Thursday, June 2, 2011

Top 10 Towing Vessel Material Failures—Part II

Excerpted from “Top Ten Deficiencies Found on Vessels.” Full text available on Navigate to missions/investigations/safety reports.

See Part I here.

Propulsion Diesel
The U.S. Coast Guard Office of Investigations and Analysis compared larger propulsion diesels with smaller engines and concluded they’re at parity for failures related to cylinders and cylinder heads. Common failures include cracks and leaking gaskets.


  • The three most common causes of governor malfunction:
    inadequate lubrication,
  • improper adjustment of control linkage,loss of pneumatic pressure (control air) to the governor.
Reduction Gear/Clutch
With inflatable flexible gland clutches, either the elastomer gland or the wear elements in contact with it (typically friction shoes) are known to reach the wear-out point unexpectedly. Depending on what wore out and how, this component has been the cause of “failure to disengage” as well as the obvious failure to engage.

Many clutch-related loss of propulsion and/or maneuverability failures have also been due to loss of control air to the clutch.

The list concludes in part 3.