I AM perplexed, oil has a lower sg than water, [lighter] hence the head of oil totally required has to compensate for the total draught of the stern tube at any time in a ships life, and still have a ;head pressure to avoid failure of the stern gland under various CP Or propeller rotations under power.
Oil filled Stern Tubes
I was working at a shipyard in Tampa when they were building 5 tankers. They were ER aft jobs, so only ashort length of shafting in the ER. On the LOP system they had the ability to purify the stern tube. You had oil filled seals with a header tank on the inboard and outboard ends, plus the oil around the shaft to lubricate it with a header tank also.
We get back from trials so next day thought I would line up a LOP on this system. I ended up pulling water into the stern tube so something was obviously wrong with the system.
Never came across anything like this before. As long as your seals were ok and you had that head of oil above the water line than you shouldn't have any leaks inboard only outboard.
Though it was US designed and built and had some really backward designs.
Anybody come across this set up before?
![Wood Naval architecture Building Watercraft Engineering]()
Finished ship image to follow when on PC.
https://en.wikipedia.org/wiki/USNS_Paul_Buck this was 1st of 5.
Ocean Product Tankers Inc.
Due to a senior management faux pas the 2nd hull was ready first. They all started with Ocean ........ names which would be easier on the tongue , but reverted to the US tradition of naming them after seamen who had won medals which ended up with long Italian names complete with the inevitable middle i initial included such as Lawrence S Giannella and similar mouthfulls over VHF.
Even the Chinese names were better like Wan Long Dong and the like.
We get back from trials so next day thought I would line up a LOP on this system. I ended up pulling water into the stern tube so something was obviously wrong with the system.
Never came across anything like this before. As long as your seals were ok and you had that head of oil above the water line than you shouldn't have any leaks inboard only outboard.
Though it was US designed and built and had some really backward designs.
Anybody come across this set up before?
Finished ship image to follow when on PC.
https://en.wikipedia.org/wiki/USNS_Paul_Buck this was 1st of 5.
Ocean Product Tankers Inc.
Due to a senior management faux pas the 2nd hull was ready first. They all started with Ocean ........ names which would be easier on the tongue , but reverted to the US tradition of naming them after seamen who had won medals which ended up with long Italian names complete with the inevitable middle i initial included such as Lawrence S Giannella and similar mouthfulls over VHF.
Even the Chinese names were better like Wan Long Dong and the like.
