I am dealing with a 1959 Otis 48R escalator which was rebuilt in about 1975. On occasion, customers have reported that it lurches (forward and backward and forward) and shakes during upward travel, then returns to normal operation. This has occurred with only two light women riding side by side, and no other passengers. When checked, the escalator appears to be working fine. Any suggestions re: the likely cause, what to look for, and have you had similar experiences? The 48R is still analog, no solid state upgrades. Thanks for any suggestions.

-- Rick Klingbeil (RKlingb@Pacifier.com), May 16, 1997

Answers

Rebuilt in 1975. It's been a long time. You did not mention where the shaking is located; steps or hand rails, both. I would certainly pull some steps, inspect the chains and sprockets. Make sure the chains were not replaced with metric. Inspect every chain link for stretch. Make sure the sprockets are secure to the shaft.

Stop the elevator in the up direction. Open the machine room area. Monitor the drive movement in comparison to the step chain movement. If there is excessive play or stretch, you should see it.

-- Ken Fulkerson (Elevator@InReach.com), March 05, 2001.