Category: [TECHNOLOGY]
Type: [Engineering Standard, Starship Structure, Yard Practice]
Canon Tier: Tier 2 (Expanded Universe; pending Council review)
Tags: [NEW-TECH] [NEW-INSTITUTION] [PLOT-DEVICE]
Every Terran Sphere ship below capital size is a stack of segments on a spine, with radial modules bolted to standard sockets around it. The segments, hatches, sockets and network couplings follow one family of standards sorted into four size classes (S, M, L, XL). The yard standard that nearly everyone builds to is the Common Pattern [NEW-INSTITUTION]: a public-domain set of module drawings, kept by the Engineers’ Guild and printed at any yard from sealed blueprint cartridges. Because the sockets, hatches and couplings are standard, a captain can swap a sensor mast, an RCS quad or a whole cargo bay in a day, and a stranger’s wreck can often be cannibalised to keep a friend’s ship flying. This page is the reference for those standards. The functions of individual modules live on their own pages: Brightwing ICF Drive, RCS Thrusters, Comms Array and Sensor Masts.
Size classes. The class is set by the hull diameter; the mass range is the usual span, not a hard limit.
| Class | Hull diameter | Socket sizes carried | Usual mass | Axial hatch (clear) | Typical craft |
|---|---|---|---|---|---|
| S | 4 m | S | 10-150 t | 1.2 m | Skiffs, tenders, interceptors (Skua, 30 t), landing craft |
| M | 6-8 m | S, M | 150-1,000 t | 1.6 m | Couriers (700 t), escorts, corvettes |
| L | 10-16 m | S, M, L | 0.5-5 kt | 2.4 m | Freighters, heavy escorts |
| XL | by design | all | capital | by design | Atlas-class torchships |
A larger socket accepts a smaller module through a plain adapter ring, never the reverse. The largest stock S radial module is the UniPod clamp set, with a footprint of 2.0 × 2.0 m.
Grid and frames (all classes).
| Item | Standard |
|---|---|
| Grid | 1 m, with a 0.5 m sub-grid; axial segment lengths are multiples of 2 m |
| Ship frame | +Y is the bow (the thrust direction); +Z is dorsal; +X is starboard |
| “Down” under thrust | Aft (−Y). Decks are discs perpendicular to the spine |
| Axial origin | The aft face centre of each segment |
| Radial origin | The socket point on the hull, with +Y along the outward normal |
| Azimuth | 0° dorsal, 90° starboard, 180° ventral, 270° port (clockwise looking from the stern forward) |
| Socket label | s{station}_{azimuth}, e.g. s2_180 is the second station, ventral |
| S-class socket stations | 1 m and 3 m from the aft face on a 4 m segment (1 m on a 2 m segment); azimuths 0/90/180/270. The drive offers four sockets at 45/135/225/315° |
Access.
| Item | S-class value |
|---|---|
| Axial hatch | 1.2 m clear, on the spine axis, at both ends of every pressurized segment |
| Keel ladder shaft | Runs through the hatches of all pressurized segments; the deck annulus around it is $(4.0 - 1.2)/2 = 1.4$ m wide |
| Unpressurized segments (tank, drive) | EVA crawlway only; no pressurized passage |
| Collar and airlock | One airlock segment (2 m, cycle 40 s, ventral EVA hatch) hosts the dorsal docking collar (CP personnel collar, ISO-50 lineage, latch 10 s) |
Network couplings. Four networks run the length of the spine and tap into every segment:
| Network | S-class standard | Notes |
|---|---|---|
| Power | Superconducting DC bus, rated to the drive’s power-mode output ($1.5 \times 10^8$ W; 15 kA at 10 kV) | House loads step down through local converters |
| Heat | Heat-pipe loop in the microlattice | Feeds the radiator sockets; see Thermal Control Suite |
| Fluids | Reaction mass, capsule magazine, RCS water, coolant | Quick-disconnect lines; each tank labels its contents |
| Data | Four channels at 1 Gb/s | Each channel is far below the grey line (10 Gb/s per channel) and the trunk is far below the wildcode threshold (20 Gb/s); flight computers sit below the Grey Line |
A destroyed or severed segment cuts every network downstream of it: lose a tank section and the cab behind it loses the bus, the loop and the trunk.
