A Grey Knights Techmarine is a specialist of the Grey Knights Space Marine Chapter who is both a technician and an engineer as well as a full Astartes Battle-Brother of his Chapter. They are full members of both the Cult Mechanicus and their Chapter.
As warrior-smiths of the highest calibre, they are responsible for the creation and repair of all the equipment, vehicles and wargear employed by the Grey Knights. Techmarines are forever apart from their Battle-Brothers, for long years of training on Mars inculcate an entirely new set of traditions and rituals within them. Many of these traditions and rituals stand in direct contradiction to the aims and goals of the Chapter.
So it is that a Techmarine is called upon to balance these two opposed sides of his nature on a daily basis: to serve the goals and ideals of his Chapter, but according to the traditions of the even more ancient Adeptus Mechanicus.
Ancient pacts sworn between the Adeptus Mechanicus and the Adeptus Astartes allow Space Marine Chapters to send those warriors with an affinity for technology to Mars to train and begin the long, arduous journey of becoming a priest of the Machine God. Without the passing on of such ancient technological lore, the Space Marines would be unable to make war.
To begin his tutelage, a Techmarine-nominate takes ship to Mars. Bearing silvered seals of introduction, he passes through the Red Planet's Ring of Iron and deep into the hidden forge cities of the Martian Tech-priests. Here he is immersed in the ancient and jealously guarded lore of the Adeptus Mechanicus. He learns to master the tools of the Techmarine, which will allow him to visit miracles upon sundered technology.
Few are the harms that a Techmarine cannot make hale; he can fix minor weapon malfunctions with but a deft touch and, given time and appropriate facilities, bring wrecked and ruined battle tanks back to life. Aspiring Techmarines train for 30 standard years on Mars, steeping themselves in rites of activation and hymnals of maintenance; how to call forth a Machine Spirit or placate its wrath.
Techmarines return to their Chapter as aloof and mysterious figures steeped in superstitious awe. Much of the Techmarine's work is carried out in the foundries and workshops on Titan, yet he is no stranger to war. Such is the Techmarine's skill that he can effect all but the most difficult of repairs amidst the howling furies of battle. Hunched alone beside a wounded machine, his mind concentrated on the task at hand, a Techmarine might appear to be easy prey, save for the array of cutters, welders and Servo-arms at his command. Though primarily intended for repair, these tools can annihilate attackers just as easily.
A Grey Knights Techmarine employs a wide variety of esoteric tools and equipment not normally issued to their brethren. Many Techmarines are equipped with a Servo-harness, a specialised auxiliary machine arm grafted to the Techmarine's Power Armour and linked to his neural network. These arms can be fitted with a multitude of lastorches, vibro-saws and power drills or any number of arcane tools that aid the Techmarine in his battlefield role of vehicle maintenance and repair.
Their gauntlets are also often heavily modified to include more delicate tools or even a limited form of Mechadendrites. Many Techmarines have the organic components of their hands removed and replaced with augmetic prosthetics that allow them a greater connection to whatever machine they are ministering to, some even going so far as to incorporate mechanical interfaces that allow the Techmarine's mind to commune directly with a vehicle or device's Machine Spirit.
In deference to their training on Mars and the close bond that exists between Techmarines and the Adeptus Mechanicus, Techmarines traditionally repaint their armour red, though one shoulder guard will always remain in their Chapter's colours. Techmarines understand better than anyone the risks inherent in angering the Machine Spirits of battle gear and are careful to ensure that their Chapter symbol remains clear and unobscured.
Grey Knights Techmarines, however, despite their similar training on Mars, exhibit a fiercely independent streak by retaining their original grey armour colour throughout, with the exception of one shoulder plate displaying the colour red for their allegiance to the Machine Cult.
