As quoted from Mechwarrior 4: Mercenaries...

CLASS: Inner Sphere Assault

ARMOR TYPE, TONNAGE: Ferro Fibrous, 18.0

INTERNAL STRUCTURE: Standard

MAX SPEED (KPH): 51

GROSS TONS: 100

WEAPONS:

    Sm Laser (3)
    PPC (2)
    LRM 15
    Gauss Rifle

COMPONENTS: ECM, LAMS, IFF Jammer

JUMP JETS: No

FIELD NOTES: The original Star League designed the Atlas to ensure the superiority of its regular army over the growing armies of the House Lords. General Aleksandr Kerensky, Star League supreme commander, called for a ’Mech "as powerful as possible, as impenetrable as possible, and as ugly and foreboding as conceivable, so that fear itself will be our ally." The result was the ideal brutal-assault ’Mech, carrying more armor than any other ’Mech, capable of slugging it out with the best the enemy can throw at it.