Thorn (BattleMech)

This article is about the 20-ton BattleMech. For the planetary system, see Thorn (HL).
Thorn (BattleMech)
Production information
Manufacturer Ford Military Limited[1]
Production Year 2490[2][3][1]
Model THE-N[1]
Class Light
Cost 1,653,120 C-bills
Technical specifications
'Mech type Inner Sphere BattleMech
Mass 20 tons
Chassis Chariot Type II Endo Steel
Armor Armorscale with CASE
Engine GM 120
Communications System Opus I Ultrabeam
Targeting Tracking System Orion 80
Heat Sinks 10 single
Speed 97 km/h
BV (1.0) 484[4]
BV (2.0) 546[1][3][5]


The Thorn is a light BattleMech which was originally intended to operate as a scout. When the 'Mech first debuted for the Hegemony Armed Forces in the twenty-fifth century, it was with a great deal of hype that unfortunately the Thorn could never truly match. Critics who look at the Thorn generally see it in one of two ways: as a light 'Mech that is not fast enough for its own good, or a light 'Mech that tries to do a job only a heavier 'Mech should. Looking at the Thorn with neither bias, it is easy to see where these two viewpoints come from; the Thorn is too slow to function in the traditional light 'Mech role of scouting and it does not have the armor or staying power of heavier machines. Facing competition from the Locust, it was only when Ford Military Limited decided in 2549 to rebuild the Thorn with the very latest in technology, including the first-ever use of an endo steel chassis and Cellular Ammunition Storage Equipment, that the HAF renewed their interest. Once in service, the Thorn found its niche as a light 'Mech hunter and infantry support platform, and supporters quickly pointed out the Thorn was, ton-for-ton, superior to most other light 'Mechs in terms of combat power and could reduce an opponent of similar weight to scrap in minutes. This aspect made it very popular for light 'Mech companies expecting heavy fighting and infantry in need of fire support.[2][3][6][7]

The Thorn continued to serve following the creation of the Star League Defense Force, and often fought alongside the likes of similar designs such as Hoplites and Hussars. Unfortunately, the reliance on advanced technology doomed the Thorn when the Star League dissolved and the Succession Wars began. With the orbital manufacturing centers necessary for endo steel production destroyed by the time of the Second Succession War, it became impossible to maintain what Thorns the Great Houses inherited in their original condition. Ford Military was forced to produce the original downgraded version in an attempt to keep the line going, but sporadic production barely kept it alive and by the time the Succession Wars were over the original Thorn could only be found in service to the Com Guards.[2][3]

When ComStar decided to supply the Draconis Combine as part of Operation ROSEBUD the Thorn was among those Star League-era 'Mechs gifted to the DCMS, albeit with all of its advanced technology stripped out. That this necessitated the quite radical approach of rebuilding the 'Mech from the ground up with a standard chassis only highlighted the lengths ComStar would go to in order to maintain its monopoly on lostech. When the Clans invaded it was discovered they had also maintained the Thorn in large numbers, although most were still stored in Brian Caches and reserved for use by solahma troops. The invasion also forced ComStar to begin a hasty rearmament program that included the development of a new variant, the THE-N1. Following the ComStar Schism the Word of Blake was able to seize Terra for themselves and direct the Thorn production line to equip their own military forces for the coming Jihad.[3]

Weapons and Equipment[edit]

The Thorn carries a weapons array that is not usually seen on light 'Mechs: a Zeus LRM-5 launcher mounted in the right arm with one ton of reloads in the right torso, paired with two Hellion Spitfire medium lasers split between the head and left arm. The long reach the LRM launcher provides is necessary, since the Thorn lacks the speed to catch faster light 'Mechs, although it is easily damaged in hand-to-hand combat. In particular, if the reload system is damaged missiles will become lodged in the upper arm, a most dangerous situation, but luckily the launcher can be easily replaced in a few hours. Indeed the entire 'Mech is noted for its ease of maintenance, a factor in ComStar's ability to completely rebuild it later on, with techs able to climb into its limbs to effect repairs on the inside.[6][7]

Four and a half tons of armor provides the Thorn with good protection, especially when mated with CASE to contain any ammunition explosions. The use of an endo steel chassis is what allows the Thorn to carry all of this equipment, a bulky alloy twice as strong as standard materials. The GM 120 fusion engine gives the Thorn a respectable cruising speed of 65 km/h, but the lack of jump jets further compounds its issues with catching other light 'Mechs. Built with the standard number of 10 engine-mounted single heat sinks the Thorn is regarded as a "cool running" design, although the placement of the head laser right below the cockpit makes repeated firings uncomfortable, despite additional cooling systems.[6][7]


  • THE-F 
    The original pre-endo steel model introduced in 2490, the THE-F was replaced with the THE-N model. During the Succession Wars, when the advanced systems of the THE-N were lost, sporadic production of this variant was restarted. ComStar used its blueprints to produce the downgraded THE-S factory refit and, save for different subsystem components, both are functionally identical.[1][3]
  • THE-S 
    Supplied by ComStar to the Draconis Combine as part of Operation Rosebud in 3035, the THE-S was a downgraded factory refit of the THE-N. Stripping out the advanced endo steel chassis and CASE, the use of a heavier standard chassis forced a reduction in the Thorn's armor protection by half a ton, most of which was removed from the head and rear torso. The communications system was also changed to a more primitive Olmstead 30, although the Omicron VII targeting-tracking system was similar in capabilities to the Orion 80 it replaced.[2] BV (1.0) = 445[14], BV (2.0) = 510[15]
  • THE-T 
    Developed in 3038 by the Draconis Combine in an attempt to upgrade the 'Mech's short range firepower prior to the War of 3039, the THE-T is a field refit of the downgraded THE-S that swaps out the LRM-5 launcher for an SRM-4.[2] BV (1.0) = ??, BV (2.0) = 500[16]

Design Quirks[edit]

The Thorn has the following Design Quirk:[17][18]

Notable Pilots[edit]

See Category:Notable Thorn Pilots


  • In German products, the unit's proper name was translated to Dorn. The model code was changed accordingly to DOR-N.



  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Technical Readout: Succession Wars, pp. 12–13: "THE-N Thorn"
  2. 2.0 2.1 2.2 2.3 2.4 Technical Readout: 3039, pp. 240-241
  3. 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 Technical Readout: 3050 Upgrade, pp. 186–187: "Thorn 'Mech Profile"
  4. Combat Operations, p. 129
  5. Record Sheets: 3050 Upgrades Unabridged (Clan & Star League), p. 224
  6. 6.0 6.1 6.2 Technical Readout: 2750, pp. 18–19: "Thorn 'Mech Profile"
  7. 7.0 7.1 7.2 Technical Readout: 3025 Revised, pp. 8–9: "Thorn 'Mech Profile"
  8. Historical: Operation Klondike, p. 159: "SLDF Royal Units - THE-Nb Thorn"
  9. Record Sheets: Operation Klondike, p. 21
  10. Combat Operations, p. 135
  11. Record Sheets: Upgrades, p. 35
  12. Record Sheets: 3050 Upgrades Unabridged (Clan & Star League), p. 225
  13. Record Sheets: 3050 Upgrades Unabridged (Clan & Star League), p. 226
  14. Combat Operations, p. 137
  15. Record Sheets: 3039, p. 63
  16. Record Sheets: 3039, p. 64
  17. BattleMech Manual, p. 95: Design Quirk Table - Thorn Entry
  18. Strategic Operations, p. 193: "Easy to Maintain"