{
  "checked_on": "2026-09-27",
  "units": "m",
  "canonical_axes": "x longitudinal / y transverse / z up",
  "three_mapping": "(x,z,-y)",
  "evidence_type": "teaching_assumption",
  "scope": "Generic teaching equipment; source photos establish type and visible load paths, not vendor dimensions or construction design.",
  "models": {
    "traveler": {
      "type": "upper-supported twin triangular form traveller",
      "completed_girder_x": [
        -7.6,
        0
      ],
      "new_segment_x": [
        0,
        3
      ],
      "deck_width": 6.4,
      "deck_top_z": 2,
      "girder_bottom_z": -1,
      "web_centres_y": [
        -2.15,
        2.15
      ],
      "truss_planes_y": [
        -2.15,
        2.15
      ],
      "front_support_x": -1,
      "rear_anchor_x": -5.6,
      "front_hanger_x": 3.3,
      "rear_hanger_x": -0.5,
      "hanger_y": [
        -2.7,
        2.7
      ],
      "bottom_platform_x": [
        -0.875,
        3.675
      ],
      "movement": "none; four static force-path stages",
      "display_scale": 1,
      "anchor_type": "Removable threaded rods through explicit reserved sleeves in the completed girder, with perforated anchor beam/plates and true hollow hex nuts; all remain engaged.",
      "assumptions": [
        "All geometry dimensions chosen for teaching, not reconstructed from a proprietary formwork drawing.",
        "Existing girder left crop continues to completed cantilever and pier segment.",
        "Temporary walking restraint changeover is discussed but no travel animation is claimed.",
        "Concrete top slab and near web can be hidden only as an inspection display."
      ],
      "bottom_form_top_z": "-1",
      "front_support_contact_z": 2.64,
      "rear_anchor_bar_x": [
        -5.7,
        -5.5
      ],
      "rear_anchor_rod_radius": 0.044,
      "reserved_concrete_bore_radius": 0.073,
      "anchor_sleeve_inner_radius": 0.06,
      "hanger_sleeve_inner_radius": 0.063,
      "hanger_rod_radius": 0.051
    },
    "cablecrane": {
      "type": "twin-main-cable-supported transverse gantry with four strand-jack lifting points",
      "main_cable_y": [
        -4.4,
        4.4
      ],
      "main_cable_x": [
        -10,
        10
      ],
      "main_cable_center_z": "5.55+0.007*x*x",
      "main_cable_radius": 0.22,
      "gantry_x": [
        -1.7,
        1.7
      ],
      "gantry_lower_chord_z": 6.39,
      "gantry_upper_chord_z": 7.39,
      "hoist_y": [
        -3.3,
        3.3
      ],
      "hoist_top_z": 7.62,
      "spreader_attachment_z_initial": 0.9,
      "deck_segment_x": [
        -3,
        3
      ],
      "deck_width": 10.5,
      "deck_top_z_initial": -0.1,
      "deck_top_z_final": 2.7,
      "lift_stroke": 2.8,
      "neighbor_deck_x": [
        -9.8,
        -3.06
      ],
      "neighbor_deck_top_z": 2.7,
      "movement": "vertical hoist only; no cable profile change, longitudinal travel, or transfer to permanent system",
      "display_scale": 1,
      "assumptions": [
        "Dimensions and cable profile are teaching assumptions, not Runyang bridge dimensions or erection analysis.",
        "Two main cables extend beyond the crop to tower saddles and anchorages.",
        "Local saddle bodies and generic walking-drive cylinders are simplified visual interpretation; proprietary internal designs were unavailable.",
        "New deck remains continuously supported by four hoist points through final state.",
        "Adjacent deck is supported by four permanent hangers with visible upper bands and lower anchorages."
      ],
      "lifting_point_x": [
        -2.25,
        2.25
      ],
      "jack_bore_radius": 0.08,
      "saddle_inner_radius": 0.232
    }
  },
  "not_checked": [
    "structural capacity",
    "cable clamp friction",
    "formwork overturning resistance",
    "temporary works design",
    "strand-jack control tolerances",
    "actual proprietary machine mechanism"
  ]
}