MAIN SKELETAL STRUCTURE

The central framing skeleton to which all station structures are bonded is a series of separate assemblies comprising the core segments, ring segments, and pylons. Each framing skeleton is an open network of shaped girders making up a tension and compression grid with an average run between geometric interpenetrations of 7.25 meters. Overall, this grid is four times lighter in mass than the integumentary hull plating hung upon it, leading Starfleet engineers to believe that the skeleton acts more as an assembly template than a key load transmitting mass. In fact, vibrational and controlled shock analysis indicates that the joined hull bears most of the stress.
The framing exhibits essentially the same materials and fastening technology for all major assemblies. The Upper Core, Mid Core, and Lower Core manifest materials proportions of 31 percent kelindide, 65 percent rodinium, and 4 percent toranium dicorferite. The Habitat Ring and Docking Ring materials consist of 45 percent kelindide, 43 percent rodinium, and 12 percent toranium. The Docking Pylons and crossover bridges are manufactured from 26 percent kelindide, 70 percent rodinium, and 4 percent toranium. The relative proportions suggest that the ring structures bear less of a load than either the cores or pylons, and assumption that seems to be borne out by all analytical scanning done to date.
The framing girders are all fabricated from directionally crystallized foamed metals using a combination of helium and argon as the void producing agents. The helium and argon are delivered into the alloy furnaces as cryogenic particulate solids, which expand at a controlled rate to create the closed-cell matrix. Shaped magnetic and gravitic field generators shield the solidifying alloys from local environmental conditions, closely duplicating orbital microgravity. Six of the seven alloy furnaces assembled on Bajor were hastily dismantled during the Cardassian pullback from the system, and the remaining furnace is undergoing repairs and upgrades.
Fastening systems for the individual framing members included melt patch guns, gamma-weld torches, and forced matrix gap bonding assemblers. These last devices, also high energy gamma EM based, involved both telerobotic and crewed frame crawlers, which "walked" along grip fixtures on the girders and performed the required welds and plate patches. Inspection runs and fixes were made with individual EVA crews in environmental suits, shuttles, and teleoperated probes. Framing maintenance on the present Deep Space 12 involves deep EM penetrant scans, electron chemical migration tests, and load cell recording. Tests confirm that the basic structure of the station is sound and has accumulated only 10 percent of its approximate operation lifetime of 230 standard years. The percentage of this lifetime will vary, depending on impact, EM, and ion damage sustained in natural celestial events and military action, and relates to established alloy fatigue indices.

EXTERNAL STRUCTURAL SYSTEMS

The primary structural shell of Deep Space 12 varies from section to section in relative abundances of elements and physical configuration. At least thirty alloys are present in the hull plating, but by far the most common ones found in the hull plating, are a simple mix of four: kelindide, polyduranium, rodinium, and toranium. The densest alloys, rodinium and toranium, have been applied to areas of greatest stress, particularly at major directional changes in station geometry. One example is a the interpenetration of the Docking Ring and both Upper and Lower Pylons. Tension and compression computer simulations of Deep Space 12, based on existing sensor networks and Starfleet installed strain gauges, were conducted in mid 2370. The data analysis indicate that the "footprint" area of the pylons receives nearly 70% of its tensile strength from the hull plating covering the transitions from the pylons down to the crossover bridges. This effectively creates an exoskeleton, counter to most familiar construction methods. The internal structure provides on 22%, the remaining 8% being derived from the EPS conduit field effect, which acts as a crude structural integrity field (SIF) system. While some Starfleet engineers have looked upon this area as over designed, it has worked exceedingly well for the Cardassians, especially the pylons' ability damp out lateral and rotational forces imparted by both docking vessels and large moving masses within the pylon.

