While the basic shape of naval armor-piercing projectiles was largely set in the years 1905-1920, and most nations entered WWII with projectiles that were improved only in detail over the shells they had used then, two nations made radical departures. The Japanese optimized their shells for underwater hits, a process discussed last time, while the USN developed the most effective armor-piercing (AP) shells the world has ever seen.

A pair of 2,100 lb Mk 5 16" AP target shells at Science Museum Oklahoma¹

The original shells for the 16"/45 guns of the Colorado class were fairly conventional projectiles of 2,100 lbs. In the 1930s, the Bureau of Ordnance developed a slightly heavier, stronger shell of 2,240 lbs, with a consequent increase in penetration. It also had an improved AP cap, hardened so that it would not be torn off in oblique impacts and would instead crack the face-hardened layer of the armor, digging a hole that kept the projectile's nose in like a center punch. This was the shell that was used to develop the immune zones for the South Dakota and Iowa classes, but before any of those ships were completed, BuOrd had come up with something even better, the amazing 2,700 lb Mk 8, known as the "superheavy" shell.² The 20% increase in shell weight reduced muzzle velocity, to the point that belt penetration stayed largely the same, but deck penetration, more likely to matter at the long ranges the USN planned to fight at, rose by up to 25%, and immune zones collapsed. The zone for the Iowas went from 13,600 yrds to 5,300 yrds against the 16"/45 gun. In late 1944, the improved AP Mk 8 Mod 6 entered service, with improved hardening and an altered shape to increase penetration at long range by another 25%. It was considered so effective that the battleships in the Pacific were ordered to turn in their existing shells and rearm as quickly as possible. In fact, this shell, fired from a 16"/50 gun, was considered broadly equivalent to a conventional 18" weapon. Read more...

Lord Nelson and I took a trip down to Fort Sill, about an hour and a half southwest of Oklahoma City. Fort Sill is the home of the Army Artillery and Air Defense, as well as an old frontier fort from the Indian Wars. There are three museums on the base, one for each of these roles, and we managed to hit all three of them. I'm going to review them as a group, because it should be possible to hit all three within a day, and because the Field Artillery museum dominates to the point that it's easiest to think of the other two as detached wings.

Me with the Atomic Cannon at Fort Sill³

Read more...

By the outbreak of war in 1914, heavy naval shells had reached approximately the form they would take for the next three decades. Heavy armor-piercing (AP) shells, equipped with caps designed to prevent them from shattering on impact with face-hardened armor, could carry small quantities of explosives, 1-2% of shell weight, through armor plate and detonate on the other side. Other shells, often known as common, carried much more explosive, but were fuzed to detonate on impact, or possibly after piercing a much thinner armored plate. But there was plenty of room for variation on these themes, and some nations had done a much better job than others at anticipating the demands of war.

A British 15" AP shell of 1943

The British in particular had badly misjudged how their shells would be used in action. They had based much of their doctrine around long-range engagements with common shells, intended to destroy the enemy's unarmored upperworks, start fires and demoralize the crew, with AP shells to be held for finishing off enemy ships at closer range. This was used as a justification for not carrying out oblique impact tests on their AP projectiles, which turned out to be a serious mistake at Jutland, where few projectiles penetrated heavy German armor.⁴ Action was quickly taken to address this, and in 1918, a new shell, known as the Greenboy from its paint scheme, was issued to the fleet. It had a new, much harder, AP cap and a redesigned body for better penetration, particularly during oblique impacts, while an improved delay fuze and a new explosive, shellite, would allow it to penetrate armor and reach the ship's vitals in a fit state to burst. Read more...

