Safety 101: The Dielectric Properties of Web Strap Hoists
Lug-All Web Strap Come Along Ratchet Winch Hoists are designed for overhead maintenance and construction of energized power lines. The web strap is not an insulating live-line tool, which means if it becomes wet or dirty, the strap loses some of its dielectric properties. But, when it’s clean and dry, it does have dielectric properties typically associated with nylon or polyester fibers. For linemen, this can mean the difference between life and death.
So, what gives web strap hoists these naturally occurring dielectric properties and how can linemen make the best of them?
We know that web strap itself is generally made from a combination of nylon and polyester. These two materials are known to have dielectric properties, but don’t be fooled; they are in no way insulating. Even so, the dielectric properties of web strap hoists have made them a very popular choice among linemen working on hot power lines because they are not conducive to electricity, like a chain hoist, and those dielectric properties do give them a safety advantage, even if they are not insulating.
There have been many studies conducted on the dielectric properties of nylon and polymers. In fact, according to a 2009 study performed by the Department of Textile Technology at Indiana Institute of Technology, “The dielectric properties of polymers have been related with their mechanical and thermal properties” (Indian J. Fibre Text. Res., June 2009). In other words, it has been observed that the mechanical and thermal properties of polymers, which exist in web straps, are most likely one reason that they are dielectric. However, the same study found that there is a dielectric loss over time, and that loss is somewhat dependent on temperature, water, dirt, and soil.
The next question we have to ask ourselves is what can linemen do to elongate or maintain the dielectric properties of their web strap hoist, and how can they insulate themselves when working on energized power lines?
To start, it’s important to keep your hoist, particularly the web strap, as clean and dry as possible. Direct sunlight can also degrade the dielectric properties of the web strap, so it’s a good idea to physically dry the hoist as much as possible. Linemen can also use insulated gloves, hot sticks, or insulator sticks. Hot sticks are used to put distance between the lineman and the power line, whereas insulator sticks fit between the hoist and the power line to keep the hoist insulated.
The most important thing you can do to maintain as many of the dielectric properties in your web strap as possible is to keep it dry and clean. This isn’t always an option, but cleaning it by hand can certainly help to extend the lifeline of the web strap itself.