My '63 Studebaker owner’s guide and '77 Mercedes 300D owner’s manual both say parking brake. No, I don’t have the Stude any more.
I recall some much simpler mechanical system that used the interlock mechanism between the automatic transmission and the ignition switch to release the parking brake.
Other notes: My 85 Toyota Celica GTS convertible, still in mint condition (just bragging there), had a seperate set of brake shoes and drum on the inside of the rear wheel hubs. After 15 years the brake material had degraded and cost a fortune to replace. Not a great design in my book.
Also had an old station wagon where the parking brake pedal started falling to the floor under its own weight and engaging the brakes. Happened on a trip out of town. I got a piece of wire to hold it up, but the only nearby attach point was the hood release lever. I imagined heading down the highway when suddenly the hood would fly up, and the car screeching to a halt.
A quick Google shows that the DMV in several states is very fond of the term, here’s one example:
From here
Just sayin’…
State DMV’s don’t sell cars and are not liable when they don’t fail to prevent an accident and someone gets killed due to said failure to stop in an emergency situation. The OP wanted to know if parking brakes were poorly designed and it is my intention to insure him that they are designed properly for it’s intended use. Intended use by the manufactuer is for parking only, not emergency stopping.
All I’m saying is that I’m fighting ignorance and answering the OP . . .
Miss you Mitch.
So the respective DMVs have it dead wrong. Fair enough.
Since a great number of parking brakes are foot operated. This would be very hard to enforce.
And it’s not just automatics. My 84 CJ Jeep had a foot operated brake. It was a manual trany. My Wifes 03 Jeep Cherokee is hand operated. My O6 Pathdinder is foot operated as is my '76 Chevy plow truck.
Foot or hand operated parking brakes are about 50/50.
A side note, as others have said, it needs to be adjusted properly. My plow truck in low range 4x4 will move under power with the brake on, but I notice it right away. My Wife’s Cherokee needs to have the brake adjusted since it will move under power and you don’t really notice it. It depends on how hard you pull on it.
My Pathfinder won’t move an inch. Well it might, but you know right off if the brake is on.
Like Rick I don’t use the parking brake unless parked on a steep hill. Gotta know your car and not just watch for idiot lights. Even while I don’t use the brake, I check it every time. It’s sort of like a pre-flight check list. I think we all should do that.
And saying that, I need to check my brake lights more often. I have never had one go out on my current vehicle but ya never know.
The walk around. On a lot of cars, the emergency flashers are also the brake lights. If you have amber in the rear, they are your turn signal lights. It’s an easy way to check stuff with out having to jam a snow brush against the brake pedal.
No, they’re not. Maybe in trucks, but in automobiles foot operated parking brakes are virtually unknown outside the Mercedes range.
Sorry, but that’s not true. It may not be 50/50 in cars, but it sure goes beyond Mercedes.
Got to agree with Gary T here. Tons of cars have foot operated parking brakes. Among the brands that have foot operated brakes on one or more models in my personal experience
Cadillac
Chrysler
Ford
Volvo
GM
need I go on?
RNATB, you must be young. How many cars have you been in with front bench seats? Most American models with them have or have had pedal parking brakes. I’ve owned a Caprice, Grand Marquis, and Lumina with pedal parking brakes. I also owned bench seat cars (Maverick, Lark) with pull the handle out from under the dash type parking brakes. How many of those have you seen?
Do you remember floor dimmer switches? I liked those. The truth is that cars have been around so long that if you make a generalization like the Mercedes brake thing, you’ll probably be wrong.
Several european cars nowadays have electric parking brakes that engage automatically when the engine is turned off and disengage when the car starts moving.
The rest of the european cars have almost exclusively handbrakes.
In the case of total brake failure your parking brake can be used to stop the vehicle, hence “EMERGENCY” brake. You have to remember that your front brakes are responsible for about 75% of the stopping power and the rear about 25%. Using the emergency brake will take a lot longer to stop the car but it eventually will, unless you are travelling to fast and brake fade begins. You can also use the parking brake in an emergency situation as in leftfield6’s post, but most people have no idea how to properly do this. It all falls along the line that seperates regular drivers from professional drivers. Another example would be say an 8 inch log in the middle of the road. You could pile onto the brakes and run into it or you could preload the front suspension by braking hard then letting off just before you hit it, thus allowing the car to go over it. Most people learn how to drive but have no idea how to react in an emergency, I believe that alot of this stuff should be taught to drivers when they are first learning. I bet there would be alot less accidents.
Back to the other part of the question. The blow out preventer on the Deepwater Horizon rig. The sixty minutes program is mostly wrong, and has some significant flaws.
The BOP is not a single device, it is a set of separate units, designed in different ways, and that are used for different purposes. The part of the stack that the sixty minutes report referred to was one of the annular preventers, which is used during drilling operations to seal the well, as well as being able to shut the well in if there is a problem. The BOP stack contained two such preventers, only one was potentially damaged. Even this damage is not clear - these devices are actually designed to suffer more abuse than this, and the rig hand interviewed was not familiar with drilling operations, and there is considerable speculation that the rubber he found was not from the preventer anyway, but from a sacrificial seal that had been set in the well in earlier operations, and later drilled through.
The emergency blow out preventer system is not related to the annular preventer. The emergency system is a pair of massive hydraulic rams with hardened steel cutting shears that close over the well, and are able to cut through any drill pipe in their way, and seal the well in, at a moments notice. This device did fail. But it didn’t fail due to a missing interlock with ordinary operations. Indeed it seems that these devices are of sub-standard design. Mostly failing due to issues in the hydraulic control circuits. A report of activation of these systems requested by one manufacturer turned up the woeful statistic that 50% of the time they would fail to operate correctly.
Bottom line however is that the blow out preventer is what you use when the well has already blown out, and you are praying that something will save the situation. Failure of the BOP did not cause the blow out.