Tractor beam

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Tractor beam projector

"We're caught in a tractor beam! It's pulling us in!"

A tractor beam (also sometimes called a grappling ray) was a type of controlled force field that could be used to manipulate objects caught within its range and field-of-view. Tractor beam projectors were commonplace on capital ships, container ships, docking bays, and on spaceports.

[edit] Application and use

The most common use for a tractor beam was to help guide spacecraft into a safe landing at spaceports and docking bays, as well as for aid with loading and unloading of cargo. Some ships also had personnel retrieval tractor beams which enabled them to rescue extravehicular pilots.

Warships, such as Star Destroyers, boasted powerful military-grade tractor beam projectors that could capture ships; disabled or not, and drag them into a hangar or hold them in position for boarding.

[edit] Technical description

A tractor beam drew upon the inertia of the target as well as the ship from which it emanated. Ships with high inertia, typically meaning high mass, could affect smaller vessels with little strain on their own propulsion. Capital ships could tractor small freighters, for example, but if a freighter attempted to tractor a capital ship, it would actually affect the freighter's trajectory. For two ships of roughly equal size, the attraction was equal, but could be affected by the speed of the ships, which is where momentum plays a role. For example, in orbit around Selonia, Han Solo found himself in a crippled Selonian cone ship with no propulsion, orbit decaying, rapidly descending into the atmosphere. Meanwhile, Leia Organa Solo and Mara Jade in the Jade's Fire looked on helplessly, unable to affect the cone ship's trajectory with a tractor beam because the ships were of roughly equal size and the cone ship was already accelerating toward the planet, thus it had the greater momentum. A tractor beam would only have pulled both vessels to their doom.

[edit] Counter measures

There were several novel ways to escape from a tractor beam. Very small craft with powerful engines could out-maneuver tractor beams if the ship's pilot was more cunning than the tractor beam operator or targeting computer.

A Shroud was a counter-measure device fitted to some space vessels. It functioned to confuse and displace the tracking lock of a tractor beam, enabling a ship to escape the hold of the beam.^[1]

The tractor beams aboard the Death Star I took energy from the main reactor, giving them a constant flow of power and making it impossible for a vessel caught in it to escape. However, if one of the tractor beam's seven links to the reactor was severed, the projectors would be inactive and vessels would be allowed to escape, as Obi-Wan Kenobi discovered.

In 9 ABY Luke Skywalker was almost captured twice by the tractor beams of Grand Admiral Thrawn's flag ship the Chimaera. In the first instance Luke fired a proton torpedo and at the very same instant reversed his sublight engines in an unorthodox manner. This caused the tractor targeting computer to lock onto the torpedo, destroying the tractor beam projector. In the second instance, Luke used a large freighter as a disguise with his X-wing hidden inside. After the freighter was locked by the tractor beam, he destroyed the outer hull of the ship and escaped in the shielded X-wing, while the operator uselessly tried to regain the lock through the debris field of metal.

Tractor beams could also be disrupted by a Stage Three torpedo. These instances, however, were rare in relation to the number of times tractor beams reliably captured small vessels.