Production information
Manufacturer Defiance Industries[1]
Production Year 3077[2]
Model EFT-7X[1]
Class Medium
Cost 5,844,370 C-bills[2]
Technical specifications
'Mech type Inner Sphere BattleMech
Mass 45 tons
Chassis Chariot Type II-B
Armor Durallex Medium
Engine Edasich Motors 180 XL
Communications System Neil 6000-G
Targeting Tracking System RCA Instatrac Mark XXII
Heat Sinks 15 double
Speed 64 km/h
Jump Jets None[3]
BV (1.0) N/A
BV (2.0) 1,203[1][2][4]


The Eisenfaust was originally designed shortly after the Lyran Commonwealth began building 'Mechs. Based on their experience with the Commando and Ymir, the LCAF tried to build a medium class "siege engine" 'Mech. Though the trials looked promising, the battlefield performance of the early Eisenfaust was poor and the design was canceled.[3]

After the recovery of lostech and advanced SLDF technologies, Defiance Industries looked at the early Eisenfaust design again. The updated Eisenfaust entered production after simulations showed it could be an effective battlefield unit if equipped with updated technologies. In fact the Eisenfaust was one of the first designs to enter production after the start of the Jihad.[3]

The updated Eisenfaust uses an XL engine to provide power. The small weight of the engine allows the 'Mech to carry more armor and weaponry than the prototype models, as well as increasing the top speed. More importantly, the use of 15 double heat sinks allows the Eisenfaust to dissipate the heat from all its weapons.[3]

Weapons and Equipment[edit]

The Eisenfaust uses a single plasma rifle as its main weapon. Equipped with two tons of ammunition the rifle can inflict serious damage on any battlefield unit and can obliterate conventional infantry platoons. The Eisenfaust's slow top speed makes it difficult for the 'Mech to break contact and reload its plasma rifle magazine, therefore Defiance engineers installed a suite of lasers to provide the backup weapons the 'Mech needs to deal with determined opponents. Two medium pulse lasers and an ER small laser work to deal with close up threats, as well as deal with hostile battle armor. The ER large laser supports the plasma rifle at range, allowing the pilot to save the plasma rifle for a knockout punch.[3]


  • EFT-2 
    The result of a 2471[5] working group, this Eisenfaust model was intended to carry the AC/10 into a siege or defensive engagement. This simple design mandate was quickly warped into an entirely different machine. For close work the 'Mech carried two medium lasers while a large laser provided long range and ammunition free firepower. The Coventry Defense Conglomerate was unable to overcome the inherent limitations of primitive technology however, resulting in a thinly armored and clumsy 'Mech that could only reach a top speed of 32 km/h. The single ton of ammunition provided to the Eisenfaust's main weapon didn't help. The CDC only produced one prototype unit for the LCAF.[6] BV (2.0) = 775[5]
  • EFT-4J 
    This Eisenfaust model was the original prototype developed in 2515[7]. Though several were produced, Defiance Industries only used them to test weapons and equipment configurations for the EFT-7X.[1] These models remain on Hesperus II to serve as test vehicles.[3] BV (2.0) = 977[8][7]

Design Quirks[edit]

The Eisenfaust is subject the following Design Quirks:[11]

The EFT-2 Eisenfaust variant is subject to the following Design Quirks:[6]


  • The Eisenfaust was released by Defiance Industries in 2515. However, the 'Mech factories that would become Defiance Industries were founded in 2577 by the Lyran Commonwealth and the Star League, though some 'Mech factories have been on Hesperus II prior the Star League. Those factories were the property of the Terran Hegemony rather than the Lyran Commonwealth.

BattleMech Gallery[edit]


  1. 1.0 1.1 1.2 1.3 1.4 Technical Readout: Jihad, pp. 84–85: "EFT-7X Eisenfaust"
  2. 2.0 2.1 2.2 MUL online data for the Eisenfaust
  3. 3.0 3.1 3.2 3.3 3.4 3.5 Technical Readout: 3085, pp. 74-75 - EFT-7X Eisenfaust
  4. Record Sheets: 3085 Print Edition, p. 54
  5. 5.0 5.1 MUL online data for the Eisenfaust EFT-2 variant
  6. 6.0 6.1 Experimental Technical Readout: Primitives, Volume 3, p. 4 - EFT-2 Eisenfaust
  7. 7.0 7.1 MUL online data for the Eisenfaust EFT-4J variant
  8. Record Sheets: 3085 Unabridged - The Cutting Edge, p. 110
  9. 9.0 9.1 MUL online data for the Eisenfaust EFT-8X variant
  10. Record Sheets: 3085 Unabridged - The Cutting Edge, p. 112
  11. BattleMech Manual, p. 91 Design Quirk Table - Eisenfaust Entry