orcaflex-installation-analysis-common-errors-and-fixes

name	orcaflex-installation-analysis-common-errors-and-fixes
description	Sub-skill of orcaflex-installation-analysis: Common Errors and Fixes (+3).
version	1.0.0
category	engineering
type	reference
scripts_exempt	true

Common Errors and Fixes (+3)

Common Errors and Fixes

Error	Cause	Fix
FileNotFoundError: reference_model_file	Path to base model incorrect	Check reference_model_file and reference_elevation_file paths are relative to working directory
KeyError: 'Key not found in line item'	length_index doesn't match line sections	Count sections in reference model (0-indexed); verify length_index matches the section to extend
Static convergence fails at depth	Crane wire too short, structure below seabed, or tension too high	Check delta_elevation doesn't place structure below seabed; verify wire length = reference + abs(delta)
6DBuoy position error	InitialZ places buoy at impossible position	Verify reference elevation is correct; check for sign convention (negative = below sea level)
Model loads but simulation crashes	Environmental loads inappropriate for installation depth	Reduce wave Hs for splash zone cases; calm seas typical for installation
Crane wire tension exceeds capacity	Structure too heavy for depth or wire angle too steep	Add buoyancy aids; check structure submerged weight vs crane capacity
Sling connection breaks	Sling too short after depth change	Ensure intermediate slings are also updated with delta_elevation

Debugging Installation Models

def diagnose_installation_model(model_path, expected_depth):
    """Check generated installation model for common issues."""
    import OrcFxAPI
    issues = []

    model = OrcFxAPI.Model()
    model.LoadData(model_path)
    wd = model.general.WaterDepth


*See sub-skills for full details.*

## Splash Zone Analysis Checklist


- [ ] Wave Hs appropriate for installation weather window (typically Hs < 2.5m)
- [ ] Fine depth increments through splash zone (1-2m steps)
- [ ] Hydrodynamic coefficients set for partially submerged structure
- [ ] Slamming loads considered (if applicable)
- [ ] Crane wire dynamic amplification factor applied
- [ ] Structure orientation at each depth is physical

## Validation


| Check | Method | Acceptable Range |
|-------|--------|-----------------|
| Crane wire tension | Extract from static results | < crane SWL with safety factor (typically SF > 2.0) |
| Structure elevation | Compare 6DBuoy Z with target | Within 0.1m of target delta_elevation |
| Wire length | Sum of wire sections | Reference length + abs(delta_elevation) +/- 1% |
| Sling tensions | Extract from static results | Positive (no compression in slings) |
| Static convergence | model.CalculateStatics() | Converges at all depths |
| Touchdown | Check structure Z vs seabed | Structure Z > -water_depth (not through seabed) |