Had an old gearless traction machine throw a brake shoe spring at me last Tuesday

I was doing a routine inspection on a 1988 Montgomery unit in a 12-story office building downtown. Popped the governor cover and heard a loud TWANG, then something hit my safety glasses. Found the spring had snapped clean in half and launched across the machine room. Never had that happen before on this model. Anyone else seen sudden brake spring failures on older gearless units?

2 comments

2 Comments

maryadams22d ago

...and it hit your safety glasses, holy crap. That's one of those things you read about in the accident reports but never think will actually happen to you. I've seen a few brake springs get a little loose or corroded over the years, but snapping clean in half and turning into a projectile is a whole different level. On an 88 Montgomery too, those units are usually pretty solid if they've been maintained. Makes me wonder if there was a hairline crack that was just waiting for the right moment to let go. Glad you had the glasses on, man, that could have been real bad.

wade_young8622d ago

Man, that's a really good point about the hairline crack. Were you able to get a good look at the break surface after it happened, or did it just shatter into too many pieces to really tell? I've always wondered if those Montgomery springs get some kind of stress riser from how they're stamped, you know, like a little burr right where the radius starts. Would be interesting to know if the fracture lines matched up with a manufacturing mark.