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Sagebrush posted:https://en.wikipedia.org/wiki/Alfa-class_submarine lmao that is incredibly metal and holy poo poo
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Dec 30, 2022 08:37
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Phanatic posted:That thing's sitting there rotting away at pierside in Philly and it's really sad. The way I remember it, they basically crossed out the word "Boiler" from an existing set of plans and wrote in "Reactor". It wasn't until their big technology demonstrator proved itself that they bothered to design something that actually made sense.
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Dec 30, 2022 08:40
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Jabor posted:There isn't really a "top speed" on any of those boats, you can always decide to push things harder and harder for a little bit of extra speed until something catastrophically breaks. There's a speed that they'll go if they're in a hurry to get somewhere but it's not an emergency, which you might consider to be the standard "top speed", but if there is an emergency and the need is urgent enough then they'll go a bit faster and risk the catastrophic damage. I can confirm that. The ship I was stationed on in the 90's had to limp into port on aux. engines, ~8 hours behind schedule, because our main engine developed a crack 'for mysterious reasons (the Captain wanted to see how fast we could go)'. It took about 30-60 minutes to happen from hitting max speed and pushing the envelope, as I recall, but this _was_ over 20 years ago, so my memory of that is shady. I loving remember coming into port at 4:30 am, though.
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Dec 30, 2022 14:29
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Grognan posted:lmao that is incredibly metal and holy poo poo Breeder reactors used to be cooled with stuff like molten sodium,  mercury, or NaK.Note that the table in the linked article has a dedicated column for "number of coolant leaks". Zopotantor fucked around with this message at 14:32 on Dec 30, 2022 |
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Dec 30, 2022 14:30
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of course they tried using it in the Project Pluto missile
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Dec 30, 2022 14:50
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Zopotantor posted:Breeder reactors used to be cooled with stuff like molten sodium, Speaking of coolant leaks. quote:The Soviet RORSAT radar satellites were powered by a BES-5 reactor, which was cooled with NaK. In addition to the wide liquid temperature range, NaK has a very low vapor pressure, which is important in the vacuum of space.
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Dec 30, 2022 14:53
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Sagebrush posted:12 knots surfaced, 41+ knots submerged. They achieved this by building the submarine out of titanium and using a very compact nuclear reactor cooled with molten lead, meaning the submarine could have low drag and high power, but if the lead ever solidified the reactor would be permanently disabled so they had to keep the boats connected to steam plants when they were in port.  is that the port steam facilities were never reliable and most of the Alfas wound up with their reactors frozen solid.Zopotantor posted:Breeder reactors used to be cooled with stuff like molten sodium, There's a huge amount to be said for liquid metal coolants from a safety perspective.
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Dec 30, 2022 15:15
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haveblue posted:of course they tried using it in the Project Pluto missile They thought about it, but the reactors for Project Pluto ended up working just find with air cooling. Sodium Cooled reactors are really neat.
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Dec 30, 2022 15:21
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Yeah. Super heated steam is no-one's friend.
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Dec 30, 2022 15:22
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Phanatic posted:There's a huge amount to be said for liquid metal coolants from a safety perspective. This right here. People always get hung up on the burning molten metal, but the energy transfer from highly, highly pressurized water can easily do similar amounts of damage. Especially when your water inventory is almost always much larger than a comparable NaK inventory for a given reactor power.
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Dec 30, 2022 15:23
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Here comes the man train https://twitter.com/nocontextbrits/status/1608478517423149058?s=46&t=6_iofrS84pYRASR4cvHqbQ
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Dec 30, 2022 15:23
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The thing that’s loving with me isn’t the speed illusion, it’s that hosed-up tacked-on bow extension.
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Dec 30, 2022 15:29
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Groda posted:This right here. Also: 1. Not having to run at very high pressures to get any kind of efficiency is good. 2. If coolant does leak, it just solidifies, you don't need to worry about it flashing into steam and escaping into the environment. 3. If coolant does leak, you don't have the rest of your coolant flashing into steam and escaping because the only thing that was keeping it in liquid state was 150 bar of pressure that's now gone because you have a leak. 4. You can just build your reactor in a big bucket so that even if you do have a leak the coolant just leaks into the bucket. 5. You can move the coolant around with magnetic pumps which don't have any moving parts to fail or seals to leak.
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Dec 30, 2022 15:37
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Wistful of Dollars posted:The thing that’s loving with me isn’t the speed illusion, it’s that hosed-up tacked-on bow extension. Mentioned before, but pretty much every large ship will have a bulbous bow. It is much more efficient. From warships to containers, they'll all have a below the waterline bulbous bow. The reason you're seeing that one is because that ship is empty and traveling to load up. Once fully loaded the red portion of the vessel will be almost completely submerged.
