Roof Top Electrocutes Worker by Charles Samo, Safety Engineer
Published On: April 10, 2008
Thank you to safety engineer/expert Charles Samo for contributing this fascinating and informative article. Mr. Samo has been an expert witness in a multitude of litigation matters and can be reached at firstname.lastname@example.org.
Have you ever wondered why birds resting on high and bare electric conductors do not get electrocuted? It is because the birds are not grounded or rather in contact with the ground. This is an interesting phenomenon. Whenever a person comes in contact with an overhead power line, if not in contact with ground, he or she is perfectly safe but as soon as a part of the body touches an object in touch with ground, chances of survival are slim. Clearly before the invention of electricity this type of harm or hazard was nonexistent. I am reminded of an old Chinese proverb which when loosely translated, “may you live in interesting times.”
Interesting times can include exposure to unforeseeable hazards. In one case a man went to work on a roof of a commercial building. He worked for a construction roofing company. He props his metal ladder up against the concrete wall of the building, buckles his tool belt, throwing on his baseball cap but unfortunately leaving his hard hat behind. He climbed up the ladder onto the old roof, stepped up to the edge of the roof, pulled his metal measuring tape, leaned forward, bent down and began to take roof measurements. Upon committing the measurements to memory, he rose and leaned back. Whether he was busy calculating his measurements or just not thinking we will never know, his head came in contact with a high voltage power line conductor, spanning above the roof, electrocuting himself and threw him off the roof.
The lights flickered in the building manager’s office and followed with a momentary black-out. The building manager went outside to investigate and saw the man on the ground sizzling, his ball cap laid next to him with a hole burnt in the center.
The local city fire department’s paramedics arrived within a few minutes and attempted to revive the barely breathing man, but were unsuccessful. An extensive investigation was launched to determine the cause of the fatality related to this unfortunate accident. The investigation was undertaken by Electric Public Utility Company operating this particular power line, property insurance organization including U.S Occupational and Health Administration (OSHA) of the Department of Labor. Come to find that the building was constructed first and the power line went up shortly after the building was constructed. The power line poles were placed too close to the building.
THE NATIONAL ELECTRIC CODE
Electric safety standards provide safe working guidelines to prevent such accidents. Nearly 100 years prior, in 1897, a document related to electric standards was developed as a result of the united efforts of various safety, insurance, electrical, architectural, and allied interests. This document was called The National Electric Code,or NEC. It is sponsored by the National Fire Protection Agency, NFPA. At the time of the accident the NEC had specific safety procedures in place to prevent accidental contacts with overhead high-voltage lines.
FACTORS RELATED TO CAUSATION
There were a number of factors which contributed to the death of the worker. The electric utility company had failed to meet the minimum clearance standards and safety for high-voltage overhead power-lines as required by the NEC. The line spanned too low over the roof and created a significant hazard. NEC required a minimum vertical clearance of 8-feet above the rooftops and a minimum horizontal clearance of 3-feet from the edge of the roofs. Clearly at the time of power line construction these standards were not followed.
As the owner and operator of the electric conductor, the electric utility company is primarily responsible for the death of the worker. The electric company failed to inspect and maintain the line clear from the building as required by its own standards and NEC requirements.
The employer of the deceased failed to provide and maintain a safe working area for his employee who normally worked on rooftops or likely to work near or adjacent to high voltage overhead lines.
The worker did not take adequate precaution for his own safety while working dangerously close to the high-voltage power line. The deceased had been in construction and roofing business for many years. Either he knew or should have known the hazard presented by overhead electrical wires when working on buildings’ roofs adjacent to overhead lines. Sadly, he was responsible for his unfortunate accident.
10-FOOT SAFETY RULE
The worker failed to follow a simple Federal OSHA’s safety construction industry rule known as a 10-foot Safety Rule. This rule is intended to keep workers away when working near overhead power lines. The rule prohibits workers and equipment from getting closer than 10 feet (radial) to overhead electric conductors.
In our world there are many environmental and occupational hazards that we all face every day. This case is not rare. Very few things in life to which we are exposed are “zero risks”. But like the automobile, and X-rays, there are non-harmful ways to use potentially harmful electricity transported by overhead bare conductors. Applicable industry safety standard practices must be adhered to. If we all follow safety rules provided, it would help to ensure us all live long and ….interesting lives!
SAFETY CONSULTING AND ENGINEERING