- This article is about the MCY series of 20-ton BattleMechs. For the variants of the 40-ton Hermes II BattleMech, see Hermes II#Variants.
|Manufacturer||Mitchell Vehicles |
|Communications System||DataTech 401|
|Targeting Tracking System||Skyhunter IV|
|Speed||129.6 km/h (172.8 km/h with MASC)|
The Mercury debuted for the first time in 2742, intended as a replacement for the aging Wasps and Stingers in use by the Star League Defense Force. Hailed as the beginning of a new age in 'Mech design, the Mercury was faster and better-armed than its competition without sacrificing armor protection. It also featured an advancement in weapons installation, making use of a modular replacement system to allow for easier repairs. The ideal scout and raider, sales of the Mercury were limited exclusively to the SLDF. After the Amaris Civil War and the dissolution of the Star League, those SLDF units which still fielded the Mercury were either stationed on Terra or at the Graham IV factory, all of whom left with General Kerensky in the Exodus.
In the Succession Wars which followed, the Mercury factories were destroyed and the design teetered on the edge of the abyss. Of those SLDF units which stayed behind, the 3rd Regimental Combat Team had the highest concentration of the 'Mechs, with twelve Mercury's gathered together in the 8th Recon Battalion. All of them were ultimately lost during fighting on Sendai in 2798. As the years wore on those desperate few Mercuries still clinging to existence were increasingly rebuilt in haphazard fashion with less advanced and more shoddy parts until they ceased to look quite like the noble 'Mechs they once were. In the end nothing could be done to stop the decline of the Mercury and it eventually became extinct in the Inner Sphere.
It was with some surprise that ComStar unveiled their Com Guards early in the thirty-first century, a brand-new military force fielding a number of extinct designs such as the Mercury. Precentor Martial Anastasius Focht even went so far as to restart three of the mothballed Mercury production lines on Terra to resume production of the original model. A new variant, the MCY-97, was unveiled in time to meet the Clan Invasion (the Clans had also preserved the Mercury, and indeed its revolutionary design was responsible for their development of the OmniMech). One of these lines was eventually turned over to making the Nexus in 3054 while the rest continued to produce so many Mercuries that the 'Mech's life was extended for several more years. This included the dark years of the Jihad, when the Word of Blake also used the Mercury to outfit their Militia.
Weapons and Equipment
The Mercury carries an assortment of energy weapons which helps to extend its endurance on long campaigns. The primary weapons are two Martell Medium Lasers in the right arm and left torso. The right arm laser's power supply is spread across the length of the whole arm with multiple redundant systems, while the torso-mounted laser is clustered tightly in one area to decrease the chance of a penetrative hit damaging the system. These are supported by two Hessen Small Lasers in the center torso and head and feature the revolutionary modular replacement system. Using 'plug and fight' technology the lasers are bolted down and connected by wiring to the power feeds and cooling system in three places. If any part of the weapon is damaged or destroyed technicians can replace the entire system in minutes, cutting back countless man-hours of repair and maintenance.
The heart of the Mercury is its MASC System which, in combination with a LVT 160 fusion engine, allows for momentary bursts of speed up to 172 km/h. Though long-term use can damage the actuators these bursts are often the difference between life or death in some cases. They also make up for the fact that the 'Mech lacks any jump jets, while three tons of Ferro-Fibrous armor gives it superior protection compared to other 20-ton 'Mechs.
- This variant of the Mercury was created by ComStar in 3049 for recon duties. The armor, engine and MASC system are kept and one medium laser and one small laser have been dropped in favor of a Beagle Active Probe, giving the MCY-97 Mercury superior enemy detection capabilities at the cost of half of its firepower. Though an excellent scout this variant was largely discarded after the Battle of Tukayyid on account of insufficient firepower. BV (1.0) = 380, BV (2.0) = 466
- This variant of the Mercury is the downgraded version introduced during the Succession Wars in 2810. While it retains the same armament and engine of the original, the primary changes in the 'Mech is its armor, using standard plating in place of Ferro-Fibrous, and the MASC system, which has been removed to allow for the armor to be one ton heavier. These changes lower its maximum speed to 129.6 km/h and slightly increases the overall armor protection. It also features a Datacom communication system and Scarborough Track targeting system. BV (1.0) = 484, BV (2.0) = 553
- The MCY-102 is an upgrade to the Mercury introduced in 3067 by the Word of Blake. This variant retains the engine, MASC, and armor of the MCY-99 but carries two major modifications. The first is the rebuilding of the chassis using Endo Steel. The change in the chassis construction and removal of one small and one medium laser allows for the second modification: the installation of an Improved C3 Computer, making it capable of operating with five other units in a C3i unit. Both of the remaining lasers were also changed out for extended range models. BV (1.0) = 408, BV (2.0) = 510
- An upgrade fielded by the Word of Blake during the Jihad in 3069, the 104 uses an XL Engine for power. This allows the addition of an extra ER Medium Laser and TAG to the 102, with the remaining ton going into improving the armor coverage. The heat sinks are not upgraded, however, so this Mercury could find itself in heat trouble. BV (2.0) = 683
- Mercury II - The Mercury II was an enlarged and updated design of the Mercury produced by Clan Wolverine. This 'Mech lacks its predecessor's unique modular repair system, being a standard post-SLDF/early Clan era BattleMech. 
- Coyotl - The Coyotl continued the original Mercury's legacy of technological advancement, developing its modular repair system into a fully modular hot-swapping system, leading to the Omnimech.
- Technical Readout: 2750, pp. 16-17, "Mercury 'Mech Profile" Cite error: Invalid
<ref>tag; name "TRO2750" defined multiple times with different content Cite error: Invalid
<ref>tag; name "TRO2750" defined multiple times with different content
- Combat Operations, p. 106
- Technical Readout: 3050 Upgrade, pp. 184-185, "Mercury 'Mech Profile"
- Record Sheets: 3050 Upgrades Unabridged (Clan & Star League), p. 221
- Technical Readout: 3025 Revised, p. 6-7
- Technical Readout: 3039, p. 238
- Technical Readout: 3050 Upgrade, p. 184-185
- Combat Operations, p. 123
- Record Sheets: 3050 Upgrades Unabridged (Clan & Star League), p. 220
- Combat Operations, p. 121
- Record Sheets: Upgrades, p. 34
- Record Sheets: 3050 Upgrades Unabridged (Clan & Star League), p. 222
- Record Sheets: 3050 Upgrades Unabridged (Clan & Star League), p. 223
- Jihad Secrets: The Blake Documents, p. 148