Found out how many elevator cables are actually in a single hoistway and it blew my mind

I was reading through an old Schumacher maintenance manual last week that an old timer gave me. It says for a typical 20-story building with 3500 lb capacity, you need 6 separate cables running from top to bottom. Each one is about 3/8 inch thick but can hold over 10,000 pounds alone. That stuck with me because I always figured it was just two or three cables doing all the work. Has anyone else looked into the actual specs and been surprised by what you found?

2 comments

2 Comments

alexlewis17d ago

Six cables for a 3500 pound car? That seems like overkill until you think about how much a full car of people actually weighs. I remember reading somewhere that a single 3/8 inch cable can handle about three times the weight of a fully loaded car by itself. The other five are basically insurance in case one snaps, which makes sense when you're launching people up and down a shaft at 500 feet per minute.

anthony12717d ago

Jump right in on that. The redundancy is the whole point. You don't want a single point of failure when you're talking about dropping people down a shaft. Those cables get inspected daily too, they're looking for any little fray or kink. The safety factor is huge, like 10 or 12 to 1 on top of the weight you mentioned. It's the kind of overkill you can't really argue with.