This is fun… I’m not sure where I’m going with this.
The vampire machines vary in form but all possess one literally iron-clad quality: They contain a multitude of engines. Our brightest minds can tease out the dependencies and form some understanding of how these mechanisms interplay, but it is akin to making a new man out of a pile of bones. The boilers cannot be fired. The mills are dead and blank.
A steam engine provides motive force, and consists of a piston or piston array, a piston and connecting rod assembly, a crosshead bearing, numerous cranks, one or more valves of eccentric, or sliding configuration, a flywheel and a centrifugal governor. These parts are connected to a boiler and various functional appurtenances. Some vampire machines, like the terrible Rust Mountain, use steam merely to power other engines. Others direct it to arms, legs, and various useful and mysterious appendages. Multiple steam engines are not uncommon. Ancillary to the means of generating and employing steam are means of collecting liquid for conversion — simple water pumps and scoops as well as highly refined instruments designed for efficiently extracting mammalian blood. These exsanguinators can remove five quarts in a minute or so, with utterly fatal consequences.
An analytical engine provides the ability to reason, and consists of one or more mechanical mills for the accommodation of thought and memory, a pinwheel arithometer for analysis, poppet valves regulating the supply of steam to the thought-mills, and a variety of sensory appliances for perception and detection. Typically a vampire machine enjoys a brace of analytical engines, one large and one small. The larger is reserved for operation when blood steam is plentiful and imbues the mechanical horror with greatly enhanced mental faculties.
Within these broad parameters a vast flowering of mechanical ingenuity reigns. There are harvester machines that collect blood in great distended tanks, blood to be employed in the thought-mills of some greater, sessile intelligence. There are machines no larger than rats, optimized for the task of observing and reporting. There are machines who can throw a village into shadow by raising a single, groaning leg. Machines that seem to exist only to destroy. Machines that mock our form. Machines that fly in the air beneath glowing bags of human skin.