Wednesday, August 14, 2019

Unrestricted Submarine Warfare

Sinking of an enemy armed troopship steamer by German submarine in the Mediterranean Sea.
by Willy Stöwer
Early submarines were rather fragile beasts. They had two sources of propulsion: diesel engines for running on the surface, and electric motors for running submerged. The electric motors were run off of battery power. Running at speed underwater would quickly drain the batteries which would force the submarine to surface and use its diesel engines to recharge the batteries. Something best done at night when the submarine, due to its not having much of a superstructure, was harder to spot.

Early submarines had two types of armament: torpedoes and one or more guns mounted on the deck of the submarine. Obviously the guns couldn't be used while submerged whereas the torpedoes could be used either surfaced or submerged. As torpedoes were generally rather large items, a submarine couldn't carry many of them so, in the early days of World War I, a submarine captain's preferred method of attack was to surface and use the submarine's deck gun(s) on the target.

If you think about it, it seems clear that surfacing to bang away at a target with a gun isn't a very good idea against a warship, they typically have more (and bigger) guns than a submarine. Generally submarines were used as commerce raiders, sinking the ships supplying an enemy nation, not the enemy's warships. (Though in World War II, Japanese doctrine expected submarines to attack warships, not merchant ships.)

According to the old rules, submarines were required by international law to stop merchant ships, check their papers to see if they were carrying "contraband" or war material, then, if the ship was carrying something which would allow the submarine to sink it, the submarine had to make provisions for the crew to be "removed to safety," and guess what, taking to the lifeboats didn't count.

So submarine captains, in order to stay alive, started bending the rules. So lifeboats were considered, by the sub captains, "removed to safety." No doubt the merchant crews disagreed when they were hundreds of miles from shore!

So let's say you're an island nation, like the United Kingdom, and you're getting rather tired of German submarines sinking your ships. Not always playing by the rules either, mind you. Now there's a couple of things you can do if you're concerned about this sort of thing: 1) have your merchant ships sail in convoys, escorted by warships, while this won't prevent a submarine attack, it will force them to stay submerged, or 2) arm your merchant ships with guns of their own, so they can blast away at any submarine precocious enough to surface and demand that you stop.

Now if you're a submarine owner, odds are you will no longer surface to attack a merchant ship. Odds are you will simply put a torpedo into the ship and, as is said, "let God sort them out." Now as submarines back in the day were generally slower than a merchant ship while traveling submerged, you'd want to lie in wait where enemy ships were likely to appear. Subs would travel on the surface at night (where they could travel rather fast, even faster than most merchant ships) to position themselves for an attack.

At night they could use torpedoes or guns to attack the often unarmed merchant ships, then dive to avoid the escorts before they could fire back at the sub. Necessity, being the mother of invention, is why the Allies invented (during WWI) what the British called ASDIC* but which we impertinent Yanks called (and still call) sonar (actually SONAR is more correct**), a device used to detect offending submarines in order to drop explosives on them, causing them to sink.

Now under the old rules, submarines were restricted in what they could do as regards attacking shipping. They had to obey the rules, what was considered "restricted submarine warfare." As the folks who were getting their ships sunk by submarines came up with new ways to stop that, the best way being to sink the enemy submarines, merchant ships began to be armed. The British went one better, they would take older merchant ships and hide guns on them, the unsuspecting German U-Boat commanders would sail up, demand they heave to and...

Yup, hidden guns come out, submarine gets blown out of the water.

Eventually word gets out and the Germans start sinking anything flying an Allied flag. Without regard to any rules, what is called "unrestricted submarine warfare." Generally ships which looked like (and actually were) passenger liners were left alone. Until the Allies started using them to carry troops and war material that is.

Passenger liners were designed to be very fast, after all, the faster they were, the faster they could travel across the ocean, deposit their paying customers, then pick up more paying customers. So they were actually (in general) faster than a submarine, even running on the surface. So the U-Boats would lie in wait for them, near where they sailed from, or where they were sailing to...

