Interstellar commerce ground to a halt when the Pirates of Boskone developed faster and more powerful ships then those used by Civilization's Galactic Patrol. The Boskonian ships could outfight any Patrol vessel fast enought catch them or out run anything heavy enought to stand up against Boskonian beams.
In a desperate attempt to collect information on how Boskonian ships were designed and powered the Patrol developed the Q-Ship "Brittania". She was the fastest thing in space, but to acheive that speed all conventianal offensive armaments had to be sacrificed. Her main and only weapon was the Q-Gun.
As Port Admiral Haynes explained to new graduated Lensman Kimbal Kinnison who was to take command of the Brittania.
"Somewhere in the galaxy you will find a pirate vessel of the new type. You lock to him with tractor beams and go screen to screen. You blast a hole throought his screen using the few short range needle beams the Brittania carries. The mussle of the Q-Gun mounts annular multiplex projectors which put out a helical Q-type tube of force that effectually extends the gun barrel all the way to the enemy's wall shield. The Q-Gun then fires a shell containing 20 tons of duodecaplylatomate that when detonated generates 40 millions degrees in less than one micro-second. You are to target a section of the pirate ship far enought away from the power rooms so that their essential mechanism will not be destroyed by the blast. You then board and storm with Valerian Space Marines. Examine and collect all the information you can about their power system and report back to Grand Base."
- The Lensmen Series by E.E. Doc Smith