{
  "schema": "c11-riser-interfaces-v1",
  "scope": "Rigid metallic riser design, no flexible/nonmetallic extrapolation.",
  "interfaces": [
    {
      "boundary": "Topside",
      "data": [
        "Piping/structure terminal geometry",
        "Pigging/valve maintenance access",
        "Electrical isolation",
        "Analysis overlap"
      ]
    },
    {
      "boundary": "Jacket",
      "data": [
        "Structural geometry/deflection",
        "Support type/location/reactions",
        "Protection and installation clearance"
      ]
    },
    {
      "boundary": "Pipeline/tie-in spool",
      "data": [
        "Approach and tie-in geometry",
        "Temperature/pressure expansion",
        "Seabed/soil resistance",
        "Overlapping analysis"
      ]
    }
  ],
  "states": [
    {
      "state": "Installation",
      "changes": [
        "Handling and loadout support/contact",
        "Upending/retrofit gravity",
        "Vessel motions",
        "Temporary braces/seafastening"
      ]
    },
    {
      "state": "Hydrotest",
      "changes": [
        "Contents/pressure",
        "Actual supports/environment",
        "Residual loads"
      ]
    },
    {
      "state": "Operation",
      "changes": [
        "Thermal/pressure/residual loading",
        "Wave/current/wind/other environmental cases",
        "Guide/weight/anchor functions",
        "Fatigue/vortex effects"
      ]
    }
  ],
  "support_distinctions": [
    "Guide controls transverse movement with intended axial/rotational freedom",
    "Weight clamp establishes weight path and detailed downward restraint/freedoms",
    "Anchor restrains specified movement and rotation"
  ],
  "intelligent_pig_bend_table": {
    "scope": "Specific adopted riser inspection criterion; D is nominal pipe diameter in mm.",
    "rows": [
      {
        "nominal_D_mm": "<=100",
        "minimum_radius": "10D"
      },
      {
        "nominal_D_mm": "150 to250",
        "minimum_radius": "5D"
      },
      {
        "nominal_D_mm": ">=300",
        "minimum_radius": "3D"
      }
    ],
    "unlisted_sizes": "No interpolation; applicable tool/detail required."
  },
  "friction_basis": "Critical direction depends on state/method: low seabed resistance can maximise expansion; higher contact resistance can govern pull-in. No single conservative coefficient."
}