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Dec 30, 2022 15:59
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Mr. Nice! posted:Mentioned before, but pretty much every large ship will have a bulbous bow. It is much more efficient. From warships to containers, they'll all have a below the waterline bulbous bow. Mate, I’m not talking about the bulbous bow - I know what those do. I’m talking about that triangle that’s welded on to the front of the ship. The one whose paint doesn’t match the rest. E: maybe that triangle is part of how they looney-tuned a bulbous bow on it, idk - looks awful. Wistful of Dollars fucked around with this message at 16:10 on Dec 30, 2022 |
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Dec 30, 2022 16:08
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The SS United States is cool, and another cool fast ship to read about is the previous Blue Riband winner, the RMS Queen Mary (which was a much bigger ship at about 80,000 tons). QM was converted to a troopship during the war, and crossed the Atlantic unescorted most of the way with thousands of troops on board. In July 1943, Queen Mary carried 15,740 soldiers and 943 crew, the record for the most people carried by one ship. On another trip she got hit by a rogue wave and rolled 52 degrees, with 10,000 troops on board. No U-boat could intercept her at speed and no escort ship could hope to keep up. Even fast ships like destroyers that could match the liner's speed would run out of fuel in a few hours at 32kts. They tried escorting the liner in and out of port but in October '42 a light cruiser blundered into the liner's path and got sliced in half. Cruiser sank with 239 of its crew. Queen Mary had a division of troops on board and was under orders to never stop for any reason and kept going after the collision.
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Dec 30, 2022 16:10
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Jabor posted:There isn't really a "top speed" on any of those boats, you can always decide to push things harder and harder for a little bit of extra speed until something catastrophically breaks. There's a speed that they'll go if they're in a hurry to get somewhere but it's not an emergency, which you might consider to be the standard "top speed", but if there is an emergency and the need is urgent enough then they'll go a bit faster and risk the catastrophic damage. I recently read the memoirs of Tameichi Hara - apparently the only Japanese destroyer captain to survive all of WW2 - called Japanese Destroyer Captain. While he was in command of Shigure, they were on a solo mission to do something, probably deliver supplies, and an Allied plane attacked them. It dropped a bomb, the bomb barely missed, and Hara ordered what he called an "immediate boost", mentioning that normally boosting a destroyer took about 30 minutes. I dunno what the actual procedure is beyond adding more fuel and the chief engineer fretting about the dilithium crystals. The crew did this immediate boost and the XO freaked out because there's fire pouring out of the funnels because fuel is burning in the exhaust still. Then the radio room picked up up a transmission from the allied plane. The flight crew saw the fire from the ship's funnels, but decided that meant their bomb hit and that the ship was sinking, so they were heading home. The Shigure headed back to Rabaul or Truk, and the maintenance crews there were just like "Yeah, this engine is hosed, you'll have to go back to Japan to get it fixed." Well, that's my naval OSHA story, thanks for reading.
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Dec 30, 2022 16:51
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my favorite fast ship is the Turbinia, the first ship powered by a steam turbine:quote:Charles Algernon Parsons invented the modern steam turbine in 1884, and having foreseen its potential to power ships, he set up the Parsons Marine Steam Turbine Company with five associates in 1893. To develop this, he had the experimental vessel Turbinia built in a light design of steel by the firm of Brown and Hood, based at Wallsend on Tyne[1] in the North East of England. Imagine what that would have been like to witness. It'd be like going to an air show where the Blue Angels are performing, and then some random engineer appears in a Mach 5 UFO he built in his shed, powered by an anti-gravity engine of his own design, and flies circles around them to show off.  You can just tell in that picture that the ship is fast. Sagebrush fucked around with this message at 16:54 on Dec 30, 2022 |
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Dec 30, 2022 16:51
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Vlaphor posted:Attach everything together first and it's much easier to weld. Cheramie Botruc No 39 https://www.marinetraffic.com/en/ais/home/shipid:430917/zoom:10  
Wee fucked around with this message at 17:02 on Dec 30, 2022 |
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Dec 30, 2022 16:59
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Sagebrush posted:my favorite fast ship is the Turbinia, the first ship powered by a steam turbine: This owns so hard. I love it when inventors just clown on the establishment, kind of like that Finnish pilot that keeps building planes in his shed and flying them till they get seized and then building another one.
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Dec 30, 2022 17:02
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https://www.youtube.com/watch?v=JbmtxvF8Sz0
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Dec 30, 2022 17:09
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Goose, locomotive and farty gas tank were the best. My eyes are watering from laughing at these.