Techmarines are full members of their Chapter, and although not directly connected to the Adeptus Mechanicus, they are still considered members of the Cult Mechanicus. Therefore, they have access to a number of superior cybernetic and technological enhancements not available to their fellow Battle-Brothers within the Chapter. Techmarines can also be accompanied by a retinue of Servitors, including Gun Servitors, Combat Servitors, and Tech Servitors. The following is a list of the typical wargear employed by a Techmarine:
- Artificer Aegis Power Armour - A Techmarine's Power Armour is modified to accommodate their cybernetic enhancements and their backpacks are upgraded with several Servo-arms. Their armour is painted grey like their brother Astartes, but one shoulder plate is painted the red of the Cult Mechanicus, so as not to anger the armour's Machine Spirit.
- Servo-Harness - Like a Servo-arm, a full Servo-harness integrates with the Techmarine’s Power Armour and is controlled through the same spinal interface that makes him one with his armour. Radiating from a boosted fusion backpack capable of powering them all, this cluster of auxiliary limbs aid in battlefield repairs as well as combat. The composition of each Servo-harness is unique, customised with the tools most preferred by its previous owners for tending to Machine Spirits and laying waste to the God-Emperor’s enemies. Some bear only a few appendages, while others are great spiders of diagnostors, interface tines, drills, weapons, Plasma Cutters, and even more arcane elements that future inheritors of the apparatus may struggle to fully understand. At a minimum, a Servo-harness consists of two Servo-arms, a Combi-tool, a fyceline torch, and a Plasma Cutter. The torch is identical to an Astartes Flamer. The Plasma Cutter can cut through a metre of Adamantine plating up to 20 centimetres thick every minute (thinner material can be cut through faster). It may also be used as though it were an Astartes Plasma Pistol with a range of 10 metres and no option to fire on Maximal Mode. The ingenious Machine Spirit of a Servo-harness is capable of far more sublime communion with its master than a simple Servo-arm.
- Servo-Arm - Techmarine Servo-arms are powerful manipulators tipped with crushing pincers, useful for field repairs and punishing enemies. Ports for these detachable appendages are installed at the shoulder of the Techmarine's Power Armour, and the Battle-Brother’s armour must also be upgraded with more powerful gyro-stabilisers to use one effectively. So supported, a Servo-arm can lift one side of a Rhino Armoured Personnel Carrier to repair a broken tread link. Astartes Servo-arms are more than just repair tools, and make deadly weapons, as one can extend up to 1.5 metres.
- Wrist-Mounted Storm Bolter
- Nemesis Force Sword
- Omnissian Power Axe (Astartes Pattern), Optional - Often carried by Techmarines to show their devotion to the Omnissiah, this weapon has a long, staff-like body tipped with half of the circular Cog Mechanicum icon. The symbol forms a blade and is sheathed in a power field. Arcs of energy illuminate the ridged blade and light the skull’s eyes with a hungry glow, leaving little doubt that—even while covered with inscribed circuitry indicating its sacred nature—this religious icon is also a deadly weapon in a Space Marine’s powerful hands. The Ommnisian Axe also functions as a Combi-tool.
- Frag Grenades
- Krak Grenades
- Psyk-Out Grenades
- Liber Daemonica - The Liber Daemonica is an enduring symbol of the Grey Knight's devotion to his mission, and contains the cardinal tenets of lore culled from the dark knowledge caged within the Sanctum Sanctorum's walls. Every Grey Knight carries a copy of the Liber Daemonica in a ceramite case on his breastplate. These gnarled tomes contain the Chapter's rites of battle and detail the traditional duties of every Grey Knights' rank. The books themselves are also potent psychic talismans in their own right, with pages illuminated in silver and bound to a spine carved from the thigh bone of a martyred Imperial saint.
- Hammerhand - Focusing the raging power of their minds, Grey Knights can augment their already prodigious might. Even unarmed, such a warrior can crush flesh and bone -- given blade or warhammer there is little limit to what they can slay.
- Reconstruction - The potent psychic abilities of a Grey Knights Techmarine allows him to use the power of the Warp to enhance the overall connective pattern and information retrieval properties of his mind, guiding his hands to greatly speed the repairs he must complete.
- Codex Adeptus Astartes - Grey Knights (8th Edition), pp. 44-45, 48-49, 71
- Codex: Grey Knights (5th Edition), pg. 32