Heaven's Wall Engine (H.W.E)

The H.W.E. (pronounced Hewies) is a device made using an artificial chakra to power a motor using The Wheel's planetary roi stream known as the Heaven's Wall. Hence the name.
The discovery, advancement, and implementation of this device has led to an industrial revolution throughout the world.

Utility

H.W.E.s can be used just like any gas motor. It produces kinetic force that can be used to power cars, cranes, boat engines etc.

Manufacturing

First, a chakra must be extracted from a host. An animal is usually chosen and at a point when the chakra is still developing (Many agree that this process is cruel but demand often trumps ethics far more then it should). Extraction is difficult and expensive but once done the second thing to do is place the extracted chakra into the specially designed nutrient tank. The tank will keep the chakra olive despite its lost host. Thirdly the tank with the chakra will be placed in an engine and through a trigger device an electric shock will cause the chakra to emit earth roi in all directions which starts the motors faster and stronger then just using steam or electricity.

Access & Availability

The H.W.E. is a well known technology throughout the world but Skyhold is the furthest ahead with its implementation into the society as a whole.

Complexity

The mechanics in the engine alone are very complex. The entire device is part car motor and part home aquarium.
The chakra is grown and preserved in a nutrient rich tank where it discharges a burst of active Earth roi every few seconds which when the gear apparatus is connected causes them to move and produce usable energy. There are a lot of moving parts and the chakra's tank has to be refilled with nutrient rich liquid every day. Even with regular maintenance H.W.E has a life span of under five years.

Discovery

The Heaven's Wall Engine was not discovered through chemistry or engineering. Oddly enough it was discovered by accident through biology experiments with chakra preservation and recovery during Skyhold's golden age of medical science.
At first the applications of having a partially functional chakra working outside the body were overshadowed by the experiment's strides towards successful chakra transplants. It took a few years before the applications the H.W.E. were fully realized.