@ AFP

So for roll-on/roll-off ships, what's the preferable prefix?

Edited by HallowHawk on Jul 22nd 2021 at 8:16:49 PM

According to Wiki, it's RORO or ro-ro. There are also some specific types that get their own designations like the LST (Landing Ship, Tank) from WWII, which was designed to beach itself and then disgorge its contents onto the battlefield.

Edited by AFP on Jul 22nd 2021 at 3:36:01 AM

CNO: Too Much New Tech On Ford Was A Mistake

Question for a story!

In the early 1900s US Navy, what would be the rank of the gunnery/ordnance officer of a battleship commanded by a rear admiral?

According to Wikipedia, gunnery officers were typically the third highest ranking officer in a warship, next to XO and captain. So I'm guessing it would be somewhere along the range of O-3 to O-5?

Edited by dRoy on Aug 7th 2021 at 8:14:54 PM

Edit: You asked this question long ago, but I don't know if any battleships were commanded directly by flag officers of any flavor, or if they'd have a Captain in command with a Rear Admiral or higher flying their flag on the ship.

The newest Virginia-class attack sub, USS Oregon, enters service.

Edited by AFP on May 28th 2022 at 8:36:25 AM

China Launches Fujian, Its Most Advanced Aircraft Carrier.

Unlike Shandong and Liaoning, this one appears to be full CATOBAR style.

I don’t know any specifics otherwise.

The USS Gerald Ford is out to sea for two months of stress tests and exercises

Heard that the Russian Navy operates a "missile fuel tanker" and a "special waste tanker" (According to this, the former is to transport missile fuel while the latter is employed in collecting liquid fuel waste).

Other than the French Navy, who operate "support and pollution control" ships, no other navy seems to operate specialized tankers. Why only the Russian Navy?

Because the Russians use particularly toxic fuels.

None of the other navies that operate SLBMs use liquid propellants in them except maybe North Korea, and even they're working on fully solid-fuelled ones.

Though in the case of what missile fuel tankers do, would, say, the US Navy, have needed specialized tankers to deliver solid fuel for their missiles?

Solid rocket propellants are a lot less volatile/toxic/corrosive than their liquid counterparts, you can just stuff them into the missile at the factory rather than having to wait until you're about to launch.

Yeah, the big advantages of solid-fueled rockets are that they don't need to be fueled before launch, and the fuel is much more stable and safe to work with (which is what allows the first thing). Open the launch tube door, turn the keys, and party on Garth.

Farewell aircraft carrier São Paulo.

Brazil (Portuguese): “And good riddance!”

Ammunition Cum Torpedo Cum Missile (ACTCM) Barge, Yard 125 Lsam 15 was Launched by Capt Prashant Saxena

The launch ceremony had to be fairly small due to uncontrolled giggling from the larger audiences.

Advice for designing a realistic submarine for my story idea?

The story is set in the late 2010s or early 2020s. It's a civilian sub designed to explore the extreme depths and be as self-sufficient as possible with little surfacing, operating with a very small crew. It's mostly one inventor's idea, sort of a private expedition. I thought about it being named "The Ray" or "(Something) Ray", so it might also vaguely resemble a ray?

Edited by Nukeli on Jun 4th 2023 at 6:18:19 PM

Basically you'd want an Akula/Typhoon class submarine but with the hull reinforced to hold more pressure, instead of missiles a reinforced hull, heavy on automated system health management, a fairly large supply storage for parts, food and other condiments. Possibly a greenhouse for food and ad-hoc air filtering and use the control surfaces built like a plane to push the submarine down, instead of just relying on the ballasts for diving.

That's nuclear, would it be allowed?

Nuclear civilian ships aren't baned, a couple even exist.

There just too expensive to really go any where beyond a couple novelty creations.

