This article is about the BattleMech. For the EPUB anthology, see Onslaught: Tales from the Clan Invasion.

Production information
Manufacturer Solaris Arms
Production Year 3062[1]
Model SA-OS2
Class Heavy
Cost 20,046,687 C-bills
Technical specifications
Mass 75 tons
Chassis Endo Steel
Armor StarGuard III with CASE
Engine 375 XL Fusion
Speed 86 km/h
Jump Jets Standard Jump Jets
BV (1.0) 1,388
BV (2.0) 1,693[2]


A Solaris VII BattleMech, the Onslaught was originally designed as a technology testing platform. Approximately one hundred of these 'Mechs were built. A capable heavy BattleMech, the original Onslaughts most noticeable feature was its high speed. Its cruising speed of 58 km/h was more commonly seen on medium 'Mechs. The Onslaught's limited numbers and ease of maintenance has led to a situation where many damaged Onslaughts are used as the basis for a FrankenMech. Solaris Arms offers an upgrade package for owners of the original Onslaught design which can bring it up to the SA-OS2 standard.[3]

Weapons and Equipment[edit]

The Onslaught is armed with an experimental SA Light AC/5 and an experimental SA Large X-Pulse Laser as its main armaments. This is backed up by six Voelkers 200 Machine Guns and two SureShot Mk VIa SRM-6 launchers.


  • SA-OS1 
    This is the original version of the Onslaught. It was protected by only 12 tons of armor and was armed with an Ultra AC/5 in place of the SA-OS2's Light AC/5 and carried an ER Large Laser in place of the Large X-Pulse Laser. BV (1.0) = ??, BV (2.0) = 1,562[4] Note: The original design, called SA-OS, used a Large Laser in place of the Extended Range model.[5]


  1. MUL online date for the Onslaught
  2. Record Sheets: 3055 Upgrades Unabridged, p. 268
  3. Technical Readout: 3055, p. 164
  4. Record Sheets: 3055 Upgrades Unabridged, p. 267
  5. Solaris VII: The Game World 'Mech record sheets, p. 14
  6. Record Sheets: 3055 Upgrades Unabridged, p. 269