{
  "title": "Tramp",
  "era": "Gill-net fishing-tug interpretation",
  "version": "1.1",
  "modelStatus": "Interpretive reconstruction; no original lines plan recovered",
  "detailLevel": "full",
  "units": "metres",
  "axes": {
    "up": "+Y",
    "bow": "-X",
    "starboard": "+Z"
  },
  "historicalDimensions": {
    "lengthFeet": 55,
    "beamFeet": 13.4,
    "depthOfHoldFeet": null,
    "beamInferred": true,
    "holdDepthUnknown": true,
    "dimensionsSourceQuality": "Selected documentary baseline; see vessel research notes for length and beam conflicts"
  },
  "geometryReference": {
    "hullBowX": -8.382,
    "hullSternX": 8.382,
    "deckY": 2.15,
    "waterlineY": 1.5,
    "waterlineIsInferred": true
  },
  "bounds": {
    "min": [
      -8.48998,
      0.0050000000000000044,
      -2.1471600000000004
    ],
    "max": [
      8.4912,
      6.2075979733396816,
      2.1471600000000004
    ]
  },
  "triangleCount": 32698,
  "trianglesByGroup": {
    "hull": 12668,
    "bulwarks": 8900,
    "fittings": 2252,
    "deck": 3244,
    "propulsion": 206,
    "anchors": 636,
    "deckhouses": 168,
    "windows": 216,
    "cabin_roofs": 1480,
    "machinery": 64,
    "working_doors": 120,
    "rub_rails": 2712,
    "tow_post": 32
  },
  "drawCalls": 30,
  "mastCount": 0,
  "supportsSails": false,
  "visibilityNodes": {
    "roofs": "cabin_roofs"
  },
  "deployedSailCount": 0,
  "inferredFeatures": [
    "Underwater hull lines and draft",
    "Exact colors, fittings, hatch layout and rigging routes"
  ],
  "configurationCaveat": "The preserve records a 55 ft fishing tug built in 1926. The enclosed turtleback form uses documented contemporary Katherine V as a close comparison. The Rogers City Tramp account gives 62 ft; its link to this wreck and the differing length basis remain unconfirmed. Beam, house arrangement and finish are inferred.",
  "sources": [
    {
      "title": "Preserve identification",
      "url": "https://www.michiganpreserves.org/grand-traverse-bay-underwater-preserve/"
    },
    {
      "title": "HAER MI-421, Katherine V, comparison vessel",
      "url": "https://tile.loc.gov/storage-services/master/pnp/habshaer/mi/mi0700/mi0754/data/mi0754data.pdf"
    },
    {
      "title": "Kahlenberg engine installation list; identity association unresolved",
      "url": "https://www.harveyhadland.com/k_berg01.htm"
    }
  ],
  "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": [
    "The preserve describes a 55 ft fishing tug built in 1926. [Preserve identification](https://www.michiganpreserves.org/grand-traverse-bay-underwater-preserve/)"
  ]
}