I've decided to cover the former cruise liner Queen Mary, the WWII-era cargo ship Lane Victory and the Los Angeles Maritime Museum in one post. I certainly didn't visit them all in one day, but there wasn't enough material to sustain a full post for each.

Queen Mary

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Queen Mary from outside²

Queen Mary is a major attraction in the Long Beach area, with a hotel, restaurants, and the like. I'm ignoring all of that, and treating this just as a museum ship. Read more...

When I discussed underwater protection, I focused only on the systems designed to keep water out of the ship. But naval architects had long been concerned about flooding, and included a second line of defense to deal with water that got inside the ship. This could be from a torpedo, a mine, a shell hit near the waterline, being rammed by another ship, or even running into rocks. In any case, the basic principles were the same, as were the problems they faced.

Patching a hole in a partially-flooded compartment

The first and most important line of defense was compartmentalization. Ships sink when the inside fills with water, and dividing the interior of the ship up into watertight compartments means that, in theory at least, the ship will only sink if enough of those compartments are damaged and opened to the sea. The downside to this arrangement is that watertight bulkheads get in the way of actually using the space. Machinery, for instance, requires large spaces below the waterline, and living spaces are more difficult to use if access routes have to go through a limited number of doors. The resulting inefficiencies drive up cost and ship size. As a result, standards have been developed specifying that all large ships, military and civilian, must be able to remain afloat and stable with a certain number of compartments flooded. The general measure of resistance to sinking is known as "reserve buoyancy", and is calculated as the volume of the hull between the waterline and the height at which water will begin to enter the ship if the ship sinks that far.³ Read more...

It's time once again for our regular Open Thread.

I've taken to highlighting a link in these posts, and for today, I'm going to call out the blog WWII after WWII. It's an investigation of the postwar careers of various pieces of equipment, ranging from guns to ships. Particularly good posts are on the experimental destroyer Timmerman, the mothballing of the fleet, and catapult aviation.

Also, anyone who can't see the captcha should try going to navalgazing.net. I'm migrating to my own domain, and it seems that a few things aren't working at the previous one.

When World War I ended, the world looked poised on the verge of another naval arms race. The United States, which had aimed at parity with Britain under the 1916 Naval Program, was talking about an even larger fleet program, to firmly surpass the Royal Navy. In the Pacific, Japan was building the so-called 8-8 fleet, aiming to have 8 new battleships and 8 new battlecruisers. This would pose a major threat to British and American holdings in the Far East. Britain would traditionally have simply outbuilt these threats as they had with Germany a decade earlier, but the war had left them nearly bankrupt. So when American Secretary of State Charles Evans Hughes called a conference on naval armaments in November 1921, all three countries showed up, as did France and Italy.⁴

Hughes opened the conference with a dramatic series of proposals, calling for the immediate suspension of all capital ships currently under construction, no new construction for the next 10 years and rules on when older ships could be replaced. Older ships would be scrapped to bring capital ship tonnages in Britain, the US and Japan to 600,000, 500,000 and 300,000 respectively.⁵ All other categories of ship would be limited on similar lines. Read more...

My first visit back to Iowa after my move to the Midwest was great. I got to see the ship again, meet readers, hang out with my friends on the crew and take a look at what they've been up to in the past year.

First, there's the Full Steam Ahead tour, which was about to start when I left. All five people who showed up to the meetup did the FSA in the morning, and said that they enjoyed it. I shadowed part of the tour, as I wanted to get to the boiler room and plotting rooms. Read more...

While the heavy AA guns and their dual-purpose successors could be potent weapons against aircraft in the right situation, there were also cases where their limits were sharply revealed. Even the fastest-firing of them was limited to no more than one round every three seconds or so, and when the target was a strafing fighter or a torpedo bomber closing in for the drop, they simply could not respond fast enough. Smaller weapons, of limited range but capable of filling the air with steel, were needed.

