Guided weapons were first deployed during WWII, most famously by the Germans in the form of the Hs 293 and Fritz-X guided bombs. But the Germans were far from alone in their efforts, and I've also discussed the efforts of the US Army and various other powers to develop air-to-surface guided weapons. However, the weirdest and most interesting program was that of the US Navy, who took a common airframe and build a bewildering array of weapons around it, ranging from the successful to the absurd.

Pelican

The USN's guided weapons program was built around a common airframe developed by the National Bureau of Standards and usually carrying a 1,000 lb warhead, with a wide variety of different guidance systems. The first versions, known as Robin and Dragon, used standard radio guidance, with or without a TV camera to pass images back to the operator. These were not hugely successful, and the program was soon terminated in favor of radar guidance. The first result was Pelican, which would home in on radar signals reflected from a target illuminated by the launching aircraft's radar. After some teething troubles in the guidance system were ironed out, it worked rather well by the standards of the time.¹ However, the delay had opened the door for another guidance system, which the Navy decided to put into combat use.² Read more...

I've previously discussed the early German guided bombs at some length, but the Germans weren't the only power to try to make guided weapons during WWII.³ Most of the other powers also tried to make their weapons more accurate, sometimes with hilarious results.

GB-1 glide bomb

By far the most prolific of these efforts were those of the US. The normal wartime procurement pattern was for the US to produce a system or two that worked well, and Germany to saddle itself with a dozen different ones, all inadequately debugged and competing for resources. Guided weapons are one of the few cases where this was reversed. The Germans only had a handful of programs, mostly in different niches, while the US tried several systems for each role, and only a handful saw combat. Read more...

It's time for our regular open thread. Talk about whatever you want, so long as you avoid culture war stuff.

The list of updates is particularly long, as I'm beginning another round of yearly overhauls. From 2018, I've updated underbottom explosions, Survivability - Mission Kills, The Last Days of the High Seas Fleet, Samar, Turret and Barbette, The Space Force and the FAA and Russian Battleships Part 4. The 2017 overhauls are A Brief History of the Battleship, Iowa Parts One and Two, and Fire Control Part 1.

Today is the traditional day to celebrate the United States Navy, even if it has been deprecated in recent years thanks to a conspiracy of a mustache-obsessed CNO and pro-Air Force elements in the Pentagon. OK, that was mild hyperbole. Officially, Navy Day was deprecated in favor of Armed Forces Day at the order of Lewis Johnson, SecDef to Truman, who tried to gut the Navy in favor of the Air Force. The ceremony was partially recreated when historical research showed that the Continental Navy was founded on October 13th, 1775, and Elmo Zumwalt ordered celebrations to be held on that day, which cannibalized unofficial Navy Day celebrations. But I'm a traditionalist, so I'm going to celebrate it today.

Missouri and Renshaw during Navy Day 1945

It's also the second anniversary of Naval Gazing as an independent blog, and an excellent year it has been. I've continued to enjoy writing, particularly with the recent reduction in pace, and interacting with my readership in the comments. Seeing people reading my stuff and thinking about it is one of the great joys of doing this. Read more...

Gentlemen,

We are at war with Italy for a third time so far this century. Not much has changed in the 18 months since the last one ended, except that we have commissioned a pair of new battleships, while Italy still has only one Irresistible-type. As such, we currently plan to essentially implement the strategy we used last time. We have solved most of the bottlenecks that kept our forces out of Sicily, and after a minor victory in the opening battle of the war, are prepared to fight for control of the Mediterranean.

There aren't a whole lot of decisions pending, beyond what shape our destroyer force should take going forward. We have recently increased the maximum size of our ships of that type by 50%, but with the increased size comes an increase in cost. Four sketches have been prepared, covering a wide range of options. Read more...

Today marks the 75th anniversary of the Battle of Leyte Gulf,⁴ probably the pinnacle of the Pacific War and by some definitions the largest naval battle in history.⁵ More than that, it was uniquely complicated and multifaceted: it included every form of naval warfare yet devised, from amphibious operations to carrier duels to the last-ever engagement between battleships. And above it all, Samar, that astonishing moment when a tiny force of American ships stood up against the mightiest fleet Japan could assemble and turned them back.

