posted on Mar, 7 2013 @ 09:30 AM
reply to post by BrokenCircles
Yes thats exactly it - if brakes are released on a traction (one with cables) elevator the cab will travel upwards not downwards as the counterweights
are made to balance with the cab and full load - the machinery operates smoothly and easily when all is in balance.
There is an overspeed safety govenor device thats to engage brakes. It is operated with centrifugal force and requires a manual disengagement once
triggered. These are test annually and tagged.
The usual stoppage between floors is caused by the controls missing a positioning device in the shaftway making the controller "lose" the car - the
controller stops operation at that point for safety reasons.
I surmise that 40 minutes into the incident the elevator mechanics had arrived and went up top to manually "jog" the elevator into position with one
of the floors in order to extract the passengers and they did something very wrong in the attempt.
The "started moving slowly" perfectly descibes manual positioning and the rush to the top perfectly descibes loss of control under manual
The natural state of elevator brakes are "engaged" even with power off. It takes a mechical operation or manual operation to release them and keep
them released and its a further step to disengage the overspeed safety govenor.
I'd bet dollar to a dime when the lawsuit is over its found to be human error not the machinery.