105

SHORT ANSWER The short answer is that this was considered by the British to be the simplest and most economical way of disposing of the German U-boat fleet. The decision to sink the U-boats rather than salvage or divide them up among the ‘Big Three’ (the UK, the US, the Soviet Union) was part of the Potsdam Agreement (August 1945). It was agreed that the ...


65

It is far easier to sink than capture, especially when your main tool is the submarine. If you go further back in history, capture was indeed often the name of the game. But in a WW2 context Germany could not go head-to-head with the Royal Navy, hence submarines being the primary tool. Beyond this, ships were far more traceable and could be avoided; once ...


47

The options that submarines had were, in practice, limited to sinking Allied shipping and leaving the area as quickly as possible to avoid detection. U-boats had a disadvantage compared to destroyers (not to mention airplanes) when it came to speed, especially when submerged. They were also poorly equipped to fight surface warships as their deck guns were no ...


33

The general answer, "It's easier to sink than capture," has already been given. Now consider the specifics. In the early stages of the war: In two words - "Prize crew". Having captured a ship, it is necessary to plant on it a sufficiently large crew to either operate it by themselves or to oversee the original crew and keep them in line. This means the ...


32

Not a "hard" answer, but more than a comment. The German Type VIIC was the most common type of U-boat, but with limited range and endurance. Its fuel bunkers could keep the diesels going for 20-35 days non-stop at a speed of 10-12 knots (own calculation, using the various "range X at speed Y" data points given here and here). The Type IXC/40 would, by the ...


30

According to a 1999 article by Mark A. Bradley in Proceedings, the U.S. Naval Institute's professional journal ("Why They Called the Scorpion "Scrapiron," July 1998), on May 20, 1968, the Scorpion was ordered to intercept a Soviet flotilla near the Azores that included one Echo-II-class nuclear-propelled submarine, a submarine rescue vessel, two ...


29

To prevent torpedoes from becoming a navigational hazard in the event of a miss the 1907 Hague Convention VIII had a section on mines. Once a torpedo was out of fuel it was buoyant. Therefore any torpedo that missed its mark (which was a lot!) would become a random and deadly hazard to navigation. The easiest solution to this was to detonate the torps at ...


21

The original source for the stories you heard is apparently the book "Scorpion Down" by Ed Offley. The book's statements are questionable to say the least and this book review makes a good point. I checked what the Russian sources say about K-129. This 2008 interview with Viktor A. Dygalo, the commander of the division that K-129 belonged to, covers this ...


21

The allies blockaded Germany in WW2. Even if the Kriegsmarine could capture ships (and Orangesandlemons's answer correctly explains that this was unlikely) - there was no way to actually bring them to German ports. The British navy would just re-capture/sink them on the way.


21

An anecdotal addition to the excellent points in the existing answer: At the end of WWII, my mother was discharged from the ATS before my father was discharged from the army, so she got a job as bookkeeper to a scrap metal merchant operating near the base where they were stationed. Her boss was the winning bidder on a contract to scrap some damaged, ...


20

The reason is simple: nobody wants an uncontrolled explosive device floating around. You yourself, or someone else, other then your enemy may later accidentally hit it. For the same reasons all anti-aircraft shells explode at the end of their trajectory: who knows what they may hit on the ground.


18

When German Raiders Did Use Captured Ships In addition to the other answers, there were a few examples of German raiders sending captured ships back early in the war. These were auxiliary cruisers, fast, long ranged merchantmen fitted with enough hidden weapons to overpower lone merchant ships. If they encountered a warship they'd disguise themselves as a ...


15

I found a reference to a WWI submarine (SM UC-44) doing this here. "Two aspects of her service are noteworthy. UC-44 was the first submarine to use the tactic of releasing oil and debris from her torpedo tubes to fool the enemy into believing it had been sunk by depth charges." "During a particularly intense depth charge attack on 15 February 1917, ...


15

An underwater explosion creates turbulence in the water, creates bubbles, and perhaps mixes waters of varying temperatures or salinities, all of which affect the refraction of sound in water. For ASDIC to work best the water should be homogeneous, with laminar flow only.


15

How come that in WWI, the Germans were able to maintain a submarine blockade of Britain... They weren't, at least not one which had a major impact on the war effort. Submarines and submarine tactics were in their infancy. They were slow, short ranged, largely blind, vulnerable on the surface, and they had to spend most of their time on the surface. Rather ...


