On this day in Navy history (March 4) the USS Cyclops
a collier departs from Barbados and is never seen again. The mystery is popularly connected with The Bermuda Triangle.
Also today, the Battle of the Bismarck Sea a rather lopsided PT boat and air campaign against a Japanese fleet came to an end with the near annihilation of the Japanese force.
I considered doing Bismarck Sea, and also HMS Hood or HMS Prince of Wales, but my love for the obscure took over.
SC-497 class subchasers
If you look up this class on Wikipedia, their entry has only four paragraphs. They are small, at 110 feet 10 inches long, 17 feet 10 inches wide, and with a draft of 10 feet 10 inches. Armament varied over the production run, as the early subcahsers were rushed into service during the spring and summer of 1942 and frequently inadequately armed, but generally consisted by mid-1943 of depth charges (two racks and two K-gun throwers), Mousetrap forward-thrown ASW weapons, two 20mm/70 Mark 3 or Mark 4 Oerlikons, and either a 40mm/60 Mark 2 Bofors or a 3"/23 gun on a DP mount
◊. On some of them rocket racks also appeared, although I have seen some sources claim that in truth it was just a matter of the Mousetrap racks forward
◊ being able to accept the standard 3" and 5" rockets without modification. Their frames were metal, and their hulls were wood, earning them the nickname of "the Splinter Fleet". Originally powered by a pair of 880 HP diesel engines, they were rated for 15.6 knots; the discovery that German submarines had a top speed of 18 knots on the surface caused those built after June of 1942 to be given a pair of 1540 HP engines for a 21-knot speed instead. They were quite numerous, with 438 having been built. And from their obscurity, type, and size, you would assume they had spent all their time in safe waters accomplishing nothing of import and none of them compiled noteworthy combat records.
It would be hard for this to be further from the truth.
The genesis of the subchaser program goes back to WW 1, where a ship very much like the SC-497s, USS SC-1, was developed as a coastal escort and harbor defense craft against German U-boats. Like its progeny it was wooden-hulled, steel-framed, designed for rapid production to meet war needs. Over three hundred were built, and while none was ever credited with sinking a U-boat during WW 1 (USS SC-3, flying the flag of Cuba by that point, was credited with sinking a U-boat during Black May in World War 2) their real value was that they floated and they were scary, while subchasers freed up more capable ships like destroyers for mid-ocean escort and combat duty. The SC-1s were unlike their progeny in a very important way, though: they were only marginally seaworthy for open-ocean work.
With World War 2 on the horizon and the United States facing the possibility of a two-ocean war against two navies with very capable submarine arms on paper, the concept was revived. Relatively little effort was invested in the SC-497s initially, but the disasters off the Eastern Seaboard during the German Operation Drumbeat revealed a desperate need for coastal escort vessels gave the program legs. The design's ultimate adaptability and the discovery that while it was not comfortable in open ocean it could certainly go there also helped.
Yet none of the SC-497s actually sank a submarine during WW 2, though USS SC-669 is often incorrectly credited with sinking RO-107. When submarines encountered them,many of the subs might have technically been able to win a gunfight: but it was not without the risk of being damaged so that they could not submerge; the SC-497 in turn was usually content to drop a couple of depth charges on the submarine to make it go deep so it couldn't harass the convoy, and then leave it alone. Instead, it was their many other duties and under other flags in which the class won its various glories. 78 ships served with the Soviet Union; little is known of their combat records, though they did see action during the Kuriles campaign at the end of the war. 50 served Free France in the South Pacific, Caribbean, and Indian Ocean protecting French overseas possessions. Eight served Brazil, protecting coastal convoys around South America; another three did similar duties for Mexico. Three served in the Royal Norwegian Navy where they made frequent voyages to occupied Norway, supplying Resistance groups and inserting Allied agents.
