Electrical Power Lines —A Live Threat to Tower Ladders
DEPARTMENTS
Trainning Notebook
At the turn of the century, the workhorse of the fire service was just that, the horse-drawn and hand pumped fire engine.
During the civil disorders of the late 1960s and the vacant building fires of the 1970s, a new workhorse was born. It was, and still is, very versatile with six rubber tires and six steel support arms. Referred to as a “shower tower” or “cherry picker,” it is better known by its more common name, the tower ladder.
Sometimes, it seems that there is nothing that this apparatus cannot do as long as it can reach its objective. However, while we all have experienced or heard of the tremendously effective job that these apparatus can do at some extremely tough and previously uncontrollable fire situations, we must also be made aware of some of the problems encountered by these pieces of machinery. These special problems go beyond those of proper positioning and nozzle angling in tight spaces. They can and do threaten the life safety of our members.
When a tower ladder is placed in operation, it is supported on steel arms and legs for greater stability. As you can note from the front cover photo, apparatus placement is extremely important. At times, positioning is hampered by terrain conditions, parked cars, as well as the distance between the street and the fire building. However, all these problems exist at ground level. What about the overhead problem? Electrical overhead power lines. We must consider the potential electrical problems when placing apparatus if we are to ensure the safety of our members.
Once we have positioned the tower ladder and set its jacks and outriggers, put two firefighters in the bucket, and started water flowing, we have made the perfect electrical grounding device. The only block missing is an electrical power source.
A few years ago, a tower ladder unit in the South Bronx, NY, was operating at a vacant three-story frame structure when the unexpected occurred. Two firefighters were in the bucket operating a 1 1/2-inch nozzle fed via a 3 1/2-inch line from a pumper at approximately 200 pounds engine pressure. The rotation drive gear sheared off. This allowed the bucket to freewheel in a 360° arc with the members 30 feet above the ground.
In their normal operating arc, the firefighters were clear of overhead electrical lines. But as the bucket was instantly propelled by the force of the stream reaction, it struck nearby wires about six times before becoming entangled in the electrical lines. The entire apparatus was charged with electricity.
The two firefighters received electric shocks each time the tower bounced against the wires. When the bucket came to rest against the hot wires, the firefighters became constantly charged with electricity as the electrical circuit to ground was complete.
The electric utility company arrived and cut the power lines affecting the apparatus. The firefighters were then removed, and after a recuperative medical leave, returned to full duty.
Soon after this incident, this same tower ladder unit was involved with a second electrical problem, also lifethreatening to a firefighter. The unit had responded to a fire in an occupied, six-story, multiple dwelling. The fire had already melted the insulation from a live electrical line running from the basement up to the third-floor level along the side of a metal fire escape.
The wire, which provided illegal electrical service to some of the tenants, had now fused itself to the fire escape. As a firefighter attempted to step from the bucket of the tower ladder to the balcony of the fire escape on the fifth floor, the electrical current entered the firefighter’s body. A muscle reaction to the electrical stimulus caused the man’s hand to clamp itself to the fire escape railing. His feet were still in contact with the bucket floor and his body completed the electrical circuit to ground through the jacks and tormentors of the apparatus.
Only the quick thinking and swift action of a brother firefighter inside the structure reversed what could have been a painful injury or death. Sizing up the situation, the firefighter swung the six-foot wooden handle of his hook (pike pole) and knocked the electrocuted firefighter’s hand off the rail and broke the circuit. With the grace of God, the firefighter fell backwards into the bucket.
One of the interesting things at this operation was that other firefighters had been using the fire escape to get from one floor to another because the interior stairway had burned away. However, these members had mounted the fire escape from the first-floor level and were not affected by the electrification of the fire escape as it had no connection with ground. Grounding was completed only when the firefighter reached from the bucket to the fire escape.
These are only two of the many electrical safety problems that can arise at fire operations.
All members must be alert to the myriad hazards (both actual and potential) on the fireground and report to the commanding officer. Only through these reports and information, as well as his own sizeup, can the incident commander piece together the situation at hand and formulate a safe and efficient plan to mitigate the emergency.
