Interial Damping System
On starships, even normal maneuvers involve massive acceleration. The forces involved would crush the crew if they weren't protected by a series of forcefields.

The fact that starships move at great speeds has serious implications for the safety of the crew. Without some form of protection, the human body would be incapable of resisting the kind of forces generated by the impulse drive and would be pulverized. Starships prevent this from happening by using a series of variable-symmetry forcefields which absorb the inertial forces. This network of forcefields is known as the inertial damping system (IDF), and without it even the most basic interstellar journey would be impossible.

The inertial dampers operate in all the habitable areas of the vessel. They generate a low-level forcefield which averages 75 millicochranes. In order to maintain an inertia-free enviroment as the forces acting on the ship change, the IDF attempts to predict the amount of force that will be generated by starship maneuvers. The computers then adjust the strength of the forcefields to absorb the appropriate amount of inertial force. The ship's computers can cope with most maneuvers programmed in by the flight controller because they know exactly what is going to happen, and the crew are rarely aware of any acceleration. There is a timelag, but at impulse speeds this is only in the region of 300 milliseconds. The inertial dampers are less effective when the ship is hit by weapons fire or the flight controller initiates extremely sudden or sharp maneuvers. On a Galaxy-class starship, power for the inertial dampers is provided by six generators, two in the engineering hull on deck 33, and four in the primary hull on deck 11. A further six generators provide an emergency backup: three in each hull. Each of the generators has a cluster of twelve 500 kilowatt graviton polarity sources which feed a pair of 150 millicochranes subspace field-distortion amplifiers. Under normal circumstances, the primary generators operate in 48-hour shifts with a 12-hour rest period for maintenance and degaussing. The graviton polarity sources are rated for 2,500 hours of operation before the superconductive elements require routine servicing. The inertial damping system uses its own network of molybdenum-jacketed waveguides, which are parallel with those used by the structural integrity field. The inertial dampers are conducted by synthetic gravity plates.

If necessary, the IDF can function on one generator. However, in normal flight mode, at least two of the generators are active in each hull. If extreme maneuvers are required, the remaining generators can be brought on line. At Red and Yellow Alert, all the inactive generators are brought to hot standby so that they are available for immediate use.