HULL PLATE MANUFACTURING

The layering process for the original Nor Class hull plating involved the use of large scale allow furnaces, rapid electrohydraulic milling, and high energy plasma coating devices. In some rare instances, focused EM field devices were employed to form complex matrices required for conformal com systems, ion venting surfaces, defensive shield grids, and embedded utilities conduits. At typical hull plate 2.8 meters by 3.7 meters by 37 centimeters was fabricated from a directionally directionally grown, single crystal kelinide core 15.4 centimeters thick. Inboard, the core was built up with six alternating layers of rodinium and toranium, each 2.3 centimeters thick. Machining of plate joints and hull penetrations could take place either at a fabrication site or in space. The location depended on delivery scheduling or special configuration issues in the particular station section receiving the part. Joints were made with microexplosive cording, thermal EM or gamma welding, or a combination of the three. Certain areas, such as the Habitat Ring, received additional focused EM filleting to insure the creation of a single contiguous volume of metal.
Added to most base hull plates was a radiation attenuation layer of polycrystalline ferric diallosillicate infused with carbon 60 macrochains. Any unwanted EM or subspace radiation is temporarily trapped within the carbon 60 and then bled off into space at a known, controlled rate. The use of this type of attenuation layer is certainly unique to Cardassian building methods, though the use of the layer itself is thought to have been gleaned from Starfleet shipbuilding technology. A final micrometeoroid and thermal layer for protection in the Bajor system consisted of 1.7 centimeters of plasma sprayed pyoceramic Tritanium.

INTERNAL STRUCTURAL SYSTEMS

In a comparative study of Cardassian and Starfleet engineering, one would immediately be struck by the significant differences in internal framing and partitioning over all other station elements. The Nor Class builders have relied more heavily on the exterior plating to hold atmospheric pressure than the individual room modules. Few instances have been discovered of total hermetic sealing of habitable spaces, and those volumes are mainly laboratories and hazardous materials storage and use areas. The maintenance of a breathable atmosphere in the common use areas is not, as one might assume, a Criticality 1 issue. In a case of minor hull leaks below 6.5 cm2 (square centimeters), most welds and patches can be applied within two hours without a detectable loss of overall station pressure. Hull plating penetrations or linear separation larger than 6.5 cm2 would have to be produced by weapons fire, explosive devices, or unusually energetic EM events. Specific emergency measures would be taken to counter the pressure loss, including bulkhead knife doors, force fields, and the deployment of damage control teams. The Cardassians had indeed developed the procedures, and subsequent Starfleet protocols have built upon the existing concepts.
Attached to the main skeletal framing of the station are level grids, primary and secondary utilities conduits. At this stage, the final arrangement of work and residential spaces can not yet be visualized by the casual observer, and the volume can be broken down in a number of different ways.
The level grids were fabricated from expanded toranium foam surfaced on top and bottom with rodinium dicorferite sheeting to form lightweight intermediate stiffeners for the major core and ring assemblies. The average grid segment measures 5.3 meters by 6.1 meters by 13.6 centimeters, with conduit and turbolift penetrations cut away only where needed, indicating either that precision matter cutting was utilized on orbit, or that all conduit locations were finalized prior to grid fabrication. The primary an secondary bulkheads were fabricated from toranium foam and facing sheets, but densified to carry high-amplitude vibrational loads through all core, ring, and pylon assemblies. The primary load-bearing bulkheads measure 3.3 meters by 21.1 meters by 53.2 centimeters and are penetrated by conduit, security gates and turbolift passthroughs.
Most of the visible station internal structures, starting from the top down, consist of ceiling modules, partition walls, and floor panel. These three types of surfacing segments produce the required living volumes and work areas for all station activities. The ceiling spaces include EPS user lines, induction lighting devices, com pickups, and airflow ducting. The partition walls, which blend to the level grids by removable melt patches, are by far the heaviest of the three room components and carry EPS lines, active and passive environmental control circuits, and force fields emitter circuits. The floor spaces carry EPS lines, optical data network (ODN) taps, short range force field grid for equipment lashdowns, and station gravity net. The gear lashdowns and gravity net operate through common EPS taps and control circuitry, and provide rapid hold on objects in the event of severe translational motions.
The pedestrian and crew corridor network accesses all major station assemblies. The larger cargo transfer aisles are limited to the Docking Ring and crossover bridges. All involve toranium foam and sheeting construction similar the the level grids and bulkheads, with a maximum wall thickness of 7.37 centimeters. Within the foam are molded micro EPS conduits, com pickups, ODN lines, and security scanning pickups. Continuity between segments is provided by induction node junctions in order to route encrypted signals to their proper destinations. Corridor segments are interrupted at regular intervals by force field arches and knife doors.
Access tunnels run perpendicular to most corridors and service a variety of station systems. The typical access tunnel measures 1.3 meters by 1.4 meters in cross section, and is fabricated by toranium frames and duranium skinning panels. Records indicate that the access tunnels were produced in an automated rapid forming and welding jig on Bajor and shipped by into orbit to be taken to the station. Access tunnels are equipped with standard EPS, ODN, and com monitoring panels, plus specialized maintenance control as required for particular areas. They are effectively shielded from EM interference as well as active scanning beams, making some security functions difficult. The tunnels, similar in function to Starfleet's Jefferies tubes, have been the focus of a uniquely Cardassian problem. Numerous gaps in wall construction have allowed some species of Cardassian vole to elude capture and disrupt EPS service, due to the voles' proclivity for gnawing through live conduits. The total run of access tunnels in the station measures some 18.1 kilometers. Most tunnel hatches are placed under restricted entry protocols, with security systems tied into the corridor ODN lines.

