VW will stop firing ‘hail cannons’ after farmers protest | Hacker News Reader

VW will stop firing ‘hail cannons’ after farmers protest

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39 pointsedh64941 comments

How about they built the fscking cars so they would survive being outdoors? I certainly don't have anti-hail navy-grade cannons at home.

I never really understood why cars have the outer finish of an indoor piece of art. My car have scratches from my fingernails near the door handles. What's up with that? Should I wear white gloves when I approach the car?

Scratches and dents are 2 different things.

All modern cars have paint which is then covered in clear coat (which is then covered in wax). The wax layer can easily be scratched but it also easily buffs out. The clear coat layer is VERY strong and will put up with quite a bit of abuse; you can make that coat even thicker if you so wish, with aftermarket products.

Hail doesn't directly damage the clear coat or the paint, it dents the actual metal itself. To make a car that resists those heavy hail storms would require quite a bit of extra weight, and overall this problem is cheaper to solve via insurance than by building a bullet-proof carapace that will add weight and rarely ever get used.

It would only be a lot of weight if you use steel. Remember the 90s saturns with plastic doors that would just pop back after being dented? The problem is that deformation properties in steel are used to absorb impact as a safety device during collision.

> ...building a bullet-proof carapace...

I see what you did there.

It was an example. It's delicate in every possible way. It tolerates water, marginally, but that's it.

I also understand that it's better for the manufacturer that I pay through my insurance or otherwise, but that is not my point.

I agree. I'd like a nice form, but I don't really care too much about having something flashy. I want an exterior that can withstand the elements and last the lifetime of the vehicle.

> I never really understood why cars have the outer finish of an indoor piece of art. My car have scratches from my fingernails near the door handles. What's up with that? Should I wear white gloves when I approach the car?

I don't understand why people even care. My bicycle has scratches all over the frame, and other users seem to don't care either and park their bicycle against mine without worrying about scratches.

Also, I don't understand car bumpers. They look sturdy, but one small parking error and they're basically destroyed beyond repair.

My main message to designers: don't make products that look sturdy but are in fact fragile!

Cars are designed to buckle around the occupants in order to absorb as much of the crash energy as possible resulting in more saved lives. Older cars, the ones people remember being built like tanks, were designed[0] to save the car, not the occupant.

[0] If not intentional, it's the way it ended up.

Good point, but can't we have both? I.e., bumper deforms, but then takes back its original shape after impact is over?

Or save car if speed <5mph and save occupant if speed >=5mph?

My understanding is that a 5mph collision should not even harm the bumper. As in, that's how they are designed. Maybe some paint will trade, but nothing that requires a repair

That was over thirty years ago. In 1983, standards were changed to cut the collision speed in half, resulting in the delicate little things we call "bumpers" today.

(Don't know that it worthy of a downvotes just because you haven't kept up with U. S. automotive safety standards, though.)

Bumpers are federally required to do roughly this. However, SUV, light trucks and minivans are exempt, as are after market changes

Rubber bumpers would just hit people with a lot of elastic potential energy. Like being hit with a police baton but from a car in movement. Your shinbones would explode practically

Car bumpers must be designed to be soft and shatter in a collision because sometimes a car hits a biker.

I'm curious why you are so worried about those scratches (which probably will easily buff out). If you don't think cars should have such a finish, why are you so worried about maintaining it as such?

> My car have scratches from my fingernails near the door handles

Are you sure it's from fingernails and not keys?

While I share your sentiment to some extent, it's somewhat unrealistic to expect automobiles to be impervious to any size of hailstorm to the extent that they may be sold as-new on the showroom floor afterwards.

The main issue I believe is the use of relatively thin aluminum body panels to save weight. They could be made from composites like carbon fiber and wouldn't be as vulnerable to hail damage, but that's still a relatively exotic high-cost material.

The environment is full of extremely abrasive particles. It probably isn't your fingernail itself that is scratching the paint, but the microscopic grit between your nail and the paint which acts like sandpaper. You drag those particles across the paint and they dig in like tiny cutting tools.

This is the same reason that keeping eyeglasses and other optics scratch-free takes careful cleaning technique. One careless wipe when there is the wrong kind of dust on the lens or on the cloth, and you gouge the surface.

"In response, VW said it would install netting above the cars to protect them from hailstorms in the future."

It seems a comparatively much more reasonable and non-invasive low-tech solution...

Or, even cheaper, you just dismantle the "hail cannons", since there is no scientific evidence of their effectiveness or even a hypothesis on why their working principle would have anything to do with hail. So since they do nothing, have never done anything, you clearly didn't need them in the first place.

To the HN meteorologist/physicists: Do hail cannons even work ? It really seems strange that producing shockwaves prevent hail from falling. I have experienced hailstorms with lots of thunder and lightning.

nice try, financial times subscription department

De-paywalled rather than linking to another source. https://outline.com/yBhsWR

Do they even work?

https://en.wikipedia.org/wiki/Hail_cannon

"There is no evidence in favor of the effectiveness of these devices. A 2006 review by Jon Wieringa and Iwan Holleman in the journal Meteorologische Zeitschrift summarized a variety of negative and inconclusive scientific measurements, concluding "the use of cannons or explosive rockets is a waste of money and effort"."

Articles say science unproven. Thunder notably creates similar shockwave. It’s in the category of who knows but cheap enough to atempt anyway.

Or they needed it for insurance. The finished cars will likely be insured and maybe the insurer forced them to show reasonable effort to reduce damage.

... and even if they do work, would they affect rainfall?

The farmers quoted in the article seem convinced that they prevent rainfall at least.

There are probably farmers to this day that are convinced dowsing rods work.

How could they even work? Think of the energies and distances involved.

> My car have scratches from my fingernails near the door handles

Professional car painting is expensive for avoiding things like that. There are a lot of super-cheap brands also of course, but in the end, you have what you pay for.

FT Article is paywalled. Try this link:

http://uk.businessinsider.com/volkswagen-hail-cannons-mexico...

...Or click on "web" in the HN comments.

Which is just a google search. Some people don't like doing that.

I don't even know what "not liking" Google searches is supposed to mean.

Some people avoid using Google.

Or use this (disclaimer, this will redirect you from your logged in Facebook account):

https://www.facebook.com/flx/warn/?u=https%3A%2F%2Famp.ft.co...

or https://outline.com/jmv5nJ

> Scientists say there is no way to prove if these cannons really work, but farmers say it is cheaper to try the cannons than to buy hail insurance

I don't even...

Firing shockwaves every 6 seconds?

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