Pressor field

A Pressor field was a type of force field similar in principle to a tractor beam but instead inverted so as to create an effect of applying external pressure to an object. It essentially pushed an object rather than pulled.

Usage
Pressor fields were artificially generated for numerous applications. The Imperial-class Star Destroyer Devastator used a pressor field to contain the Tantive IV in the event that the Rebels attempted to explode the ship once it had been brought onboard using tractor beams. In this instance the pressor field was created akin to a ray shield type of deflector shield in that it followed the contours of the captured craft.

During the surgery to save Admiral Daala following the Battle of Despayre, a pressor very small field was used in a medical application to stem the flow of bleeding from a haemorrhage. In this instance the field was used to apply pressure to a specific point.

Behind the scenes
It would seem logical, given the ubiquitous use of tractor beams in the Galaxy that pressor field technology would be equally widespread, especially since it appears only to be a modified application of the same principle. In that case, however, it is unclear if all Star Destroyers, or indeed any ship equipped with a tractor beam, was also equipped with a pressor field; or whether the Devastator was a special case given it's status as Darth Vader’s flagship. It is also unclear whether the pressor field was created by the same device that generated the tractor beam, or by a separately installed piece of hardware.

Appearances

 * Death Star