Even after a battleship's hull had been successfully launched, there was still a great deal of work to do to turn it into a fighting machine. Particularly in the early days of battleship construction, the hull at launch was pretty much just that. All of the other equipment necessary to turn it from a bare mass of steel into a fighting machine still had to be installed, tested, and made ready for sea.⁵

Iowa fitting out under the 350-ton crane at New York Navy Yard

This work would be done at a fitting-out dock near the shipyard, which had as its most prominent feature an extremely heavy crane to lift aboard things like boilers and turbines. These were passed through openings left in the deck and covered with bolted plates for strength, then attached to their foundations. Through about 1900, sheerlegs, which were strong and simple, were used to shift loads aboard; these could only move loads directly out from the dock, which meant the ship had to be positioned very precisely. Later, enormous cantilever cranes were installed, some capable of lifting loads up to 350 tons and placing them anywhere within a 100' circle. These cranes were very expensive, and by leaving fitting of the heaviest components until the end of the construction process, the shipbuilders could economize on their use. Astonishingly, a few of these cranes remain in existence today, most notably the Titan Clydebank, having outlasted the ships they originally helped assemble. Read more...

Megasilverfist, an Australia-based friend of mine, has graciously agreed to serve as the blog's correspondent in his corner of the world.⁶

Several months ago my work hosted a social function aboard Polly Woodside and I’ve finally gotten around to writing up a review.

Polly Woodside

Website

Polly Woodside is a museum ship in currently in Melbourne Australia on the Yarra river. Despite the name, Polly Woodside is actually an iron-hulled barque. The name Woodside is from the name of the original owner, not a reference to construction methods. Read more...

This month marks the 50th anniversary of the Royal Navy's Continuous At Sea Deterrent. Since the fifth patrol of the ballistic missile submarine HMS Resolution, there has always been a British SSBN at sea, ready to respond should the unthinkable occur. The USN has been on the job even longer, although I don't have a precise figure for the start of continuous deterrent patrols. I do know that in 2014, they celebrated their 4,000th patrol since the USS George Washington took the Polaris missile to sea in 1960, which probably brings their total to around 4,150 today.

HMS Vanguard returns from a patrol

For over half a century, the ultimate hole card of Western leaders has been men⁷ in submarines, providing a nigh-undetectable reserve of nuclear firepower. These men have spent three months at a time in cramped metal tubes, year in and year out, missing birthdays and holidays, rarely getting to see the sun and sacrificing time with their families to protect all of us. Read more...

It's time for our regular Open Thread. Talk about whatever you want.

I'm going to highlight a truly excellent Thin Pinstripped Line article on retention in a modern military. While the US isn't in quite the same place, it's still a very interesting look at a complex issue.

Posts revised since last time are the posts on sensors and weapons for WWII ASW, the first part of my series on main guns, British Battleships in WWII, my review of Iowa, and the second part of Pobog's sea stories.

Today is Easter, and I thought it was appropriate to highlight an oft-overlooked portion of the American military, the Chaplain Corps. Charged with the spiritual health of the troops, they have played an important part in supporting and sustaining the men and women on the front lines mentally and morally.

Clockwise from top left: Goode, Poling, Washington and Fox

On February 3rd, 1943, the troopship SS Dorchester was part of a convoy taking American troops to Greenland. Among the 904 men aboard were four chaplains, Methodist minister George L. Fox, Rabbi Alexander D. Goode, Catholic priest John P. Washington and Reformed minister Clark V. Poling. The ship, originally designed to carry only around 400, was very cramped, and despite the danger of U-boat attack, many of the men aboard disregarded the order to sleep in their clothes and life vests. Read more...

30 years ago today, while conducting gunnery exercises off the coast of Puerto Rico, one of Iowa's turrets exploded. 47 members of her crew were killed. Every year, a memorial ceremony is held for them, and this year, I'll be in attendance.

