elevator crash test

[Mercedes414]

*G, JR, *J

[Mercedes414]

What are the floors on this otis traction elevator?

[kurtzim62]

this is called a traction elevator. The brake is on the machine in the machinery space. The car safeties are on the bottom, not the brake. Whe the car overspeeds, it trips the governor, which is usually in the machine spcace. The governor jaws grab the governor rope thus pulling up on the safety linkage, setting the safeties. I have inspected thousands of these type elevators since 1999.

[Arabhacks]

The mechanical "Otis" safety is standard equipment on all modern traction elevators.

And, yes, if triggered it stops the elevator car in a most abrupt manner!

[elevaguy]

@Arabhacks This was a buffer test not a safety test. Two completely different things.

[Arabhacks]

The brakes are on the car bottom and a cable is wrapped around a spool.

This connects to a governor by way of an endless loop of cable and 2 pulleys on each end.

As long as things are fine there is a correct amount of tension on each side of this endless loop.

But if something goes wrong, overspeed, cable failure, etc, and the spool under the car is released.

There are pictures on the web of Mr. Otis cutting the rope on an elevator car to show how this works as an example to the public.

[iToasterman]

@Arabhacks not shure if these exist any more, but there is a elevator at my local mall that should have this. in the event the elvator starts to speed up uncontrobbily, there are bars in it that snap out violently grabbing the walls stoping the elevator from finishing the fall. It prevents death. idk if any have it anymore / at all. since the buffer seems, better

[bobbie4]

I had a licensed cab refinisher redo the interiors of some cars in a building. One of the cars had a high top to allow for 12 foot pipes and such to be brought up the building. The refinisher designed a hinged drop ceiling. I wasn't impressed with the latches he was using. The KONE techs weren't and neither was the safety inspector. The car failed the buffer test miserably. When the car hit the buffer, the ceiling swung down and destroyed the mirror on the rear on the cab.

[sasukedetonator]

If I was in that elevator, I would crap myself before the elevator hit the ground.

[produKtNZ]

Is the buffer filled with oil and that oil is pushed out in a controlled manner to stop the car or ...;?

[elevaguy]

@produKtNZ yes there is oil that is forced out in a controlled manner plus there is a large spring in it to push it back

[Arabhacks]

Hello.

There are several safeties, and cutting the ropes will do nothing dramatic, there is a governor in the machine room, excess speed will cause the governor to trip an overspeed switch first, failing that it will set the car brakes and the car would lock up.

The overrun test is to see what would happen if it were to, well, overrun.

[mathieupoussin]

@Arabhacks And how will the machine room set the car brakes if all links between the machine room and the car are cut ?...

[Atomsmasher420]

Not what I expected

[sonic2batt]

Can too many people in an elevator cause the cables to lose traction on the sheave and make the elevator slide down?

[NukeAttackWarnings]

soooo, what if the buffer didnt work lol... Big bang at the bottom of the shaft?

[jmeeliz]

Show me buffer test of a 1200fpm car with no oil in the buffers. Love to see the car doors mangled :-)

[elevaguy]

The cables were not loosened, a couple of limit switched were jumped out so that the elevator would not stop at the bottom floor.

[Sharkie626]

@elevaguy Ahh, I had just happened to notice the slack in them, but that's cool :D

[Sharkie626]

cool vid! but, how exactly were the cables loosened? 

[theantinignog]

@elevaguy Unless the governor rope is cut too, what local you work out of?

[johnnyrottenwigan]

load weight plus 25%, loved those ropes whipping,,,,,

[johnnyrottenwigan]

was there any weight in the car ?

[elevaguy]

Once the elevator goes faster than a set speed the govenor would trip and the safeties would stop the car, even if all the ropes were cut.

[christofer128]

ohhh i forgot.......and if the building will collapse ? :)

[christofer128]

if you cut both ok it will fall....but this is extreme case which in my opinion cannot happen due to 1 wire can hold all the lift....a lift usually has min 4 wires....so?

if we take the case if and if and if and if...thennn.....who cares....die

[christofer128]

if you cut the governor rope again the lift will stop.becouse the encoder which read the speed on the governor will not read read any speed becouse the governor will not turn

[christofer128]

The buffer doesnt save you if you cut the ropes...but something else.....

If you cut the ropes as you said the safety gear will recognise mechanically that the elevator is going down more than the normal speed so it will engage and stop the lift.

The safety gear is under the elevator and is working like brakes on the guide rails

[elevaguy]

No, if the car goes past the terminal floor it breaks a normally closed (NC) limit switch and opens the circuit shutting the elevator down electrically also there is a NC switch on the buffer that would be opened if it hits the buffer.

Mechanically the machine would not be able to run the counter weight into the machine room floor because with no weight on the car side of the cables it would lose traction.

The same applies if the car overshoots the top floor.

[produKtNZ]

@elevaguy Perfect answer :)

[patricknedz]

thats what happen in the empire state building in 1940

[patricknedz]

even if you cut the ropes it wont crash, they have governors for safety reasons.

[creidv]

@patricknedz if all the ropes, including the governor rope, are cut together, its a free fall to the pit.

[patricknedz]

@creidv that is unlikely to happen though, there are about 6 Cables, on the elevator, one cable alone is designed to hold the fully loaded car, they have so many extra cables to make it safer, what are the odds of the cables just breaking on their own? unless something like a plane, such as the Empire state building in 1940, where the elevator plummeted to the ground,

[creidv]

@patricknedz  Regardless of unlikely or not, if all are cut, its a freefall. What most are not aware of is the potential of brake failure with little load, which results in a launch to the roof. Cwt safeties are not on most installations.

[theantinignog]

@creidv well if it is a new job most of em have rope grippers,

[creidv]

@theantinignog True,but only if the cables are cut on the cwt side. Actually, any event that could sever all the ropes including governor rope is extremely unlikely. Grippers did address the issue of brake failure as well as any unintentional movement, and should be retrofitted on all elevators.

[mrmattandmrchay]

Love the sound of those ropes slapping each other!

[Labratoria]

@mrmattandmrchay Me too, it is somehow sexy!

[celtic73]

Looks like Thyssen and it was not a test tower

[g4tech]

Otis or Thyssen Krupp or Schindler ?

[g4tech]

is that a test tower?