Insulated bucket trucks were created in an effort to help protect workers from electrocution. This applies to linemen who may be working on utility lines such as telephone poles or transformers, etc. These jobs have the added danger of not only being located in high places, but working near extremely high voltage lines. This is why there was a need to create something that could additionally protect these workers and reduce the risk of electric shock.
There are three main aspects of an insulated bucket truck that can provide protection from electric shock. These are the most important components to maintain and keep within the standards as defined by ANSI:
Bucket Liner – This will protect the portion completely inside the liner, such as a person standing. Once the electricity touches the liners, it will become ineffective to anything inside the liner.
Upper Boom Insulating Section – This will prevent the flow of electricity from the boom tip through the boom elbow only.
Lower Boom Insert – This piece will provide a section of insulation between the elbow and the truck chassis.
A common misconception is that the rubber from your utility truck tires will provide shock protection. This is false as they were not built to provide electrical insulation. Dirt and salt that accrue in the tire tread can actually act as a conductor of electricity. Your body is an even better conductor of electricity, so you should never touch a bucket truck that is in contact with electrical lines even if you are operating with controls that are wooden. Here are some effects of an electrical current on the body:
Freezing Current – 5-25ma – can cause an involuntary muscle spasm
Knockout Current – 25-100ma – unconsciousness may occur and breathing could stop
Nerve Block Current – 100-200ma – your heart could stop and you would almost certainly need CPR
Frying Current – over 200ma – this will literally cook the part of the body that the current came in contact with. Death is almost always instantaneous if the path of the current is through the chest.
It’s a good idea to always keep these factors in mind when working near electricity. Additionally, you should consider the humidity of your current surroundings as well as atmospheric electricity such as lightning. You should never be working in a bucket truck, near power lines or not, if there is a lightning storm taking place.
Hopefully this article has helped you to better understand what an insulated bucket truck is and why workers can benefit from them. Keep in mind that you should only operate or use an insulated bucket truck if you have had approved training. It is not intended as a substitute for OSHA or ANSI standards, so, again, please make sure you have the proper training and certifications, where applicable, before use.