i used to work at a large chemical works,we had similar crash gates around the site for emergency vehicles,and if need's be a fire engine could drive straight through them,after all a small padlock aint gonna stop a 50 ton fire engine.
however it might struggle to barge down the steel girders that now form a barrier on the airside at man.
perhaps the airport fire crew's and local fire brigades carry a small key with them to open the padlock,or failing that some bolt cutter's.
