I've previously discussed the early development of the ammunition used in naval guns, but in the 1880s, developments in armor and fusing quickly left those early projectiles behind. Soon, improved versions of both shot (simple chunks of metal) and shell, with explosive fillings, were being put into service.

A selection of 9.2" shells

The cast-iron Palliser Shot had been effective enough against wrought iron, but it was easily shattered by better armor. The obvious choice was to switch to steel projectiles, but the chilled hardening process didn't work with cast steel.¹ In fact, cast steel was not particularly suitable for Armor-Piercing (AP) shot or shells, and projectiles had to be forged instead.² Steel was poured into a die in the rough shape of the shell, but somewhat larger. Once the shell blank solidified, it was moved to another furnace, and then steam hammers or a hydraulic press were used to work it against a die, producing a shape close to the final shell. It was then annealed by heating in a furnace for several days to relieve any undesirable stress concentrations, and machined down to the final shape. The shell was forged with the nose closed and the base open, and after the base cavity was bored to the desired size, the opening was threaded to accept the base plug. Read more...

In early April, 1982, Argentina invaded the Falkland Islands, a few desolate rocks in the South Atlantic. The British mobilized their fleet in response. The carriers arrived off the Falklands on May 1st, swiftly defeating the Argentine Air Force. The Argentine Navy tried to interfere the next day, but withdrew after the cruiser General Belgrano was sunk by a submarine. Two days later, the Argentines struck back, sinking the frigate Sheffield with an Exocet missile. Two weeks later, on May 21st, British troops landed at San Carlos Water on the west coast of East Falkland.³

An Argentine MB-339

It took only a few hours for the first Argentine aircraft to appear over the beachhead. At 0845⁴ an MB-339 armed trainer making a circuit of the island from Port Stanley passed through the narrows at the north end of Falkland Sound. The pilot attacked the frigate Argonaut, wounding two men, then turned and flew up the valley towards Port San Carlos, directly over the invasion fleet. The fleet below opened fire with everything from machine guns to Seacat missiles, but he escaped undamaged to Port Stanley and delivered his report. Another early recon sortie, by a Pucara light attack aircraft from Goose Green, ended when it met a Stinger missile fired by an SAS team. The pilot ejected safely and walked back to Goose Green. Read more...

It's been too long since I posted one of Jim Pobog's sea stories, so I thought I'd share this one, about a mishap he had while tending the boilers. For those who've forgotten, Jim served as a boiler technician (BT) on the oiler Mispillion, off the coast of Vietnam.

A view of Mispillion from another ship approaching to refuel. Note the service station ball on the stern.

I was not without screw-ups of my own in The Hole.⁵ There was a very common mistake to make; it seems that at some point in their Navy career, everyone did this…some more than once.

The Babcock & Wilcox 450lb. sectional header boilers on Mispillion were fired with NSFO (Navy Special Fuel Oil). At the time, this was the lowest grade of fuel oil, the heaviest and least processed. There were other grades that we carried as cargo for replenishment of other ships. This oil when cold (a relative term) is very thick, almost like tar. Before it is piped to the boilers it is run through a heater and its viscosity becomes very much like kerosene. It doesn’t look like kerosene however, it is extremely dark brown, almost black, and hence is usually called “black oil”. Read more...

When I discussed battleship main guns, I mostly glossed over the shells that they fired. The time has come to rectify that omission, and discuss the wide variety of shell types that have seen naval service over the centuries.

Early shells, with shot on the left⁶

In the age of sail, the basic naval projectile was round shot, a simple round chunk of metal. This had the advantage of being cheap and fairly effective at making holes in a target. The problem was that poking small holes in something as big and tough as a ship, even a wooden one, was not a particularly fast way to kill it. A few men might be killed by flying splinters, but the holes were easily plugged by the ship's carpenter, and it took an awful lot of battering to actually kill another ship. Ordnance designers thus came up with a number of specialized projectiles that would have other effects. Chain shot, when two halves of a cannonball were linked by a chain, was used to slash through rigging and batter masts. To attack the enemy crew, canister or grapeshot was used, turning cannons into giant shotguns. However, all of these specialized projectiles lost velocity quickly and were thus limited to short range. The only way to improve round shot as a ship-killer was to heat it in a furnace so it would set fire to the target. However, this had serious drawbacks. The shot had to be heated, which took time, and the safety implications of trying to use heated shot from a wooden ship are obvious. As a result, its use was mostly confined to coast-defense batteries, although a furnace for heating shot was installed aboard USS Constitution.⁷ Read more...

It's our biweekly open thread. Talk of whatever you want.

A thing I have recently started playing is Rule the Waves, a game that puts you in command of a fleet in the 1900 era. You get to pick the country, and then design, build, and fight the ships. It's one of the most addictive games I've ever encountered, to the point that I'm afraid I'll have to give it up.

Overhauled posts since last time include So You Want to Build a Battleship - Design Part I, The Pursuit of the Goeben and Breslau, Operation Staple Head, and my posts on the early dreadnoughts and the forces that fought the submarine in WWII.

