mooring-design

What it does

Design and analyze mooring systems for floating offshore structures, including CALM buoys, SALM buoys, and spread mooring configurations.

How it works

• Provides data models for mooring systems, lines, anchors, environmental conditions, and design results.
• Offers a CatenaryAnalyzer to solve catenary geometry given line properties and horizontal tension, returning tensions, arc length, distances, angles, and a grounded length.
• Includes a MooringDesigner that:
  • Computes simplified environmental loads (wave drift, current, wind) and total load.
  • Analyzes intact condition by estimating line tension via catenary, computing safety factors against MBL, and producing per-line results.
  • Analyzes damaged condition by removing one line, scaling loads for remaining lines, re-solving catenaries, and producing per-line results with updated safety factors.
• Contains an OrcaFlexModelGenerator to produce OrcaFlex model inputs:
  • generate_line_data builds line data mapping to OrcaFlex format, including anchor and fairlead connections and segment definitions.
  • _get_line_type_name creates descriptor strings for line types.
  • generate_line_type defines line type properties (OD, mass, EA, EI, drag coefficients).
  • generate_model_yml compiles a YAML model with General, Environment, LineTypes, and Lines sections from the system data, ensuring unique line types are included once.

The implementation is Python-based, with classes and dataclasses modeling the mooring system, and functions that assemble inputs for analysis and model generation.

When to use it

• CALM buoy design
• SALM buoy analysis
• Spread mooring configuration design
• Mooring line sizing and material selection
• Environmental load calculations
• Safety factor verification
• Mooring analysis setup for OrcaFlex

What it can touch

• System: MooringSystem (with water_depth, lines, vessel_type, etc.)
• Lines: MooringLine (segments, anchor, fairlead_location, pretension)
• Segments: MooringLineProperties (line_type, length, diameter, mbl, weight_water, ea, drag_coeff)
• Anchors: AnchorProperties (anchor_type, holding_capacity, location)
• EnvironmentalConditions (wave_hs, wave_tp, wave_direction, current_speed, current_direction, wind_speed, wind_direction, return_period)
• Interaction points: OrcaFlexModelGenerator writes YAML model to a file, and LineTypes/Lines data are prepared for OrcaFlex consumption

Caveats

• Relies on simplified environmental load calculations and a catenary-based tension estimation rather than full finite-element or OrcaFlex results.
• Safety factors and behavior are implemented as per the defined constants; real-world validation with authoritative standards and site data is required.
• YAML model generation assumes the provided system data is complete and consistent; missing fields may cause generation errors if not handled upstream.