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Nauticus Controllable Pitch Mechanism Tool

Nauticus Machinery Knowledge Centre Help library Tools and Calculations Controllable Pitch Mechanism Tool

Module Description

The Nauticus Controllable Pitch Mechanism tool evaluates the static and fatigue strength of key components in controllable pitch propeller (CPP) systems. It ensures compliance with DNV Rule Pt.4 Ch.5, Class Guidelines 0039, and Ice-Class Rules. The tool assesses the strength for critical components such as blade bolts, shear pins, propeller hub, blade carrier, servo mechanisms, and push-pull rods, helping engineers design and verify pitch mechanisms under free water condition and ice-class condition.


Key Features

  • Static Strength Evaluation for pitch mechanisms under maximum hydrodynamic loads, blade failure loads (ice class), and ice impact conditions.
  • Fatigue Strength Calculation considering cyclic loading from pitch changes, start/stop operations, and ice-induced vibrations.
  • Component-Specific Analysis for blade bolts, shear pins, propeller hubs, blade carriers, servo cylinders, clamping bolts, guide blocks, and push-pull rods.
  • Ice-Class Load Calculation to evaluate spindle torque, blade failure loads, and maximum ice loads based on IACS Unified Requirements and Finnish-Swedish Ice Class Rules.
  • User-Defined Load Inputs allowing manual input of force, torque, and stress cycles for custom analysis.
  • Default Values and Estimation Functions provided based on DNV experience to assist users in defining key parameters.
  • Automated Report Generation for compliance verification and classification approval.

Workflow

  1. Define General Data including propeller operation type, system configuration, and ice class notation.
  2. Input Design Data for blade bolts, shear pins, propeller hub, blade carrier, crank pin, guide block, push-pull rod.
  3. Specify Ice-Class Data by defining maximum bending ice loads, spindle arms, blade failure loads and ice load cycles.
  4. Modify the default values in Optional Input page if necessary.
  5. Perform Analysis to obtain the main class results (and ice class results if relevant).
  6. Check the Warning messages for potential correction.
  7. Result evaluation by comparing calculated stress and safety margins against criterions.
  8. Generate Reports including input data, intermediate results and finial evaluation results.