Wading into the heart of the beast
The Ninth Aetheric Vapor Squad are an elite firefighting unit of the Wulfenbach forces.[1] Their name, "Aetheric Vapor" is a poetic allusion to the chill of the upper atmosphere (from Latin æther (“‘the upper pure, bright air’”) < Ancient Greek αἰθήρ (aithēr), “‘upper air’”) < αἴθω (aithō), “‘I burn, shine’”)[2]), since they use gas (possibly nitrogen) condensers mounted on giant clanks to literally freeze the fire in place. Not only is the fire smothered instantly by a lack of oxygen, but any subsequent heat/heat transmittal damage is also quenched.
The Aetheric Vapor Squads are strategically positioned at ground stations around the Empire, usually near major cities or valuable resources, in order to be able to respond as quickly as possible to situations in which local fire brigades find themselves overwhelmed. The Ninth are closest to Mechanicsburg and Beetleburg.
The members of the squad wear insulated gear and facemasks as they operate their clanks through the inferno. The size of the clanks (the firefighter rides in a turret on top of the clank's head) not only provides sufficient room to power the condensers and carry the tanks, but keeps the firefighter him or herself further from harm. A "deadman" circuit is built into the clank's rudimentary intelligence to carry its passenger safely out of harm's way should they be overwhelmed by heat, smoke or falling debris.
Note the triple-lensed optical system is used on these firefighting clanks the same as on the Wulfenbach soldier clanks. The triplicate-stereo optical input allows for greatest possible accuracy in aiming the liquid gas streams at the designated target.
It has been theorized ✣ that the Aetheric Vapor equipment could also be used as weaponry. Gilgamesh Wulfenbach extrapolated the Baron's order for the Ninth to report to Mechanicsburg so that their equipment could be used on a larger-than-usual scale to freeze Castle Heterodyne to the point of shattering; an example is seen here. Although the showier demonstrations of the power of liquid gasses are based on the sample materials being mostly water and therefore freezing quickly, sufficient chilling on a larger scale will eventually affect denser materials as well (note eventually).