It's time for our regular open thread. Talk about anything you want that isn't culture war.

For my readers in SoCal, two reminders. First, we have our meetup on Iowa coming up in slightly less than two weeks. Second, LA Fleet Week is this coming weekend, and that should be a lot of fun. I'd encourage you to go.

And for a bit of fun, I'd encourage you to check out Duffelblog, which is essentially the military equivalent of the Onion. It's mostly from a junior enlisted/veteran point of view, but there's some really good stuff.

While battleship designers had long tried to protect against underwater attack, the first months of World War One showed the full extent of the threat posed by torpedoes and mines. The existing underwater protection systems installed in pre-dreadnoughts proved totally inadequate, and numerous vessels were lost to these causes. Even the dreadnoughts were not immune, as shown most notably by the loss of Audacious in the first months of the war.

Bulge on monitor HMS Glatton

The British quickly began to look for ways to improve protection, finding one in the form of the bulge. In their simplest form, these were just expansion chambers mounted on the outside of an existing hull, with a free-flooding liquid layer behind the air chamber. This increased the depth of the TDS, and provided an effective air-liquid layer system. Bulges were first used on ships operating close inshore, a particularly good area for submarines and small torpedo craft, and proved very successful. Even the earliest bulged ships took torpedo hits with no damage. The only drawback was a slight reduction in speed,¹ and even battleships were soon being fitted with bulges. Ramillies and later capital ships were fitted with them while under construction, while older ships gained them in refits. Read more...

I recently ran across the following spread from a 1940 edition of Popular Mechanics. It's an interesting study in the way that outsiders get warship design very, very wrong.

I can sort of see where the designer of the main ship was coming from. He was trying to solve a few real problems, but did so in bizarre ways. Smoke interference was a fairly big issue for most warships, and finding another way to dispose of it would be nice, and would simplify topside arrangement, possibly leaving space for more guns. But his solution was the sort of thing that only a lunatic would come up with. Similar exhaust ducting had been tried on HMS Argus, an early carrier, with poor results. Heat was a major problem, and Argus was slow and low-powered compared to this ship. I suspect that backpressure would have given issues, too. Worse, the duct literally could not have been placed for greater vulnerability to underwater damage. Whoever drew the picture of it deflecting torpedoes had no idea how torpedoes worked. It would have been utterly destroyed by the first hit, and at very best, that would merely have forced half the boilers to be shut down. More likely, it would have provided a ready flooding path deep into the ship. I honestly cannot fathom how anyone believed this would be a good solution. Read more...

While visiting Sister Bean in Boston, we took the Freedom Trail, and ended up at the Charleston Navy Yard, home to the USS Constitution, the oldest commissioned ship in the US Navy, and the destroyer Cassin Young. It was an enjoyable visit, although I wasn't blown away.

Me at Constitution

• Constitution
• Constitution Museum
• Charleston Navy Yard

Let me start with the good. Constitution is basically the bedrock on which the traditions of the US Navy, the greatest navy the world has ever seen, were built. She was one of the original six frigates built for the USN when the United States decided to build a proper navy in 1794 to fight the Barbary Pirates. After a treaty with the Barbary States was concluded, George Washington managed to convince Congress to complete Constitution, and two other ships, Constellation and United States. Read more...

As it gained seagoing experience, the US Navy's dreadnoughts began to diverge from their British sisters. The Americans believed that long-range battle would be prevalent in future wars, and thus had begun with the New York class to fit the ships with the necessary fire control gear. However, it was not until the 1912 battleship design that the change took full effect.

Nevada, the first of the Standards

The USN concluded that at long ranges, the use of AP shells would dominate, as there was no way to control where on a ship hits would be made, and HE shells would be useless against belt and deck armor. As a result, it wasn't worth armoring against anything but AP shells, which required thick armor. Light armor would be a waste of weight and merely serve to burst the AP shells.² This scheme became known as all-or-nothing protection, and within a decade, the lessons of Jutland had resulted in its wide adoption by other nations. Read more...

In 2018, I went to visit my sister, who had a summer internship in Boston. On my first day there, we met up in Natick,³ and visited the International Museum of World War II. It was an enjoyable way to spend a couple of hours for us both, and she's way less into this stuff than I am.

They had a model of New Jersey, even if not of Iowa⁴

Website Read more...

Battleships faced two great threats. The first and most obvious was from shellfire, and it was dealt with by the armor that was in many ways the signature of the battleship. But armor can only protect against threats from above the water. The other great threat, attack by torpedoes and mines, required different solutions because of the nature of underwater explosions. But solving it was imperative, because it turned out to be the more lethal in the long run.

Torpedo hits on West Virginia and Oklahoma during the attack on Pearl Harbor

Underwater explosions are very different from explosions in air, due to the greater density of water. This allows it to transmit shockwaves more effectively, but more importantly it contains the gasses created by the explosion. Instead of expanding rapidly into the relatively sparse air, they are contained and have to accelerate the water around them outward. Even when the pressure inside the bubble is equal to the pressure outside, the inertia of the water carries it outward. By the time the bubble stops expanding, the inside is rarefied, and the bubble begins to collapse, compressing the gasses. Eventually, they are compressed by the inertia of the inrushing water, and the cycle repeats.

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It's time for our regularly-scheduled open thread. Talk about anything that's not culture war.

A couple of reminders. First, we have the meetup at Iowa in September. Please RSVP if you plan to attend.

Second, I'm still interested in guest reviews of various museum ships. This Friday begins the 2-month barrage of reviews from New England, but once that's done, I'd be interested in expanding the range of ships I've been able to cover myself. The process that I did with DismalPseudscience was basically him writing up his review in the style I use (which is pretty broad) and sending it to me with pictures. I put it into a blog post, added links and made some editing suggestions, and sent him an account so he could see it.

In 1982, Argentina invaded the Falkland Islands in the South Atlantic, which had long been the subject of a sovereignty dispute with Britain. They had expected the British to accept their occupation, but were surprised when the British instead assembled a fleet to retake the islands. The carrier group, centered around HMS Hermes and HMS Invincible, took a few days to sort itself out at Ascension Island and take on extra Harriers, before sortieing for the South Atlantic on April 18th.⁵

A Sea King flying from Invincible

The task force moved immediately to a war footing. An anti-submarine screen of Sea Kings was airborne day and night, the 20 aircraft flying a total of 2,253 sorties during operations in the South Atlantic. One crashed on April 23rd, and a crewman, Petty Officer B. Casey, was killed, the first casualty of what the British dubbed Operation Corporate. Operations spaces and weapons were manned around the clock, and formica panels and mirrors were removed to reduce the effects of damage. All personnel were prohibited from sleeping below the waterline, exacerbating the crowding on the carriers. Read more...

The maritime world uses a very different set of measurements than those used on land every day. Where did they come from and what do they mean?

A Chip Log

Distance is measured in nautical miles, which can be seen as a spiritual predecessor to the meter, both units initially being defined as some fraction of the distance from the equator to the pole.⁶ Specifically, the nautical mile was long defined as equal to one minute (1/60th of a degree) of latitude. Today, it's defined as 1,852 m, or 6,076 ft. It's used by both the nautical and aviation⁷ communities as a world standard.

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