Home Forums Elevator Photos Photo Gallery Cartop Sheave in Machine Room

Here are some images of an elevator's cartop sheave that went through the machine room floor. Were not really sure how this happened or what the circumstances were that could have caused so much damage. Notice how the shackles are pulled into the cartop sheave. This must have been a hell of a ride!

All I can say is WOW! Are there more cars like this one? Is this building so tall that the machine would continue to provide traction from the weight of the cables only????

Apparently, this happened during an emergency power test. This was the only car to go through the overhead. Another car went into the overhead but did not push through. Our best guess is that some how the phasing was reversed and the elevator took off out of control in the wrong direction.

There is no way the machine crushed the cwt frame and buffer and had enough inertia to send the car that high at normal speed. That is a reduced stroke buffer so is prob <500 ft/min car. I'm guessing the brake picked and the low line circuit was jumped out causing it to free fall because the EP generator couldn't output enough current. what controls drive that 155ht machine? Guess that's why we do our emergency tests to find crazy stuff like this.

Amazing, What was the runby like...Over the years have seen many units with limited head room. That's the first time I've seen that!

The runby appeared to be good. This is a 700 FPM Otis 401 controller with MGs. GreenPants, that is a good Hypothesis. It is very likely that's what happened. Good Job!

check to see if all the MG's started at the same time causing a EP gen overload.also the phases for the EP gen is a good call. normally 401 WL drives will have one car selected on the EP car selection to prevent all the MG's from starting at the same time.

This would make a good commercial for the ROPE GRIPPER!

but where would you put it? dont say overhead

Wow crazy! What City was this in?
Have you guy ever heard of them using Sheave brakes if they can't fit rope grippers on a job?

GreenPants, on the 401, what if the power phases changed/reversed? is the controller looking for feedback in one direction but was going in the other? Phase monitor in place?

I would like to see what happens on an emergency power test here. This is not a building that we service. We were just called to give a competitive bid on the repair. I did see the video from the camera inside the elevator. It closed its doors on the Lobby (1st Landing) then proceeded to go straight to the 22nd floor (Top Floor) according to the P.I.. It had plenty of time to trip the governor and open the safety circuit if the car was overspeeding. This is just a weird deal!

Ya this seems wierd that it didn't stop electrically a 401 has a few redundant systems that should have dropped ees or c. I would check the brake a 155ht brake arm needs adjusting sometimes do to worn bearings on the armature and or worn bottom bushings on the arm. It causes only part of the brake pad to apply friction. I doubt that it broke traction being a 180deg wrap with liners.

A similar thing happened years ago, but was a Otis 260VIP, a contractor was stoning the comm. on the genny and the mechanic was watching while the lift was running on normal operation!!!....and the lift took off in the up...the first problem they noticed was when they heard a bang and the rope hitches were coming through the secondary floor...made a mess and they had to cut a hole through the top of the shaft to actually make sure noone was inside!!!!

Amazing! Is this the Martin V. Smith Building in Oxnard?
I just finished reading the article in Elevator World from Mr. Marv Jacobs (RIP).

This photo would be a poster for doing full maintenance as opposed to oil and grease. If the owner is shopping for a cheaper company to do the work, they obviously have not learned a thing from this lesson. Their sister building (the smaller brown building) had a similar thing happen to the ibm type relay controller with the car top. I would hope that one day, insurance companies would catch on to the value of doing service on conveyances as opposed to finding some one who will provide paper work for cheaper.

Another good example why the Timeout Jumper should be the only jumper carried in our industry. How would you of liked to be trouble shooting when that baby hit.

I think I would rather be a couple of States over

Im with you. That way you wouldnt need a change of undies!!!

One comment...Once the "time-out" jumper is fully accepted in our trade as you say..and mechanics are installing them everywhere because, you know! they time-out. And one just happens to fail and doesn't "time-out" who accepts the responsibility? I'm not trying to down grade it's inception, only wondering how many of these things will be left on controls! As I see it now if most mechanics see a jumper on a controller they usually investigate it's purpose. Just feel that these timer-out jumpers will be looked at as alittle less important to remove. We have all heard about the escalators that had "safety circuits" jumped out and that is just criminal! I think it has merit...Just a little worried on how it will be used!

But if you were troubleshooting WITH the timeout jumper couldnt the same thing happen..doesnt the jumper "timeout" after a certain period....what if it happens when the mechanic is still there!!!