Open main menu

BattleTechWiki β

Mass Driver


Mass Driver systems have been used by civilian orbital mining and manufacturing interests for centuries as an economical means of moving materials. Functioning as a primitive Gauss Rifle, a load is placed into a cradle which is accelerated via a series of magnets. The load then flies off on the directed course at a relatively slow speed, requiring no rockets, fuel, or guidance systems. Once it reaches its destination the load is captured by an orbital tug or DropShip and maneuvered into its final place. Careful operations and strict safety guidelines were needed to make sure the system's planets were not affected by a load that missed its target. If the load entered a planetary atmosphere, when it impacted the surface it would liberate energies similar to those of a small tactical nuclear device.[1] Due to the massive damage and fallout these weapons can inflict upon a planet, mass drivers were rightly considered weapons of mass destruction and access to their control systems was heavily restricted and regulated. These safeguards failed at Cor Caroli, resulting in several nickel-iron asteroids landing on the planet's surface.[2]

Though the Terran Hegemony created a few prototypes in 2715, Word of Blake engineers created the first WarShip mounted versions in 3070.[1] These massive weapons fired a 'Mech sized iron slug at their target, and inflicted mind-boggling amounts of damage. Fortunately, there were several restrictions on Mass Drivers as weapons that greatly reduced their effectiveness on the battlefield:

Like other capital weapons, the Mass Driver was broadly split into three categories:


Game RulesEdit

  1. Mass Drivers simply cannot fit into any chassis smaller than a WarShip or Space Station, and even then the WarShip had to meet or exceed certain tonnage (between seven hundred and fifty thousand and two million tons depending on which variant) to carry the weapon.
  2. WarShips could only carry one Mass Driver system.
  3. Space Stations could only carry one Mass Driver system per firing arc.
  4. Mass Drivers aboard a WarShip had to be mounted along the length of the ship, with the muzzle at the bow of the ship. This restricted their firing arc to targets directly off the WarShip's nose (NOT the front arc used by traditional Capital Weapons).
  5. Mass Drivers aboard a Space Station could only fire on targets directly in front of the Mass Driver (NOT the firing arc used by other weapons).
  6. Mass Drivers have a hard time targeting anything: They add a +2 to hit penalty to all rolls.

Though capable of inflicting mass amounts of damage, the Mass Driver failed as a weapon for several reasons:

  1. It is simply too large to be fielded on many vessels, so employing it is difficult.
  2. It is ineffective against any target smaller than the size of a planet or moon.
  3. Attacks via orbital bombardment are greatly restricted by Article II of the Ares Conventions.
  4. The indiscriminate damage of a Mass Driver round can have horrific consequences on a planet, including extinction of indiginous life.[3] The use of a Mass Driver therefore could fall under restrictions of Article I and Article IV of the Ares Conventions.
  5. A Mass Driver is more expensive than nearly any other weapon system. The Light Mass Driver cost 150 million C-bills, which is enough to outfit at least a regiment of BattleMechs. The Heavy Mass Driver cost a staggering 500 million C-bills.


  1. 1.0 1.1 Tactical Operations, p. 323, "Mass Driver"
  2. Dark Age: Republic Worlds, p. 179, "Cor Caroli"
  3. See Extinction of Terran Dinosaurs for one example.