The breakage was caused by the metal-on-metal contact wearing its way through the hook over a period of almost a century. Like a dripping gutter slowly wearing

The breakage was caused by the metal-on-metal contact wearing its way through the hook over a period of almost a century. Like a dripping gutter slowly wearing a groove into a block of stone below it. Being a closed loop would now have changed the outcome here, at best it might have bought more time. But as this fault probably developed over a time period of almost a century, I doubt that more time would have changed the outcome. > And this makes think if this could be designed so that inspection is easy and a replacement could be scheduled before the breaking point is reached. Based on the photos, it looks like the groove cut into the hook was almost half the width of the hook at the point of failure. Either the hook simply wasn’t inspected, or the inspector simply didn’t care that solid lump of steel had a half inch slot cut into it. I would hope that something like that would be a clear enough indicator that the hook needed replacing.