In US service, it was the converted ships that did the most interesting work. 18 ships, having made the Atlantic voyage to England, were converted into AMC (Auxiliary, Minesweeper, Coastal); their wooden hulls reduced their magnetic signature and made them ideal for coping with the more sophisticated German magnetic-triggered mines. Eight ships served in the South Pacific and Southwest Pacific where they were converted into PGM (Patrol, Gunboat, Motor), armed with 3"/23 forward, a Bofors aft, and four twin .50s amidships
◊. These ships were originally designed to assist the PTs in actions against heavily armed Japanese barges and landing craft, and did so on several occasions; but their greatest success stories came in the Philippines, where they were used in riverine warfare reminiscent of that on the Mississippi and its tributaries during the Civil War. Four of them doing so played a substantial role in the capture of Mindanao, by advancing up various rivers, dueling with Japanese troops and artillery along the way, to capture Fort Pikit and a critical highway bridge; this advanced the US campaign on the island by at least a month.
But the most important role the SC-497s played, the one which should earn them the greatest respect and which saw them give their best performances in combat and sustain most of their losses, was that of SCC; Sub Chaser, Control. Configured in this circumstance for extra crew and radios, they served the vital role of control boats for amphibious landings this way. Down at the line of departure, getting them into the right groups and then raising the signal flags for another wave of landing craft or amtraks to go in to the beach, were the SCCs. Seventy ships were fitted for this role during the war, and they served in nearly every US landing operation after Guadalcanal. Several of them compiled formidible records stretching from the Gilberts to Okinawa in the process; at least one became famous in the fleet for it.
That ship was SC, and later SCC, USS SC-1066. Her career in the Gilberts began inauspiciously, when she took station off the wrong islet. Her commander was sacked for that. Yet she ultimately participated in every Central Pacific landing
◊, knocked out a Japanese tank in a direct-fire duel the night after the landing on Saipan only to be bombed and strafed the next day, shot down an aircraft at Guam, and narrowly avoided a pair of kamikazes at Okinawa. Even when her luck ran out and she was damaged by one of the kamikaze's bombs exploding close aboard, her crew managed to beach the ship and save her, and she was practicing for a part in Operation Coronet, the invasion of Kyushu, when the war ended.
In general, the SC-497s can be said to have performed their tasks well, and to have far outdone the initial expectations for the class. They proved supremely adaptable and carried a load in the amphibious war far out of proportion to their small size. Their reward, at least in USN service, was to be immeditately transferred to the agency responsible for selling surplus military equipment to foreign nations; after that, their fates are mostly unrecorded. Only one SC-497 is known to remain afloat today: His Norwegian Majesty's Ship
◊ Hitra, which was preserved as a museum ship after her role in WW 2 supporting the Norwegian Resistance. It is possible other ships of the class remain afloat as either civilian vessels or in the navies of third world countries, but any that do probably bear little resemblance to their original forms.
edited 4th Mar '15 10:02:54 PM by Night
Nous restons ici.Probably not much less than it took originally. Many of the timesaver improvements in modern shipbuilding have to be incorporated at the blueprint stage of design to have much effect. Building from the original design invalidates that.
Honestly, it might take longer than it originally did. Shipbuilding today employs fewer people on a project not so much because of automation but rather because the industry itself is just a lot smaller and it builds to higher standards. There just may not be as many people in Japan doing the work in total as were originally employed on Musashi.
edited 6th Mar '15 5:01:14 AM by Night
Nous restons ici.It depends on whether or not you're on wartime or peacetime footing. American shipyards in WW 2 churned out the Iowas from scratch in less than 2 years. Especially once the wartime footing got underway. (Same deal with the Essex class carriers. They didn't take long to build compared to peacetime.)
In peacetime it can take 10+ years if you have no hurry on it. (Or let the shipbuilders meddle...)
@Night, Sabre's Edge:
That's incredibly interesting! ...And far more information than I ever got from other sources, to be frank.
