Insulated Bucket Trucks
An insulated bucket truck has three components that provide some protection from electrocution. Be sure to maintain these components in accordance with manufacturer and ANSI standards.
[You need approved training to make use of this type of truck.]
- A basket liner will protect the portion completely inside the liner. Anything conductive that extends out of the liner will conduct electricity into the liner and make it ineffective.
- The insulating section of the upper boom will prevent current flow from the boom tip through the boom to the elbow only.
- The lower boom insert will provide an insulation section between the elbow and the truck chassis.
Warning: Rubber tires do not provide shock protection, even for 120 volts, because they are not meant to provide electrical insulation. Salts in dirt which has accumulated on tires make them poor insulators. Even so your body will conduct electricity better than a wet dirty tire! DON'T TOUCH A BUCKET TRUCK THAT IS IN CONTACT WITH ELECTRICAL LINES. Don't attempt to move the bucket away from a high voltage line, even by operating controls with a wooden stick (for example). If you are on any piece of equipment that has come in contact with a live power line do not move; call for help.
Note: I've read that the boom tip contains metal structural support components and so it does not provide any insulation. Insulated bucket trucks have a band of arrows on the upper boom which indicate the end of the insulated section.
Covers and guards are installed to provide some protection from electric shock but you should not rely on them; they are not maintained or tested for this purpose.
Effects of Current on the Body
Freezing Current - 5-25ma - can cause an involuntary muscle spasm.
- You could injure yourself by inadvertently striking something, falling, or you could grasp the source of current involuntarily causing higher current flow.
Knockout Current - 25-100ma - breathing may stop or unconsciousness.
- A 100ma electrical shock is a very painful shock; you'd be done for the day.
- CPR would probably revive the victim... if someone is near.
Nerve-block Current - 100-200ma - ventricular fibrillation or the heart stops.
- The difference between this and knockout is often the path through the body.
- Death is almost certain without CPR.
Frying Current - over 200ma - cooks the portion of the body affected.
- Amputation is nearly always required for a limb.
- Death is instantaneous if the path of the current is through the chest.
The design of the bucket truck that you are using, humidity and even atmospheric electric charges create conditions which can cause an unexpected discharge of electricity through your outstretched arm that can kill you.
Working in the Vicinity of Power Lines
Always treat overhead lines as energized even if they are down or appear to be insulated. In emergency situations due to accidents or adverse weather conditions, anything in contact with an energized conductor may conduct electricity.
Observe where power lines are and never lose awareness of them while working.
Use a trained, qualified worker as a 'spotter' to observe the clearance of equipment operating near power lines when you cannot judge the distance.
Maintain a minimum clearance of at least 10 feet from the nearest overhead line.
Any conductive object that can be contacted must also be kept at least 10 feet from overhead lines. Conductive objects include:
- Wires and Transformers
- Pipes and Ducts, including antenna towers and masts
- Metal and some fiberglass poles
- Metal, wooden and some fiberglass ladders
Using Ladders Near Power Lines
Never use aluminum ladders while working near power lines or while using tools powered with an extension cord. You'd get a jolt if a drill or saw insulation fails while working on the ground; under the same circumstance you'd fall from a ladder.
Wooden and most fiberglass ladders do not provide adequate protection for a person contacting a live power line. Even if you get a minor electric shock you will likely lose your balance and fall.
Tree Trimming Around Power Lines
OSHA enforces special rules for trained and untrained workers during the maintenance of the right-of-way for transmission and distribution lines and equipment. They are contained in 1910.269. It is a big section with very specific rules.
Below you will find a table of safe distances for qualified tree trimmers. It is only listed here to make you aware that at high voltages even ten feet is not sufficient clearance around live electrical lines. [This guide is not sufficient for personnel whose job requires them to work around power lines; obtain OSHA certified training.]
To reiterate... the design of the >bucket truck that you are using, humidity and even atmospheric electric charges create conditions which can cause an unexpected discharge of electricity through your outstretched arm that can kill you!
