Hi all I've been charged with coming up with an imaginative solution to a problem, so having racked my own brains I've come along here to rack everyone else's! We're in the process of implementing a Salvo drive-away prevention system - Salvo susie locks combined with trapped key interlocks on loading bay doors, to ensure "bay door open" and "insecure vehicle on bay" can never coincide. So far so normal - where my problems start is that sometimes we'll need to have a bay door open without there being a vehicle there, for example to take deliveries into the factory by FLT. I've thought about an interlocked safety chain a sensible distance back from the loading bay door (on the inside), so the bay door can be open EITHER with a secured vehicle in place, or the safety chain secured. The trouble is, when big deliveries are coming in, the constant cycle of Take pallet in Close bay door open safety chain move pallet to storage close safety chain open bay door for next pallet ...etc Is going to be a pain in the bum from day one. Operatives are going to be looking for sneaky ways to defeat the safeguard and sooner or later they will succeed I've also thought of having a spare key for the door interlock in the hands of a responsible person, but that requires a solid process to ensure it remains safe, and the whole point of doing this is to replace a process-centred solution with a not-easily-defeatable physical solution. There must be other people out there who've faced this one...any ideas?

Thanks Brian, that was exactly the nudge my imagination needed As you've guessed we can't allocate a loading bay solely for this activity - however, you set me off down the line of a movable platform in the yard, which is placed against the LB by FLT: The platform is then locked against the edge of the dock using a Castell lock, which releases a trapped key to open the bay door! I have in mind a low lip on the forward edge of the platform (furthest from the dock) so that a pallet truck can't roll forward beyond the edge - this ensures that the platfom has to be removed before a truck can be unloaded on the dock. I'll remember you when I'm rich and famous...