Home Forums General Discussion Technical Questions Otis 22 CT Hamilton machine

Hey guys I know that it's probably going to be hard to get an answer on this question, but I'm doing a mod on a late 70's Otis 22ct Hamilton machine. Was wondering if anyone knows what the maximum sheave gear/worm strength would be on that machine. Already exceeded maximum cable strength with new cab. A total of almost 1300 pounds was added to car wieght. Contacted united already still waiting to hear back. Becoming a safety concern if that worm or gear is not capable of full load.

Any deviation beyond 5% of the original specified car dead weight or counterweight has to be submitted to the OEM's engineering department, that would be Otis in this case.

I'm sorry you have found yourself in this position.

Just a few thoughts right off the top of my head...

Before you added any weight to the car, did you know how much the car weighed?
Did you know how much the counterweight weighed?
When you added 1300lbs to the car, did you add 50 or 40% of that weight to the counterweight? I've found several Otis counterweights at 50%.
Adding the additional weight affects more then your hoist cables and machine gears. What about your car and counterweight slings, rail bracket spacing, machine mounts, ect, ect...

This sounds like a can of worms with a exploration date from the 70s...
I'm with E311, always try to stay close to the OEMs original weight. It sounds silly but we hang the car and counterweight and use a dynamometer to check their weights.

Good point JKH, it goes beyond just the machine itself. What about the building structure that supports this elevator, is this elevator only one of a group and they all are in the same situation? Pit floor is another issue, the maximum ratings for the safeties being another, sounds like they might be "Go Line" safteties. It IS the preverbial can of worms.

Cshields, it surprises me that you ended up with more weight in/on the car. The most weight tends to be the PDO of which you replace when doing upgrades. Why the big change. as you talking about 500k. That is a huge difference. Also as other have said, weighing the car/cwt is good to do, if you have already done this you could just weigh what you have removed to find out what has changed.