Military submarines aren't really built for extreme depths. You'd want to look at deep-submergence vehicles (DSVs), which are built for deep-sea exploration. One classic example is the Alvin, which was launched in 1964 and is still in operation today:

Right off the bat, you'll notice some key design features. These things are usually pretty small and squat. Their hulls are built to survive extreme pressure, not for speed or lateral range. Deep-diving submarines basically have two layers: an outer "weather hull" with thin walls, which can compress under pressure, and an inner "pressure hull" with thick reinforced walls, where the crew resides. In a DSV, this pressure hull is spherical◊ (the shape best optimised to withstand pressure), and is only big enough for a handful of crewmembers. The propulsion machinery, ballast tanks, batteries and sensors all lay between the pressure hull and the weather hull. They're not really built to travel far: they're practically tethered to a mothership on the surface and usually operate for just a few hours, maybe a day at most.

So obviously, military submarines have very different design principles, with much larger crews and operate for weeks to months at a time. They have hydrodynamic, teardrop-shaped hulls that are optimised for speed, but don't deal with extreme pressures nearly as well. And they obviously have a lot more space inside, for living facilities as well as the much more powerful machineries they need to cruise underwater. Let's just take a quick look at some of the life support stuff that a single-crew submarine might need:

• Air circulation system (fetches oxygen from water through electrolysis + filters out harmful gases + HVAC)

• Sleeping quarters

• Small greenhouse to grow food crops like potatoes and strawberries, possibly using hydroponics (think The Martian)

• Food/medicine refrigeration

• Composting toilet to feed the greenhouse (should need little water, but might need some power if you use a vacuum flush design)

• Leg room for stretching/exercising

• Entertainment (maybe not a high-powered gaming rig, but you'd want to bring along maybe some Chuck Tingle novels, or keep a modest laptop charged so you could watch some K-Dramas on it).

And then you'd have the submarine's own keystone systems:

• Batteries

• Propulsion

• Radio/satellite comms/navigation (surface only)

• Lighting (internal and external)

• Sensors: water flow sensor, thermometer, CCTV cameras mounted outside the hull. To navigate seabed terrain, you can opt for an active sonar (maybe not as fancy as the kind carried by military submarines); but these take up a bit of space and a lot of power. For a less precise (but more practical) modern alternative, you might want to consider a gravimeter, which measures the Earth's gravity at a particular point to find the lay of the terrain.

All of these will need power. A nuclear reactor can give you a lot of continuous power for upwards of a decade; but it's extremely complex and expensive to build, requires a lot of space for moving parts like the pumps and steam turbine(s), and your single crewmember might not be able to do anything if something breaks.

One possible alternative would be a radioisotope thermoelectric generator, which is a kind of nuclear-lite generator used to power satellites, extraterrestrial rovers and other things you don't expect a human being to ever maintain. Basically, a radioactive source (usually plutonium-238) emits continuous heat from its decay. The heat powers a battery through thermoelectric effect; no need for a turbine or any other intermediary component. These generators don't put out a whole lot of power, but they last a similarly long time with zero maintenance — and you could theoretically hook up a few of them in series for more juice.

One of my favourite fictional submarines is the Cyclops from Subnautica, which is closely inspired by real-life DSVs like the Alvin. It's designed with some Artistic License – Physics, as you'll notice from the big glass dome and forcefield dock. It's also a compromise design that's not super optimised for extreme deep diving: the elongated outer hull doesn't resist pressure that well, and it's reflected in-game with its limited ability to navigate the game's deepest areas.

But you can still see the engineering rationales at play here. The Cyclops basically has three pressure hulls: a spherical one at the cockpit and two cylindrical ones behind it, in a double-decker configuration. The sensors are housed in a small sail at the top and a pair of winglets to the sides, and the sub has a long, beefy propulsion shaft at the back, more akin to a military submarine than a DSV (which, again, are built for depth, not speed).

One nifty feature it has is a fabricator that you can use to craft various gadgets from the raw materials you find in the game. This is obviously a piece of sci-fi tech that doesn't yet exist in real life. I suppose you could theoretically craft stop-gap replacement parts with a 3D printer/SLM machine; but these things aren't a one-size fit all, take up more space and power and might give off dangerous fumes that put more stress on your air circulation. You might also need additional processes (like welding) to join the products into something usable, and the whole process requires you to carry the required materials (polymer filaments and metal powders) in the first place.