Douglas MacArthur and his staff observe the invasion of Leyte

Leyte Gulf was sparked by the American selection of the Philippines as the next stepping stone on the road to Tokyo, fulfilling Douglas MacArthur's promise to return and liberate it from the Japanese. The island of Leyte, in the center of the archipelago, was selected as the first target, giving the Americans a forward base from which they could spread out and liberate the rest of the Philippines. After extensive strikes from the carriers covering the operation, troops began going ashore on October 20th, initially in the face of only light opposition. The Japanese decided that the time was right to launch their fleet for the "Decisive Battle" they had been attempting to fight since the start of the war. Read more...

The damage of an explosion doesn’t scale linearly with size. The general rule of thumb is that the radius for a given amount of damage scales with the cube root of the weight of the explosive charge. This means that trying to destroy a larger area by just making bigger bombs has sharply diminishing returns. It’s much more efficient to drop multiple smaller bombs, particularly on soft targets like trucks and troops in the open. Taking this to its logical conclusion, the best way to destroy a soft area target is to drop dozens or hundreds of small bomblets on it. The easiest way to do this is to package a cluster of bomblets into something that can be handled and used more or less like a normal bomb, and these devices were soon dubbed cluster bombs.

A B-1B dropping cluster bombs

The first cluster bombs were developed before WWII, primarily to carry incendiary bomblets.⁶ Incendiaries are particularly well-suited to cluster deployment, as starting a fire is fairly easy if the bomb lands in the right place, and cluster bomblets multiply both opportunities to land in the right place and the problems of firefighters trying to contain the resulting blaze. The Soviets used an early version of this in the Winter War with Finland, with Foreign Minister Vyacheslav Molotov claiming that they were dropping food to starving Finns. The Finns, who were not starving, dubbed the devices Molotov bread baskets, and later said that they were giving the Soviets drink to go with the food when they improvised incendiaries from bottles, creating the Molotov cocktail. Read more...

For a continent that was the focus of world affairs for so long, and that has such a violent maritime history, the history of riverine warfare in Europe is strangely sparse. Both the Rhine and the Danube are major navigable rivers, and both hosted fleets in Roman times, but information on gunboats and other ships that used them for military purposes is sparse or nonexistent. It is perhaps telling that the most famous riverine battle in Europe during the last 400 years was fought on the Medway, a tributary of the Thames, entirely by seagoing ships and forts.⁷

The Dutch raid on the Medway

Rivers did play an important part in campaigns going back millennia. The Romans operated fleets on the Rhine and Danube to protect the Empire's frontiers, and Charlemagne used the Danube and Elbe in his campaigns against the Slavs, Saxons and Avars. The Vikings would often base themselves at the mouth of a river, then launch ships upriver to raid settlements along it, even reaching Paris up the Seine. Much like the Union armies in the American Civil War, the armies of revolutionary France were named after the rivers they fought over, including the Rhine, Danube and Moselle. The Austro-Hungarian Empire had long operated gunboats, first powered by sail and oar and later by steam, on the Danube, and their gunboats had beaten the Italians on Lake Garda during the Third Italian War of Independence.⁸ Later, during the Franco-Prussian War, the French used a flotilla of gunboats on the Seine during the Siege of Paris, some of which were later taken over by the Paris Commune. The Commune was unable to use these gunboats effectively, and the French Army managed to sink one and send the rest back to port to take no further part in hostilities. Read more...

It's our regular open thread. Talk about whatever you want, even if it's not military-related.

Lord Nelson and I recently watched the series Empire of the Seas on Youtube. It's a four-part BBC documentary about the importance of the Royal Navy to British and world history. It was very well-done, although I thought that the last episode (1800s to WWI) would have been better if they hadn't had to trim so much nuance. (I might be a geek.) Highly recommended.

Overhauled posts this time are Going Back to Iowa, The Washington Naval Treaty, the survivability posts on flooding and fire, my review of LA maritime sites, and Falklands Part 7.

The Joint Direct Attack Munition (JDAM) is one of the great military procurement success stories of recent decades. Development began in the aftermath of the Gulf War, with the intent of producing a weapon capable of attacking precision targets in all weather. This would be enabled by GPS, which had just come through its first combat outing with flying colors, allowing the forces that liberated Kuwait to navigate in the trackless desert. It could also, in theory, allow a bomb to hit any target that the operator had coordinates for.

JDAMs are staged on the mess deck of the USS Abraham Lincoln during the invasion of Iraq

The basic concept was the same as the one behind Paveway. Take a standard iron bomb and fit it with new fins and a guidance kit that turn it from something that will hit the ground into something that will hit the target. This greatly simplified the task of the designers, who didn’t have to worry about a warhead, as well as aiding operators who could take advantage of the wide variety of bombs already in the US inventory. Read more...