Updated: Apr 22, 2021
From the mid-cycle of 1792 F.D.S to late 1793, a series of crushing defeats in the Tempest Campaign of the Radacri Wars, would see the once mighty UTN Federal Navy all but decimated, and mark the turning point of the war; when UTN Military commanders started to realise the war could not be won.
This is Part 2 of a series on the Battle of Montes Lumen.
Radacri Hive fleets approach
The one-hundred twenty warship strong UTN Fleet faced the largest Radacri Hive fleet ever recorded in the War. Known to UTN Naval Command as 'Radacri Core Hive Fleet Alpha', estimates to the size of the mass of organic biowarships numbered between on thousand and two thousand individual vessels, similar in size to the entire arsenal of the Federal Navy at the beginning of the war. Some three hundred of which were of sufficient mass to be considered 'Capital Ships'.
The main force was flanked by two smaller Radacri hive fleets, whose trajectories placed them on arrival in two nearby Solar Systems, Montes Ignis to G-South, and Tempest Sigma to G-North. However, the entire force would have to pass through the Montes Lumen system's gravity well; the ideal place for the Federal Navy to stage a defensive action.
Contact - 0331 (Local System Time)
Approximately three local system hour cycles after the UTN's 2nd Expeditionary Fleet arrived in Montes Lumen, the ORP-7 installation orbiting super gas giant 'Montes Lumen BD-1A' detected space-time distortion signatures at extreme range, approximately three million KL from the platform, which rested in high geo-stationary orbit over BD-1A. Admiral Urich, who had already assumed command of all Federal Navy assets in the system, effectively now the acting Sector General, had predicted first contact in almost the exact location; owing to earlier encounters with the alien hive species and their tendency to attack head-on.
A direct assault on the ORP was considered extremely likely. SDS (Space Density Distortion) Ranging Sensors calculated the bulk of the Radacri force would make visual (and thus, action) range in approximately an hour cycle, LST. The Radacri force was cruising at unusually high speed towards the passage through the Montes Lumen ice-fields. It was considered likely that the alien forces would use BD-1A's immense gravity well as a slingshot to accelerate their approach to open space beyond the ice barrier; were they could enter Subspace and bypass the Federal Navy's defensive position.
Admiral Urich ordered two of the three CCH divisions into a line-abreast pattern, flanking both sides of the ORP off to about two thousand KL on either side. The standard line-abreast pattern for Vengeance-class Ship of the Line was a wall, six vessels long, three tall, with a single vanguard behind the line accompanied by the division's command ship, in this case an 1.2-million ton Endeavour S3A-class battlecruiser (CB).
The remaining CCH and Carrier division and escort, the former of which was Heavy Cruisers down, including the stricken Vengeance-class UTNS 'Katoruma', remained in reserve (but still within main-battery range) of the other two formations.
First Action - 0412 (Local System Time)
Smaller Radacri bioships broke off from the main formation and entered a hypercruise towards Urich's two forward cruiser divisions around 0400 LST. Since the bulk of the main alien force was well within short-range high-resolution sensors, the UTN Fleet was well aware in advance of the manoeuvre, with the aliens not seemingly taking any measures to conceal their action.
First action occurred around 0412 LST. Under orders from the Admiral, the vanguard of the two forward CCH divisions fired Long Range Concussive Torpedoes with timed area-burst detonation configuration about 1000 KL ahead of the approaching alien fleet. The two Phoenix-LRM3 missiles detonated at approximately 0418 LST, disrupting the alien hypercruise and dropping an estimated 100 to 150 light warships into weapons range of the main force. Trajectory estimates placed the larger Radacri force about three local system hour cycles behind the smaller force. This played directly into Admiral's Urich's plan to use the UTN fleet's firepower to wear down the alien forces over time, trapping them in the natural chokepoint near BD-1A.
Urich's cruiser divisions opened fire with their main batteries using Concussive Blast ammunition in a broad-side, staggered action with the top most vessels discharging first, followed by the mid, then the lower, allowing times for the warships to reload their magazines. The first salvo found its mark moments later as the 770 mm mass driver ammunition detonated within a klick of the approaching alien vessels, which were almost entirely destroyed. Concussuve Space-Burst ammunition using a high-explosive Hydrogen-Helium Fusion warhead encased in series of tungsten alloy shells with depleted uranium pellets between each layer.
Initially, Urich expected that the alien force would spring the trap and take heavy losses before the larger vessels entered weapons range, but the Radacri fleet soon adjusted its approach to counter the barrage. Vengeance-class heavy cruisers recorded approximately 100 confirmed kills on Radacri vessels of around frigate class, and at least two dozen destroyer-sized vessels - while taking no losses. However, the smaller Radacri force slowed its approach into the BD-1A straight, and instead broke into two smaller formations just outside the effective range of Urich's cruisers' main batteries.
At this point, the bulk of the heavy Radacri force was almost within weapons range. Predicting that the aliens were preparing to bring in their capital-sized vessels, Urich ordered the two line-abreast formations of Vengeance-class cruisers into a stand-off formation with their primary armament of 1280 MM SMRG Siege cannons facing towards the alien formations. They completed this by spinning on their axis using lateral thrusters. Despite the fact that the 1280 MM SMRG's effective range was well beyond the smaller Radacri forces, Urich ordered her cruisers to hold fire, waiting for the aliens to make the first move, as it wasn't believed that the Radacri had stand-off range weapons themselves.
Continued in Part 3.