>Lessons Learned from Improper Assembly of Shaft Seal

>The Office of Investigations and Analysis (CG-545) recently issued Lessons Learned 02-10 regarding the dangers that may result from the improper assembly of shaft seals. A towing vessel had a new shaft seal installed. During assembly, three-quarter inch bolts were used rather than the M20 metric bolts that were called for. The two sizes are very similar, but not the same. The bolts soon loosened, allowing the seal assembly to separate from the flange mounting service. When astern propulsion was applied, water passed up the shaft into the engine room, resulting in flooding. The master intentionally grounded the vessel to avoid sinking. This and other Lessons Learned are available on CG Homeport under Missions > Investigations > Lessons Learned. [Summary from Bryant’s Maritime Blog].