Swing each gate closed until they meet to close off the entrance.
Wrap the chain around each section of gate, enclosing the framework of the gate.
Open the padlock with the key and loop the opened padlock through the links of the chain, securing both ends to the lock.
Close the lock and pull on it to ensure it is in a locked position.
Check the security of the gate, trying to open it. If it opens enough to allow entrance, unlock the padlock and repeat Steps 2 through 4, pulling the chain tighter and placing the lock further up the chain to shorten it.