{
  "title": "Congress",
  "era": "Early steam-freighter form, c.1861–1865",
  "version": "1.1",
  "modelStatus": "Interpretive reconstruction; no original lines plan recovered",
  "detailLevel": "full",
  "units": "metres",
  "axes": {
    "up": "+Y",
    "bow": "-X",
    "starboard": "+Z"
  },
  "historicalDimensions": {
    "lengthFeet": 139,
    "beamFeet": 25,
    "depthOfHoldFeet": null,
    "beamInferred": true,
    "holdDepthUnknown": true
  },
  "geometryReference": {
    "hullBowX": -21.183600000000002,
    "hullSternX": 21.183600000000002,
    "deckY": 3.9,
    "waterlineY": 2.8,
    "waterlineIsInferred": true
  },
  "bounds": {
    "min": [
      -21.24189492131849,
      0.0050000000000000044,
      -3.8950000000000005
    ],
    "max": [
      21.24896005375225,
      23.512355569547722,
      3.8950000000000005
    ]
  },
  "triangleCount": 42124,
  "trianglesByGroup": {
    "hull": 12668,
    "bulwarks": 9356,
    "fittings": 2844,
    "deck": 5896,
    "propulsion": 208,
    "anchors": 636,
    "deckhouses": 3504,
    "pilothouse": 720,
    "cargo_hatches": 120,
    "hatch_covers": 336,
    "machinery": 576,
    "standing_rigging": 1152,
    "skylights": 92,
    "ship_boat": 1816,
    "spars": 1528,
    "running_rigging": 600,
    "cargo_ports": 72
  },
  "drawCalls": 57,
  "mastCount": 2,
  "supportsSails": false,
  "visibilityNodes": {
    "hatches": "hatch_covers"
  },
  "deployedSailCount": 0,
  "inferredFeatures": [
    "Underwater hull lines and draft",
    "Exact colors, fittings, hatch layout and rigging routes"
  ],
  "configurationCaveat": "Early interpretation of the vessel originally named Detroit. A partial 1864 photograph informs limited cabin and funnel details, not the complete arrangement. NOAA’s 139 ft catalogue length sets scale; 25 ft beam is provisional. Two bare masts, hull lines and deck layout are inferred. The later 1868 oil-burning machinery is not reconstructed.",
  "sources": [
    {
      "title": "NOAA Thunder Bay condition report",
      "url": "https://repository.library.noaa.gov/view/noaa/2668/noaa_2668_DS1.pdf",
      "use": "139 ft length baseline, wooden propeller classification, dates"
    },
    {
      "title": "Congress / Detroit partial historical photograph",
      "url": "https://commons.wikimedia.org/wiki/File:Congress.png",
      "use": "1864 photograph attributed to Brady; limited cabin, funnel and side-detail evidence"
    },
    {
      "title": "Great Lakes Shipwreck Files: Congress",
      "url": "https://greatlakesrex.wordpress.com/c/",
      "use": "Name history; secondary dimension discrepancy only, not verified enrollment"
    },
    {
      "title": "NOAA archaeological resources",
      "url": "https://repository.library.noaa.gov/view/noaa/10726/noaa_10726_DS1.pdf",
      "use": "1868 petroleum-firing history, not modeled machinery"
    }
  ],
  "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": [
    "NOAA lists an 1861 wooden propeller vessel, 139 ft long, lost in 1868. [NOAA Thunder Bay condition report](https://repository.library.noaa.gov/view/noaa/2668/noaa_2668_DS1.pdf)"
  ]
}