It’s a little more interesting than this even. Your brain knows the stair riser heights after 2-3 steps, so individual stairs can be different riser heights, 125-200mm (5-8”). Each riser can’t be more than 3mm different in an individual stair. Not uncommon for your upper stairs to be slightly different from the bottom if there’s a landing.
So those people do consciously need to remember step 15 is different or they can trip. The rest would be pretty normal.
We had some stone steps in the yard of a house I grew up in and I could still run those even in the dark, but I’m sure anyone running after me, unfamiliar with the steps would stumble.
I’m just wondering whether the ingenuity was from someone who actually designed them as such, or someone who did a poor job, almost got a bollocking, but then launched into a rant about how it’s actually a defensive feature.
It’s a little more interesting than this even. Your brain knows the stair riser heights after 2-3 steps, so individual stairs can be different riser heights, 125-200mm (5-8”). Each riser can’t be more than 3mm different in an individual stair. Not uncommon for your upper stairs to be slightly different from the bottom if there’s a landing.
So those people do consciously need to remember step 15 is different or they can trip. The rest would be pretty normal.
Also varied tread depth.
https://upload.wikimedia.org/wikipedia/commons/thumb/2/21/Stumble_steps.jpg/500px-Stumble_steps.jpg
We had some stone steps in the yard of a house I grew up in and I could still run those even in the dark, but I’m sure anyone running after me, unfamiliar with the steps would stumble.
I’m just wondering whether the ingenuity was from someone who actually designed them as such, or someone who did a poor job, almost got a bollocking, but then launched into a rant about how it’s actually a defensive feature.