Common Pattern S-class catalogue (mass is dry; all figures are the stock module):
| Module | Mount | Mass (t) | Power (kW) | Role |
|---|---|---|---|---|
| Micro-torch drive | axial, 6 m | 9.5 | −50 | 150 kN, Isp 10,000 s; +150 MW$_e$ power mode |
| Tank segment | axial, 4 m | 3 | −0.5 | 18 t reaction mass, 40 kg capsules, 3 t RCS water |
| Airlock segment | axial, 2 m | 2 | −2 | EVA and boarding |
| Cockpit cab | axial, 4 m | 6 | −15 | Helm and astrogation, 2 seats |
| Hab pod | axial, 4 m | 7 | −25 | 2 berths, closed-loop life support |
| Cargo bay | axial, 4 m | 4 | −1 | 30 m³ and 12 t |
| Nose cap | axial, 2 m | 0.8 | 0 | Structural closure |
| RCS quad | radial | 0.25 | −0.5 | Four 6 kN nozzles |
| Comms array | radial | 0.2 | −2 | See Comms Array |
| Sensor mast / survey mast | radial | 0.3 / 0.5 | −3 / −6 | See Sensor Masts |
| Radiator panel (Vari-E) | radial | 0.4 | −0.2 | 16 m² two-sided, 94 kW at 600 K and ε = 0.8 |
| Docking collar | radial | 0.6 | −0.5 | Requires an access segment |
| PDC turret | radial | 1.2 | −20 | Point defence |
| Drone bay | radial | 1.5 | −2 | One scout drone |
| UniPod clamps | radial | 0.5 | −0.5 | One 40 t UniPod-120 |
| Landing leg | radial | 0.2 | 0 | Fitted as a set of four |
Outfitting limits for S-class starters (the yard’s acceptance test):
| Check | Limit |
|---|---|
| Generation / nominal load | ≥ 1.2 |
| Radiator rejection (at ε = 0.8) / steady heat | ≥ 1.3 |
| Hotel load on battery with the drive off | ≥ 2 h |
| Main thrust / wet mass | ≥ 2.5 m s⁻² |
| Weakest RCS translation, wet | ≥ 0.4 m s⁻² |
| Weakest RCS rotation, wet | ≥ 5° s⁻² |
| Centre of mass off the thrust axis | ≤ 0.15 m |
Worked example (utility skiff). Drive, tank, airlock, cab and nose make an 18 m stack ($6+4+2+4+2$); a hab pod or cargo bay makes it 22 m. With eight RCS quads, collar, comms, one sensor mast and two radiators the dry mass is 25.2 t, and with 21 t of fluids it is 46.2 t wet. Steady heat is 77 kW (drive module 50 kW), so 1.3 × 77 = 100 kW needs two radiator panels (188 kW at ε = 0.8; one gives only 94 kW). The cab’s 1 GJ store carries a 27 kW hotel load for $10^9 / 2.74 \times 10^4 \approx 3.6 \times 10^4$ s, about 10 h. Thrust is $1.5 \times 10^5 / 4.62 \times 10^4 = 3.2$ m s⁻² (0.33 g).
The thrust axis is the ship’s one reliable gravity. A ship under the standard 0.3 g burn has a floor that faces the engine, so the Common Pattern makes every deck a disc perpendicular to the spine, and every pressurized segment shares the same hatch on the axis. A runner climbs forward through the keel ladder shaft under thrust and floats through it in free fall; the rungs are on a 0.3 m pitch and the handrails are rated for a Flex-Rig glove. Because the hatch is on the axis and the deck is an annulus around it, the same ladder runs from cab to airlock on every S-class ship and a crew from one ship can find the airlock of another in the dark.
Tanks and drive segments carry no walkable interior. A crawlway, 0.8 m across, runs along the tank wall for EVA repairs, and the drive is serviced from outside.
The Common Pattern [NEW-INSTITUTION] is a public-domain set of module drawings and toolpaths first published by the Engineers’ Guild (Yard Hall, Callisto L-1; see Guilds of the Sphere) so that no yard could hold a colony hostage with a proprietary bolt pattern. It is distributed on sealed, write-once blueprint cartridges: passive crystal-memory rods with no live code, and so nothing for wildcode to inhabit. A yard with a Zero-G Shipyard Dock, a Foundry-Foam cell and a bank of Picoforge clusters can print any stock module and certify it. The result is plain, honest and cheap: nothing is the best of its kind, but every part is replaceable. Proprietary yard sets (heavier, cleaner or fancier) are built to the same sockets and bolt patterns, but their drawings stay behind the yard’s lock.
A cab (S) provides two crash couches (Flex-Rigs) and the helm and astrogation stations, a 48 h open-loop life-support reserve (so a skiff can fly without a hab pod) and a 1 GJ storage bank (2 MW peak). The canopy faces the bow, and the couches recline so that “down” is aft. A bridge (M and L) adds engineering, gunnery and comms stations, so that every station of a crewed warship has its own seat. No station is mandatory except helm: without a cab or bridge a ship cannot be flown at all.
| Station | Controls | Provided by |
|---|---|---|
| Helm | Attitude, thrust, docking | Cab, bridge |
| Astrogation | Plotting, navigation arrays | Cab, bridge |
| Engineering | Power, heat, fluids, damage control | Bridge |
| Gunnery | Remote turret fire control | Bridge, or a manned turret (its own seat) |
| Comms | Traffic control, messages, transponder settings | Bridge (on a skiff, the helm handles it) |
A manned turret has its own gunnery seat and reaches the keel through a 0.8 m tube, so the gunner shoots with a direct view. A remote turret has no crew seat and is slaved to a gunnery station over the data trunk, so it can be smaller, but it needs a bridge, which an S-class cab does not provide; Common Pattern skiffs therefore carry crewed turrets or none. Turrets declare a firing arc and may not be mounted where their arc is blocked by hull or radiators.
Carried craft are first-class assemblies. A hangar offers slots, each with a size and a kind. A cradle is an external clamp, with the craft in vacuum: it is cheap, quick to launch, and suited to S-class parasite fighters riding a corvette’s flank. A bay is an enclosed, pressurized berth for a larger craft, with a launch and recovery cycle set by its plate. A vehicle bay adds a ramp for carried ground vehicles, so a landing craft with a bay can set rovers on a planet’s surface. A docked craft is attached in its carrier’s frame: its mass and inertia add to the carrier’s, and the carrier’s fluids and power top it up through the umbilical.
A yard does not sell a ship; it sells a plated ship. Four plates matter:
A ship without the plates may fly, but ports may refuse her.
Story Seeds: