{
  "title": "Shamrock",
  "era": "Comparative later steam-carrier 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": 146,
    "beamFeet": 30,
    "depthOfHoldFeet": null,
    "beamInferred": false,
    "holdDepthUnknown": true,
    "dimensionsSourceQuality": "Selected documentary baseline; see vessel research notes for length and beam conflicts"
  },
  "geometryReference": {
    "hullBowX": -22.250400000000003,
    "hullSternX": 22.250400000000003,
    "deckY": 4.0,
    "waterlineY": 2.8,
    "waterlineIsInferred": true
  },
  "bounds": {
    "min": [
      -22.321507356664565,
      0.0050000000000000044,
      -4.657000000000001
    ],
    "max": [
      22.329360658123928,
      24.004582838650055,
      4.657000000000001
    ]
  },
  "triangleCount": 50386,
  "trianglesByGroup": {
    "hull": 12668,
    "bulwarks": 9380,
    "fittings": 2644,
    "deck": 7466,
    "propulsion": 208,
    "anchors": 636,
    "deckhouses": 3600,
    "pilothouse": 36,
    "steering": 412,
    "machinery": 392,
    "standing_rigging": 1164,
    "spars": 892,
    "cargo_hatches": 120,
    "hatch_covers": 264,
    "deck_cargo": 8448,
    "ship_boat": 1816,
    "ventilators": 240
  },
  "drawCalls": 55,
  "mastCount": 1,
  "supportsSails": false,
  "visibilityNodes": {
    "cargo": "deck_cargo"
  },
  "deployedSailCount": 0,
  "inferredFeatures": [
    "Underwater hull lines and draft",
    "Exact colors, fittings, hatch layout and rigging routes"
  ],
  "configurationCaveat": "NOAA describes conversion from a schooner barge to a steam lumber carrier. Surviving hull and propeller support that class and scale. Bridge, funnel, cargo mast and lumber arrangement are contemporary comparisons; no complete ship portrait was recovered.",
  "sources": [
    {
      "title": "NOAA vessel record",
      "url": "https://thunderbay.noaa.gov/shipwrecks/shamrock.html",
      "use": "Identity, dimensions, history and surviving evidence"
    },
    {
      "title": "NOAA paddling guide",
      "url": "https://nmsthunderbay.blob.core.windows.net/thunderbay-prod/media/archive/pdfs/kayak_handout_web.pdf",
      "use": "Indexed text describes schooner-barge conversion to steam lumber carrier; full PDF not downloaded"
    },
    {
      "title": "Historical Monohansett photograph",
      "url": "https://commons.wikimedia.org/wiki/File:Monohansett.png",
      "use": "Inspected two masts, twin funnels, forward wheelhouse and aft machinery house. This is an earlier career form, not the reduced late coal-carrier form."
    }
  ],
  "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 a 146×30 ft wooden steam barge built in 1875. [NOAA vessel record](https://thunderbay.noaa.gov/shipwrecks/shamrock.html)",
    "A propeller survives at the wreck. [NOAA vessel record](https://thunderbay.noaa.gov/shipwrecks/shamrock.html)"
  ]
}