Ramilies built

Fleet Base Metis does not orbit any of these worlds, instead following an orbit amongst the outmost asteroid ring. Imperial strategists cunningly calculated the placement of the station so the approaches are limited by the surrounding field, and several seemingly accessible approaches are covered by minefields and macrobattery emplacements built into the larger rocks. The shifting orbital paths of the asteroids, coupled with the formidable perimeter defences and Battlefleet warships on station, make simply approaching the Fleet Base an onerous task. Even if a foe could reach Metis, they may well find themselves outclassed by the firepower the station can bring to bear. The base itself is an extremely powerful bastion—a Ramilies-class star fort. Originally designed by Artisan Magos Lian Ramilies from STC components, the Ramilies is as heavily armed as a squadron of warships and can remain self-sufficient for decades if not indefinitely More importantly, a Ramilies can erect a warpbubble over the entire structure, enabling it to enter the warp and be towed by fleets of tugs to different star systems. Originally commissioned for the Crusade into the Jericho Reach, Fleet Base Metis was towed to System 028-3B8-4D in preparation for transport through the warp gate. However, lastminute studies of the gate and its properties by the senior magos of the Adeptus Mechanicus determined it would not survive the journey. Transit through the gate is extremely turbulent, too much so for an unwieldy convoy of tugs and supply ships towing an unwieldy star fort. Unfortunately, just passing through the Maw had proven extremely dangerous for the procession, and the risk of taking Metis back into the Calixis Sector was deemed too great. After the strategists who suggested using Metis in the Crusade had been punished for incompetence, the massive star fort was left in System Designate 028-3B8-4D, where it was reassigned to Passage Watch 27 Est almost by default. Since its accidental arrival, Metis has proved incredibly useful to the Crusade and Battlefleet Koronus. Not only is it a vital resupply and staging point for Horne’s fleet, it also serves as a transit point for a large portion of the supplies still flowing through the warp gate to the Jericho Reach. Although some ships travel directly to the gate, many others off-load their cargos at Metis and depart, never knowing the ultimate destination of their supplies. In turn, other ships make a continuous run through the warp gate to the fortress worlds on the far side.
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Fleet Base Metis, like all Ramilies-class Star Forts, is an extremely powerful adversary. The station is divided into four “quadrants,” each able to be sealed from the others and capable of fighting as near independent entities. Each quadrant is heavily armed with multiple long-range lance turrets and macrocannon broadsides rivalling the strength of a Navy cruiser, as well as multiple launch bays for attack craft. The four quadrants surround a central bastion, itself heavily armed with additional weapon batteries and torpedo silos. Though the most prominent portion of Fleet Base Metis is the Ramilies at its heart, in the decades since its arrival a number of smaller installations have grown up around it. These include several space docks, over a score of orbital supply depots, several hab-installations dedicated to food production, and a number of auxiliary weapon platforms for defence. Each share a close orbit with the Star Fort, as to never be outside the protective reach of its guns. Though it does not have facilities to construct new ships, Metis can repair any warship in Battlefleet Koronus

Rogue Trader: The Koronus Expanse