Tractor Beam
Starfleet missions sometimes
require direct manipulation of relatively large objects in
proximity to a starship. Such operations can take the form of
towing another ship, modifying the speed or trajectory of a small
asteroid, or holding a piece of instrumentation at a fixed
position relative to the ship. The execution of such missions
generally requires the use of tractor beam remote manipulators.
The tractor beam utilizes polarized subspace gravitronic fields
(collimated into a beam) to attract objects towards it. Tractor
Emitters are normally kept retracted within a special bay behind
protective shutters. When deployed, the emitters extend at the
end of a 30 meter telescoping boom, allowing a wide field of aim.
Each Emitter is actually a twin unit, capable of being both a
Tractor and Pressor Beam Generator. Tractor emitters employ
superimposed subspace/graviton force beams whose interference
patterns emits a conic field of negative gravitic potential,
these patterns are focused on a remote target, resulting in
significant spatial stress being applied on the target. By
controlling the focal point and interference patterns, it is
possible to use this stress pattern to draw an object toward the
ship.
When the Pressor Beam is used, the Projector emits a conic field
of positive gravitic potential, which acts to repel any object
within range. With careful adjustment, the unit can also act with
both Tractor and Pressor fields in parallel, to grab and hold an
object stationary relative to the ship. Extreme care must be
exercised in such cases, as, if one or both power levels
fluctuate, the result will be a violent shaking-up of the object
Uses of the Projectors
| Tractor | - To
bring smaller spacecraft or objects within transporter or
sensor range. - To pull smaller spacecraft into the Hangar Bay. |
| Pressor | - To
repel hazardous materials from the vessel. - To boost smaller spacecraft from the vessel. - To launch unpowered buoys. |
| Tractor/Pressor | - To
anchor the vessel to a stationary planetoid. - To tow a smaller, unpowered spacecraft. - To stabilize a geosynchronous orbit |
Tractor beam emitters are located at key positions on the ship's
exterior hull, permitting objects at almost any relative bearing
to be manipulated. Key among these are the two main tractor beam
emitters, located fore and aft along the keel of the Hull as well
as a third main emitter located on the aft surface of the main
hull. Additional emitters are located near each shuttlebay for
use in shuttle landing maneuvers. Mooring tractor beam emitters,
used when the ship is in dock, are located at each reaction
control thruster quad. The retractable booms are firmly anchored
to the ships frame members.
The main tractor beam emitters are built around two variable
phase 16 MW graviton polarity sources, each feeding two 450
millicochrane subspace field amplifiers. Phase accuracy is within
2.7 arc-seconds per millisecond, necessary for precise
interference pattern control. Secondary tractor the beam emitters
have lesser performance ratings. Main tractor beam emitters are
directly mounted to primary structural members of the ship's
framework. This is because of the significant mechanical stress
and inertial potential imbalance created by tractor beam usage.
Additional structural reinforcement and inertial potential
cancellation is provided by tying the tractor emitter into the
structural integrity field network by means of
molybdenum-jacketed waveguides.
Effective tractor beam range varies with payload mass and desired
delta-v (change in relative velocity). Assuming a nominal 5
m/sec2 delta-v, the primary tractor emitter can be used with a
payload mass approaching 8,900,000 metric tons at lass than 1,000
meters. Conversely, that same delta-v can be imparted to an
object massing about two metric tons at ranges approaching 20,000
km.
Tractor Beams come in a variety of sizes and power ranges.
Starfleet employs specialized platforms in the form of
specialized Starships and shuttlecraft, solely designed around
massive tractor beam emitters. Of note are the old and venerable
Faranarton Class Heavy Tugs and the Todega Class Tug, both are
Class Two Starship platforms built with tractor beam emitters
capable of towing whole starships at warp speeds. Even though
these designs are over 80 years old, they are capable of towing
2.06 x 107 mt and 1.29 x 107 mt respectively.
Also worthy of special mention is the ShuTug. The ShuTug (or
shuttle-tug) is an old design still in production after some 75
years. Upgraded to meet newer computer and power generation
enhancements, the basic design has remained mostly unchanged. The
ShuTug is roughly the size of a medium cargo shuttle and looks
very much the same from the front. From the side and rear, the
massive dual tractor beam emitters and tractor power supply
cooling vanes are easily noticeable. Capable of towing up to 7.82
x 105 mt (about the mass of a light cruiser) at impulse speeds,
these tough little vessels are found in numbers at every Starbase
and Fleet dry-dock. They also are usually deployed on Mobile
Dry-docks and Fleet Repair Starships where they can be used to
maneuver the vessel under repair into position. Some ShuTugs are
also found on search and rescue Starships where they frequently
are called upon to move disabled vessels out of harm's way.
Bibliography
Star Trek The Next Generation Technical Manual
– by R. Sternback and M. Okuda
Starfleet Dynamics - John David Schmidt
Author – Chief Engineer Lt. Wayne N Snyder
Date: August 22, 1998