Skip to Main Content

Danger: Overhead Electrical Lines - MOSH

Up to ONE YEAR imprisonment or a fine not to exceed $1,000, is the penalty you could be subject to if you fail to comply with or violate the High Voltage Line Act. Cranes, ladders and other equipment coming in contact with High Voltage Overhead Electric Power Lines along with other electrical accidents have resulted in workers being severely burned and injured.

An employee of a roofing contractor...moved his metal extension ladder from one location to a fully extended vertical position...he lost control...the ladder struck a 7,2000 volt overhead line 28 feet behind him...he was electrocuted.

A construction employee on a job in Greenbelt operated a back-hoe under several electric power lines that should have been de-energized, grounded or relocated. After clearing an area in an excavation for a water pump...he made contact with the overhead wires...A fellow worker, who was holding a chain attached to the back-hoe was electrocuted.

Why do these accidents happen?

The accidents involve ladders, cranes, truck mounted lifting devices, digging equipment and other apparatus that come within reach of overhead lines during an operation.

There isn't a single reason why these accidents happen, but there is one common factor. TRAINING! The Maryland Occupational Safety and Health Law places the responsibility of instructing employees in the recognition and avoidance of unsafe working conditions and practices on the employer. An analysis of the accidents indicates that employees have not been trained in the following areas:

  • Recognition of the threat that overhead lines pose when working adjacent to them;
  • The correct positioning and use of ladders, cranes and other equipment in relation to any overhead lines; and
  • The requirement of insuring that overhead lines are de-energized, visibly grounded, relocated or provided with barriers to prevent accidental contact.
Be aware! Be safe! Yes Needs Action
Are all overhead lines considered to be energized, unless the line is visibly grounded and the owner or operator has indicated that it is not an energized line?      
Are cranes, derricks and other equipment restricted from operating within ten feet of any electrical distribution or transmission line?      
Are appropriate safety precautions taken when operating on electrical lines? (Reference to MOSH Standard 1926.550(a)(15))       
Are special hazard signs posted instructing operators to keep equipment such as cranes, attachments and loads away from overhead lines?      
Has the employer instructed each employee in the recognition and avoidance of hazards associated with working with cranes and other equipment adjacent to power lines?      
Are employees encouraged to look up and be aware of where power lines are that may pose a threat?      
Before any work is started within ten feet of high voltage electrical lines, is the owner or operator of the line contacted and safety measures taken before the work starts?      
Are employees made aware that metal ladders are not to be used where they may contact electrical conductors or equipment?      
Are they also aware that metal ladders cannot be used when working on or near electrical equipment such as changing light bulbs or fluorescent tubes?      
Are employees aware that ladders should not be carried in an upright position whenever electrical lines are around?        

Avoid overhead power lines!

Never operate a crane closer to an overhead power line than the "absolute limit of approach"*. This limit varies according to voltage: the greater the voltage, the greater the clearance between any part of the equipment and the power line. THE CLEARANCE MAY NEVER BE LESS THAN 10 FEET. Operation of equipment within 10 feet of energized high voltage lines also violates the Maryland High Voltage Line Act, and may result in fines and/or imprisonment.

The basic rule is "Don't locate equipment in a position where it can come in contact with overhead power lines." Maintain the required distance from the lines. Whenever possible, operators should place their equipment where the swing radius of the full-extended boom is completely outside the absolute limit of approach.

Consider the size of the load because although the boom may be a safe distance from the lines, the load may enter the dangerous area.

There are various means of insulating the wires or the boom, as well as barriers and alarms that may be available to reduce the risk of injury to workers, but the use of such devices does not change the requirements of any other applicable standards or laws. In addition, these and other measures (such as grounding the equipment itself) may not be fully effective but may create a false sense of security. Only the utility company is authorized to de-energize, insulate or handle the lines. No one else may attempt these operations.

This is not intended to describe every Maryland law, regulation and standard that applies to work near electric power lines, or to discuss all possible steps that may be taken to prevent an accident. For more information, contact MOSH.

What to do in an emergency…

If equipment contacts an overhead wire, DON'T PANIC. The safest thing to do is to stay put until the utility company turns off the power and confirms that conditions are safe. Instruct all other people in the area to keep away.

If the boom must be moved, be certain that everyone is at a safe distance in case a line falls.

If there is immediate danger, such as fire, the operator must jump completely clear of the equipment. Jump with feet together. After hitting the ground, move away slowly taking small steps. Be careful not to lose your balance and stumble back against the equipment.

The KEY is to not touch the ground while you are still in contact with the equipment.

Carry ladders safely, properly!

  • Never attempt to carry a ladder in a vertical position. Ladders should be lowered and turned horizontally when transported from one location to another.
  • Extension ladders should be collapsed before lowering from a vertical position.
  • Never attempt to raise or lower an extension ladder without assistance.
  • The improper carriage of ladders has been responsible for a significant number of fatalities.
  • When working around overhead electric lines or with electrical equipment, wooden or fiberglass ladders provide a safer alternative.

Safety aids

In response to the electrocutions occurring in the State of Maryland, the Commissioner of Labor and Industry launched an electrical awareness campaign. In addition to this fact sheet, the following materials are available:

  • For companies with construction equipment that may contact overhead lines, an "emergency instruction" sticker which can be placed inside the cabs, etc.
  • A small sticker urging employees to look overhead which can be given to employees for hardhats, tools, equipment and ladders.
  • A Power Tool Safety Fact Sheet (Word) which is available to be posted.

To order these items and many others, submit a Publications Order Form.

Consultation Services

FOR EMPLOYERS: MOSH's On-Site Consultation Service Program can assist employers in assuring safe and healthful workplaces. This service is provided to employers, free of charge, through federal and state funds. A request for service can be for the entire workplace or can be limited. FOR ASSISTANCE OR FURTHER INFORMATION CALL 410-537-4500.

* (The formula for absolute limit of approach equals ten feet plus 0.4 inches for each kilovolt over 50 kilovolts. Kilovolt equals 1,000 volts.)