Octuple Pom-Pom on HMS Rodney

Initially, these were simply versions of the standard machine guns used ashore, fitted with ring sights and bolted to a convenient railing. These were adequate in World War I, but shortly after the end of the war, the British saw the need for something better. They had also made use of the 2-pdr Pom-Pom,⁶ a 40mm autocannon, for AA firepower and decided to base their future light AA weapon on it. Development began in 1920, but lack of funding slowed development, and the famous octuple 2-pdr Pom-Pom didn't enter service for another decade.⁷ It was a revolutionary weapon, introducing director control⁸ and power operation to automatic AA weapons. The 2-pound shell was powerful enough for aircraft of the era, with a 0.16 lb bursting charge. On the downside, rate of fire was only 90 rds/min/gun, and the choice to use existing ammunition limited muzzle velocity to only 1,900 ft/sec. By the late 30s, this was clearly insufficient, and an improved version capable of about 2,300 ft/sec was designed. It was not capable of firing the old ammo, and for some bizarre reason, both low and high-velocity weapons were kept in production throughout the war. Read more...

The battleship had emerged from the First World War with two separate batteries of medium-caliber gun, one for shooting at surface targets, and one for air targets. Some nations embraced this, but elsewhere the obvious inefficiency of having to carry two separate sets of guns of approximately the same size prompted a search for a gun, and a mounting, which could fulfill both roles. Both destroyers and aircraft were getting larger, tougher and faster, and countering them required a gun with reasonably high muzzle velocity, a large shell, and a high rate of fire. The US and Britain both installed these weapons on their treaty battleships, and refitted their older battleships with similar batteries where possible.

Iowa's starboard DP mounts⁹

Another major driver of DP guns was improved AA fire control. The first generation of AA guns had relied on barrage fire, attempting to saturate a patch of sky the target airplane would fly through. During the interwar period, however, systems like the British High-Angle Control System and the American Mk 37 director¹⁰ were developed which would theoretically allow accurate engagement of aerial targets. However, this method required high muzzle velocity, as the target could maneuver in the dead time between aiming and the shell reaching the target. This fit well with the need for higher muzzle velocity to reduce the dead space for anti-destroyer fire. Read more...

On the morning of my last day in New England, I headed north to New Hampshire to see USS Albacore, the second of the vital forerunners of the modern submarine. Sister Bean had to go back to work, so I was on my own. While Nautilus had pioneered nuclear propulsion, she had retained the general hull design of previous submarines, only partially optimized for underwater operations. Albacore, while propelled by diesels and batteries, was the first to be fully designed for performance underwater.¹¹

Me at the control panel, for real this time

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The airplane entered the world only a few years before Dreadnought, but its immediate impact was much smaller. The slow, short-ranged aircraft of the first decade of heavier-than-air flight were incapable of meaningful contribution to naval warfare. However, this was to change radically over the next few decades, and navies were not slow to realize this.

QF 3" 20 cwt onboard HMS Royal Oak

The first battleships to carry AA guns were the British Iron Dukes, who received a pair of 3"/45 guns upon completion in 1913. These weapons were mounted in open high-angle mountings, designed exclusively for AA fire. They proved to be excellent weapons, well-suited to the demands of shooting at aircraft, a very different challenge from the usual problems of surface gunnery. Airplanes were small and fragile, but moved much more quickly than surface ships, and in three dimensions. This meant that the most prized features in AA weapons were handiness, so that the gun could be brought on target quickly and kept there, and a high rate of fire.¹² Time fuzes were used to make the shells explode near the predicted target position, greatly increasing the lethal area, but the target could maneuver while the shell was in flight, so a high muzzle velocity was also desired. However, this required a long barrel, so larger-caliber weapons tended to be short and low-velocity.¹³ Read more...

It's time for our regular Open Thread. Talk about whatever you want, so long as it isn't culture war.

I've found a strong contender for the Naval Gazing Award for Excellence in Defense Journalism Failure. The Military's Addiction to Oil, an effort to quantify the military's impact on global warming. It's from 2007, but it was so bad that HuffPo actually pulled the rest of the series. The man has clearly never been near a member of the military, except maybe during a protest. Favorite points include his mention of the "B-52 Stratocruiser" (merely one of many misunderstood aircraft), a claim that the "Seals" have a philosophy of "spray and pray" (a statement I would not like to make near actual SEALs), random shots at defense contractors unrelated to the article's thesis, an assumption that the military doesn't care about fuel economy (fuel logistics are a big concern, and if they could cut the amount of effort devoted to it, they would), and the claim that the Abraham Lincoln "fired 1.6 million pounds of ordnance from its guns" during the early stages of Iraqi Freedom (all three CIWS would have had to fire for almost 9 hours straight to do this). Read more...