I suppose that part of the rationale for the sea denial doctrine was that it seems like Russia has historically been a weaker naval power - hence there wasn't much point trying to contest complete control when your opponents had such a decisive advantage.
One of my books did mention the Polish marine/naval infantry units, but I suppose that'd be a bit outside the scope of the thread. Or would it?
Locking you up on radar since '09Ok did some quick poking around for you Tam. I picked a Nimitz class carrier for a large US ship. The first three Nimitz carriers Nimitz Sub-Types took 5 years to build. The Theodore Roosevelt sub Class has a bit more variation with two taking as long as four years, two took 3, and another took just two. The two Reagan Sub class each took 3 years.
The rough average for all of them is something like 3 and half years per carrier. For Nimitz Sub-Class alone 5 year average across the board. The Roosevelt's just over 3 years. The Reagans roughly the same. Give or take a few months in either direction. All three sub-classes have the nearly the same overall dimensions its the internals that vary the most with various bits of kit and some lay out differences. Those are craft larger then the Musashi.
I did a quick look for rough build times from laid down to launch. For battleships across the board the average is around two years. A small handful of examples took about year to build and some took up to three. That includes pre-WWII build times and during WWII. It remained surprisingly consistent.
Given that we could probably churn out even the larger battleships in about 2-3 years maybe a little faster but without more info to make a comparison it is a very rough estimate.
If you could figure out the rough overall cubic volume of several ships and their laid to launch time more accurately you could work out a ratio of time per cubic meter and do a rough comparison that way.
Who watches the watchmen?Since we've discussed them a few times, here's a link re: the Clash of the Ironclads.
The original action reports
from the USN SOPA, the exec of the USS Cumberland, the exec of the USS Congress, the captain of the USS Minnesota, the exec of the Monitor, a letter from the chief engineer of Monitor to her designer, the exec of the Virginia, SOPA CSN, and SOPA CSA.
So today...let's talk about something a little more broad than normal.
Depth Charges
So how do you sink a submarine, anyways? Well, at least during the World Wars, and surprisingly for a long time after with some navies retaining depth charges until the 1990s, this involved the use of depth charges. It is a weapon type about which there is a surprising amount of confusion despite its fairly simply operation.
A depth charge has simple operation in theory. Designed to detonate at a set depth, adjustable or not, they damage submarines by the pressure wave from the explosive. Any who has ever bellyflopped off a diving board knows that water doesn't compress as well as air, meaning that the pressure wave of an underwater explosion is significantly more powerful, but has a much shorter range. Get the depth charge close enough, and the pressure wave will crack the submarine's hull and sink it. Even if not that close, the depth charge can still cause mischief by throwing engines and shafts off their mounts, putting out the lights, smashing gauges, causing leaks, and jostling the crew. The effective radius of a depth charge is not very large, however. During WW 2 the British estimated the lethal radius their WW 1 300-pounds of explosive Type D Mark 3 at only 14 feet. The more modern Mark VII was considered to have a lethal radius of 26 feet; it had only 290 pounds of explosive, but of a better type. Damaging radius was considered twice lethal: this was probably being generous, but the numbers arrived at by actual test.
The story of the depth charge, like the story of anti-submarine warfare in general, begins with World War I. Several countries were developing depth charges during and before the war, largely without references to each other. The UK and Germany developed their first depth charges in 1915, the US followed suit in 1916, Italy in 1917. The other seapower countries during the war either did not develop depth charges (Austria-Hungary, Russia), or used imported British ones (Japan).
The beginnings were rather humble, as this British-made, USN-flirting-with Type A shows.
◊ The Type A was only fifty pounds, usually used by having the strongest sailor aboard just chuck it over the side. It, and most early depth charges, operated on a float-and-lanyard principle. The top half of the charge floated; the bottom half with the explosive sank. A lanyard played out between the two, until a break set by crank or the lanyard's preset length played out. The jerk on the lanyard when it stopped playing out set off the charge. It was a simple and in theory elegant system. But it was absolutely nothing like the depth charge most people would recognize from footage of WW 2.
