Bolo!

MARK VII BOLO (2163):

The Mark VII was a “heavy” Bolo, whose introduction inspired the first use-though still unofficially-of the term “siege unit.” It had the same electronics fit as Marks V and VI, but its main direct-fire armament was one 200mm railgun backed by fourteen heavier (75mm) infinite repeaters. The Mark VII’s heavy missile load was biased towards the bombardment function, but it was equally capable of operating SAMs in the area defense role. This vehicle has a very heavy layered durachrome war hull (120 millimeter) and required a two-man crew, rather than the Mark V’s and VI’s one-man crew, but in the VII/B the second crewman served solely to control the indirect fire armament. In later models, the second position was upgraded to a dedicated air-defense/missile intercept function. Weight was approximately 348 tons in the Model B, with a maximum road speed of 40 kph and a maximum cross-country speed of 30 kph. (The Mark VII was never very fast, but its sheer mass meant most terrain features tended to crumple when it hit them and so did not slow it as severely.)

MARK VIII BOLO (2209):

The Mark VIII was the next-generation “main battle” (or “standard”) Bolo. Main armament remained a railgun, though muzzle velocity increased still further and projectile size fell slightly (to 170mm), but this Bolo marked the first appearance of energy-weapon (laser) infinite repeaters. (By the time of the Mark VIII, any Bolo’s secondary battery had come to be referred to as “infinite repeaters” whether or not they fired actual projectiles.) Although the new laser infinite repeaters were actually marginally less effective than the last-generation railgun infinite repeaters on an energy-transfer-per-hit basis, mass per weapon fell, and the shift meant magazine capacity for the secondary battery was no longer a design factor. Missile capability was limited to the SAM and point defense role, but the Mark VIII received four hull-mounted 150mm rapid fire howitzers to compensate. The VIII/B was fission-powered, with solar charge backup capability, a one-man crew, and a weight of approximately 225 tons. Improved power train and suspension permitted a sustained road speed of 65 kph and short-range “sprint” speeds of up to 85 kph, but maneuverability at high speed was poor.

MARK IX BOLO (2209):

The Mark IX was the next generation “siege” unit, introduced simultaneously with the Mark VIII as companion vehicle. The main battery railgun was suppressed in favor of additional missile power and four high-trajectory 180mm howitzers in two back-to-back twin turrets. Further improvements in electronics allowed the Mark IX, unlike the Mark VII, to be crewed by one man. Weight was approximately 400 tons, and maximum road speed for the IX/B was 57 kph.

MARK X BOLO (2235):

The Mark X saw the first appearance of an energy main armament (laser ca

MARK XI BOLO (2235):

The Mark XI was essentially a backup, designed to cover the possibility that the Mark X’s laser main armament might prove impractical in service. Main armament was one 18cm railgun firing depleted uranium long-rod penetrators in the anti-armor role and a wide range of cluster, incendiary, chemical, and fuel-air rounds against unarmored targets. Otherwise, the Mark XI was identical to the Mark X. This vehicle remained in service longer than might otherwise have been anticipated because the projectile-firing capability of its main gun proved extremely popular with tacticians.

MARK XII BOLO (2240):

This was the first true “continental siege unit,” designed for strategic indirect fire with VLS cells capable of handling missiles with intercontinental range. The Mark XII was capable of MIRVed FROB attacks and of engaging orbital targets with hyper-velocity surface-to-space missiles. Main anti-armor armament was deleted, but the Mark XII was equipped with extremely capable anti-air/anti-missile defenses (in effect, it was an area defense system, as well as a bombardment unit). The vehicle was normally mated with a BAU (Bolo Ammunition Unit), a Mark XII with all offensive armament deleted to provide magazine space for multiple load-outs for the Mark XII’s missile batteries. Although the Mark XII continued to carry a one-man crew, it was primarily designed for pre-loaded computerized battle plans. Weight was 500 tons, with a road speed 50 kph.

MARK XIII BOLO (2247):

The Mark XIII was essentially a Mark XII with main anti-armor armament restored. Although the main gun ate up almost 25 percent of the to

MARK XIV BOLO (2307):

The Mark XIV replaced the never entirely satisfactory laser “main gun” of earlier marks with the far more destructive “Hellbore” plasmagun. This 25cm weapon, originally designed for the Concordiat Navy’s Magyar-class battlecruiser’s main batteries, had a half-megaton/second energy output and, unlike the earlier Bolo laser ca