Root Cause Analysis and Solutions for the Decline in Freshwater Generator Production: A Case Study of MV Top Diligence

Abstract

A freshwater generator is a crucial system in ship operations that produces fresh water from seawater via vacuum distillation. This research aims to identify the causes of decreased fresh water production in fresh water generator and analyze the effectiveness of corrective measures undertaken. The research employed a case study method with a qualitative approach conducted on MV. Top Diligence during the period from October 2024 to August 2025. Data collection was conducted through participatory observation, in-depth interviews with the Third Engineer and related crew members, and a documentation study of the daily record book, the planned maintenance system, and the instruction manual. Data analysis used the root cause analysis method with the 5 Whys technique and a fishbone diagram. Research findings indicate that production decrease from 20-23 tons/day to 13.8 tons/day (30.8% reduction) was caused by three main factors: seal damage on evaporator plate which reduced system vacuum from 0.9 bar to 0.6-0.7 bar, fouling or scale accumulation of 2-5 mm thickness that impeded heat transfer, and ejector pump pressure reduction from 3-3.5 bar to 1.5 bar. Corrective measures, including mechanical scale removal, gasket replacement, and ejector pump maintenance, proved effective, resulting in production recovery to an average of 20.8 tons/day (46% increase). This research concludes that preventive maintenance with intervals adjusted to operational conditions (3-4 months) and strict monitoring of critical parameters are essential to maintaining optimal performance of fresh water generators. The research findings provide practical contributions in the form of recommendations for planned maintenance system revision and early warning system implementation to prevent performance degradation in the future.