Electrical Storms
At the first indication of an electrical storm, stop working and immediately lower the bucket. A lightning strike can travel across miles of electrical, telephone or television cable and discharge through your body which can kill you. It doesn't matter if you are using an insulated bucket truck - lightning has a potential of more than a hundred million volts. WORKING IN A RAISED BUCKET WITH LIGHTENING NEARBY CAN KILL YOU.
SAFE DISTANCES TO ENERGIZED OVERHEAD POWER LINES AND PARTS
(This is for qualified, trained tree trimmers & trainees only.)
Voltage range (phase to phase, RMS) Distance
- 300 V and less Don't touch
- Over 300V, not over 750V 12 inches
- Over 750V not over 2 kV 18 inches
- Over 2 kV, not over 15 kV 24 inches
- Over 15 kV, not over 35 kV 28 inches
- Over 35 kV, not over 46 kV 30 inches
- Over 46 kV, not over 72.5 kV 36 inches
- Over 72.5 kV, not over 121 kV 40 inches
- Over 161 kV, not over 169 kV 44 inches
- Over 230 kV, not over 242 kV 60 inches
- Over 345 kV, not over 362 kV 94 inches
- Over 500 kV, not over 552 kV 132 inches
- Over 700 kV, not over 765 kV 180 inches
Hydraulic Systems
Bucket truck hydraulic systems pose an unexpected danger around electricity in the case of a leak. Inspect all hoses for wrinkling just beyond the fitting - a sign that a hose failure is imminent. If a hose or seal breaks and hydraulic fluid contacts an electric line it can cause an arc. The arc may melt a hole in the hose, ignite the mist of hydraulic oil escaping from the damaged hose or electrocute you.
Subcutaneous Injection of Hydraulic Fluid
Accidental injection of hydraulic fluid under the skin is a special hazard when operating or repairing equipment that utilizes hydraulic fluid under high pressure. Bucket trucks typically operate at 1,500 PSI and can deliver over 2,500 PSI when overloaded. Escaping fluid, in a fine stream at only 350 PSI can penetrate the skin and soft tissue!
Injection of hydraulic fluid or suspected injection of hydraulic fluid under the skin MUST BE TREATED AS A MEDICAL EMERGENCY. The injection site may be painless at first but serious injury, even death, can result unless immediate medical attention is obtained. Any fluid injected into the skin must be surgically removed within a few hours or gangrene may result. Doctors unfamiliar with this type of injury should reference a knowledgeable medical source. Surgical debridement is usually required. Information may be obtained in the United States and Canada by calling 1-800-822-8262. To see a picture of an injury from hydrolic fluid obtained while wearing a leather glove, click here.
Never use your hands or fingers to search for hydraulic leaks. Gloves do not offer adequate protection from injection hazard. Search for leaks with a piece of cardboard.
CPR and First Aid
OSHA recommends that employees be certified to perform CPR annually and first aid every three years. If you volunteer at Scout Camp they may train you for free; ours does. You can also obtain training for a small fee from the Red Cross and most ambulance associations. At any rate do it; it could save some one's life.
CPR consists of chest compressions and rescue breaths and is intended to maintain a flow of oxygenated blood to the brain and the heart until emergency workers arrive. A person beginning CPR must be prepared to continue it without stopping unless someone else is present who can take over. This is essential for successful resuscitation without permanent brain damage.
Emergency first aid and CPR is a messy job. People cough up fluid, vomit and mess themselves. You will notice that the first thing listed in our first aid kit is disposable latex gloves. Even without these deterrents people, trained or not, are reluctant to preform CPR. If your close friend is lying there you may become so excited that, in performing chest compressions, you will break a rib. Annual training may prepare you for this or it may not. EVERY MINUTE COUNTS IN THE EVENT OF A HEART ATTACK.
In 2008, the American Heart Association recommended that chest only compressions without rescue breathing are acceptable for the following reasons:
- CPR with rescue breathing interrupts the rhythm of regular chest compressions which provide blood circulation to the heart and brain. Time is lost and the rhythm is interrupted when you attempt to give rescue breaths with chest compressions.