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Dec 30, 2022 17:58
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HenryJLittlefinger posted:This owns so hard. I love it when inventors just clown on the establishment, kind of like that Finnish pilot that keeps building planes in his shed and flying them till they get seized and then building another one. It wasn't so much clowning on the establishment as showing off so they'd buy his stuff. Which they did.
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Dec 30, 2022 18:07
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Dick Trauma posted:Goose, locomotive and farty gas tank were the best. My eyes are watering from laughing at these. I'm partial to the last clip DIE DIE DIE
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Dec 30, 2022 18:12
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Vincent Van Goatse posted:It wasn't so much clowning on the establishment as showing off so they'd buy his stuff. Which they did. And it's not like he just showed up out of the blue to debut the ship, he'd been working on it for a while and the Admiralty was completely up to date on how it was coming along and was *very* interested in turbine propulsion. It's just that nobody expected him to show up at the Jubilee like that.
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Dec 30, 2022 18:22
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Also, for comparison, civil war era ships had a max speed of 12kts or so. A modern DDG has an unclassified top speed at least 30+kts. This dude was flying around ships three times their max speed. He was so quick that small boats of the time couldn't keep up. That's just insane.
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Dec 30, 2022 18:26
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Dick Trauma posted:Goose, locomotive and farty gas tank were the best. My eyes are watering from laughing at these. I had to excuse myself from the office. I haven't laughed that hard at something in a while.
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Dec 30, 2022 18:45
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Wistful of Dollars posted:Mate, I’m not talking about the bulbous bow - I know what those do. It's the same paint, the difference is that the triangular part is flat and showing that flat side to the camera. The bow is round and is not.
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Dec 30, 2022 19:09
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Wistful of Dollars posted:Mate, I’m not talking about the bulbous bow - I know what those do. Wow, it took me a while to understand what's going on with that ship. I was certain something big was behind it, but it looks like it's just a sheet of metal filing in the gap between the front of the ship and "the bulbous bow". I lived in a city with 3 big shipyards and never saw that kind of design. Icebreaker maybe?
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Dec 30, 2022 19:51
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gbut posted:Wow, it took me a while to understand what's going on with that ship. I was certain something big was behind it, but it looks like it's just a sheet of metal filing in the gap between the front of the ship and "the bulbous bow". I lived in a city with 3 big shipyards and never saw that kind of design. I think most icebreakers slide up on top of the ice and it breaks under the weight, instead of slicing through like you'd expect.
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Dec 30, 2022 20:12
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All this talk of bulbous bows has gotten Bulbous Bouffant stuck in my head.
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Dec 30, 2022 20:13
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 https://va.media.tumblr.com/tumblr_rnpjcn1rcP1r0uzl6.mp4
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Dec 30, 2022 20:26
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Another fun experimental ship- Yamato 1. It was a testbed for magnetohydrodynamic propulsion, literally the caterpillar drive from Hunt for Red October, which is real and does work more or less as depicted. Unfortunately it doesn't work well. Yamato 1 never hit its performance targets and everyone gave up on the whole thing
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Dec 30, 2022 20:55
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haveblue posted:Another fun experimental ship- Yamato 1. It was a testbed for magnetohydrodynamic propulsion, literally the caterpillar drive from Hunt for Red October, which is real and does work more or less as depicted. Unfortunately it doesn't work well. Yamato 1 never hit its performance targets and everyone gave up on the whole thing I appreciate that they took the time to make it look like a Star Trek shuttlecraft.
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Dec 30, 2022 21:13
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https://va.media.tumblr.com/tumblr_rnpogr8KE01r0uzl6.mp4
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Dec 30, 2022 21:51
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Just looking at the first frame I said to myself "This is going to be a floor collapse video."
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Dec 30, 2022 22:21
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I was worried it was going to be another Versailles Halls disaster but thankfully that pothole is not very deep.
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Dec 30, 2022 22:42
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Phanatic posted:There's some qual they have to do periodically that looks like this: I get that it's mid turn, like so code:EDIT: gently caress, lining that poo poo up was harder than I thought it would be thisusedyet fucked around with this message at 23:24 on Dec 30, 2022 |
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Dec 30, 2022 23:22
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thisusedyet posted:But it really looks like that carrier's drifting It probably is but not as much as the image portrays; the conservation of energy says that it has to burn that forward momentum somewhere.
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Dec 30, 2022 23:25
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They call it Sinkhole de Mayo for a reason. All this talk about ship speed is boring, speed is boring. Acceleration is where it's at. I thought I read somewhere that the big US aircraft carriers can take off with a similar kick to a jetski, is that true? Seems to me achieving high acceleration in water presents a different host of challenges than with land vehicles. I know there are those incredibly dangerous drag racing boats, what kind of design considerations go into making a boat that can get off the line insanely quickly?
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Dec 30, 2022 23:26
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