USS ORTOLAN (ASR-22) Forward Foil Seakeeping Trials

Abstract

This report presents and discusses the results of seaworthiness trials conducted aboard the USS ORTOLAN (ASR-22) subsequent to the installation of a between-hull forward foil and modifications to the forward bridging structure. Ship motion, hull strains, and bridging structure impacts are presented with comparisons made between the 'as built' and the 'modified' conditions. Results indicate that the addition of the foil, along with the bridging structure modifications, significantly improved the seaworthiness characteristics and operational limits of ORTOLAN, yielding a capable, seaworthy craft. Bridging structure impacts did not limit ORTOLAN's ability to transit at any heading or speed in seas up to and including a state 6 sea. Ship motions, while large, are not abnormal and strain measurements indicate that the main structural integrity of the ship at the locations investigated was not endangered at any time during the trials. However, local structural modifications are required on the second deck between Frames 12 through 21 along the port and starboard inboard hull plating. The foil did not break the water surface in seas having a maximum wave height over 30 feet.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1975
Accession Number
ADA021582

Entities

People

  • D. A. Woolaver

Tags

Communities of Interest

  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Amplitude
  • Engineering
  • Frequency
  • Gages
  • Long Wavelengths
  • Measurement
  • Oceans
  • Pressure Gages
  • Seakeeping
  • Seaworthiness
  • Ship Motion
  • Short Wavelengths
  • Strain Gages
  • Structural Integrity
  • Transducers
  • Transfer Functions
  • Water

Readers

  • Marine Hydrodynamics
  • Structural Health Monitoring of Composite Structures.