MARK XXV BOLO (Stupendous) (3001):
After forty T-years of experience with the Mark XXIV, even diehards conceded that many of the inhibitory software features which had been incorporated into every Bolo since the Mark XX were no longer justified. The most restrictive features were deleted from the Mark XXV, Model B, although it was not until the Model D (introduced in 3029) that virtually all inhibitions were suppressed. A core package of override programming was retained to restrict the volition of (or even, in the case of the so-called “Omega Worm,” to destroy) a Mark XXV which went “rogue” as a result of battle damage or “senile” due to poor maintenance, but most of the restrictions which had required human approval for almost all non-battle decisions were progressively relaxed over the operational life of the Mark XXV, with a tremendous increase in efficiency. The practice of deploying totally independent Bolo brigades lay well in the future, but the Mark XXV’s capabilities clearly pointed the way to them. The Mark XXV essentially duplicated the offensive and defensive systems of the Mark XXIV, yet further improvements in metallurgy and fusion technology dropped weight to 13,000 tons while normal speed rose to a maximum of 95 kph, though “sprint” speed remained unchanged.
MARK XXVI BOLO (Monstrous) (3113):
The Mark XXVI was the first Bolo to incorporate improved “hyper-heuristic” features based on the work of Major Marina Stavrakas. Armament, size, weight, and speed remained largely unchanged from the Mark XXV, but the Mark XXVI was capable of constructing a “learning model” in accelerated time. In some ways, this almost equated to precognition, in that the Mark XXVI could project changes in an enemy’s tactical or strategic actions before even the enemy realized he intended to change them. The new systems also meant that, accompanied by a much improved ability to break hostile communications security, a Mark XXVI could actually invade an opponent’s data net, access his computers, scan them for useful data, and (in some cases) even implant its own directions in those computers.
MARK XXVII-MARK XXIX BOLOS (3185-3190):
The Mark XXVII (Invictus), XXVIII (Triumphant), and XXIX (Victorious) marked a temporary reversion to the older practice of assigning mark numbers on the basis of armament and function rather than psychotronics technology. All three had essentially identical cybernetics, which concentrated on further improvements to their hyper-heuristic packages, but the Mark XXVIII and XXIX also incorporated a complete changeover to molecular circuitry throughout, aside from the power linkages to their energy armaments. All three of these marks were used in the new, independent brigades which replaced the old regiment structure of the original Dinochrome Brigade, but, in some ways, the units marked a reversion to the old “specialist” designs. All mounted the new 110cm “super” Hellbore (2.75 megatons/second), but the Mark XXVII was a “light,” fast Bolo, with greatly reduced secondary armament, limited indirect fire capability, and a vastly improved sensor suite, intended to serve in a scouting and screening role for the independent brigades. (This function had been performed by light manned or unmanned vehicles, and the old Mark XXI/I, with psychotronic upgrades, remained in service for special forces applications. The new strategically self-directing Bolo brigades, however, required an integral scouting element, one not limited by “stealth” considerations and capable of fighting for information at need.)
The Mark XXVIII was the “generalist” of this trio of marks, with much the same armament as the old Mark XXIV, although that armament was even more deadly and effective under the control of the improved psychotronics of the newer units.
The Mark XXIX was an unabashedly “heavy” Bolo—indeed, it remained the heaviest Bolo ever deployed prior to the Mark XXXIII. It reverted to the twin Hellbore armament of the Mark XXIII (though still in 110cm caliber), coupled with a much enhanced indirect fire capability, and an integral logistics/maintenance function which it could extend to other units of the brigade. (The maintenance/repair function became standard in all succeeding Bolo designs.) The independent brigades normally consisted of four regiments of three 12-unit battalions each: one of Mark XXVIIs, two of Mark XXVIIIs, and one of Mark XIXs. Weights for these Bolos were 11,000 tons (maximum normal speed 110 kph) for the Mark XXVII, 15,000 (maximum normal speed 90 kph) for the Mark XXVIII, and 24,000 (maximum normal speed 75 kph) for the Mark XXIX.
