I’ve noticed that shopping carts now have little dangling wires between the two front wheels. Just long enough to touch the ground.
“Wire” isn’t quite right. More like small gauge metal cable?
For dissipating static charge would be my guess.
Because …
If you’re like most people, you’ve headed to the nearest Wal-Mart or grocery store, pulled out a cart and felt that all too familiar “zap.” Perhaps you were even zapped periodically as you walked through the store. What gives? Does this only happen on windy days or is there some other scientific reason for this shocking problem?
Some chains, fortunately, have found a simple fix that you may have never noticed before. Many stores have added a small metal wire to the cart, which hangs down to the ground. This small wire provides a path for the static to travel without having to go through the shopper. Next time you hit the store, look under the cart for this little drag wire!
Frequent grocery store shopper here and I’ve never been shocked anywhere I’ve shopped nor have I ever noticed a wire that drags the ground. Is it obvious or hidden ?
That was my assumption as well.
Last week while I was shopping, I was getting zapped by everything. I ended up touching the shelves with a can first before grabbing anything. There’s still an arc, but it doesn’t hurt since it’s not jumping to/from my skin.
I do the same thing at work, where I’ll use a paperclip to ground myself before I touch a filing cabinet or safe. Same with my car. Find something grounded (a screw in the door handle works well) and keep a finger on it while getting in and out. Before smart keys that stay in your pocket, I touch the car with my key first.
I’ve never noticed one either, but I found this picture:
It is to prevent the build-up of static electricity. Static shock happens very infrequently but some customers freak the hell out when it does.
I’ve been shocked but not in a while. It may matter what your shoe soles are made of.
They’re fairly new AFAIK. The store I work at only got them about a year and a half ago.
Weird. I’ve gotten static shocks at home, and at the gym, but never at a grocery store.
I know what it is a sensor that will detect when the cart reaches a no go zone boundary for theft prevention of the cart and presumably groceries. Think invisible fences
Not by the price of eggs? Of bacon???
Probably not.
Those are usually connected to a wheel lock. So when the device detects the fence it locks the one wheel it’s attached to. The whole device looks something like a plastic fender or cuff surrounding about half of one wheel. The sensor / antenna is built into the device. Grocery store cart wheel lock - Google Image Search.
If it was a separate flimsy wire, people would simply cut or break them off first then steal the cart which would no longer detect the fence since its antenna was absent.
IMO the folks claiming this is a static dissipater are correct. The tendency to build up static electricity depends on temperature, humidity, floor material, cart wheel material, and customer clothing & shoe material. The first 4 items are local to each store. As a result, some stores in some areas are prone to it, and others are not. I’ve never been static-shocked by anything here in Florida. It used to happen to me routinely in St. Louis, mostly in winter.
So it makes sense that some people have no idea this is an issue and have never seen these things while for other people it’s a bigger deal and dissipaters are becoming commonplace in their area.
FYI here’s a thread I started a few months ago asking questions on the topic of static shocks in the wild. I learned a few things from folks there and you might too:
In which one person mentions Wal*Mart shopping carts as their big source of static shocks. And in which another provides the remedy for impending shocks:
The carts used to zap me all the time, especially on warm dry days. No more.
I occasionally get zapped at Walmart when I have a cart and I touch the door handles in the dairy section. Usually in the winter, though, which is when the RH is low. I use my car key to discharge myself before touching the handle.
I don’t know if this has anything to do with it, but some stores in my area have an “electric fence” set up so that you cannot take the shopping cart out of the parking lot. Kind of like those invisible fences that keep your dog from leaving the yard. Could the wire have something to do with that?
No. That’s a different thing entirely (and a much more expensive technology).
I almost never get a static shock anywhere, yet others at my workplace complain about getting shocked, particularly in the winter when humidity is lower. It seems to vary quite a bit from one person to another.
Birmingham University in the UK says:
Why do I experience shocks, when my colleagues do not?
There are many reasons why this might be so. Firstly, some people are more
sensitive to shocks than others. For most people, the threshold for feeling shocks
is in the range 2,000-4,000V.Secondly, you may be storing more static electricity than others. This depends on
the size of your body and feet, and the thickness of your shoe soles! A bigger
body, bigger feet, and thinner shoe soles, means more charge has to be stored
to produce the same voltage. This gives a higher energy electrostatic discharge.Thirdly, you may be generating more charge than others. This may be due to the
material of your shoe soles, or the way that you walk. If it happens when sitting, it
may be due to the material of your clothes and/or the material covering the chair.
My wardrobe skews strongly toward cotton fabrics and Nike shoes. Maybe my coworkers are wearing synthetics or wool that accumulate more of a charge?
I have never had a grocery cart shock in my life.
In fact I almost never get static shocks anywhere.
Maybe I have an organic force field surrounding me.
Footwear matters a lot. I sometimes dance in a gym with a rubbery floor, and the people wearing socks all generate static. Those who are barefoot never do. Those with shoes vary.