The lanyard system was soon dismissed as mechanically unreliable by the Allied powers, though Germany persisted with it to the end of the war. Problems with the lanyard getting tangled, breaking, or otherwise failing to function correctly were commonplace. Sometimes the part of the charge that was supposed to float sank. Sometimes the jerk just wasn't enough to trigger the charge. A better method was needed.
That method came, in late 1916, with the British Type D depth charge and its hydrostatic firing pistol. The hydrostatic pistol measures water pressure to determine depth; at the correct depth, it fires and the charge detonates. Though more complex, it proved to be vastly more reliable. Results were immediate: after months of ineffectiveness and frustration, the first depth charge kill was scored on December 16th 1916, when HMS Landrail sunk UB-29 with a Type D. The USN introduced the Mark 2 depth charge, with an improved hydrostatic pistol, in 1917; Italy's first depth charges in 1917 were also hydrostatic pistols though with only one setting. Germany did not develop such a design until the '20s, and Japan's first domestic design in 1928 was also hydrostatic. Because the whole charge sank, and nothing had to float, depth charges could get larger and be designed for faster sink rates, both important to their effectiveness.
However, the RN persisted in other errors. Rather than the familiar rolling charges off the stern, they would place them in slings, swing them out, and dump them over the side that way; a torturous and poorly-controlled method that rarely allowed the deployment of more than a couple of charges per run. The USN rejected this philosophy out of hand; depth charges, with their by guess and by god method of deployment and the lack of any way to determine actual submarine depth, need to be used in numbers to be effective. They instead introduced the second critical improvement to reach the depth charge attack most of us will recognize: the Mark 1 Depth Charge Rack
◊.
The Mark 1 was a simple, gravity-fed mechanical rack of eight charges (thirteen with an extension). It could be controlled from the bridge or at the rack and used a gearing system to allow the charges to be fed off the rack and into the water at a measured pace, allowing their placement in a controlled "stick" that would not cause them to interfere with each other as they exploded. It was a simple and commonsense solution to a problem, one that doubtless some RN officers kicked themselves for not considering. But it was not the end of the need to find ways to work a "pattern" of charges.
The next step was widening the pattern. For this, the British designed the Thornycroft Depth Charge Thrower (this particular image is of a Mark IV at New South Wales, Australia, being tested; note the lack fuzing mechanisms in these practice charges)
◊. The weapon went through four Marks between the wars, but all were mechanically very similar. A depth charge was placed on a fitting that allowed it to be pushed inside what was essentially a large mortar; a large "piston" provided motive force. The fitting and piston break off on contact with the water, and the charge sinks. The Americans, however, were unimpressed, pronouncing the Thornycroft DCT overengineered to deal with recoil, and came up their own solution: nullify recoil by throwing a charge to both sides. This was the Y-gun
◊, and like the Thornycroft DCT it saw action before the end of World War 1.
The stage was now set, in late 1917, for the use of depth charges as most of understand them. And innovation told: after sinking only two submarines in 1916 by depth-charge attack, and seven in 1917, in 1918 the number more than tripled to twenty-two sinkings in 1918.
Between the wars, development focused in two areas: faster-sinking depth charges and more powerful explosives. The Royal Navy developed first Minol and then Amatol explosives; the USN pursued the even more powerful Torpex. The British developed the Mark VII
◊, and the USN designed a smaller, more capable depth charge thrower, the K-gun, to complement their Mark 6
◊. The addition of sonar to the arsenal of a destroyer removed some of the guesswork from depth charge attacks, and allowed the kind of sustained attack over time that made damage or destruction of a submarine a near certainty; but it would not be until relatively late in WW 2 that actual depth-determining sonar came around. Still, the popular image of the "ashcans" and a destroyer going over the top to attack is basically one using these two charges.
