A Viper-class Destroyer is a variant Cobra-class Destroyer converted to carry Boarding Torpedoes. Some of these warships retained their torpedo armament, even after they were no longer needed. The Viper-class has been designated as a Missile Destroyer by the Imperial Navy and is usually organised into separate flotillas which are able to be brought to bear in massed torpedo attacks at critical moments during a battle.
During the Gareox Prerogative, many Cobra-class Destroyers were converted to carry Boarding Torpedoes as part of the Young School's obsession with ordnance. Their main weapon battery was removed and extra torpedo launch batteries added. The experiment was not a success; Destroyers could not carry large enough crews to man the torpedoes properly and still fight the ship. Most of these Destroyers were gradually converted back to the Cobra-class' standard armament but a number still retain the torpedo armament, even though they no longer use boarding torpedoes. These warships are now designated as Missile Destroyers and are organised into separate flotillas within an Imperial Navy fleet. They make poor convoy Escorts but have been surprisingly successful as fleet support flotillas. Massed torpedo attacks at critical moments during a battle have often turned the tide for Imperial fleets. The 204th Grey Sharks Flotilla caught the Ork Kroozer Fow-Masha in a devastating cross-fire which blasted the pulse engines off the back of the Terror ship, leaving it a helpless cripple. The 193rd Flotilla is credited with finishing off the crippled Heretic Battleship Pustulence with salvos of torpedoes fired at near maximum range.
- Hull: Escort
- Class: - Viper-class Destroyer.
- Dimensions: - Approximately 1.5 kilometres long, 0.3 km abeam at fins.
- Mass: - Approximately 5.7 megatonnes.
- Crew: - Approximately 15,000 crew.
- Acceleration: 7.6 Gravities maximum sustainable acceleration.
Notable Viper-class Destroyer Flotillas
- 59th Rat Runners - A notable flotilla of Battlefleet Bakka of the Segmentum Tempestus that gave excellent service during the Macraggan War.
- 76th Silver Spears - A notable flotilla of Battlefleet Bakka of the Segmentum Tempestus that performed admirably in many battles during the Macraggan War.
- Battlefleet Gothic Magazine 2, "D'aynes Fighting Ships of Segmentum Tempestus - Battlefleet Bakka," pg. 40