STATION COORDINATE SYSTEM

Recovered computer records dealing with the Nor Class measurement system indicate that few specific external applications were ever necessary once the facility construction was completed. It has been assumed by Starfleet that the simplified set of coordinates and component names were sufficient for all station maintenance and repair operations. Unlike the Starfleet space vessel external reference system, which can occupy 8.65 megaquads of computer memory, the Cardassian system filled an isolinear partition barely 505.43 kiloquads long. A translated Starfleet reference system has been added to all onboard computer systems to aid in coordinate conversions. Both measurement systems are based on the stations average local gravitational vector.
The original external reference system oriented the station on a circle divided into 729.0 tarims, each tarim equivalent to 0.4938 degrees. The zero radius of the commandants main window, at an eye line extending outward exactly 176 centimeters up from the floor. The circumference ticks proceeded around in a counter clockwise direction, as seen in a top plan view, and all construction numbers reflected a subtraction of 60.753 tarims, or 30 degrees, for reasons only hinted at in the Cardassian history. The central line coincides, after the requisite subtraction, with Docking Port 12, not Pylon 1, to the -X direction.
All station hardware coordinates when they were given, were in a variation of standard polar mode, and quite similar to starship bearings and headings. For example, in translated Cardassian notation, the hatch seal at the top of Docking 2 was located at <243+158.42. The < (angle) symbol and first number indicated the azimuth angle reading around the circle, the + denoted the measurement direction above the commandant's eyeline (a - would indicate a negative elevation), and the last number equaled the distance from the origin point to the location desired, measured in Cardassian korshins (1.0 korshins = 2.732 meters). At least three measurement systems exist in the current Cardassian culture; the korshinic system is known to be used in most space-based construction, Reconstructed data alludes to extensive use of EM range finding technology to establish the coordinates, both in virtual computer-driven design and actual manufacturing.
The translated coordinate system has established a modified three-dimensional vertex and vector measuring scheme, with centimeters as its operative value. The three axes are labeled X, Y, and Z. The X axis runs through the station core to Docking Pylon 1, with -X toward the pylon. The Y axis runs dorsal ventral, with the +Y to dorsal, up from Ops. The Z axis runs through the core to the Docking Ring at 90 degrees from Docking Pylon 1, with +Z to the Docking Ring. Planes passing through the station are labeled according to the station axes. The X-Y plane extends vertically and laterally toward and away from Docking Pylon 1, the X-Z plane extends laterally from the Mid-Core/Lower Core interface, and the Y-Z plane runs vertically and bisects the station into +X and -X halves.