{
  "title": "John T. Johnson",
  "era": "Photograph-guided working towing form, before 1904",
  "version": "1.1",
  "modelStatus": "Interpretive reconstruction; no original lines plan recovered",
  "detailLevel": "full",
  "units": "metres",
  "axes": {
    "up": "+Y",
    "bow": "-X",
    "starboard": "+Z"
  },
  "historicalDimensions": {
    "lengthFeet": 171,
    "beamFeet": 31,
    "depthOfHoldFeet": null,
    "beamInferred": false,
    "holdDepthUnknown": true,
    "dimensionsSourceQuality": "Selected documentary baseline; see vessel research notes for length and beam conflicts"
  },
  "geometryReference": {
    "hullBowX": -26.0604,
    "hullSternX": 26.0604,
    "deckY": 4.1,
    "waterlineY": 2.95,
    "waterlineIsInferred": true
  },
  "bounds": {
    "min": [
      -29.991168201527103,
      0.0050000000000000044,
      -4.809400000000001
    ],
    "max": [
      26.595303668846228,
      34.10304492820914,
      4.809400000000001
    ]
  },
  "triangleCount": 53536,
  "trianglesByGroup": {
    "hull": 12950,
    "bulwarks": 9538,
    "fittings": 2892,
    "deck": 7828,
    "propulsion": 52,
    "anchors": 636,
    "deckhouses": 1200,
    "skylights": 64,
    "spars": 2296,
    "standing_rigging": 2316,
    "running_rigging": 336,
    "furled_canvas": 2320,
    "cargo_hatches": 120,
    "hatch_covers": 288,
    "deck_cargo": 8448,
    "centerboard_trunk": 24,
    "steering": 412,
    "ship_boat": 1816
  },
  "drawCalls": 58,
  "mastCount": 2,
  "supportsSails": false,
  "visibilityNodes": {
    "cargo": "deck_cargo"
  },
  "deployedSailCount": 0,
  "inferredFeatures": [
    "Underwater hull lines and draft",
    "Exact colors, fittings, hatch layout and rigging routes"
  ],
  "configurationCaveat": "The historical photograph guides two unequal masts, a low aft cabin and a large deck load of lumber. Wreck evidence supports a centerboard trunk. Exact load quantity, covered deck arrangement, hull lines and paint are inferred. No powered propulsion is added.",
  "sources": [
    {
      "title": "NOAA vessel record",
      "url": "https://thunderbay.noaa.gov/shipwrecks/john_t_johnson.html",
      "use": "Vessel identity, scale, history and surviving evidence"
    },
    {
      "title": "NOAA-hosted Johnson historical image",
      "url": "https://thunderbay.noaa.gov/media/img/20201203-john-t-johnson-1000.jpg",
      "use": "Inspected ship-specific mast proportions, cargo and cabin"
    }
  ],
  "revisedDate": "2026-09-08",
  "revisionNote": "Added sourced documentary features and repaired metadata and research-note formatting; this collection cleanup is not a new full historical or geometry audit.",
  "documentedFeatures": [
    "Wooden schooner barge built by John Squires at Huron,Ohio in 1873. [NOAA vessel record](https://thunderbay.noaa.gov/shipwrecks/john_t_johnson.html)",
    "NOAA dimensions 171×31 ft and a surviving centerboard-trunk pocket. [NOAA vessel record](https://thunderbay.noaa.gov/shipwrecks/john_t_johnson.html)"
  ]
}