The clan gate structures can't be used as a gate untill it's a complete level 1 gate we all know, but after it is complete and able to use as a gate it can not be repaired if it's damaged, it only allows you to enter or exit and you can no longer upgrade it.
If the clan duke or lord had the ability to lock the gate from being accessed any member of that clan would be able to repair it.
If this could be implemented many players would be very greatful because it saves all the hours and gold cost it took to build the gate of course it will require many stones and planks but it will be less aggravating from having to upgrade it every 20 seconds or so.
I have seen many complaints on this so I figured I would make a small suggestion.