{
  "title": "Sagamore",
  "era": "Steel unpowered whaleback barge in its 1892–1901 working form",
  "version": "1.1",
  "modelStatus": "Interpretive reconstruction; no original lines plan recovered",
  "detailLevel": "full",
  "units": "metres",
  "axes": {
    "up": "+Y",
    "bow": "-X",
    "starboard": "+Z"
  },
  "historicalDimensions": {
    "lengthFeet": 308,
    "beamFeet": 38,
    "depthOfHoldFeet": 24,
    "beamInferred": false,
    "holdDepthUnknown": false,
    "dimensionsSourceQuality": "Selected documentary baseline; see vessel research notes for length and beam conflicts"
  },
  "geometryReference": {
    "hullBowX": -46.9392,
    "hullSternX": 46.9392,
    "deckY": 7.4,
    "waterlineY": 4.8,
    "waterlineIsInferred": true
  },
  "bounds": {
    "min": [
      -46.9792,
      0.17519999999999972,
      -5.824433035094611
    ],
    "max": [
      47.239200000000004,
      17.4,
      5.824433035094611
    ]
  },
  "triangleCount": 98820,
  "trianglesByGroup": {
    "whaleback_hull": 21744,
    "steel_seams": 38160,
    "rivets": 24192,
    "cargo_hatches": 144,
    "hatch_covers": 432,
    "deck_rails": 2176,
    "turrets": 288,
    "turret_roofs": 288,
    "portholes": 1400,
    "turret_rails": 1488,
    "deckhouses": 2032,
    "pilothouse": 36,
    "steering": 424,
    "ship_boat": 1816,
    "stove_pipe": 48,
    "staffs": 64,
    "towing_gear": 1600,
    "name_board": 160,
    "name_board_letters": 2328
  },
  "drawCalls": 30,
  "mastCount": 0,
  "supportsSails": false,
  "visibilityNodes": {
    "hatches": "hatch_covers"
  },
  "deployedSailCount": 0,
  "inferredFeatures": [
    "Twelve small low hatch covers are an interpretation of whaleback practice; the photograph does not establish their exact count or spacing.",
    "Underwater lines, concealed fittings, exact turret measurements, paint pigments and name-board lettering geometry are interpreted."
  ],
  "configurationCaveat": "308 ft steel whaleback; a single photo caption says 328 ft without an established reconciliation. The lettered end with three rings and accommodation is the stern. Small low hatches, hull lines and fittings remain interpreted; this is an unpowered barge.",
  "revisedDate": "2026-09-08",
  "revisionNote": "Corrected the September 2026 audit findings and distinguished documentary evidence, interpretation and unresolved conflicts.",
  "documentedFeatures": [
    "The wreck inventory records a steel whaleback built in 1892, US 57932, with dimensions 308 × 38 × 24 ft. [3 DShipwrecks](https://3dshipwrecks.org/shipwreck-sagamore/).",
    "The 1892 photograph shows a rounded turtleback, low end turrets, an accommodation house at the lettered end and three rings there. The hailing-port board reads SAGAMORE OF ASHTABULA. [Ashtabula Archive photograph](https://www.flickr.com/photos/115892967@N03/50518631932/).",
    "On July 29, 1901 Northern Queen struck Sagamore near the after turret in fog while the barge lay off Point Iroquois with Pathfinder. Captain E. Joiner, the cook and a sailor were lost. [Sagamore history](https://en.wikipedia.org/wiki/Sagamore_%28barge%29)."
  ],
  "sources": [
    {
      "title": "3 DShipwrecks inventory",
      "url": "https://3dshipwrecks.org/shipwreck-sagamore/",
      "use": "See the cited evidence and uncertainty sections in the research notes."
    },
    {
      "title": "1892 photograph, Ashtabula Archive",
      "url": "https://www.flickr.com/photos/115892967@N03/50518631932/",
      "use": "See the cited evidence and uncertainty sections in the research notes."
    },
    {
      "title": "Sagamore history",
      "url": "https://en.wikipedia.org/wiki/Sagamore_%28barge%29",
      "use": "See the cited evidence and uncertainty sections in the research notes."
    },
    {
      "title": "Whitefish Point preserve",
      "url": "https://www.michiganpreserves.org/whitefish-point-underwater-preserve/",
      "use": "See the cited evidence and uncertainty sections in the research notes."
    }
  ]
}