• Tung Thanh Adams - Fire Controlman 3rd class (FC3) Alexandria, VA
• Robert Wallace Backherms - Gunner's Mate 3rd class (GM3) Ravenna, OH
• Dwayne Collier Battle - Electrician's Mate, Fireman Apprentice (EMFA) Rocky Mount, NC
• Walter Scot Blakey - Gunner's Mate 3rd class (GM3) Eaton Rapids, MI
• Pete Edward Bopp - Gunner's Mate 3rd class (GM3) Levittown, NY
• Ramon Jarel Bradshaw - Seaman Recruit (SR) Tampa, FL
• Philip Edward Buch - Lieutenant, Junior Grade (LTjg) Las Cruces, NM
• Eric Ellis Casey - Seaman Apprentice (SA) Mt. Airy, NC
• John Peter Cramer - Gunners Mate 2nd class (GM2) Uniontown, PA
• Milton Francis Devaul Jr. - Gunners Mate 3rd class (GM3) Solvay, NY
• Leslie Allen Everhart Jr. - Seaman Apprentice (SA) Cary, NC
• Gary John Fisk - Boatswains Mate 2nd class (BM2) Oneida, NY
• Tyrone Dwayne Foley - Seaman (SN) Bullard, TX
• Robert James Gedeon III - Seaman Apprentice (SA) Lakewood, OH
• Brian Wayne Gendron - Seaman Apprentice (SA) Madera, CA
• John Leonard Goins - Seaman Recruit (SR) Columbus, OH
• David L. Hanson - Electricians Mate 3rd class (EM3) Perkins, SD
• Ernest Edward Hanyecz - Gunners Mate 1st class (GM1) Bordentown, NJ
• Clayton Michael Hartwig - Gunners Mate 2nd class (GM2) Cleveland, OH
• Michael William Helton - Legalman 1st class (LN1) Louisville, KY
• Scott Alan Holt - Seaman Apprentice (SA) Fort Meyers, FL
• Reginald L. Johnson Jr. - Seaman Recruit (SR) Warrensville Heights, OH
• Nathaniel Clifford Jones Jr. - Seaman Apprentice (SA) Buffalo, NY
• Brian Robert Jones - Seaman (SN) Kennesaw, GA
• Michael Shannon Justice - Seaman (SN) Matewan, WV
• Edward J. Kimble - Seaman (SN) Ft. Stockton, TX
• Richard E. Lawrence - Gunners Mate 3rd class (GM3) Springfield, OH
• Richard John Lewis - Fire Controlman, Seaman Apprentice (FCSA) Northville, MI
• Jose Luis Martinez Jr. - Seaman Apprentice (SA) Hidalgo, TX
• Todd Christopher McMullen - Boatswains Mate 3rd class (BM3) Manheim, PA
• Todd Edward Miller - Seaman Recruit (SR) Ligonier, PA
• Robert Kenneth Morrison - Legalman 1st class (LN1) Jacksonville, FL
• Otis Levance Moses - Seaman (SN) Bridgeport, CN
• Darin Andrew Ogden - Gunners Mate 3rd class (GM3) Shelbyville, IN
• Ricky Ronald Peterson - Seaman (SN) Houston, MN
• Mathew Ray Price - Gunners Mate 3rd class (GM3) Burnside, PA
• Harold Earl Romine Jr. - Seaman Recruit (SR) Brandenton, FL
• Geoffrey Scott Schelin - Gunners Mate 3rd class (GMG3) Costa Mesa, CA
• Heath Eugene Stillwagon - Gunners Mate 3rd class (GM3) Connellsville, PA
• Todd Thomas Tatham - Seaman Recruit (SR) Wolcott, NY
• Jack Ernest Thompson - Gunners Mate 3rd class (GM3) Greeneville, TN
• Stephen J. Welden - Gunners Mate 2nd class (GM2) Yukon, OK
• James Darrell White - Gunners Mate 3rd class (GM3) Norwalk, CA
• Rodney Maurice White - Seaman Recruit (SR) Louisville, KY
• Michael Robert Williams - Boatswains Mate 2nd class (BM2) South Shore, KY
• John Rodney Young - Seaman (SN) Rockhill, SC
• Reginald Owen Ziegler - Senior Chief Gunners Mate (GMCS) Port Gibson, NY

They came to the Navy as strangers. Served the Navy as shipmates and friends and left the Navy as brothers in eternity. - George H.W. Bush

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.⁸ In fact, cast steel was not particularly suitable for Armor-Piercing (AP) shot or shells, and projectiles had to be forged instead.⁹ 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...