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Stick Legs 2 October
talking of bows (and I've probably asked this question before, but can't remember the answer frown ).... in 1910 we had the the bow angled forward, 1940 angled back, 1980 angled sharply back and then in 2023 we're back to having the bow angled forward again. Does that mean that the designers of the Dreadnought got their prow design right and subsequent designs were wrong? ISTR part of the answer had to do with how the ship went through heavy seas which modern ships try to avoid (especially those carrying passengers) but...
said:
hidetheelephants said:
The ram bow typical of the Dreadnaught and pre-Dreadnaught era were only accidentally beneficial as knowledge of how bow waves interact with hulls was either only theoretical or hadn't yet emerged.
Positively raked bows, generally with flare, provide seaworthiness by giving a rising waterplane area(gives rising buoyancy) as the bow plunges into a wave and deflect water away from the deck.
Plumb and negatively raked bows give a much softer motion in heavy seas as the water plane area either stays the same or actually reduces as the bow enters a wave, at a cost of the motion being greater in magnitude and needing more freeboard.
The steep reverse rake of Zumwalt etc are mostly about radar cross-section reduction although they also affect seakeeping.
appreciated Positively raked bows, generally with flare, provide seaworthiness by giving a rising waterplane area(gives rising buoyancy) as the bow plunges into a wave and deflect water away from the deck.
Plumb and negatively raked bows give a much softer motion in heavy seas as the water plane area either stays the same or actually reduces as the bow enters a wave, at a cost of the motion being greater in magnitude and needing more freeboard.
The steep reverse rake of Zumwalt etc are mostly about radar cross-section reduction although they also affect seakeeping.
The speed of a ship / boat is power (obviously) but also the ratio of the the length at the waterline to the beam. A longer LWL will, all other things being equal, result in greater speed.
I think they were right back in the 'olden' days when they had vertical bows. Mid 20thC ships with their sharply raked bows just 'looked' faster though. Even naval acrhitects can be slaves to fashion I suppose!
View of the U.S. Navy aircraft carrier USS Midway (CVB-41), mid-1946. She used the propeller thrust of 32 of the embarked Vought F4U-4 Corsairs to swing the carrier.
This was first used by USS Randolph (CV-15) off Guam in June 1945 when the proximity of dangerous shoals and heavy harbor traffic made it impossible for the carrier to turn around under her own power.
Randolph's commanding officer, Captain Felix L. Baker, ordered that 5 aircraft each be placed on the port bow and the starboard quarter, facing inward.
As the props of the starboard planes turned at cruising speed, the carrier's bow turned to the left so that the carrier's port bow caught the trade wind.
Since then this method was occasionally used in the U.S. Navy as an emergency procedure (and named "Operation Pinwheel").
US Navy All Hands Magazine - June 1946
MartG said:
View of the U.S. Navy aircraft carrier USS Midway (CVB-41), mid-1946. She used the propeller thrust of 32 of the embarked Vought F4U-4 Corsairs to swing the carrier.
This was first used by USS Randolph (CV-15) off Guam in June 1945 when the proximity of dangerous shoals and heavy harbor traffic made it impossible for the carrier to turn around under her own power.
Randolph's commanding officer, Captain Felix L. Baker, ordered that 5 aircraft each be placed on the port bow and the starboard quarter, facing inward.
As the props of the starboard planes turned at cruising speed, the carrier's bow turned to the left so that the carrier's port bow caught the trade wind.
Since then this method was occasionally used in the U.S. Navy as an emergency procedure (and named "Operation Pinwheel").
US Navy All Hands Magazine - June 1946
Midway is now a museum ship in San Diego, CA. If ever in the area it’s well worth a day.
generationx said:
MartG said:
View of the U.S. Navy aircraft carrier USS Midway (CVB-41), mid-1946. She used the propeller thrust of 32 of the embarked Vought F4U-4 Corsairs to swing the carrier.
This was first used by USS Randolph (CV-15) off Guam in June 1945 when the proximity of dangerous shoals and heavy harbor traffic made it impossible for the carrier to turn around under her own power.
Randolph's commanding officer, Captain Felix L. Baker, ordered that 5 aircraft each be placed on the port bow and the starboard quarter, facing inward.
As the props of the starboard planes turned at cruising speed, the carrier's bow turned to the left so that the carrier's port bow caught the trade wind.
Since then this method was occasionally used in the U.S. Navy as an emergency procedure (and named "Operation Pinwheel").
US Navy All Hands Magazine - June 1946
Midway is now a museum ship in San Diego, CA. If ever in the area it’s well worth a day.
Baron Greenback said:
generationx said:
MartG said:
View of the U.S. Navy aircraft carrier USS Midway (CVB-41), mid-1946. She used the propeller thrust of 32 of the embarked Vought F4U-4 Corsairs to swing the carrier.
This was first used by USS Randolph (CV-15) off Guam in June 1945 when the proximity of dangerous shoals and heavy harbor traffic made it impossible for the carrier to turn around under her own power.
Randolph's commanding officer, Captain Felix L. Baker, ordered that 5 aircraft each be placed on the port bow and the starboard quarter, facing inward.
As the props of the starboard planes turned at cruising speed, the carrier's bow turned to the left so that the carrier's port bow caught the trade wind.
Since then this method was occasionally used in the U.S. Navy as an emergency procedure (and named "Operation Pinwheel").
US Navy All Hands Magazine - June 1946
Midway is now a museum ship in San Diego, CA. If ever in the area it’s well worth a day.
LimaDelta said:
The last 'big' ship I was on (a bit bigger than the USS Midway) had about 6MW of bow thrusters (3x2MW). A Corsair put out a little over 2000hp which is about 1.5MW, so you wouldn't need that many to make it work. 32 suggests running at less than max power, or a lot of efficiency losses.
Maybe it just span very quickly. 
Battleship Tirpitz camouflaged as a group of civil buildings in order to cheat spies and reconnaissance aircraft
https://navalhistoria.com/the-mighty-tirpitz-a-bat...
RizzoTheRat said:
That's fantastic, a bit of googling turned up this wider shot
My grandfather ended up stuck in Russia for a few days on one of the raids on the Tirpitz.
My great uncle was also on one of the raids.My grandfather ended up stuck in Russia for a few days on one of the raids on the Tirpitz.
https://losses.internationalbcc.co.uk/loss/118338
According to the Express, this is HMS Vanguard back in action after a 7 year refit. I'm surprised it only took 7 years to fit 15" twin gun turrets to a nuclear submarine 
https://www.express.co.uk/news/uk/1862174/uk-nucle...
https://www.express.co.uk/news/uk/1862174/uk-nucle...
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