I saw the picture of the 401 cartop sheave that punched through the MR slab, and was interested about what other things people have seen over the years in the industry that were dangerous or catastrophic?

I'm only a young mechanic been in the game for 6 years, i haven't seen too many strange or dangerous incidents. One thing i have seen were building maintenance staff using the elevator to move a safe from the top floor to the basement. The safe exceeded the payload, and when we got there, the car was firmly on the buffer, the car had drifted away from floor and sailed into the pit haha. They had to use a gas axe to cut the safe into small pieces to get it out and have the lift move again.

Years ago on a mod we were doing I came into the machine room and hear a strange clanking sound. We were doing a mod on an 8 bank and had the first four cars in service. The noise was coming from the brake of a Haughton #10 gearless machine. We had replaced the brake shoes in accordance with the spec for the job. The new factory supplied shoes had the brake material bonded to the steel backing plates. The glue or bonding material had failed and one side of the 3/8" thick brake pad had slid off of the steel plate and nearly completely off. The car was at the lobby with about 10 car calls registered. Only one side of the brake was actually properly holding the sheave. The failed pad was partially wedged against the drum when the brake set. My biggest fear was that if I shut the car down there was a possibility that the car could drift with absolutely no control. I made a quick gamble and thew the doors on disconnect so they could not reopen once they had closed. I sent a helper running down to the top floor. I got the car to the top floor but also physically held the door close relay in which kept the machine at full motor field until my helper radioed me that he was at the unit. The car got to the top floor and we got everyone out with no problem other than they were mad because the elevator had skipped their floor. Little did they know the danger they could have had. Never was I happier to see an empty elevator in my life. We then replaced all of the pads with riveted and glued brake linings. The dumb thing was that there was nothing wrong with the old shoes. It's hard to wear out a set of brake shoes on a dc gearless machine. Apart from dismantling, cleaning and then a lite sanding to knock off any glaze from the old shoes, they were fine.

i took a overnight call at a hospital and same thing happened the gearless brake pad came off and flipped around and kept the other brake arm from dropping all the way. the call was for the car not being level as they rolled hospital beds in and out. the car was just coming into the floor and bouncing up and down on the selector. thankfully they didnt hit the stop switch.

at another hospital job they were remodeling the waiting area and saved a bunch of money by not preforming a xray of the floor. the concrete cutter cut through the remote hydro line with the elevator at the 4th floor. luckily no on was in the car. he thought he hit a water line used a piece of sheetrock to deflect to oil away from him. he then fired up the cutter again and cut a nice line through the oil line 3 more times, he also cut right through the electrical run. mixed the high and low volt circuits on a dmc destroying every electrical component on both cars. the only thing that stopped him was flash he saw after hitting the electrical run. it was quite the repair.
almost forgot after we repaired both cars and ran a new oil line, another contractor jackhammered a hole in the other hydro line.

wow...makes me seem like ive got no experience in the field considering i cant top those stories. or maybe thats a good thing.

I was working on a 30 story Gearless job with a secondary with grate flooring. One of the hoist ropes broke a strand and created a big ball on the hoist rope. As the car was traveling up, the balled up hoist rope hit the grate floor and broke the welds causing the 100 pound grate piece to just hang there by each corner. The slightest movement of the other grate pieces would cause the loose one to fall down the hoistway. At the same time the grate floor was hit the governor electrical tripped (probably by the jerk from the hoist rope hitting the floor ) causing the elevator to stop with a car full of people. I showed up and picked the door to get on top of the elevator to open the doors and let the people out, not knowing that this unstable grate floor piece is hanging over my head 10 stories up. Luckily, got the people out and everything was fine. But when I opened that secondary to reset the governor and saw that grate floor piece hanging there, talk about pucker factor 5.
We couldn't even walk in the secondary to rig the piece because the slightest movement would have let it loose. We had to fish a rope through it from the machine room floor and finally pulled it up.

Scary stuff!

Once I was walking accross a parking garage, looking at an elevator about 200 feet away. With the doors wide open, it took off at full speed, leaving the shaft exposed. Reminded me of a huge guilotine.

I ran and shut it off, closed all the doors.

Turns out, that the long, underground electrical run put about 80 volts of noise on the door lock input to the control. That version of MCE control could not distinguish between a genuine "doors locked" signal, and merely 80 volts of noise.

A 15 k ohm, 2 watt resistor, placed between the door lock input and ground, served to drain the noise from the input, but also not get hot when the door locks were genuinely made up.

Which makes me wonder this- Why are safety and door lock inputs designed with such high input impedance? Seems they should "test the waters", just a bit, by partially loading the input signal, to make sure it's not just noise. (Cars running full speed with their doors wide open is, ahem, unacceptable)