line or load could get closer than 20 feet for power lines less than 350 KV if operated up to the equipment’s maximum working radius.
- If the answer is yes, they have three options:
- Confirm from the utility that the line has been de-energized and visibly grounded.
- Ensure that no part of the equipment gets closer than 20 feet (<350KV) or 50 feet (>350KV) by implementing the encroachment precautions.
- Crane Operator contacts the utility to determine the line voltage. The utility provides that information in two days. They then need to refer to the distances below:
- Up to 50 KV – 10 feet
- 50 – 200 KV – 15 feet
- 200 – 350 KV – 20 feet
- 350 – 500 KV – 25 feet
- If they are working under option 2 or 3, they will need to implement the Encroachment Prevention Precautions:
- Conduct a planning meeting with the operator and other workers.
- Tags lines must be non-conductive (if used).
- Erect and maintain elevated warning line, barricade, or line of signs, in view of the operator 10’ from the power line.
- If the operator is unable to see the warning line, a dedicated spotter must be used.
- In addition to the encroachment prevention precautions, the operator must implement one of the following:
- Use a proximity alarm, designed to give the operator sufficient warning to prevent encroachment.
- Use a dedicated spotter who is in continuous contact with the operator.
- Use a device that automatically warns the operator to stop (range control warning device).
- Use a device that limits the range of movement, set to prevent encroachment.
- Use an insulating link between the end of the load line and the load.
Safety Tips on the Job
Always consider all power lines as energized and dangerous. Any contact with a crane boom will probably cause serious injury to operators and workers, and damage to equipment.
Look up before you unload or load a crane from a truck or lowboy. Make sure there are no overhead lines before you start.
Educate your crew - particularly new employees - about the dangers of overhead power lines. During crane operations, the most hazardous thing a ground worker can do is touch the crane or load line.
That's why it makes sense to add an extra margin of safety by barricading your crane's operating area. A well-placed barricade also serves as a visual reminder of the danger zone and can minimize risk to those in the area, or those handling the load line, slings or cable (see OSHA Standard, above).
Be safe. The crane's mast or boom must be kept at least 10 feet away from a normal distribution power line at all times - this includes the load line and the load (see OSHA Standard, above). Skilled crane operators know that distances in the air are hard to judge, and that a spotter is a good safety measure. When working near any power line, use the shortest boom possible. Never move a crane under a power line unless there are adequate clearances.
If your crane boom or mast contacts a power line, the operator should immediately try to swing the boom into the clear.
If it is necessary to leave the equipment, anyone on the machine should jump entirely clear of the unit. Jump so that both feet hit the ground at the same time, and keep them close together.
Walk away in a small-step shuffle because a lot of power flowing into the ground can create differences in electrical potential around the problem - enough differences to actually shock anyone whose feet are too far apart.
Once clear of the equipment, do not return for any reason until the power line has been grounded or determined to be safe by your electric utility or the owner of the line. Keep anyone nearby from touching or approaching the equipment.
Remember, it's the law.
Many states like Virginia and North Carolina have a state law which requires that the operator/owner of a crane notify a utility or line owner at least 48 hours before they work in close proximity to any power line.
- If you are performing work in Virginia, learn about the Overhead High Voltage Line Safety Act. You also can download our poster illustrating the 10-foot danger zone.