Home » Case Studies » Propeller Damage Revealed as the Real Cause of Engine Issue Saving $44,000 on Engine TOH on Tugboat
Table of Contents
Case Study
Propeller Damage Revealed as the Real Cause of Engine Issue Saving $44,000 on Engine TOH on Tugboat
Table of Contents
Background
Industry
Marine
Solution
Engine Condition
Monitoring System
(ECMS)
Make & Model
Niigata
Engine
Asset
Twin-Screw Tugboat
with Two Main Engines
Objective
To conduct a standard Niigata Engine Overhaul and Repair Services
(ToH) service on the tugboat’s and ensure optimal engine health through pre-maintenance condition monitoring.
Challenge / Problem Context
The vessel was scheduled for a Top Overhaul on both main engines.
All operating parameters on the engines were within acceptable range.
The port-side engine had abnormal vibration patterns and mechanical stress indications despite normal readings.
Neptunus needed to determine whether an internal engine issue existed or if there was an external cause affecting performance.
What Did We Do?
Conducted a pre-overhaul health check using Neptunus’ advanced vibration-based condition monitoring tool under the ARMs solution.
Diagnosed that the port-side engine exhibited consistent bearing deterioration and high mechanical stress, despite normal running parameters.
Investigated further and found minor damage to the port-side propeller tips, which had gone out of balance, confirmed to be caused by impact with a floating log.
Advised customer to repair the damaged propeller before proceeding with any engine work.
Reassessed engine condition post-propeller repair, confirming bearing health had returned to normal—indicating no internal engine fault.
Results That We Achieved
Avoided unnecessary engine intervention, saving an estimated USD 14,000.
Reduced vessel downtime by over 50%, allowing quicker return to operations.
Prevented possible engine and Z-peller damage that could have led to dry docking and repair costs of ~USD 30,000.
Deferred the Top Overhaul using scientific data, optimizing maintenance scope and improving cash flow for the customer.
