Memory Alpha
Memory Alpha
USS Saratoga 2367 attacked

USS Saratoga in a Borg tractor beam

A tractor beam or stabilizing beam was an attenuated linear graviton beam used by starships and space stations to control the movement of external objects. The tractor beam placed spatial stresses on the object in specific areas, allowing it to hold the "tractored" object in a fixed location or alter its position and/or trajectory. While tractor beams were normally used to pull objects towards the beam source – usually to tow objects – conversely, they could also be set to repel objects. They were most often employed to tow a disabled or vulnerable ship to safety, or sometimes, used by an enemy ship to control the movement of the target vessel. (DIS: "Battle at the Binary Stars"; TOS: "Who Mourns for Adonais?"; TNG: "The Naked Now", "The Battle", "The Masterpiece Society", "Cause And Effect"; DS9: "Emissary"; VOY: "Scorpion", "Renaissance Man")

Tractor beams were generally only used at sub-warp velocities. To safely tow a vessel at warp speed, the target vessel's engines had to be deactivated to avoid shearing forces against towing vessel. A tractor beam could be used at warp speed only if both vessels' speeds were exactly matched. (VOY: "Day of Honor", "Renaissance Man"; TNG: "Final Mission", "The Emissary")

Before the development of the tractor beam, Earth starships such as Enterprise NX-01 instead used the more primitive grapplers. Other species like Vulcans, Klingons, and Malurians already used tractor beams by the mid-22nd century. (Star Trek: Enterprise; ENT: "Breaking the Ice", "Civilization")

The 2006 video game Star Trek: Legacy established that the tractor beams had started being used by Starfleet during the Earth-Romulan War around the year 2159, when Enterprise had its grapplers replaced with the more advanced technology.

Tractor beam model

A model tractor beam

The First Federation vessel Fesarius was capable of towing a Constitution-class vessel at high warp for prolonged periods without stressing the hull of the target ship. (TOS: "The Corbomite Maneuver") Borg vessels also had the capability of holding starships securely while traveling at warp speed. (VOY: "Scorpion, Part II")

In 2293, a tractor beam was one of several pieces of equipment and personnel lacked by the USS Enterprise-B during its maiden voyage, as it was not slated to be installed until the Tuesday after. (Star Trek Generations)

Wesley Crusher created a model of the type of tractor beam that the USS Enterprise-D used as a science project, before Geordi La Forge inadvertently infected him with the Psi virus brought over from the SS Tsiolkovsky. While under the infection's influence, he seized control of engineering and was able to reconfigure the ship's tractor beam into a repulsor beam, allowing the Enterprise to push itself away from the Tsiolkovsky and avoid a stellar core fragment from a nearby collapsing red giant. (TNG: "The Naked Now")

If a vessel's tractor beam is strong enough, its graviton field can reinforce the structural integrity of a target vessel, keeping its hull from succumbing to stresses normally exhibited by a tractor field. (DS9: "Captive Pursuit")

USS Enterprise-D tows the USS Stargazer

Tractor beam as used for towing

When using a tractor beam to force another vessel out of warp speed, otherwise known as a "warp tow", both vessels needed to match velocity at the time of the tractor beam initiation. This brought tremendous risk to both vessels. However, if both vessels' hulls were strong enough to withstand the stress, they could both be brought out of warp with the tractor beam still engaged if the towing vessel carefully disengaged the warp drive while engaging the impulse engines. (DS9: "Paradise")

Internal tractor beam emitter

An internal tractor beam emitter in the shuttlebay of the USS Enterprise-D

Most Federation vessels were equipped with a tractor beam emitter on the aft ventral hull, as it was the best location for towing objects. Secondary emitters were also placed in other locations. Smaller emitters were installed within shuttlebays to assist in docking and landing maneuvers. (TNG: "Time Squared")

A low frequency tractor beam projected against a planet's tectonic plates was capable of producing minor earthquakes. (TNG: "Devil's Due")

The stress of a Romulan tractor beam caused sub-microscopic deformations in the structural integrity, specially the nose section and aft thrusters, of the Type 15 shuttlepod Onizuka, when used in an effort to stop a target craft. (TNG: "The Mind's Eye")

The Borg favored the use of a considerably more advanced tractor beam when engaging in combat. The Borg beam was capable of rapidly draining a vessel's shields while holding the vessel in place, rendering it virtually helpless against the cutting beam that it was often used in conjunction with. Furthermore, the sheer size of the Borg cube permitted the tractor beam to be used with considerable effectiveness against even ships as large as the USS Enterprise-D. They also had the ability to utilize tractor beams at warp velocities. (TNG: "Q Who"; DS9: "Emissary"; VOY: "Scorpion")

In 2369, the Klaestrons disabled the tractor beam aboard Deep Space 9 when they kidnapped Lieutenant Jadzia Dax by creating a residual charge in the graviton generator. (DS9: "Dax")

The same year, Deep Space 9's tractor beam was holding the Federation freighter Norkova after it was hijacked by Rao Vantika, Durg, and two Bajoran mercenaries. Later, Lieutenant Dax sent an electromagnetic pulse via the tractor beam to free Doctor Julian Bashir from the consciousness of Vantika. (DS9: "The Passenger")

USS Defiant tractors Vorcha class

Use of a modulated tractor beam to affect ship-to-ship weaponry

DS9 tractor beam

The tractor beam of Deep Space 9

A carefully modulated tractor beam could be used to affect ship-to-ship weaponry. In 2372, Lieutenant Commander Worf of the USS Defiant suggested using such a beam against a Vor'cha-class attack cruiser. When put into practice, his plan was successful, deflecting some of the vessel's disruptor fire and reducing its effectiveness by fifty percent. (DS9: "The Way of the Warrior")

In 2371, B'Elanna Torres devised a plan to create a subspace tractor beam, which was a standard tractor beam modified to match subspace interference. This modification required more power than a standard tractor beam and could cut through subspace interference. This tractor beam was also able to project long distances. (VOY: "Parallax")

See also[]

External links[]