discussion Ships boats colours and rigging of the KGV

[BattleshipBob]

Cheers Chris

 

[boatman]

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 colour
chris

 

[Dave Ward]

The 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.........................


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

 

[boatman]

VERY well put Dave spot on an some great pics on the prop sharfts an on nimitz aircraft carrier the prop sharfts are about 4 hundred feet long an in 4 sections i read somewhere when i was building my nimitz
chris

 

[BattleshipBob]

The 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.........................


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

Thanks Dave

I use to show my students ships engines when covering truck engines, just to compare size, power and pollution.

 

[Dave Ward]

On virtually all the ships I served on, the main engine was a large marine diesel, either 4,6 or 8 cylinders - power from 11,000hp to 22,000hp. The main engine not only supplied propulsion, but the exhaust gas generated steam in a waste heat boiler, which was used for all sorts of purposes, mainly heating. The return water from the main engine water jackets was used to make fresh water in a partial pressure evaporator ( 20+ tons a day ), and also to heat the domestic fresh washing water. The engine ran on what was known as 'heavy residual' oil - basically what was left after the expensive parts of crude oil ( petrol, paraffin etc ) has been distilled, or refined out. It had to be heated to about 40C before it could be pumped, and 90C before centrifuging, and finally being injected into the cylinders. No oil was wasted - any oil leakage into the bilges was separated & pumped back into the service tanks
OK the exhaust gases were polluting, but the overall plant efficiency was pretty high
Dave

 

[Tim Marlow]

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.

 

[Dave Ward]

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.

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..................
Dave

 

[Tim Marlow]

I know the feeling. I stripped the Westfalias daily for about twenty years. It was the only way we could recover the cell paste. Once learned never forgotten.... that was the great advance of the CSC-20s. They were continuous discharging, self cleaning and fitted with PLC automatic steam sterilisation.
We had Alfa Lavals as well. A little smaller than the Westfalias, but solid bronze lids......ours were set up for solid/liquid separation, but yours would have been Liquid/liquid I suppose. We also had Sharples ultracentrifuges, tubes about a metre long that rotated at about three times the speed of the disk stacks. Never had the privilege of working on a Podbilniak heavy/light phase separator though.

 

[Defiant911]

I was going to create a new thread but seeing as your thread is about rigging maybe I can add my question in.
I was trying to find information regarding how best to do your rigging.
For instance if your rigging your smoke stacks to the decking how do you go about it?
Do you drill small holes
In deck and smoke stack and glue in the rigging between? Do you start at the smoke stack and stretch down to the deck or vice versa?
Or do you use some form of small loop stick to both deck and smoke stack to adhere the rigging to. I see lots of models rigged up but very few explanation how they went about it?
Carl

 

[Tim Marlow]

Not sure how the rigging is done Carl, but fixing at the bottom then stretching to the top will be easier to accomplish. In fact, if there are a few lines in the same area I would be inclined to cut them over size and fix them all at the bottom first...it just makes later stages easier. You can then stretch them, stick them, then cut them.