The square-cube law is your adversary here. A bigger hull means more weight means more power consumption, both for propulsion/ballast and life support systems. If you design your sub to be squat and spherical for extreme deep diving, then don't expect it to move very gracefully at all; and vice versa for a hydrodynamic teardrop hull designed for speed.

I have thought the crew should have 4-5 people. So that i can afford to kill off one or two characters, and there's somebody left for character interaction instead of just being in the lone survivor's head.

One is the captain, the other the first mate, the third the nuclear technician if it's a nuclear submarine. There should propably be another nuclear technician on board. If there's a fifth crewmember, what should their onboard job be?

Navigator.

In any good submarine story, you need a cook, in case you need to fight folks trying to take over the sub.

X-Posted from the Military Thread because this is all navy news.

Navy Looking For Counter-Drone Systems That Can Be Rapidly Added To Its Ships

The Navy is interested in quickly enhancing its ships’ ability to down drones, reflecting concerns over what’s happening in the Red Sea.

USN is looking for drone counter systems for its vessels, given the current spam on Ukraine and Houthi usage of cheap disposable drones, a more cost effective option with deeper magazines is desirable, specially with the issues of drone swarms depleting missile magazines.

Boat Swarm Vision Laid Out By DoD

A new program envisions swarms of drone boats autonomously finding and chasing down target ships, and maybe even attacking them directly.

Mostly involve using sUSV to track vessels, monitoring electronic emissions from other ships, provide targeting data for manned vessels, navigate on crowded shipping lanes safely, operate after the loss of one or more sUSVs and be easy to store and deploy from containers.

Ukraine Sinks Russian Navy Missile Corvette In Drone Boat Attack

The Russian corvette Ivanovets was hit by six Ukrainian uncrewed surface vessels and sunk in the Black Sea, Ukraine’s spy boss told us.

More footage and details on the sinking of a Russian Tarantul-III class missile corvette on the Black Sea by a drone boat swarm, the damage was done fast enough to sink the ship with all 44 crew on the freezing sea.

Navy’s SM-6 Missile Used In Combat: Report

The use of the multi-purpose SM-6 missile in the ongoing battle with the Houthis would mark a major milestone for the versatile weapon.

The USN Anti-Everything SM-6 was fired on the Gulf of Aden near the Red Sea, by the DDG USS Carney.

The details aren't fully revealed but it is believed to be fired at Houthi short range Anti Ship Ballistic Missiles, with a lower flight profile compared to IRBM, that the SM-3 is meant to engage.

Phalanx CIWS Downs Houthi Missile Dangerously Close To Destroyer: Report

For a Navy warship, using a Close-In Weapon System against an approaching anti-ship missile is a method of last resort.

By CNN report, the DDG USS Gravely had to use its Phalanx CIWS to intercept an undisclosed target near its engagement envelope on the Red Sea. The US CENTCOM hasn't made any statements about the shoot down of Houthi drones or missiles using CIWS.

Edited by AngelusNox on Feb 2nd 2024 at 3:24:17 PM

Russian Ship Under Drone Boat Attack Seen In Dramatic Onboard Video

A Russian Landing ship was sunk by drone boats in Crimea, the Caesar Kunikov was filmed firing its guns are the drone's general direction but was struck and sunk. Reducing even further the number of active Russian vessels in the Black Sea.

Red Sea Turkey Shoot: Allied Warships Down Dozens Of Drones Within Hours

An EU lead naval task force shot down at least 28 drones on the Red Sea. With a mixed use of naval guns, mostly the 76mm rapid fire deck guns and missiles.

They join the USN with dealing with the Houthi's blockage of the Red Sea.

Edited by AngelusNox on Mar 10th 2024 at 10:51:15 AM