HarJel III Auto-Repair System
BattleMech HarJel System


HarJel is a black gel developed by Clan Diamond Shark. It is created from a naturally occurring (petroleum-like?) substance, of which Clan Diamond Shark vigilantly guards their virtual monopoly over[1]. The monopoly was threatened after the Great Refusal, when the Clan Hell's Horses and Clan Ice Hellion's developed a way to create a synthetic replacement for HarJel.[2]. But the Sharks, who were mediating between both clans, act quickly, and after two Trial of Position took both Hellion facilities, taking the procedure, which only served to double the production of HarJel, and leaving the Horses with it.[3].

After moving his entire Clan to the Inner Sphere, the Sharks managed to continue the HarJel production, and keep the monopoly, thanks to the discovery, and taking of, the base material in the Twycross system[4] and in the Clan Homeworlds. Clan Diamond Shark sells HarJel to all the other Clans.


HarJel is used in two capacities:

  1. As a component of Elemental armor it is used to absorb shock, seal breaches in the armor and control the Elemental bleeding.
  2. As hull sealant on Clan space vessels.

BattleMech HarJel System[edit]

The Diamond Sharks introduced this system in 3059, but by 3067 the Lyran Alliance had reverse-engineered the system.[5] The BattleMech HarJel System is an experimental piece of equipment that closes gaps in the armor of a BattleMech. This allows a 'Mech equipped with such a system (like the Aquagladius) to operate underwater without fearing a hull breach, as long as armor is still present. (Once all armor is gone from a location, it's automatically breached.) The system's main drawbacks are its bulk and its behavior when hit by weapons fire. The bulk issue results from the need to have a HarJel system in every location that needs to be protected. If a HarJel system is destroyed by weapons fire all HarJel stored in that location will expand automatically, flooding the components and weapons with sealant and rendering them useless. Removing the hardened sealant effectively doubles repair time. Ammunition stored in a HarJel-encased location cannot be dumped.[5]

Game Notes[edit]

BattleMech HarJel Systems weigh one ton and take up a single critical location in a BattleMech.[6] Each location to be protected needs its own BattleMech HarJel System, so to completely protect a BattleMech would require seven systems: One for each arm, leg, and torso location. Due to the potentially crippling drawbacks, BattleMech HarJel systems cannot be installed in the location carrying the cockpit.[5] The BattleMech HarJel System costs 120,000 C-Bills per critical slot.[6]

BattleMech HarJel Systems can also be used by combat vehicles, but cannot be installed in a rotor or body location.[5]


HarJel II and HarJel III Auto-Repair Systems, HarJel evolutions introduced in the Age of Destruction, are prodigious automatic repair devices for light and medium 'Mechs.


  1. MechWarrior's Guide to the Clans, pp. 4-7, "Blood in the Water"
  2. MechWarrior's Guide to the Clans, p. 4 "Blood in the Water"
  3. MechWarrior's Guide to the Clans, p. 7, "Blood in the Water"
  4. Masters and Minions: The StarCorps Dossiers, p. 152. "Corporations Of The Diamond Shark Holdings"
  5. 5.0 5.1 5.2 5.3 Tactical Operations, p. 288, "BattleMech HarJel System"
  6. 6.0 6.1 Tactical Operations, p. 405, "Heavy Weapons And Equipment Construction Data"