Whirlwind

The Whirlwind is an Imperial artillery support vehicle based upon the Standard Template Construct (STC) Rhino Armoured Personnel Carrier (APC) chassis that is now primarily used by the Space Marine Chapters of the Adeptus Astartes. The Whirlwind plays the role of artillery support, providing support fire onto enemy formations from the relative safety of geographical cover, such as behind hills, forests or other line-of-sight obstructions. It is intended to be used primarily for softening up a heavily-fortified static position or other well-defended target prior to the start of a major Space Marine assault. The Whirlwind is available exclusively to Space Marine forces and is typically deployed in squadrons of three units, though in smaller actions individual vehicles may be observed operating just as effectively.

The Whirlwind design is not used by the Chaos Space Marine Traitor Legions, although the reasons behind this are unclear as the Whirlwind was used extensively by all the Space Marine Legions during the Great Crusade and Horus Heresy eras. The Whirlwind is armed with a Whirlwind Multiple Missile Launcher that is placed on a rotating turret on the vehicle's dorsal surface that is capable of firing a number of different types of missile ordinance. Unlike the Imperial Guard, Space Marine Chapters do not rely on heavy artillery bombardments and rarely deploy artillery unless it is truly needed. Many times when Whirlwinds are deployed to the battlefield they will only ever deliver a brief yet highly effective barrage against enemy targets, after which the Space Marines will engage any enemy forces that remain. When compared to the artillery tanks of the Imperial Guard, such as the Basilisk and the Medusa, the Whirlwind's range is much shorter, but it can unleash its weapon's payload with a much faster reaction time. The Whirlwind is one of only a handful of Space Marine vehicles that are capable of firing at their targets indirectly. This capability, combined with the vehicle's great mobility allow it to fire upon an enemy and then quickly relocate to avoid enemy return fire.

Typically, squadrons of Whirlwinds are used to provide artillery fire in support of Space Marine tactical deployments and advances. Though a Whirlwind's missiles lack the capability to penetrate heavy vehicle armour, they can be highly effective against large formations of lightly-armoured infantry or light vehicles. The flexibility of the indirect fire of a Whirlwind should also not be overlooked. Given a pragmatic initial deployment, it can provide fire support to friendly units almost anywhere on the battlefield.The Whirlwind can fire barrage after barrage of missiles into enemy formations or static defences, softening them up before the front-line units arrive and then the Whirlwind can provide tactical support as the Astartes forces require it.

Armament
The Whirlwind is equipped with a dorsal-mounted Whirlwind Multiple Missile Launcher that is placed on a rotating turret on the vehicle's top that is capable of firing a number of different types of missile ordinance. The most common variant of the Whirlwind in use by the Adeptus Astartes during the late 41st Millennium is the Helios Pattern. The Whirlwind Helios originated on the Forge World of Helios, and the Whirlwind Multiple Missile Launcher on this pattern is capable of carrying 60 missiles, while the Hyperios anti-aircraft variant is capable of carrying 40 surface-to-air missiles to fire upon enemy aircraft. The Whirlwind, like all other Rhino variants, can also be outfitted with dozer blades, extra armour plating, a Hunter-Killer Missile Launcher, improved communications equipment, a Pintle-mounted Storm Bolter, a searchlight, and smoke launchers. During the Great Crusade and Horus Heresy in the late 30th and early 31st Millennia, the Whirlwind was capable of being outfitted with weapons and technologies no longer known or used by the Imperium in the late 41st Millennium, such as twin-linked Bolters (Deimos Pattern Rhino chassis only), Pintle-mounted twin-linked Bolters, and an auxiliary drive system. The Whirlwind was also able to replace its standard missiles for Hyperios air-defence missiles in order to engage enemy aircraft. During these ancient times a Whirlwind could also be used as a command vehicle for Legion artillery formations.

Ammunition
The Whirlwind Missile Launcher is capable of firing multiple types of missiles, including:
 * Vengeance Missiles - Vengeance Missiles represent the standard high-explosive missile warhead used by the Astartes.
 * Castellan Missiles - Castellan Missiles are tipped with a special warhead that can be set to explode at specific times and altitudes to scatter small, mine-like bomblets across a designated target area. Castellan Missiles can establish makeshift mine fields quickly and without exposing Imperial forces to unnecessary dangers by laying mines.
 * Incendiary Castellan Missiles - An Incendiary Castellan Missile's warhead had been further modified to scatter burning Promethium over a designated target area rather than bomblets. These horrific weapons are used to literally burn to death lightly-armoured enemy infantry and light vehicle formations.
 * Hunter Missiles - The Hunter Pattern Whirlwind is capable of firing Hunter Missiles that are guided by a large scanning array that features an algorithmic precognitive targeter lock on approaching enemy aircraft that can bring them down with ease. The Whirlwind Hyperios Pattern uses similar missiles.
 * Hyperios Air-Defence Missiles - Hyperios Air-Defence Missiles are anti-aircraft surface-to-air missiles (SAMs) that were developed shortly before the outbreak of the Horus Heresy in the early 31st Millennium to replace the larger and more costly to produce Hunter Missiles used at the time for anti-air defence. The Hyperios Missiles would eventually get a fully redesigned launcher system allowing for more missiles to be loaded at once when the Whirlwind Hyperios variant of the vehicle was created.

Mark I
Originally deployed as part of Space Marine armies, the Mark I Whirlwind was an earlier variant of the standard Astartes artillery support vehicle. It possesses a distinctive shape with its functional-looking, boxy Whirlwind Multiple Missile Launcher. This older Whirlwind is still to be found as a part of many military forces in use across the Imperium of Man. It is armed with linked barrages of Vengeance Missiles and, like its Rhino cousin, a Pintle-mounted Storm Bolter and smoke grenade launchers for defensive purposes. Its crew complement includes a driver, a co-driver/gunner and a two-man missile weapons team.