- Cardiac arrest victims frequently gasp prior to collapsing so the oxygen level in their blood is fairly high. They need chest compressions to circulate their blood more than they need additional oxygen (from mouth-to-mouth).
- During chest compressions, some air is sucked into the lungs so the victim is still getting small amounts of oxygen with chest compressions alone.
First Aid Kit
AAOS recommends that first aid kits be filled with the items most likely to be used on a regular basis. Consequently a '25 person office first aid kit' will have bandages, first aid cream, a kiddie scissors, etc. It's a good place to start for non-emergency use. But anyone trained in CPR and First Aid recognizes that those kits are not for accidents.
The requirements for a real first aid kit are in any Standard CPR and First Aid book.
This is what we have in our main first aid kit. We don't bother with many small items; a 4" x 4" sterile pad will do for an eye patch.
box of disposable latex gloves roll of 1/2" adhesive tape
box of alcohol swabs box of 1 3/4" x 4" band aids
box of 1" band aids box of 3/4" band aids (we use a lot of these)
knuckle and fingertip band aids three triangle bandages (plain muslin)
box 5" x 9" surgical dressing pads box 4" x 4" sterile pads
box 4" x 4" absorbent sponges 3 rolls 2" gauze bandage
4" ace bandage roll 1" stretchy 'athletic' tape
bag of 6" wooden splints stretchy thing that fits over your head
antihistamine tablets - 4 mg real scissors, flashlight, oral thermometer
Bacitracin ointment (kept in the kit for ordinary use; it isn't a trauma item)
Bucket Truck Certification
While you may be competent to change hydraulic hoses, fluid and filters, lubricate gears and bearings, inspect and perhaps even correct class C2 welds on your bucket truck, you most certainly will want to seek professional assistance in certifying the safety of a used bucket truck. Ask a business or municipality that has a fleet of bucket trucks and they will be happy to tell you where their trucks are maintained and certified.
Summary: Keep Safety Your Main Concern
As you become very familiar with your equipment and perform commonplace tasks it is tempting to skip the use of fall arrest equipment or other PPE. But that is just when unexpected emergencies occur. Safety training, recertification, equipment maintenance, and enforcement of rules become even more important as you and your equipment age.
To preserve life, limb and property, establish and maintain a comprehensive bucket truck training and recertification program if for no other reason than to remind you yourself.
Follow all safety policies and procedures that you have developed. If you are ever unsure about how to safely operate your equipment in a new situation, seek help before proceeding or refer to this guide, user's manuals or current information on the internet.
Citations
We found resources for writing safety manuals on the site of Telecom Insurance Group.
We also used portions of two articles taken from our blog about bucket trucks.
After we finished this Safe Practices guide we found another great resource with introductory videos and course outlines at the site of T. D. Power Skills.
And of course sections of 29 CFR 1910 and 1926 are quoted directly and indirectly. Standards 1910 and 1926 are a miniscule portion of the United States Department of Labor's Occupational and Safety Health Administration's Code of Federal Regulations. It can be found at: http://www.osha.gov/index.html by clicking on the Regulations tab.
All U.S. codes and regulations belong to us [you and me]; we paid for them. OSHA's codes can all be downloaded from their site as HTML documents or, better yet, cutting and pasting them into a word processing or publishing application.
Portions of the U.S. Code can be downloaded (by title, chapter and section) in PDF form at http://uscode.house.gov//search/criteria.shtml. You may be interested in Title 4, otherwise known as "The Flag Code". Title 4 tells you every law congress has passed regarding the flag of the United States and the Pledge of allegiance.
The U.S. Code is available on CD-ROM for $47.50 [stock number 052-001-00511-2] (stock number and price may change) from the U.S. Government Bookstore by phone or mail or on the internet.
Disclaimer
We compiled this guide for our own personal use. If you find portions of it useful that is great; you may print it and use it, with written permission from Southwest Equipment and Bucket Trucks Online.
In no event shall we be responsible or liable, directly or indirectly, for any damage or loss caused, or alleged to be caused by, or in connection with, the use of or reliance on any information contained herein.
We recondition, sell and rent insulated bucket trucks, so if you are looking for one, visit the link.
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