From Bravo Fleet Infobase
Primary Frame Work
The primary frame work is composed of interlocking tritanium/duranium microfilament truss frames. These trusses are 1.37 m2 in cross section and are spaced an average of every 25 meters across the ships exterior. The spacing between the primary frame trusses is reduced in areas of the space frame that are prone to high levels of stress such as around the impulse engine mounts. A series of smaller trusses 0.53 m2 in cross section are located ever five meters on average and also proved internal supports within the deck and core of the space frame.
A parallel series of aluminum crystalfoam stringers are phase-transition bonded to the primary trusses. These proved low-frequency vibration attenuation across the main truss structure as well as supports for utility conduits. Also, attached to these stringers are various devices built into the hull structures. This includes elements of the deflector shield grid and subspace antennas.
The exterior hull substrate is joined to the primary load bearing trusses by means of 4.8 cm diameter electron-bonded duranium pins at 1.25 meter intervals. Theses pins are slip fitted into an insulating AGP ceramic fabric jacketed to provide thermal insulation between the space frame and the exterior hull. The pins, jacket and hull segments are gamma-welded together.
Secondary Frame Work
Mounted to the primary frame work is a secondary frame work of microextruded terminium trusses. These trusses are mounted by 3.2 cm diameter by 5.1 cm long semirigid polyduranide support rods. This permits a limited amount of mechanical isolation from the primary space frame for strain relief along with sound and vibration isolation. The secondary frame work trusses segments are mechanically attached to each other to allow replacement of inner hull segments and associated utilities infrastructure during a layover at a Star base or other repair facility.
The internal hull is mounted to the secondary frame work by the use of the same duranium pins used to secure the exterior hull to the primary space frame. The molybdenum-jacketed wave guides used to distribute the energy for the Structural Integrity Field is mounted to the secondary space frame.