Forcefield technology is one of the most massively useful technological advances ever made. Initially prophesied by science fiction in the early 20th century, this is one of those technologies which has developed along almost lines almost identical to those forecast by those early "imagineers". The first forcefield technologies were developed during the mid 21st century by the team working under Doctor Cochrane as part of the warp flight project. Since these early pioneering days, forcefield technology has diversified to the point where there are literally thousands of different types of field, each with properties carefully designed to fulfil a specific range of functions. Below is a listing of some of the more common types of forcefield currently in use.
The Inertial Damping field is one of several types of forcefield which makes space flight practical. Essentially, a modern inertial damping system is a network of variable symmetry force fields which serve to absorb the inertial forces involved in space flight;even interplanetary craft routinely accelerate at hundreds of gees, and without this protection a person within such a ship would experience an apparent weight equivalent to many tons.
Most damping systems operate under the direct control of the ships main computer systems, which allow it to anticipate the forces which will result from use of the engines. The degree of fine control which this allows is such that it is virtually impossible to tell from within that a vessel is accelerating at all, let alone to feel any discomfort.
However, when the forces on a vessel are generated by an external source - such as weapons fire for example - it is a slightly different story. In this case the system can only react rather than anticipate, and this leads to a small lag between the action and reaction. This is manifested by a certain leakage through the IDF field, resulting in a noticeable effect on the passengers. Ensuring that this effect remains within safe limits is one of the primary concerns of all Starship designers.1
The structural integrity field (SIF) is another of the basic requirements for any modern spacecraft. This field is projected through the structure of a vessel,essentially turning the material into a cross between matter and forcefield. This increases the strength and rigidity by orders of magnitude, allowing the materials to withstand the stresses associated with both normal and combat operations.
The Structural Integrity Field of Starfleet vessels can also serve as a secondary backup to the ships main shielding system if required; when run at above normal capacity the system is capable of protecting a vessel from even multiple direct hits by heavy weapons. This makes the SIF a key component in the protection of a starship.2
The shield system provides the modern Starship with its principle protection against both violent natural phenomena and enemy weapons fire. Most shield systems are composed of highly focused spatial distortions which contain an energetic graviton field. The shield itself is projected by a set of transmission networks located on the hull of the ship; when matter or energy strikes the shield, field energy is concentrated at that point to create an intense localized spatial distortion.3
The shape of the field can be varied at the discretion of the tactical officer - the most common configuration is a set of curved fields which interlock to form a large bubble over vessel4, although some users prefer to make the shields closely match the ships hull.5 In the former case shield burn-throughs are more likely, as the shield must enclose a somewhat greater volume. However, in the latter case those burn-throughs which do occur are much more damaging as they are directly adjacent to the hull. Most of the information on this subject is highly classified, but since even individual vessels are known to utilize both configurations, it appears that bubble shields are preferred under certain tactical situations, conformal shields under others.6
Shields are carefully tuned to create windows which allow matter and energy to pass through under certain specific circumstances - for example, visible light is allowed to pass through unhindered. This allows the crew of a vessel to see out whilst the shields are up - or more importantly, to use visible light sensor systems. This window renders the shields invisible to the naked eye under normal circumstances. Other windows exist to allow sensors and weapons to operate through the shields.6
Impacts on the shield cause Cerenkov radiation to be released, often perceived as a flash of colour which "lights up" the shield, rendering it briefly visible. To an observer it appears that the intruding object bounces off the shields - in fact the spatial distortion becomes so great that the path of the object is radically altered, and to an zero dimensional observer on the incoming object it appears that it is the starship which has suddenly changed location while his/her course is unchanged.3
For over a century after the invention of the shield it was impossible to use transporters to beam to or from a shielded location7, but to an extent this limitation has now been circumvented.8 In general sensor and weapon windows are insufficient to allow beaming; whilst technically there is nothing to prevent a ship opening a window in its own shields of sufficient size to allow transport, in practice such windows are almost always large enough to be detected and exploited by enemy vessels and it is far simpler just to drop the shields briefly altogether. The more modern Starfleet shield designs have now reached a point at which transporters can be operated via a large wide frequency window which is briefly opened over the hull emitters. This gives greater flexibility in using the transporter during high threat situations, but it remains a somewhat risky proposition - should an enemy score even a near miss on such a window the effects on the ship would be considerable.9
Beaming through an opponents shields is an altogether more difficult proposition, but this can be accomplished successfully if the transporter operator has a detailed knowledge of the shield configuration s/he is attempting to beam through. A notable example of this is the occasion when the USS Enterprise managed to beam a crew member on board the USS Phoenix whilst that vessel was engaged in unlawful operations within Cardassian space10, or the Defiant's use of the transporter to board the Constitution class USS Enterprise whilst that ship was modulating its shields for sensor operation.11 Such operations remain the exception rather than the rule, however - and against the unknown shield configuration of an enemy vessel, beam through remains impossible.
The most recent advance in shielding systems is the Regenerative shield. This system was employed by the Dominion in the planetary defence network around Chintaka.12 The regenerative shield allows a portion of the enemy fire to be diverted through the shield generator to reinforce the shield layer - the amount of damage that a weapon impact does is thus greatly reduced. The effectiveness of the reinforcement depends on the shield generator design, but typically the effectiveness of a shield will be increased several fold by the addition of regenerative capacity.
The Containment Field has become the standard method of confining objects and isolating them from their surroundings for a wide variety of purposes. Some of the main applications common on board the modern Starship are listed below :
Many medical applications of containment fields exist. Typically these are designed to contain samples such as viruses which cannot - usually - attempt to physically force their way out of a container.13
Engineering applications include the storage of material samples collected via transporter. This generally requires higher strengths, since the samples collected can include the likes of high temperature plasmas or highly radioactive materials.14
A step up from these levels of field are those used in the shuttle or cargo bays of a starship in order to contain the atmosphere whilst allowing vehicles to pass through relatively unhindered.15 The atmospheric containment field of even a small cargo bay must hold against a force of over half a million Newtons, whilst the field used on the main hangar bay of a Galaxy class starship must withstand some two hundred and fifty times this.16
Probably the biggest use of the containment field on board a starship is in the field of security. These are generally used to block corridors17, or keep prisoners contained within the brig whilst allowing visual checks on their condition to be made.18
Starships by their very nature must employ ultra strong fields in a few selected locations. Whilst these fields can be many times stronger than even the ships main shielding system, this is usually gained by generating the field over a very restricted volume and projecting it directly within the generator network itself. Such fields are used to contain the matter-antimatter reaction within the warp core and power transfer conduits which permeate a starship.
A type of forcefield used in medical applications. Quarantine fields are designed to contain biological hazards to prevent their spreading to the rest of the ship.19