Which is how the Lusitania was sunk by a German U-Boat. She was getting close to her destination when a torpedo sent her to the bottom. Killing a number of civilians (including a hundred plus Americans) but also sending a quantity of war material to the bottom as well. Technically, Lusitania was a valid target. Not one of the British Admirality's finer moments.

RMS Laconia was a former passenger liner converted to a troopship in World War II. On the 12th of September, 1942, she was torpedoed off the coast of West Africa by the German U-156 under the command of Korvettenkapitän Werner Hartenstein.

Laconia had some 2,732 crew, passengers, soldiers, and Italian prisoners of war on board...
Operating partly under the dictates of the old prize rules, the U-boat commander, Korvettenkapitän Werner Hartenstein, immediately commenced rescue operations. U-156 broadcast their position on open radio channels to all Allied powers nearby, and were joined by the crews of several other U-boats in the vicinity.

After surfacing and picking up survivors, who were accommodated on the foredeck, U-156 headed on the surface under Red Cross banners to rendezvous with Vichy French ships and transfer the survivors. En route, the U-boat was spotted by a B-24 Liberator bomber of the US Army Air Forces. The aircrew, having reported the U-boat's location, intentions, and the presence of survivors, were then ordered to attack the sub. The B-24 killed dozens of Laconia's survivors with bombs and strafing attacks, forcing U-156 to cast their remaining survivors into the sea and crash dive to avoid being destroyed.

Rescue operations were continued by other vessels. Another U-boat, U-506, was also attacked by US aircraft and forced to dive. A total of 1,113 survivors were rescued; however, 1,619 were killed – mostly Italian POWs. The event changed the general attitude of Germany's naval personnel towards rescuing stranded Allied seamen. The commanders of the Kriegsmarine were shortly issued the Laconia Order by Grand Admiral Karl Dönitz, which specifically forbade any such attempt and ushered in unrestricted submarine warfare for the remainder of the war.
Much has been made (by some) of the "war crime" committed by the crew of the B-24 and the officer who ordered them to attack the submarine. The ability of an aircrew, during peace or wartime, to spot banners and light communications from a small ship on the surface are very limited. They may (or may not) have noticed any sign from the rescuers that they were indeed rescuing people from the Laconia.

German admiral Dönitz issued another order regarding the rescuing of people from a sunken ship, War Order No. 154. At Nuremberg, this (and the Laconia Order) were introduced into testimony in order to convict Dönitz of war crimes.

The United States had also practised unrestricted submarine warfare, under their own equivalent to the Laconia Order, which had been in force since they entered the war. Fleet Admiral Chester Nimitz, the wartime commander-in-chief of the US Pacific Fleet, provided unapologetic written testimony on Dönitz's behalf at his trial that the US Navy had waged unrestricted submarine warfare in the Pacific from the very first day the United States entered the war.
The prosecution has introduced much evidence surrounding two orders of Dönitz, War Order No. 154, issued in 1939, and the so-called Laconia Order of 1942. The defence argues that these orders and the evidence supporting them do not show such a policy and introduced much evidence to the contrary. The Tribunal is of the opinion that the evidence does not establish with the certainty required that Dönitz deliberately ordered the killing of shipwrecked survivors. The orders were undoubtedly ambiguous and deserve the strongest censure.

The evidence further shows that the rescue provisions were not carried out and that the defendant ordered that they should not be carried out. The argument of the defence is that the security of the submarine is, as the first rule of the sea, paramount to rescue and that the development of aircraft made rescue impossible. This may be so, but the [Second London Naval Treaty] is explicit. If the commander cannot rescue, then under its terms he cannot sink a merchant vessel and should allow it to pass harmless before his periscope. The orders, then, prove Dönitz is guilty of a violation of the Protocol.

In view of all the facts proved and in particular of an order of the British Admiralty announced on 8 May 1940, according to which all vessels should be sunk on sight in the Skagerrak, and the answers to interrogatories by Admiral Chester Nimitz stating unrestricted submarine warfare was carried on in the Pacific Ocean by the United States from the first day of the Pacific War, the sentence of Dönitz is not assessed on the ground of his breaches of the international law of submarine warfare. (Source)
I thought this was an interesting story. It's hard to enforce rules upon combatants during wartime. But afterwards, make sure your own guys are innocent before going after the losers of the war.

