Fortress

Fortresses are quasi-static constructs.

Overview
Fortresses are characterized by Sky Fortress Turbines, which allow them to hover perfectly statically, and even allow a very slow rate of movement (about 1 m/s). They are unaffected by physics, making them a good choice for permanent resource gathering bases, as unlike vehicles there is no risk of them unintentionally drifting out of resource zones, and unlike structures they do not require a connection to the ground.

Components

 * Sky Fortress Turbine
 * Fortress Controller

For a fortress of mass $$m$$ and center-of-mass height $$h$$ above surface level the base static power draw is

$$P_{fb} = \frac{m}{8} \left(1 + \frac{h^2}{100}\right) \gamma$$

where $$\gamma$$ is the game speed (a bug).

This is then multiplied by an efficiency factor $$\alpha$$ according to the base power draw and the number of turbines $$n$$ to get the net power draw:

$$\alpha \approx 0.25 + \frac{P_{fb}}{16410} \gamma$$

$$P_f = \alpha P_{fb}$$

Each turbine holds up to 10000 MJ of energy and can sustain a power draw of 10000 MW. If the turbines run out of power, components on the fortress will start to take damage at the rate of 1 damage per missing MJ of energy.

The Fortress Controller allows the fortress to be moved along any of its six axes at 1 m/s and/or yawed at 10 degrees/s. Each costs 1 power per 8 tons with the same efficiency factor as above.