Advertisement

Failure Analysis of a Jet Boat Steering Linkage

  • A. L. Beardsley
  • M. V. KralEmail author
Case History---Peer-Reviewed
  • 16 Downloads

Abstract

As part of a steering linkage mechanism in a jet boat, two D-ring shackle pins were safety wired together in order to prevent either of the shackle pins from falling out. Relative movement of the D-ring shackles from maneuvering the boat caused fluctuating stresses in the stainless steel safety wire, resulting in a fatigue fracture of the wire. Without the constraint of the safety wire, a pin from one of the D-ring shackles became dislodged, resulting in the failure of the steering mechanism, loss of control and crash of the boat. As well as a demonstration of the key features of the components that led to the determination of a fatigue fracture, the significant flaws in the installation and configuration of the steering linkage are discussed.

Keywords

Fatigue Safety wire Steering linkage 

Notes

Acknowledgments

The authors would like to thank Nicholas Breeuwer (postgraduate student at University of Canterbury) and Matthew Owen-Eales (Maritime Officer, Maritime New Zealand) for many helpful discussions.

References

  1. 1.
    Y. Chen, Q. Gao, Z. Guan, Self-loosening failure analysis of bolt joints under vibration considering the tightening process. Shock Vib. (2017).  https://doi.org/10.1155/2017/2038421 CrossRefGoogle Scholar
  2. 2.
    D.P. Hess, Threaded fastener secondary locking requirements. J. Fail. Anal. Prev. 17(4), 724–730 (2017).  https://doi.org/10.1007/s11668-017-0308-1 CrossRefGoogle Scholar
  3. 3.
    AIA/NAS, NASM33540—Safety wiring, safety cabling, cotter pinning, general practices for—Rev 3 (2015)Google Scholar
  4. 4.
    SAE-International, SAE AS567K—(R) Safety cable, safety wire, key washers, and cotter pins for propulsion systems, General practices for use of (2015)Google Scholar
  5. 5.
    FAA, Federal Aviation Authority AC 43.13-1B—Acceptable methods, techniques, and practices—aircraft inspection and repair, Chapter 7 (1998)Google Scholar
  6. 6.
    D.P. Hess, Threaded fastener locking with safety wire and cotter pins. J. Fail. Anal. Prev. 18(5), 1216–1223 (2018).  https://doi.org/10.1007/s11668-018-0513-6 CrossRefGoogle Scholar

Copyright information

© ASM International 2019

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringUniversity of CanterburyChristchurchNew Zealand

Personalised recommendations