War is messy, things aren't always clear cut.

U-156 (foreground) and U-507 pick up Laconia survivors on 15 September, three days after the attack.
Yup, war sucks.

* ASDIC = Anti-Submarine Detection Investigation Committee, the group of British, French and American scientists who developed early sonar devices.
** SONAR is an acronym standing for SOund NAvigation and Ranging. In common use though it's usually rendered as "sonar."


  1. Surprised that it took three years into the war for an incident like the Laconia sinking to occur. Wonder who gave the order to that B-24? Being a submariner on both sides during the war was pretty darn risky considering the amounts of casualties.

    1. It was a captain, who later went on to be a brigadier general in the Air Force. Without knowing the full circumstances of the comms between bomber and base, I won't throw stones. Flying at speed, and low, with a U-Boat on the surface, who can really say what that crew saw, or communicated back to base. Mistakes happen in wartime, sometimes innocents die. It sucks but it is war, all war sucks.

  2. The WW2 influence was still pretty strong when I was growing up in the 60's and 70's. We called a 4 door car with a hopped up motor a "Q Ship". They usually looked like a family car, but performed like a hot rod.

    I remember using the acronym ASDIC in school and getting some strange side-eyes. Non-historians are a weird group of people. I mean, come on, everyone should know what ASDIC is, amIright? That was some important stuff!

  3. A large percentage of WW I subs had gasoline engines, as the diesel was not very reliable, at that point. Which must have made things even more muserable.

    1. Gasoline engines on submarines were extremely hazardous, the switch to diesel couldn't come soon enough for the sub crews.

  4. Hey AFSarge;

    Unrestricted Submarine Warfare, the United States did it in the pacific as you have stated was the proper action. I remember a quote from Ulysses Grant during the war between the states, "Pay the butcher bill now or pay it later when it will cost more". I know that is a brutal truth but War is brutal, no half measures. If the United States had lost the Pacific War, would have Japan insisted on Nimitz being tried? In this day and age, there would have been Americans eagerly assisting the Japanese haul Admiral Nimitz up on trial. The winners set the rules. On a different note...How is the finger and the eye? From the volume of material on your blog the finger is better, LOL

    1. They wouldn't have put Nimitz on trial, they would have simply executed him. That's the way they rolled in WWII.

      Eye is improving, the finger is doing very well. Still a bit of a challenge typing but I've learned a few workarounds to keep that finger out of harm's way.

  5. The USCG Barque EAGLE and her sister ships (I believe one went to Chile and the other to Russia) originally had the same engines as the U-boats and were used to train the engineers for the submarine fleet. I was part of an inspection team as a GTMO FTG instructor residing in Bristol.

    1. Not a surprise as she was built in Germany by Blohm & Voss and began life as the Horst Wessel. She has a much better name now.

      A lovely ship indeed.

  6. Which brings up the coincidence that , for some time in the 1920's, the navy's top expert on diesel engines was (drumroll) Chester Nimitz, who had been sent to Germany to study them. Funny how some people keep popping up; it seems to have something to do with qualities of mind and character, but that's a confused jumble where I haven't figured out all the correlations yet.

    1. Queue Twilight Zone theme: the building I work in is the (wait for it) Nimitz Building.

      The admiral was a brilliant guy.

      Speaking of diesel engines, did you know that he that lost part of one finger in an accident with a diesel engine, saving the rest of it only when the machine jammed against his Annapolis ring? I didn't know that either until just now when I was looking at his entry on Wikipedia.

      He was born in juvat's neck of the woods.

      Qualities of mind and character, aye.

  7. Interesting. In high schools I read everything I could about WWII submarines in the Pacific. Very little was available about their activities elsewhere. Should add, that interest never extended to serving on one!

