The Maunalei: Crew Feedback and Vessel Data

In a significant investigation, the U.S. National Transportation Safety Board (NTSB) has reported that a defective propeller blade led to a loss of propulsion and a major hydraulic oil spill from the vessel 'Maunalei' in August 2022. The incident occurred during a voyage destined for Portland from Anchorage, where the faulty controllable pitch propeller failed to comply with the required design standards. The findings, released on May 21, 2023, indicate that the propulsion failure transpired approximately 245 nautical miles from the Columbia River entrance, placing the ship in close proximity to Portland. During this malfunction, the 'Maunalei' lost more than 1,632 gallons of hydraulic oil, with damage costs projected at around $3 million. The NTSB identified that the propeller's manufacture was below standard, with visible cracks and fractures detected at the base of one blade that did not meet specification for impact toughness, tensile strength, or yield strength. Although the NTSB deemed the blade damage to be an isolated incident — with no issues found in the analysis of other similar propellers — the manufacturer has since revised its specifications to enhance the fatigue fracture resistance of its products. For more detailed information, you can access the full report at [NTSB Report](https://www.ntsb.gov/investigations/AccidentReports/Reports/MIR2411.pdf).