13

WWII submarines making a journey of any length would run on diesels on the surface during the day, if there were reasonable odds of not being sighted. Rapid ("crash") diving was a very important tactic for them, and the ability to do it quickly was an important factor in both sub design and crew training. If they were travelling through a contested area ...


13

Commander Michel Thomas Poirier, USN wrote a paper/study in October 1999 called Results of the German and American Submarine Campaigns of World War 2. In it he details many factors of both campaigns; it's well worth a read in its entirety if you are interested in the subject. However, most relevantly to this topic is Appendix 1. In it, the author details ...


13

If you look at ace sinking by year you'll find that aces could only develop their sink counts during "happy times," when a technical and doctrinal superiority favoured mass sinkings. These times often involved unimpeded surface running, surface attacks on individual ships, an absence of convoy systems and loosely protected convoys. While it may be ...


13

Your expectation "does that not mean that any echos should die down more quickly" is largely inaccurate for that portion of the explosive energy directed vertically, or near vertically. Precisely because sound travels so much faster in water than air, and that water is much denser than air, the transmission coefficient from water to air for sound is very ...


12

The first submarine was developed by Cornelis Drebbel, a Dutchman, in 1620. The first submarine that went into action was the Turtle, developed by David Bushnell in 1776. It went in action, but never sank a ship. The first submarine to do that was the Hunley in 1864. (With the loss of the submarine, and its entire crew). The first modern submarine that ...


11

You are really talking not about seaworthiness, but about stability. "Together with the Hague Visby Rules, the common law provides that the concept of "seaworthiness" covers: the ship, its equipment and supplies, the crew, the vessel's suitability for the particular cargo and its suitability for the particular voyage or for particular ports". If the physics ...


10

The old naval term 'hulk' is applied to vessels that are no longer in sea service but still perform some support role in port. So in the case of a "battery charging hulk", it's used to provide additional battery charging facilities for the other diesel-electric submarines. In most cases, hulks are stripped of any items that are not essential to their new ...


10

How do you imagine that's gonna to happen? You are talking about convoys, not single and unarmed merchant ships etc. which have been in fact captured by German raiders like Schwern answered in detail. A British convoy is surrounded by destroyers/frigates and several columns of ships transporting goods, the most valuable (most volume and expensive cargo) in ...


9

Actually, no... the first submarines used in warfare appeared in the Revolutionary War, and two more were deployed (unsuccessfully) by the US in the War of 1812. 1) No, because they weren't very practical or successful until John Phillip Holland and Electric Boat perfected the battle submarine at the turn of the century. 2) The first modern military ...


9

I think that the key to this is considering the reflected waves and their interactions with the environment and each other. The initial explosion will send out shockwaves in all directions. These shockwaves will bounce off any surface, especially the sea floor and the surface with the air. Importantly, these reflected waves will also reflect as they hit ...


8

In short, politics. The Flensburg Government (Doenitz's German government) wanted to surrender to the Western allies (the United States and United Kingdom) rather than the Allies as a whole, primarily because of the Soviet reputation for how they (mis)treated prisoners. To this end, Admiral Friedeburg was sent to Field Marshal Montgomery's headquarters. ...


7

The Venturer also sank U771 which was not submerged while being hit by torpedoes. This is wikipedia info, but apparently the British also used submarines for ASW. They seem to have lured in places where retreating/coming out of port, and would not be detected by passing submerged submarines. Alas, let us consider which other wars might have seen submarine ...


7

Each of these submarines were sunk in separate incidents, so I wanted to make sure that anyone seeing this understood that these two were not directly involved with one another in any form of conflict. The Soviet sub K-129 was sunk a few weeks prior to the loss of the USS Scorpion, and some theories suggest that the Scorpion was sunk in retaliation for the ...


7

Not mentioned so far is the Allies' progressively better use of radar. Diesel submarines spent a lot of time on the surface, at least until the Germans developed snorkels. If they could be seen on radar, they were easy pickings. They could also be located by radio triangulation, so toward the end of the war they had to maintain radio silence. In such ...


7

By 1944, US submarines were very experienced and had ironed out their problems with their equipment. They had been conducting an extremely successful offensive campaign against Japanese shipping since the beginning of 1942, and unlike German U-boats, had not taken heavy losses and so gained in experience. They had fixed the flaws in the Mark 14 torpedo ...


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