MARK XXX BOLO (Magnificent) (3231):
Introduced on the eve of the Human-Melconian “Last War,” the Mark XXX was the direct descendant of the Mark XXVIII. The incorporation of counter-grav into the Mark XXX’s suspension and power train went far towards offsetting the mobility penalties increasing weight had inflicted on preceding generations. The Mark XXX incorporated still further improvements to the hyper-heuristic capabilities of the Marks XXVII-XXIX, new dual-ply battle screen (which was not only more effective against kinetic weapons but also capable of absorbing at least some of the power of almost any energy weapon and diverting it to the Bolo’s use), and a new and improved cold-fusion power plant. Weight dropped from the Mark XXIX’s 24,000 tons to 17,000 and normal speed increased to 115 kph. For very short intervals, the Mark XXX could divert sufficient power to its counter-grav units to achieve actual free flight at velocities up to 500 kph, but could not operate its battle screen or internal disrupter shields or fire its main armament while doing so.
MARK XXXI BOLO (3303):
Over the course of the thirty-third century, the galaxy slid with ever increasing speed into the maw of the “Last War’s” gathering violence, and Bolos after the Mark XXX did not receive the “type” names which had become customary with the Mark XV. The Mark XXXI was an enhanced Mark XXX with a main armament of one 200cm Hellbore (5 megatons/second). Secondary armament, though still referred to as “infinite repeaters,” consisted of two lateral batteries of six 20cm Hellbores each, and many small-caliber, hyper-velocity projectile weapons were retained for close-in defense and anti-personnel use. Indirect fire capability was degraded in favor of the assault role, for which purpose the Mark XXXI’s duralloy war hull was given an average thickness of 90 centimeters, rising to 1.5 meters for the glacis and turret faces. All secondary and tertiary weapons were mounted outside the “core hull” which protected the Mark XXXI’s power plants and psychotronics, and last-generation internal disrupter shielding was used heavily. The Mark XXXI retained the counter-grav assist of the Mark XXX and, despite a weight increase to 19,000 tons, could match the preceding mark’s speed.
MARK XXXII BOLO (3356):
The last Bolo whose year of introduction is known with certainty, the Mark XXXII was essentially a Mark XXXI with the added refinement of direct human-Bolo neural-psychotronic interfacing. Provision was also made for attachment of a counter-grav unit sufficient, under emergency conditions, to permit the Bolo to make an assault landing without benefit of transport. Offensive and defensive systems were comparable to those of the Mark XXXI. The Mark XXXII was the final version of the “standard” Bolo.
MARK XXXIII BOLO (?):
The last—and largest—Bolo introduced into service. The Mark XXXIII weighed no less than 32,000 tons and mounted a main armament of three independently-turreted 200cm Hellbores with a secondary armament of sixteen 30cm Hellbore infinite repeaters in two lateral batteries. Equipped with a very sophisticated indirect fire system, the sheer firepower of the Mark XXXIII was a reversion to the old siege unit thinking, though it was normally referred to as a planetary siege unit, not merely a continental one. No one knows how many Mark XXXIIIs were actually built, but official planning called for them to be deployed in independent brigades of 24 units each. Despite the increase in weight, speed remained equivalent to the Mark XXXI, and the Mark XXXIII’s internal counter-grav could supply the assault landing capability for which the Mark XXXII had required an auxiliary unit.
Bolo Armament
Bolo Mark
Year
Weight
Road Speed
Sprint Speed
Main Armament
Secondary Armament
Indirect Fire
Self-Aware?
Mark I
2000
150
80
80
1 150mm DSFSLRP
point def/AP gatlings
None
No
Mark II
2015
194
80
80
1 150mm DSFSLRP
4 InfRpt railguns
None
No
Mark III
2018
300
50
50
1 150mm DSFSLRP
8 InfRpt railguns
Tac/Theater
No
4 155mm howitzers
Light VLS missile system
Mark IV
2116
210
60
60
1 165mm railgun
6 InfRpt railguns
Strategic
No
VLS missile system
Mark V
2160
198
80
80
1 190mm railgun
12 60mm gatling InfRpt
None
No
Mark VI
2162
238
80
80
Heavy VLS missile system
14 60mm gatling InfRpt
Strategic
No
Mark VII
2163
348
40
40
1 200mm railgun
14 75mm gatling InfRpt
Strategic
No
VLS missile system
Mark VIII
2209
225
65
85
1 170mm railgun
12 laser InfRpt
Tactical
No
4 150mm howitzers
Mark XIX
2209
400
57
57
VLS missile system
12 laser InfRpt
Strategic
No
4 18cm howitzers
Mark X
2235
350
70
70
1 laser cannon
12 laser InfRpt
None
No
Mark XI
2235
350
70
70
1 18cm railgun
12 laser InfRpt