A group of us are trying to secure a small property, canal-side, such that members of that group have easy access and that the general public is, at least, discouraged (Think tool store)
We currently have a reasonably secure padlock and an awful lot of keys. But if someone leaves the area and doesn't hand their key back we can end up buying a new lock and re-issuing a large number of keys. The costs mount up.
A combination padlock has been suggested. The problem is that anyone who knows the combination can re-set it. So an individual could decide to lock everyone else out.
We have found one (very expensive, ~£140) combination padlock which can be set once and once only. If we have to, we'll buy one and then, once a year bin it and buy a new one (and program it with a different number). But, as a Danish friend said, "It's shooting Starlings with a Cannon"
There must be a market for a combination lock where anyone who knows the number can get in but only one person can change it. Mustn't there? If anyone has any thoughts, please shout.
(For info - there is no power available and we don't want to go down the road of adding swipe card readers or electric locks)
Thanks - in anticipation