The U.S. Coast Guard has issued a new Safety Alert outlining concerns surrounding propulsion loss linked to material failures within exhaust gas recirculation (EGR) cooler welds on a Tier 4 / IMO Tier III marine diesel engine.
According to the alert, a recent incident involved a propulsion shutdown triggered by a rapid rise in jacket-water temperature. Subsequent inspection identified a cracked weld seam on the EGR cooler, resulting in coolant leakage into the system. The investigation noted that this failure type had occurred multiple times over a two-year period, each well before the expected overhaul interval. A manufacturer notification addressing the issue had been released earlier; however, it had not been directly communicated to all operators using the affected engine type.
The Coast Guard pointed out that several factors may contribute to accelerated deterioration of the cooler, including trapped air within the piping system, coolant treatment issues, and non-optimal routing or installation of cooling-circuit components. Some abnormalities—such as gradual inlet-water pressure changes—were highlighted as indicators that may appear before an alarm is triggered.
The Safety Alert emphasises several operational points:
- Vessel crews are advised to conduct focused inspections of EGR coolers for weld integrity and potential leakage during routine checks.
- Operators with a Safety Management System are encouraged to integrate these checks within their documented procedures.
- Engine-specific guidelines note the importance of proper expansion-tank height, correct pressure settings, removal of air pockets during maintenance, and maintaining coolant chemistry in alignment with manufacturer requirements.
This alert is intended to raise industry-wide awareness regarding the potential impact of EGR cooler weld degradation on propulsion reliability, particularly for vessels operating engines of similar configuration.
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Source: U.S. Coast Guard