With the brilliant South Dakota class, American designers built the finest of the treaty battleships. However, the clouds of war were gathering on the horizon, and rumors were circulating of Japanese battleships that dwarfed the ships being built under the Second London Treaty. In an attempt to prevent this from happening, the authors of that treaty had included an "escalator clause", which allowed the treaty powers to raise the treaty limits if ships that breached them were built by other powers. Public opinion was still largely pacifist, so it wasn't until March 31st, 1938 that the US, Britain and France exchanged notes invoking this clause, ultimately signing a protocol raising the battleship tonnage limit by 10,000 tons. This laid the foundation for the greatest of all battleships, the Iowa class.

Iowa in 1945

The extra 10,000 tons gave designers several options, and studies began almost immediately. One possibility was to fit another triple 16" turret on a stretched South Dakota hull, with the tonnage going into a longer citadel and bigger engines to maintain 27 kts. Another was to upgrade the guns to 18",⁸ which kept the length of the citadel down and allowed the armor to be upgraded. Both of these would have been entirely in keeping with the traditional American policy of prioritizing firepower and protection over speed. But some in Preliminary Design suggested a radical alternative, a very fast ship intended not to stand in the line of battle but to hunt down Japanese cruisers.⁹ The first sketches were of a ship armed with 12" guns, capable of cruising for 20,000 nautical miles at 15 kts,¹⁰ and with a top speed of 35 kts. To hold displacement down to even 50,000 tons would have meant that the ship was armored against 8" weapons, with an immune zone of 10,000 to 30,000 yards. Read more...

Lord Nelson and I recently took a trip to northeast Oklahoma. Our primary destination was Boarding House Books in Claremore, who are selling off a 15,000 volume private library. I picked up another set of Morison's History of US Naval Operations in WWII, as well as a gorgeous leather-bound edition of Mahan's The Influence of Sea Power Upon History. But while we were there, we stopped in at the Tulsa Air and Space Museum and Planetarium.

Lord Nelson with the museum's F-14

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Today, the destroyer is the premier surface combatant, with only a handful of navies operating larger combatant vessels of any type. Its name is a contraction of "torpedo boat destroyer", which tells us where we must look for the origins of these vessels. The self-propelled torpedo,¹¹ invented by Robert Whitehead in the 1860s, was a revolutionary weapon. Before, the only effective weapons against a big ship were big guns, which required another big ship to carry them. Now, virtually any vessel could be armed with weapons that were able to sink a battleship.

Torpedo Boat HMS Lightning

One obvious way to use this new weapon was to mount it on a small, fast vessel, which became known as the torpedo boat. The first torpedo boats, such as HMS Lightning of 1876, were extremely small, usually under 50 tons, and fast for the day, somewhere north of 18 kts. However, they were fragile and short-ranged, limitations that were often overlooked by their advocates, most notably the French Jeune Ecole, who believed that the torpedo boat had rendered the battleship obsolete. The British, who had long planned on a strategy of coastal attack, found themselves in a bind. They needed some way to keep their heavy ships safe while operating off enemy ports, and began to construct smaller ships to hunt down torpedo boats. Their first effort, known as torpedo gunboats, were built starting in the mid-1880s. They were armed with small QF guns and a few torpedoes of their own. They were seen as unsuccessful because they weren't fast enough to catch torpedo boats, although they would probably have performed well in action against their smaller, more fragile opponents. Read more...

Most of have probably heard of the Philadelphia Experiment. The common story is that the USN conducted experiments during 1943 involving somehow making a destroyer escort, the Eldridge, invisible and/or able to teleport. It's obviously complete nonsense, and several explanations have been offered for the story. But it turns out that the actual explanation is rather strange. The story we know today was created as a cover for something very different.

Philadelphia later in 1943

It turns out that the Philadelphia in question was not the city, but the ship. The light cruiser Philadelphia was a unit of the Brooklyn class, serving in the Mediterranean in 1943. She had gained distinction during the invasions of Morocco, Sicily and Salerno, and during the last invasion, she was the target of numerous German guided bombs. While she survived unscathed, several other ships did not, and the Allied navies began to scramble for an answer to the new weapons. Read more...

Once a battleship's hull had been assembled, the builder was faced with the task of getting it into the water. Launch was the most difficult and involved part of building a ship, as tens of thousands of tons of steel had to be slid down into the water without damage to itself or to the surroundings.¹²

Iowa slides down the ways

This was harder than it sounds. A careful balance had to be struck between making sure that the hull didn't hang up on the launching ways, the concrete tracks that it was built on, and making sure that it didn't go into the water so fast that it got damaged or ran into the opposite bank, a particular problem for yards on narrow rivers. Possibly the most fraught part of the process was when the ship left the ways, which didn't extend very far below the surface of the water. If the stern of the ship wasn't buoyant enough when the center of gravity passed the end of the ways, the bow would tip up, which was unlikely to end well. If things went well, the loads would instead be concentrated on the bow as the stern started to float, which meant that the launching cradle, the ways, and the bow itself all had to be specially reinforced. Read more...