I’ve never been shocked by a grocery cart either. Although, I get a shock every time I reach for a can of dog food! One of my dogs has allergies so I’ve been sticking to salmon dog food. I put a spoonful of it in his salmon dry food. This is the only canned item that gives me a shock at the grocery store. And only this specific brand. I get other canned food for the other dogs and I never get a shock not to mention all of the other canned food I buy. Weird
I remember when gas trucks used to drag a heavy chain from their back axel to dissipate static charges. I think they decided it wasn’t worth the effort and no longer do it.
Given that they’re hauling gas and if they don’t deal with the static, there’s likely to be a spark when their hoses come in contact with the underground tanks, I’m guessing they’ve just found a different, less visible way to do it. It could be something as similar as using tires that will conduct electricity well enough to handle it.
I’ve seen chains dragging on the ground (usually unconnected trailer safety chains), they spark. I assume that’s not a good idea on a fuel truck.
Looking online for examples of a fuel truck with some type of ground, what I’m seeing is pictures of fuel trucks attaching a ground connection to something while they’re unloading the fuel. I can’t say I’ve ever seen it in real life, but I’ve never looked that closely either.
I do, however, see steel cables dragging off the back of busses.
Before Loading and Unloading
When grounding a vehicle, there are three vital functions that you must perform before the operations for loading and unloading:
- You must verify that your grounding clamp is securely connected to the ground.
- You must verify the loadout pipe is bonded with the ground.
- You must connect the grounding clamp to the body of the tank truck.
I’m sure it’s for static and I’m also sure it wasn’t worth the trouble. Shopping carts aren’t particularly prone to static trouble.
There’s a grocery near me (Marianos Cumberland) that has a T shaped fitting between the swivel casters on their carts. Those are to engage the always-broken cart escalator to the lower level parking garage.
That said, I once had the everloving witzzz@#$&! zapped into me by a forklift. I was visiting a customer and the fork truck was helping me carry something sort of delicate. I walked alongside it from my van and when we got to the destination (a few hundred yards max), I rounded the forklift and touched a fork to unload. It was easily my worst ever static electric shock and left me literally dazed and my finger joints throbbing. I don’t remember seeing the spark but I do remember making a point to touch forklifts with a leg or elbow on approach for years after.
Something like a decade ago, I drove to a Target store about 10-15 miles away because it’s a two-story store with a cart escalator and I’d never seen one previously. (No, I have no life.)
What’s a cart escalator? (asks the poster from the far North).
Do you live someplace humid?
I mostly grew up in New Hampshire, which often has the cool dry conditions that cause static electricity. But as an adult, I wisely chose to live only in warm, usually humid locales, where the idea of getting a shock from static electricity is fanciful. I’d pretty much forgotten that was a thing until I read this thread.
I don’t recall ever getting a shock while going grocery shopping. It’s a dry cold. (Or a dry hot, depending). Does that make a difference?
Literally that; an escalator designed to move a shopping cart up or down store levels.
Oooooh! multi-story grocery stores! Fancy!
I suspect this is going to be more common in a dense urban area, where two floors are needed for a supermarket or department store like Target.
An aircraft can acquire a significant charge during flight. For military aircraft, a ground strap is connect to it immediately after it has landed & parked in order to discharge it and keep it at ground potential. (Not sure about commercial aircraft, but I would assume the same.) And for any aircraft, a ground cable must be attached between the plane and fuel pump during fueling.
Now that you mention it, I do know of a Target with an Escalator for Carts to Go up: a TargEsCarGo. I quite dislike that Target’s floorplan and location and avoid it. Harlem Irving Plaza, Harwood Heights, Ill.
Dryness makes getting a shock from static electricity more likely. IANA scientist, but I don’t think the temperature matters directly, but warm air can hold more humidity than cool air, so if it’s cold it is more likely to be pretty dry.
Yea, ESD protective areas such as electronics labs (where a human body discharge can destroy certain semiconductor components in a few nanoseconds) need to maintain the RH between 40% and 60%. They also take other ESD protective measures such as wrist straps, charge dissipative garments, conductive flooring, etc.
Add heel straps (which grounds your foot to the static dissipative floor). The floor must use special wax to maintain conductivity. Here is a cart for use in ESD sensitive areas which has a drag chain to maintain ground between the cart and the floor:
The wire on a shopping cart might help with static, but the floor has to have some sort of treatment to make it at least mildly conductive. I can see grocery stores taking some ESD precautions given the proliferation of self-serve checkouts - it’s a real PITA if a terminal (or even worse the checkout system) crashes due to an ESD event.
Commercial aircraft aren’t routinely grounded while parked.
When fueling the fuel worker has to bond the airplane, the fueling appliance (truck, cart, underground pump station,), and the real planet together in a particular sequence. Hooking all that up is step 1 and unhooking it is step last.
When the airplane is plugged into building-supplied electricity there’s some level of “chassis” ground involved in that. But an airplane running on internal electricity or a separate electrical power cart (commonly powered by a diesel engine), there’s no effective ground. I’ve been zapped on occasion standing on a jetbridge and touching unpainted areas near the door. Rare, but not impossible.
Hundreds of carts in play any given day 363 days a year. I doubt a bit of wire dragging the ground is going to last 6 months in winter months