Canon Facts  Backstage Info  Speculation

A standard torpedo uses part of its matter / antimatter warhead to extend the range of the weapon. Since the ZPE system can not (yet) be used to power a warp sustainer engine, replacing the warhead of a photon torpedo with a ZPE device would automatically lead to a large drop in effective range and manoeuvring capability. When it was decided to initiate development of the quantum torpedo, Starfleet was faced with an imminent threat from the Borg and needed the weapon as quickly as possible. It was therefore decided to base the new weapon on the Class VIII / IX warp capable probes. These were already fitted with a matter-antimatter powered warp sustainer as well as a large instrumentation package and onboard guidance systems. By removing the instruments Starfleet was able to install a ZPE warhead separate from the matter / antimatter tanks, overcoming the range drop-off problem. The Starfleet quantum torpedo is therefore approximately equal in size and considerably superior in flight performance to a Mark 6 photon torpedo.

The Cardassians are known to have developed a version of the quantum torpedo which equips their Dreadnought class drone missile. It is also known that the design schematics of the quantum warhead developed by Starfleet were scanned by unauthorized personnel at least once during the development of that weapon, and it is now thought that an operative of the Obsidian Order was able to copy this data and escape with it. The Cardassian version of the quantum torpedo was apparently developed by replacing the matter / antimatter tanks of a standard photon torpedo with a ZPE warhead. Although this does confer the increase in warhead effectiveness on the weapon, it is at a cost; without the matter / antimatter tanks to fuel the sustainer engine, the flight performance of the Cardassian quantum torpedo falls well below even that of a Mark 6 photon. This makes the weapon unsuitable for use as the primary torpedo armament of a fleet vessel while still leaving it suitable for the short range defence system of a device like Dreadnought.

The Cardassians were working on creating a device similar to Starfleets quantum torpedo to equip their fleet units, but during the war with the Klingons many of the Cardassians main weapons research centres were destroyed and their personnel killed. Today the Cardassians lack the resources to mount a major weapons development project and are continuing to use standard photon torpedoes. It is not known if they have shared the technology with the Dominion, but the Dominion vessels were not known to employ quantum torpedoes during their recent war with the Federation.

Most quantum torpedo launchers are simple modifications of photon launchers. The first model introduced on the Defiant was a quantum version of the Pulse fire torpedo tube, which can fire an average of one torpedo per second. The Sovereign class introduced a quantum burst fire tube - a variant on the type 4 photon burst fire model capable of launching a dozen torpedoes simultaneously.

Also introduced on the Sovereign class is the rapid fire turret; this allows torpedoes to be fired directly at a target, rather than having to manoeuvre toward it after launch - a measure which cuts down the torpedo flight time against targets at short range. The Sovereign turret is capable of firing four torpedoes per second, a rate of fire higher than any other model of torpedo tube in service.