Mark IIb
The Mark IIb variant of the Whirlwind has left and right-side segregated Whirlwind Multiple Missile Launcher batteries, a discrete radar Auspex system and revised engine stacks that distinguish it from the Mark I. Some additional equipment has also been relocated to the outside of the vehicle. It is armed with linked barrages of Vengeance or Incendiary Castellan Missiles. However the Mark IIb no longer possesses the Mark I's defensive weaponry, including the original Rhino's Pintle-mounted Storm Bolter and smoke grenade launchers. The Mark IIb Whirlwind's crew complement includes a driver, a co-driver/gunner and a two-man missile weapons team.

Whirlwind Hunter
The Whirlwind Hunter, also known as the Hunter Multi-Launcher, is the first known dedicated anti-aircraft platform used by the Adeptus Astartes. Many years before the discovery of the Standard Template Construct (STC) designs for the Hunter variant, the Space Marine forces had attempted many times to retrofit their Whirlwinds to fire accurately at enemy aircraft, with largely negative results. The Hunter variant fired special Hunter Missiles that are faster and more accurate than those used by basic artillery Whirlwinds, and the vehicle itself has a longer operational range. The Hunter Missile is guided by a large scanning array that features an algorithmic precognitive targeter. The Hunter variant featured a single large launch tube that was fed by a rotary system, but some Techmarines modified them with dual magazines. The Hunter variant of the Whirlwind is becoming increasingly rare in the 41st Millennium and has been largely replaced by the Whirlwind Hyperios.

Whirlwind Hyperios
The Whirlwind Hyperios is the newest variant of the Whirlwind designed sometime after the Horus Heresy to replace the Hunter variant as the Astartes' only anti-air vehicle. This variant uses a redesigned launcher system that allows it to carry more of the Hyperios air-defence missiles that were developed shortly before the outbreak of the Horus Heresy. The Hyperios is rarer than the standard pattern Whirlwind, and its missile turret has been replaced with a battery of anti-aircraft surface-to-air missiles (SAMs) and a linked fire-control targeting Cogitator that is intended to lock on approaching enemy aircraft and bring them down. The Whirlwind Hyperios are most commonly deployed by Space Marine forces when their Thunderhawk gunships are not available to provide close air support. The Whirlwind Hyperios' missiles are able to target enemy ground targets during emergencies, and although they are not effective against heavy armour, they can still cause heavy damage to enemy light and medium vehicles.

Notable Users of the Whirlwind
The Whirlwind artillery tank and its variants are used exclusively by the Adeptus Astartes, and aside from a small number that have either been captured by the Traitor Legions, or were part of a Chapter that turned to the service of the Ruinous Powers, there are no Whirlwinds in service to the Chaos Space Marines.
 * Ultramarines - The Ultramarines Space Marine Chapter used Whirlwinds during the Joran IV Campaign.
 * Raptors - The Raptors Space Marine Chapter used Whirlwinds during the Taros Campaign against the Tau.
 * Space Wolves - The Space Wolves Space Marine Chapter used Whirlwinds during the defence of Betalis III against the Eldar of Craftworld Mymeara.
 * Blood Ravens - The Blood Ravens Space Marine Chapter used Whirlwinds during the Dark Crusade and the Kaurava Conflict.
 * War Bearers - The War Bearers Space Marine Chapter has made extensive use of Whirlwinds.
 * Eagle Warriors - The Eagle Warriors Space Marine Chapter has made extensive use of Whirlwinds.
 * Space Marine Legions - The Whirlwind was used by the Space Marine Legions during the Great Crusade and Horus Heresy, it is known that they were used by the Iron Warriors, World Eaters, Word Bearers, Emperor's Children and many of the other Legions. It is unknown as to why the Whirlwind is no longer deployed by the Traitor Legions in the 41st Millennium.

Notable Deployments of the Whirlwind

 * Third War for Armageddon - During the Third War for Armageddon several Space Marine Chapters, such as the Black Templars and the Salamanders, used Whirlwinds against the invading Orks.
 * The Siege of Vraks - During the 17-year-long Siege of Vraks, the Space Marine Chapters of the Dark Angels, Red Scorpions, the Red Hunters, and possibly more used Whirlwinds against the Traitor forces.
 * The Badab War - During the Badab War Loyalist Space Marines Chapters such as the Red Scorpions, the Minotaurs, the Fire Hawks, the Salamanders, the Exorcists, and the Fire Angels used Whirlwinds against the Secessionist forces of the Tyrant of Badab, Lufgt Huron.
 * The Great Crusade and Horus Heresy - The Whirlwind was used by nearly all of the Space Marine Legions during the the Great Crusade and Horus Heresy. The Whirlwind, alongside the Basilisk and Medusa, made up the majority of the Legion's mobile artillery.

Also See

 * Imperial Vehicles

Canon Conflict
It has been stated in many sources, such as Imperial Armour, that the Whirlwind's STC designs were found after the Horus Heresy, meaning that none of the Traitor Legions would possess any once they fled into the Eye of Terror unless they later acquired them from Loyalist Space Marine Chapters in the field. Yet, in the Horus Heresy: Collected Visions background book and the Horus Heresy Novels the Whirlwind was used during the Great Crusade and the Horus Heresy by both Loyalist and Traitor Astartes Legions. As the Whirlwind is featured in both the Black Library's Horus Heresy Novels and Forge World's Imperial Armour: Horus Heresy books it is now become canon that the Whirlwind was used by the Legions, although there has been no information released as of yet for the reason(s) that the Chaos Space Marines no longer make use of the Whirlwind.

Gallery
[[Category:W]]