Feature Overview

StowMind is a specialized workbench for FreeCAD 1.1, built for naval architects, cargo planners, and heavy lift engineers. It bridges the gap between 3D ship models and the calculations that depend on them — all inside a single FreeCAD document.

1 Hull & Geometry

Import hull geometry from GF spant files, DXF, STL, IGES/STEP, or FreeCAD native files. StowMind converts meshes to watertight solids, mirrors half-spants to full sections, and loft them into a complete hull. Four example vessels (Series 60, Wigley) are included for testing.

Video: Hull Import & StowMind Object Creation

2 Hydrostatics

Calculate hydrostatic tables, tank data, and cross curves directly from the hull solid. Two methods: fast slice-based calculation from existing frames, or a complete pipeline extracting 50 evenly distributed frames with full pantocarenes (KN curves) for 13 heel angles. Results are stored as FreeCAD spreadsheets and plotted automatically.

Video: Hydrostatics & Pantocarenes

3 Tanks & Weights

Define tanks as parametric solids with fluid type and fill level. Create weight objects for lightship, crew, provisions, hatch covers, deck equipment, and project cargo. All masses and centers of gravity feed directly into the load condition calculation.

4 Cargo Planning & Stowage

Import cargo lists from Excel or 3D models (STEP/IGES/STL). Automatic placement with collision detection respects deck topology, obstacles (cranes, superstructure), and already placed cargo. Stackable cargo is handled by a specialized stacking algorithm. The stowage plan is the 3D model — not a separate document.

Video: Excel Import & Automatic Placement

5 Load Condition & Stability

The Load Condition aggregates all tanks, weights, cranes, and cargo into a single spreadsheet. One click calculates total mass, center of gravity, sinkage, trim, metacentric height (GMt), and stability assessment. A floating Stability Monitor updates every 4 seconds while you work.

6 Lashing & Securing

Complete lashing calculation per IMO CSS Code Annex 13 (2021 Amendments), Advanced Calculation Method. Define lashing materials, angles, and MSL values per side. The PDF export produces a ready-to-print securing certificate with force balance, tipping check, and PASS/FAIL evaluation.

7 GZ Curve & Projected Areas

Calculate the GZ righting lever curve directly from hull geometry — no external software needed. Volume-constant bisection iteration over 13 heel angles. SOLAS criteria (area under curve, max GZ, vanishing angle) are checked and plotted. Projected wind and cross-sectional areas are computed for weather criteria.

8 Crane Operations & Rigging

Model ship cranes as parametric 3D objects with load-radius curves. Single hook and tandem lift solvers calculate optimal boom angles, distribute load between two cranes, and simulate the swing path step-by-step. Rigging verification per DNV-ST-N001 / Noble Denton includes shackle selection, grommet sizing, traverse design, and automatic BOM generation with PDF drawing export.

Video: Tandem Lift Simulation & Rigging Wizard

99 Modules, One Coordinate System

StowMind comprises 99 modules across nine functional areas. All share the same FreeCAD coordinate system, the same hull geometry, and the same data model.

Hull & Geometry

Import, convert, loft, scale

Hydrostatics

Frames, curves, pantocarenes

Tanks

Parametric fluids, fill levels, FSM

Weights

Lightship, cargo, equipment

Decks & Holds

Topology, coamings, covers

Stability

Sink & trim, GZ, monitor

Visualization

Projected areas, decals, labels

Lifting

Single hook, tandem, monopile

Rigging

Shackles, grommets, traverses, BOM

Workflow: From Hull to Rigging Certificate

One document. One model. One source of truth.

  1. Import or create hull geometry → StowMind object
  2. Calculate hydrostatics and pantocarenes
  3. Define tanks, weights, and deck topology
  4. Import cargo, place automatically or manually
  5. Calculate load condition → stability check
  6. Verify lashing, generate PDF certificate
  7. Plan crane operations, simulate lift path
  8. Design rigging, verify DNV/Noble Denton, export BOM

Every change propagates. Adjust a tank fill level, move a cargo unit, or rotate a crane — the load condition, stability, and all dependent reports update automatically.

"It is only those who do nothing who makes no mistakes"

— Peter Kropotkin