The oceans are notoriously opaque, providing the submarine with a strong veil of stealth. The only thing that oceans don't effectively block is sound, which is transmitted more effectively through water than it is through air. As a result, sonar remains the main method of detecting submarines, either in active form, producing sound that bounces off the target and is reflected back, or in passive form, listening for noise from the target. But sound doesn't travel through the ocean in a straightforward way, and as sonar has grown more sophisticated, its operators have had to contend with effects that either attenuate the sound, drown it out or bend it in surprising ways.

The Deep Scattering Layer (green) on a sonar scan

Attenuation can come from a number of sources. Obviously, the intensity of a sound weakens as it spreads out from its source, and in an infinite ocean, this would follow the inverse square law. In practice, it's often lower than this, thanks to effects discussed later, but the ocean doesn't transmit sound perfectly. Some is absorbed and turned into heat, a process that occurs more strongly at higher frequency. Some is scattered when it runs into discontinuities, which can be the surface and bottom of the sea or solid objects in the ocean, usually marine life. Most notable is the deep scattering layer, composed of deep-sea fish and the plankton they feed on that tend to cluster a thousand feet or so below the surface. Scattering is a particular problem for active sonar, as the reverberations from the surface/bottom/creatures can make it hard to pick up the actual return. Read more...

British successes against German ciphers in WWII are reasonably well-known, but far less known was the work done by their predecessors during the First World War against German naval ciphers. This group, known as Room 40 after the room it was assigned at the Admiralty, started from nothing at the beginning of the war and thanks to a combination of skill and an unreasonable amount of luck, soon played a vital role in the war at sea.

Alfred Ewing

When war broke out, the Admiralty acted quickly to cut the undersea cables linking Germany to the rest of the world, forcing Germany to rely on interceptable radio messages. But no organization was in place to intercept said radio messages, and the British were forced to rely on a combination of amateur radio operators, the Post Office and the Marconi Company for this function. Nor was analysis in any better shape, and the task of setting up an organization fell to physicist Alfred Ewing, the Director of Naval Education. He, with the help of various professors from the Royal Naval Colleges, began to set up a team to deal with the flood of traffic. Read more...

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

It's been a slow two weeks on the book, which currently stands at 88,000 words. I am interested in getting another reader or two to look over the draft, so email me if you're interested.

2018 overhauls are SYWTBAMN Strategy Parts one and two, Main Guns Part 4, my review of Midway, Russian Battleships Part 3, Falklands Part 1 and the Super-Dreadnoughts. 2019 overhauls are Shells Parts three and four, my review of Fort Sill, Spanish-American War Part 4, Pictures - Mikasa Part 1 and Falklands Part 14. 2020 overhauls are Coastal Defenses Part 2, Oil Tankers, the Navy UFO Incident and Nuclear Weapons at Sea - Heavy Attack. 2021 overhauls are Naval Airships Part 6 and all three parts on the Littoral Combat Ship.

In the aftermath of the British victory at Heligoland Bight, the Kaiser chose to keep the High Seas Fleet immobile, relying instead on submarines. These first struck on September 22nd, when U-9 came across three obsolescent British armored cruisers on patrol off the Dutch coast, Aboukir, Hogue and Cressy. These ships, part of what was known as the the "Live Bait Squadron", were moving at relatively low speed when Aboukir was torpedoed. Hogue and Cressy hove to to recover survivors, but they were swiftly torpedoed in turn. All told, only 837 of the 2,296 men aboard the three cruisers survived, and the British swiftly withdrew anything bigger than a light cruiser from the waters near Germany.

Aboukir sinking

Even this wasn't enough, as the primitive submarines of 1914 could reach across the North Sea, as demonstrated when U-9 added armored cruiser Hawke to her score on October 15th. Jellicoe became increasingly concerned with the security of the Grand Fleet's base at Scapa Flow, and began to keep his ships at sea as much as possible. This quickly wore out ships and men and forced them to spend a lot of time coaling, so he decided to withdraw to Lough Swilly in Ireland. But while this was enough to deal with the submarine threat, the Germans had other weapons they could make use of. Read more...

A great deal of ink has been spilled around nuclear strategy, and most of it has vastly overcomplicated the issue. The most basic principle is that nuclear weapons raise the cost of war to the point where it is completely obvious that there is no way that war could pay. Note that the importance of nuclear weapons here is more in perception than in reality, because while through most of human history, war was very profitable, by the start of the 20th century, the destructiveness of military force had reached the point where a war would cost more than you could gain unless you got very lucky. Both world wars showed this quite clearly,¹ but millennia of cultural memory of war paying (because, among other things, the cultures that did war were the dominant ones) meant that this wasn't particularly clear.

