Tri-cobalt torpedo
The tri-cobalt warhead is a high yield subspace device used for large scale destruction of stationary targets such as space stations.
Although the Federation is banned from using subspace weapons by the Khitomer Accords, Starfleet vessels do carry tri-cobalt devices occasionally. In 2371, the USS Voyager used two of them to destroy the Caretaker's array in order to prevent it from falling into the hands of the Kazon. The Starfleet weapon has a programmable yield which can reach 20,000 Teracochranes, more than enough to destroy even a large station like the Caretaker's array.
During the initial scare in System J-25 with the Borg, one of Starfleet's many projects was the tri-colbalt device. It was the predecessor of the quantum torpedo but in effect had 10 times the destructive capability. Again, this project used three of the most powerful explosives know to Starfleet, namely, tri-cobalt, antimatter and quantum filaments. As mentioned elsewhere, the quantum torpedo creates and uses quantum filaments that arc out over the target's hull, ripping it to shreds. However, the principle utilised in the tri-cobalt device differs from this. Tri-cobalt is normally a reasonable stable compound unless it is broken down at the molecular level. In the past, Starfleet had tried to use it as an explosive but failed due to impractical methods. With the discovery of artifical quantum filaments, though, this situation changed drastically.
The design of the tri-cobalt device is highly unique in the Alpha Quadrant. It uses a three-tier warhead. One compartment is loaded with antimatter, one with around 200 quantum filaments and an appropriate amount of tri-cobalt. Upon impact, a number of things happen inside the warhead. First, the quantum filaments are released into the tri-cobalt chamber, creating a cascade reaction, mixing the tri-cobalt into a highly volatile mixture. A millisecond later the magnetic containment field around the antimatter is released and the active tri-cobalt and anti-hydrogen mix together to create a lethal explosion. The weapon is capable of disabling starships with one blow, as Starfleet unfortunatly found out. Initial testing of the weapon took place just before Wolf 359. Designers were panicked and rushing the project through under Starfleet's hasty gaze. The USS Keel, an Excelsior class ship, was the test vessel. The first few barrages in the astroid field in the Terran system proved to be massively sucessful. However, in the final day of testing an accident occurred. One of the devices lodged itself in its lauching tube and the warhead went critical. The resultant explosion tore the saucer section clean off the Keel and the minutes later the warp core in the drive section went critical. A total of 40 lives were lost in the accident and only weeks later the battle at Wolf 359 occurred.
Designers eventually figured out what had gone wrong. The tri-cobalt device was in theory much heavier than a standard photon torpedo, and although the designers had taken this into account when modifying the lauching tubes on the Keel, they had not been sufficient. After the disaster at Wolf 359, Starfleet was still interested in using the tri-cobalt device on starships. Quantum torpedoes were now in development but the sheer destructive capability of the weapon was seen as a possible defence against the Borg, whose vessels were very large targets. The designers took the launching system back to the drawing board and eventually came up with a highly safe system. From that point on, Starfleet ordered all new ships to be fitted with this kind of launching system and a steady retrofitting of the defensive capabilities of the other ships in the fleet, such as the USS Lakota.
- The information above is taken from the Daystrom Institute Technical Library and the DS9 Technical Manual.