The Japanese, meanwhile, developed their own weapons. Their general disinterest in ASW showed through in this process; the Type 95, developed 1935, had only two depth settings: 97 and 197 feet. An improved version, with a setting for 295 feet, was introduced during the war. So was a Type 2, deployed first in 1942 and essentially a copy of the Mark VII, copies of which was
The development of the 295-foot setting was the result of a rather shabby story; USN submariners during the first couple years of the war noted in their action reports that the Japanese almost universally set their charges too shallow; most modern US submarines had a maximum depth of 250 feet or so, and the 197-foot setting was simply unable to reach them. These reports were compiled, and eventually reached the House Military Affairs Committee. Congressman Andrew J. May then quoted several such reports verbatim during a radio interview. While some of the major news outlets refused to print or air his comments, not all did; the news eventually reached Japanese ears. The USN was outraged; when May's comments were repeated in a Honolulu newspaper a delegation of skippers from Submarine Base Pearl Harbor went to Vice Admiral Charles Lockwood and accused the Congressman of treason as well as threatening to withhold their patrol reports unless COMSUBPAC could assure them they would not be seen by civilians. After the war Admiral Lockwood estimated that May's leak cost the USN ten submarines and eight hundred lives.
Across the Pacific, the USN developed their own new weapons. A magnetic influence fuzed charge, designed to detect the magnetic field of a submarine's hull and its electric motors, was deployed in 1943 as the Mark 8. It was fairly successful during its service career, and was considered in postwar studies to have been seven times more lethal than the standard Mark 6. The problem was it also took much more than seven times the maintenance to keep working, and after an initial burst of use in late summer 1943 the Mark 8 was only issued rarely. The Royal Navy designed a "Mark X" one-ton charge intended to fired from a 21" torpedo tube, meant specifically to go after very deep-diving submarines with the equivalent of a whole pattern of ten normal Mark VII charges. But the final word in the saga of the depth charge had yet to be written.
That word was the USN Mark 9. (Check out the K-guns and fittings along the rail; also the three guys, center picture, without lifejackets. Those are crewmen of U-490, captured after their submarine was sunk. The guy with the tommy gun is covering them.)
◊ Designed with a teardrop shape for faster sinking, fin-stabilized for a straight drop, and a 200lb Torpex charge, it was the last word in depth charge development, and in fact outlasted both magnetic-fuzed and acoustic-fuzed postwar "replacements". Yet ultimately the depth charge was poorly suited to deal with postwar submarines designed in the style of the German Type XXI "Electroboot" with its high underwater speed. Their blind time, between last sight of the enemy and weapon detonation, was just too long. Effective ASW in the '50s depended on ahead-thrown weapons, and ultimately the acoustic homing torpedo. Depth charges remained dangerous to a submarine in shallow, constricted waters, but easy to evade elsewhere, particularly by the high-speed nuclear-powered submarines that would shortly come to dominate ASW concerns.
What a difference 150 years makes. Those Navy guys (both USN and Confederate) sure had a lot of respect for their men and a certain personalism to their letters you no longer see in the jargon filled official stuff of today.
And that is some sweet insight. The battle was much larger than what elementary and middle school textbooks teach you.
It seems that the RN experimented heavily with ASW cannons too
before discarding them in favor of depth bombs. So-called "diving shells" were meant to enter the water and continue onward for a short distance before they hit the hull and exploded; in practice, they weren't successful. The Japanese adopted them as the primary AP armament of their heavy ships, with the intention that shells that dropped short would strike their targets beneath the waterline. In practice, this just compromised the aerodynamics of their shells, and led to a high incidence of duds due to the very long fuse setting required for diving shells to work.
Night, can you give either confirmation or denial about an Ottoman Navy ASW incident that I vaguely recall reading about? As I recall, during the Gallipoli Campaign, a British submarine bottomed out somewhere in the vicinity—it may have been in the Bosphorus, it may have been elsewhere; it might also have been tangled in an antitorpedo net. So a very brave officer from the shore establishment took a rowboat and the garrison cook, and rowed out with an explosive charge and the best submarine-hunting equipment he could lay his hands on—a lead and a line.
