I'm no expert but ... on the inside of house doors people used to make do with a mortice lock and two sliding bolts (top and bottom).
With a pair of hinge bolts and two / three, similarly keyed, mortice locks the door would be held at four / five points.
If one lock failed the other independent lock(s) would hold until such time as the other was replaced.
Of course, whichever way you did it, how would you get in, or out for that matter, if the lock failed?
With a pair of hinge bolts and two / three, similarly keyed, mortice locks the door would be held at four / five points.
If one lock failed the other independent lock(s) would hold until such time as the other was replaced.
Of course, whichever way you did it, how would you get in, or out for that matter, if the lock failed?
