F1R3W4LL

From TCWiki

The F1R3W4LL is a gas or alcohol powered wall of flame which surrounds a property's exterior. The first one was designed and implemented by Yuki Toshiro around the Second Chance Salvage and Junkyard, which he owns and operates. It reaches 100 feet high at its maximum, designed to provide protection for the facility while still allowing the Car Chucker to perform its duties. He has been heard to refer to is as a more "residential solution" than the FGTL's current force field technology, though it would only be considered civilian grade by a few people.

It relies on a deeply buried pair of flammable gas and oxygen lines leading to large tank reservoirs, as well as an electrical ignition system. Utilities are all delivered deep underground in multiple shielded pipes and cables rather than by cables or standard piping. This makes them hard to damage or disable. The oxygen goes both to the internal air systems and is mixed with the gas, then the gas/air mix is fed through electrical ignition nozzles (usually buried in concrete) to ignite it. At high speed, the gas emerges and expands and forms the F1R3W4LL. The wall's intensity and height are variable by a computer control system.

The F1R3W4LL protects in three ways, other than in the obvious psychological advantage it gives by scaring enemies. The first advantage is the ability to burn those targets which are susceptible to burning. The second is the actual force the wall exerts by the movement of the burning gas and air around it. The constant backdraft is actually enough to force a normal person to stay several feet away from the actual flame. The third is that the upward movement of the gas and flame is strong enough to throw upward a being of insufficient weight. Because of this, the F1R3W4LL is even effective against fire-resistant threats, if their physical power or weight is not high enough to force their way through.

Due to this, the wall serves well in its original function to keep out zombies, in spite of their tolerance of flame. Even lesser demons have been thwarted by it.