Upgraded staircase

Today we upgraded our staircase. It's a single column in the middle with the steps sticking out from it, without any support on the outer rim; the steps only connect to the central column. When we bought this house, it was in pristine condition; since we live here the steps are falling off one by one. One of the steps - the infamous number four - has been re-welded three times, and still managed to nearly fall off a fourth time ...

I can't help feeling guilty - it survived for 40 years, from 1964 to 2004, and then in ten years' time we managed to destroy it. Or more precisely, I managed to, because I'm significantly heavier than all other family members ...

Whatever the cause, a long list of potential repairmen came to tell us how we should deal with it, and today we finally had the staircase repaired. In an effort to solve the problem for once and for all, we've had the steps connected to each other - see the photo.

Ahead of time I was wondering a lot whether this would actually work. I didn't expect to find out any time soon - I just hoped they would never break off again. But it turns out that one can now already hear how it has helped.

The thing is, the vibration frequency of the staircase has completely changed - its frequency is now much higher than it was before, easily a factor ten. This means that it's much, much stiffer - the frequency scales as the square root of the stiffness. Higher stiffness means smaller displacement, and therefore less chance of reaching the plastic yield point. I now really feel confident that the upgraded staircase will be with us for a long time ...