How fast does a car have to be going to go through a brick wall?
I ask this because I saw something improbable-looking yesterday while taking my dad to the dentist. A large four-door sedan had gone about three feet through a brick wall at the pharmacy next door. It looks as if the woman was trying to go in or out of a head-on parking space, but instead hopped over one of those concrete things they put at the end of parking spaces, then over about three feet of sidewalk, and into the about five feet of brick topped by about another five feet of glass. This looked improbable because it’s a small, full parking lot with not much room to gather speed, particularly in the spot the car was in since it has another row of parking behind it, meaning she had to have turned into the spot. How fast must she have been going to go through the wall? Are brick walls not as smash-proof as they seem to me?
If my description is unclear, let me know. Also, we were told that no one was injured.
There is no single type of “brick wall”, it all depends on how it is made, what’s behind it, is is reenforced, etc? The mortar in the wall is what keeps the thing together, I would image that a massive blunt force (like a car) would shatter that pretty easily.
Thanks! I thought that might be the case. From the debris, it looked like it was all just bricks and mortar, no reinforcement. It just seemed so ridiculous at the time.
Its probably your classic ‘oh that was the accelerator not the brake I think Ill panic now kerrash’ scenario.
It doesnt take long to get some serious momentum going in a car when you floor it, we recently had a terrible accident here where a person did that into a cafe and killed several people :/.
Walls, even brick walls, are generally* only made to do two things: keep something (a roof, for instance) up in the air and resist wind and normal environmental forces from pushing them over. Outside of that, no, it wouldn’t take very much force (in the grand scheme of things) to knock a hole in one.
If you are specifically building a fortress or a prison or a granary or a storm shelter, you will take into account a need for greater resistance to horizontal force from blunt instruments and the like, but not generally.
You missed a key part of that scenario. When you hit the gas instead of the brake. The car rolls foward. Now since you have your foot on what you think is the brake you push it down to the floor.
Yea, you can get a lot of momentum flooring it from a stop, but get your car rolling foward at just a few mph and then do it. You can get a good bit of momentum in just a few feet.
About 15 years ago someone did that at our store. The bulding is wood, but she did ALOT of damage.
Ordinary storefront construction isn’t terribly strong. Hollow concrete block with reinforcing wire every few courses, and the brick is a facade-it offers little strength in terms of impact resistance.
If you’d like to talk about strength of a brick wall, let’s view the way brick walls used to be made-8 wythe or thicker. Now you have a structure of great density.
A castle had to withstand something greater than a storming horde of angry shoppers.
These days, it’s probably just half-inch brick veneer cemented to cinderblocks. You could do serious damage to that with an ordinary hammer.
OTOH, I used to work in a 4-story brick building, and at ground level, the walls were two feet thick - solid brick and no void space. You’d need something really dense and fast-moving to do much damage to those walls.
At last, a question I can provide a first-hand answer for.
About three years ago, a drunken neighbor across the street stepped on the gas instead of the brake and went hurtling into the front of our house. Total distance traveled from a dead stop - less than 100 feet.
The front wall of our house consisted of a single-thickness of brick facade, exterior (Celotex) sheeting, 2x4 studs, insulation battes and interior drywall.
The brick facade was buckled, but held. The individual bricks were shattered at the points of direct impact. The studs took the major brunt of the force and were pretty broken. The inside drywall was split in spots. It’s fair to say the only thing holding the walls up at that point were nails.
If he were going a tad faster, he would have easily torn clean through the wall and ended up in our computer room.
For the record, it was the easiest negotiation with an insurance company I ever had.
There is a long-term scandal in this country in which older people are sold cars with defective brake and accelerator pedals that can suddenly reverse themselves in unfortunate situations. An older woman in my home town jumped the curb in front of the post office and slammed right through the brick exterior. No matter how hard she pushed on the brake pedal, the thing seemed to go faster. Total distance travel = 6 feet. One of my grandmother’s friends was sitting at a booth in a fast food restaurant when the same thing happened to a woman outside and she was plowed down and killed. The woman simply couldn’t overcome what the car was determined to do. It isn’t simply older women though. An old man in the Boston area had the same scam pulled on him when he plowed into a group of kids killing or permanently disabling several of them. I can’t understand why our auto makers haven’t been called to task for this.
This happened again today in Houston. Linky-link. Trying to back into a parking space on the 5th floor of a parking garage, this man instead backed through a cinderblock wall and fell to his death. I can’t imagine he could have been moving all that fast in reverse.
Thanks for all the answers! I figured I must be underestimating something or overestimating another, but it was quite the talk of the dentist office. Most exciting thing that had happened there in quite some time.
I’d really need to see a cite for that. We’re talking about dedicated mechanisms here. I’ve not seen a car yet made in the past three or four decades where the brake pedal does not directly engage the master cylinder, and other than a few really new models* I’ve not seen any that don’t have a linkage running directly from the gas pedal to the throttle.
My new truck is drive-by-wire - how far down I press on the gas pedal is encoded and fed to the computer, but the brake is still a hard connection to the master cylinder.
That has to be the biggest whoosh I’ve seen on the SDMB in my entire posting and lurking career.
We should start an IMHO thread of the biggest whooshes!
The conspiracy is actually worse than you think it is. These defective pedal switching cars are only sold to the elderly. How the factory can build some of these cars and manage to keep them out of the hands of young healthy competent drivers is a mystery.
An even larger mystery is how when the pedals switch function, they only stay switched until a large object or a person is hit. Then the pedal functions switch back to work just like every other car, and leave no trace!
It has to be some type of alien technology from another galaxy. I can think of no other reason.
