these sort of fixed devices were used as far back as the 18th century and possibly before. They are considered something called a: "fougasse" some of them fired jelled flame fuels powered by black powder lifting charges (Korea, Vietnam), and historically, I had read that in Malta, massive stone fougasses were constructed literally on cliffsides and hillsides near likely enemy invasion beaches. All the defenders had to do was keep some glass on the beaches and close vessels offshore disembarking troops and set these babies from hell off, which would rain down good sized stones on the men and ships. I have heard they are still finding them today, they often had as much as a hundredweight of black powder to propel the stones out. I have also seen a reprint of a manual written by a British officer around the beginning of WWII, perhaps for the Home Guard, where he mentioned waterproofed devices set off with electric squibs. They would be almost as deadly as a Claymore mine imo.