IMCA has issued a Safety Flash, describing an incident in which during sea trials following a docking period, smoke and fire were observed coming from the turbocharger flange to the exhaust manifold of one of the engines.
What went wrong
It was found that the gasket on the turbocharger flange was damaged. The gasket in question was the wrong one for the job: it from the exhaust pipe and was designed as a “high temperature” gasket (<300°C), whereas it should have been a gasket with a specification of >500°C.
The correct turbocharger flange gasket was not available on board during the overhaul. Furthermore, the correct parts had not been properly identified, and the engine had just undergone an overhaul, during which all engine components were cleaned. However, there was a concern that residual material from the combustion chamber may have remained and reached the turbocharger area.
Cause
An incorrect gasket was installed that did not meet the required specifications. The required gasket needed to have a temperature resistance above 500°C, whereas the installed gasket had a specification below 300°C.
Lessons learned
- Check carefully that equipment and spares used, particularly in safety critical equipment, meet the specified requirements;
- There is a difference in appearance between gaskets designed for temperatures above 500°C and those designed for temperatures below 500°C. Those designed for temperatures above 500°C will feature a visible wire mesh in the middle of their structure.