Rowing around the area where they last spotted the sub, they proceeded to drop the sounding line until they came across the sub, whereupon they lowered the charge into the water and paddled like hell.
As I recall, they got credit for the kill.
It sounds too good to be true.
Charlie Stross's cheerful, optimistic predictions for 2017, part one of three.If I cover the ahead-thrown weapons, it'll be in a different post. There we'll get Hedgehog (and its failed cousins), Limbo, Weapon Alpha, etc.
Not offhand.
edited 9th Mar '15 8:45:31 PM by Night
Nous restons ici. Now for something Civil — Cruise ship Britannia: Queen names P&O luxury vessel
Captain Paul Brown, who gave the Queen a tour of the ship, said: "It is my great honour after 33 years at sea to show the Queen around. "I will be showing her the atrium and the bridge then heading down to the restaurant for lunch."
Britannia bears the same name as the Queen's former Royal Yacht Britannia, which was decommissioned in 1997 after more than 40 years of service. The 141,000-tonne ship features a 94m (308ft) union jack on its bow and will make its maiden voyage to Spain, Italy and France on 14 March. At 330m (1,082ft), the ship is longer than the Shard is tall.
British Brut NV from the Wiston Estate Winery at Pulborough in West Sussex is being used for the naming ceremony in Britannia's home port of Southampton.
The ship is being hailed as a boost to Southampton's cruise industry, which the city council said had doubled in the past 10 years. In 2004 there were 203 cruise ship visits, bringing 532,501 passengers. In 2014 Southampton received more than 430 cruise ships, with passenger numbers exceeding 1.5 million.
Stewart Dunn, chief executive of Hampshire Chamber of Commerce, said: "It is great that Britannia will be based in Southampton. There was a survey a few years ago which showed that every turnaround of a cruise ship in the city is worth £2m to the local economy. It is also good for 'brand Southampton' indirectly as it is great publicity for the city with the Queen coming here and having the word Southampton on the side, it is promoting us wherever it goes."
The Queen has previously christened the Royal Yacht Britannia and four cruise ships Queen Elizabeth 2, Oriana, Queen Mary 2 and the Queen Elizabeth. The Britannia cruise ship will sail from Southampton during the summer and from the Caribbean in the winter.
David Dingle, CEO of Carnival UKnote , the company which owns P&O said at the ceremony: "The naming of a new ship is a proud moment for any shipping line but today holds a special significance for P&O and our shared past and future.
"We are honoured the Queen is naming Britannia."
Britannia: fascinating facts about Britain's biggest cruise ship
edited 11th Mar '15 3:54:38 AM by Greenmantle
Keep Rolling OnHow well did British Navy did against Axis Navies during WWII?
In total, it was a wash. The initiation point for their Cold War decline into the frailty it is today.
HOWEVER, against the Kreigsmarine they kicked their shit in in most engagements. It was really only the U-Boats that proved any real threat to His Majesty's Navy. Aside from ASW work, the RN made the US Atlantic Fleet's foray into the war fairly boring with not much to do.
Against the Regia Marina it was pretty much a draw. Every British victory would be met with an Italian one DESPITE the British having aircraft carriers. The end win/loss tally for the RN was like just +1 wins higher than their losses.note
In the Pacific, they pretty much got their shit kicked in. At one point they were effectively removed from the Pacific and Indian Oceans as an effective fighting force by the Japanese. Once they were back in it, they played second fiddle to the Americans who did by far the most heavy lifting in that theater. (Of course the USN Pacific Fleet took some very hefty and severe losses in the process, at one point even being down to literally one functional carrier and one functional battleship left in the entire Pacific basin.)

Great find. Hope for more expeditions in the future.
Schild und Schwert der Partei