Nuclear weapons short-circuited all of this. Their destructiveness is unquestioned, and if they are likely to be involved it's extremely hard to make the case that war will pay, even to yourself. This is the major reason we are currently experiencing the longest period of great-power peace in recorded history. So long as nuclear weapons remain in play, there's a very strong incentive for even the most reckless regime to not push things too far. This is deterrence, and Bret Deveraux has laid out a fair bit of the history here. Read more...

Apologies that our regular open thread is a bit late, but overhauls ran late. Talk about whatever you want, so long as it isn't culture war.

Book update: 85,000 words. Working through WWI, and starting on the postwar years.

2018 overhauls are British Battleships in WWII, Sea Stories - The Swimming Pool and the Fuzes, Main Guns Parts one, two and three and Life Aboard Iowa. 2019 overhauls are Shells Part 2, The Four Chaplains, Continuous At Sea Deterrent, Megasilverfists's review of Polly Woodside and SYWTBABB Construction Part 3. 2020 overhauls are my review of Historic Flight Spokane, Falklands Part 21 and Merchant Ships - Bulk Carriers. 2021 overhauls are Naval Airships Parts four and five, Battle Stations and A Brief Overview of the Chinese Fleet.

When I took a broad overview of how destructive nuclear weapons are, one of the areas I looked at was nuclear winter, but I only dealt with it briefly. As such, it was something worth circling back to for a more in-depth look at the science involved.

First, as my opponent here, I'm going to take What the science says: Could humans survive a nuclear war between NATO and Russia? from the prestigious-sounding "Alliance For Science", affiliated with Cornell University, and the papers it cites in hopes of being fair to the other side. Things don't start off well, as they claim that we're closer to nuclear war than any time since the Cuban Missile Crisis, which is clearly nonsense given Able Archer 83 among others. This is followed with the following gem: "Many scientists have investigated this question already. Their work is surprisingly little known, likely because in peacetime no one wants to think the unthinkable. But we are no longer in peacetime and the shadows of multiple mushroom clouds are looming once again over our planet." Clearly, I must have hallucinated the big PR push around nuclear winter back in the mid-80s. Well, I didn't because I wasn't born yet, but everyone else must have. Read more...

33 years ago today, while conducting gunnery exercises off the coast of Puerto Rico, Turret II exploded aboard Iowa. 47 members of her crew were killed. Every year, a memorial ceremony is held for them, and I was able to attend in 2019 and honor the men who died.

• 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

While Jutland is by far the most prominent naval battle of WWI, it is far from the only battle fought in the North Sea. The first months of the war saw several clashes as both sides tested the other's strength, including several cases where the Germans came close to their desire of defeating elements of the Grand Fleet in detail.

Roger Keyes

The first battle came a month after Austria declared war on Serbia. Roger Keyes, the aggressive commander of the submarine flotilla based at Harwich, had received reports on German patrols in Heligoland Bight, just off the German coast, and proposed a sweep by the destroyers and cruisers of the Harwich Force under Reginald Tyrwhitt to attack them as they changed over at dawn, with his submarines positioned to attack any heavy ships that came out in support. In case things went wrong, the Grand Fleet would be in support. Read more...

It is time once again for our regular open thread. Talk about whatever you want, so long as it isn't culture war.

I will be speaking at the Cambridge (MA) LessWrong Meetup on Sunday at 2:30 PM Central, discussing nuclear weapons and nuclear warfare. As I live in Oklahoma, I will be attending virtually, and all of you can, too. Link.

Book update: 77,000 words, mostly done with the chapter covering pre-WWI and starting on the WWI chapter. I've been busy doing nuclear stuff instead.

2018 overhauls are Early Dreadnoughts, ASW in WWII Forces, Sensors and Weapons, my Links Index and my review of Iowa. 2019 overhauls are A Brief History of the Destroyer, my review of the Tulsa Air and Space Museum, The Iowa Class, Shells Part 1, Sea Story - Black Oil and Falklands Part 13. 2020 overhauls are Container Ships, Coastal Defenses Part 1, O'Callahan and the Franklin and French Battleships in WWII. 2021 overhauls are Father Capodanno, The Top Gun Rant and The Fate of the French Fleet Parts one, two and three.