    1. Going out to sea on a submarine is not on my "To Do" list.

      Though I wouldn't turn down such an opportunity, I won't actively seek it.

  8. Dönitz got hosed during the War Crime trials. He did everything to try to protect his people, both submariners and, at the end, civilians. Yet the crowd wanted blood, and so they got some (well, not actual blood, but winners get to do what they want, so they got to imprison a man who could have been a major player in Germany's recovery, because butt-hurt.)

    The more I read about the war-crimes trial, the more I see the same fickle attitude that was present at Versaille at the end of WWI.

    In comparison, Bomber Harris and General LeMay should have served, big time, for their unrestricted war against civilians. And so should lots of Russkies (just what was done in Poland should have sent a handful, including Stalin, to the gallows...)

    Yes, victory and all that. But don't try to ascribe moral reasons to one's petty actions after the fact when one's hands are covered with the blood of innocents.

    (The Brits in both wars played fast and furious with the 'Rules of Law' and the 'Rules of the Sea' in their defense and offense against German subs. One should not bitch about not rescuing sailors of one's sinking ships when one's own people don't rescue the submarine sailors of the enemy...)

  9. Georg von Trapp (best known as The Captain in 'The Sound of Music') was an Austrian submarine commander in WWI, and wrote a very interesting memoir. I reviewed and excerpted it here:

    Yep, gasoline engine, and yep, it was pretty miserable.

    1. That's right! He was an Austrian U-Boat skipper.

      Nice write-up at your place. I may need to track that book down.

    2. He was one of Austria's top surviving sub aces. And a really good commander of men. And a national hero (one of the few things they got right in 'TSOM.' And as usual, the actual story is much more interesting than the Hollyweird version...)

      All of which explains why the Nazis wanted him. Good guy, great commander, token Austrian Hero...

    3. And, yes, I did mean to say there was a difference between a top-scoring sub commander and a national hero. Sometimes the two are the same, sometimes one can be an ace and a jerk, while being a hero requires a 'Hero moment.'

    4. Beans the 1st - Indeed he was!

    5. Beans the 2nd - Same goes for air aces!

  10. Glad to hear the eye and finger are coming back into battery. (an inside joke for old artillery beings.)
    I remember reading the expression long ago that 'war makes monsters of us all.' There is considerable truth in that and it was in my mind many years ago when Lex offered the sage wisdom that declared that officers never lie, cheat or steal. Honestly, those are minor peccaddillos compared to launching fire raids or nuclear weapons on cities stuffed with fairly innocent kids and their mothers. In war, in the olden days, one did what it took and paid any price and few had regrets when it was them or us. Nobody under the age of 70 has fought an existential war for survival against a determined enemy and so people have lost sight of that truth. There were plenty who fought for their lives and lives of their men but there was zero chance N. Vietnam or N. Korea, or Iraq or even Afghanistan was going to launch a life or death international war in an attempt at regime change on US. The USSR? Yes, to an extent but I never thought they'd land troops on this continent of try any kind of regime change that wasn't the simple outcome of fusion weapons hitting in and around Washington DC, the Greenbrier and Site R.
    Your earlier commenter was right though. Our propaganda ministry did everything they could to dehumanize the Japanese and Germans and they weren't wrong to do so. What we know about them proves that they were inhuman monsters clothed in human flesh. The world is better off without them.

    1. Ah, artillery... I once spent a delightful summer firing an old Civil War cannon. I was told that it was a James 6 pdr. A lovely cannon it was.

      War requires monsters - the faint of heart, the kind, and the forgiving are quickly slaughtered in the face of combat.Which is why war should be avoided, if possible. In World War II that wasn't possible, great evil was loose in the world and had to be destroyed, by any means necessary.

      Now I fear that those who have forgotten their history, more likely never learned it, want to repeat the same old mistakes. They too must be eradicated.

  11. I had a class mate in college that was a submariner. He wore every piece of clothing he owned while on patrol in the north Atlantic. He said the chill was like nothing he ever experienced. I can't even imagine....


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