Heart engine

A heart engine is a hypothetical self-driving vehicle which moves with the hydraulic power of a ravening heart. Designs for such a machine have been developed by several independent inventors of the ashurtarâg dwarves.

Design

The proposed designs are all based on the ancient invention, the mine cart. Used for hauling supplies, ore and tools between mines and settlements, the low friction provided by the smooth rail tracks means there is little power lost to uneven terrain. The reliance on man or horsepower, and the risks involved with drawing heavy loads has limited the potential of minecart.
The heart engine is, in simple terms, an upscaled minecart which provides itself the power for locomotion, and for any carts linked with it. The power is transmitted through a hydraulic system, filled with a saline fluid and powered by the heart. Controlling the power output is proposed to happen through adding or releasing the saline from the heart engine's circulatory system, thus increasing or decreasing the pressure transmitted.

Proposed uses

Proponents of this invention claim such a machine could be used to facilitate overland transportation and travel over long distances, with minecart tracks stretching across great cities and even the continents. It could also be utilized for so-called crawling fortresses, great armoured vehicles which would take the place of conventional fortifications. They could supposedly defend greater stretches of land or even evade sieges if need be.

Issues

Experiments with ravening hearts have given rise to a rather dire conclusion: They are unpredictable. Though it is known that the presence of blood excites the heart and thus increases its output, it can also slow down or fly into a frenzy for seemingly no reason. Some raise concerns over the possibility that such engines could rise against their masters, becoming unstoppable monsters of steel and blood.
In addition to this, hearts large and strong enough to power a large enough engine in the first place are challenging to procure, as Beasts of Bruada of such a massive size are usually not found anywhere near large cities.