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- Apr 28, 2018
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- Bob
Cheers Chris
But Bob i think the sharfts looks nicer in SILVER STAINLESS STEEL as that shows off the A FRAMES an intermediate frame as thats what my norfolk props sharfts are but on my nimitz they were just brass prop tubes so thats why i painted them hull colourCheers Chris
Thanks DaveThe propeller shafts are large pieces of metal, they will be made of high grade steel, in smaller vessels they might be stainless steel, but for larger vessels, the cost would be huge.
This is a typical propeller shaft ( actually an intermediate shaft ) of a largish merchant ship the shaft will be about 750mm in diameter.........................
View attachment 412817
Why so big? The largest marine diesel engine can produce over 100,000hp at 120 rpm, so the transmitted torque is huge. These engines are invariably 2-stroke directly coupled, reversible monsters.
The Armed Navy used steam & gas turbines, running at very high speed, but geared down through reduction boxes, so the prop shaft would run at the same sort of speed - they produced similar power, so had similar sized propeller shafts. More modern warships have controllable pitch propellers, which complicates the shafts. ( The engine, usually a gas turbine runs at a constant speed & the thrust & direction is controlled by the pitch of the blades - very complicated ). Either way, the external prop shaft would be need to be protected from corrosion, and paint is the conventional way.
Dave
Alfa-Laval, and Titan centrifuges - used for Heavy Residual Fuel, Diesel Fuel, Lubricating oil ( all individuals sets, some self cleaning, others not ). Oily water separators were a flotation/rotation tank. I reckon I could still strip one down even now - even though it's over 25 years ago..................Westfalia KA-25 centrifuges Dave? I know they used them on large tankers, but not sure if they were used in the fuel feed train.
I used them for twenty odd years as fermentation cell separators until we replaced them with purpose built Westfalia CSC-20 pharmaceutical separators.
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