Submarine Warfare in World War I
After the enormous battleship buildup prior to WWI, the great fleets adopted play-it-safe tactics once war began. This came as a distinct anticlimax to a public expecting a new Battle of Trafalgar -- a decisive showdown on the high seas that would decide the war in an afternoon. Following the cruiser clashes and battlecruiser brushes of 1914-15, there came a lull coinciding with the tenure of Adm. Hugo von Pohl as German C-in-C. During this time there was no indication a full-blown fleet action might be imminent. The battle fleets settled into a pattern of distant blockade by the British and occasional jabs at small, undefended English ports by the fast-moving German battlecruisers. Even after the furious but indecisive Battle of Jutland in May 1916 -- especially after Jutland -- the rivalry between the British and German dreadnought fleets was no nearer resolution. Despite its horrific costs, Jutland only reinforced the status quo: a 3:5 ratio of superiority in favor of the British, significantly higher than the 2:3 margin sought by the Germans in the prewar arms race.
The High Seas Fleet blockaded in port at Wilhelmshaven.
But Germany actually came close to winning the war at sea through a cheaper, sneakier weapon: the U-boat. Despite the persistent exhortations of Jacky Fisher to develop a strong Royal Navy submarine arm, the British regarded the submarine as "underhanded, unfair, and dashed un-English." The Admiralty responded to Fisher's emphatic memorials by developing the K class, an oil-burning steam-and-electric-powered giant submarine, with elaborate snorkel funnels to carry off smoke while operating awash or slightly submerged. These 339-foot, 2500-ton (submerged displacement) vessels were designed to maneuver in unison with the fleet like flotillas of torpedo boats; predictably, the K-boats proved a costly fiasco, capable of 24 kts in calm seas but unable to keep up with surface ships in weather. Predictably, they suffered from multiple, often deadly technical failures. The German U-boats, by contrast, were more straightforward technically, and proved capable of performing a more circumscribed mission quite reliably. Early models used kerosene engines on the surface, leaving a tower of oily smoke visible for miles, leading the British to overconfidence about the U-boat threat. Initially, the U.S. and Russia had pioneered sub technology; Germany shared Britain's disdain for the submarine until forced to reconsider it after 1914.
Above, U-45, a German Type IV boat built in 1913. Driven by diesel engines while surfaced and electric motors when submerged, this craft was typical of Germany's commerce raiders in WWI, though several longer-range models were built later in the War, as were specialized submarines such as the 136 UB and UC boats -- submarine minelayers of 130 to 520 tons--, or the 1,500-ton "merchant submarine" Deutschland which crossed to America several times during the War. To begin with, the Allies greatly underestimated the range and destructiveness of the submarine. Confronted by slow economic strangulation and with their battleship strength at only 60% that of the British, the Germans turned to U-boat warfare in desperation, little guessing at first how close it would come to turning the tide for them. When Britain declared a total blockade of Germany late in 1914, high-handedly invoking the threat of starvation should the War be prolonged, the Germans retaliated by declaring the seas around the British Isles to be a submarine warfare zone -- never mind they had only 8 or 9 long-range subs available at any one time to patrol Britain's western approaches.
Although surprise attacks on enemy warships were fair game in time of war, the position with regard to enemy commerce was murkier. The U-boat occupied an anomalous position in international law. Under the "Cruiser Rules" which governed commerce raiding in war, a commerce raider encountering an enemy ship would stop it -- if necessary by putting a shot across its bows -- and inspect its papers. If it proved an enemy flagged vessel, its crew and passengers would be allowed to gather possessions and provisions and escape in the lifeboats. The U-boat commander might also make other provision for their safety before destroying the vessel or sailing it into port as a prize of war. To follow this procedure (as most U-boat captains did at the beginnning of the War) was to throw away a U-boat's main advantage. A sub's chief weapon was surprise -- invisibility; but it was slow-moving and highly vulnerable to attack while surfaced and stopped. After losing merchant vessels to submarine attack the British Admiralty began arming cargo ships and liners. In early 1915, British skippers were instructed to run down submarines and sink them by collision. Several U-boats were dispatched by ramming or fell victim to sudden attack by nearby cruisers while surfaced. In response, the German admiralty ordered stealth torpedo attacks without warning.
For this purpose, the U-boat's weapon was the locomotive torpedo. Originally developed in the late 1860s by the Englishman Robert Whitehead at labs in the Adriatic, and first used in combat in the 1870s, Whitehead torpedoes had been perfected for active service in the mid-1890s. Their range and size had improved steadily since. Propelled by compressed air, stabilized by gyroscopic mechanisms, packing 200 lbs of TNT in its deadly warhead, the WWI period torpedo (shown above) was a high-tech weapon of its day. Although a large percentage of German torpedoes early in the War were duds, those that did ignite proved their potency. Lightly built merchant ships could be crippled or sunk with one hit, though sometimes a U-boat would have to surface and finish off a slow-sinking victim by shelling it at the waterline with the sub's deck gun. As the war dragged on, torpedo accuracy and reliability improved with practice.
To the painful surprise of the Allies, the U-boat proved the Kaiser's most fearsome weapon by sea. Only weeks into the War came the scandalous sinking of 3 Bacchante-class cruisers, dubbed the Live Bait Squadron after the event (~1450 killed); soon afterwards, a sub in the Channel destroyed the pre-dreadnought battleship HMS Formidable (~550 lost); then in May 1915 came the Lusitania affair, in which a single torpedo from the U-20 sank one of the largest, fastest liners afloat in 18 minutes flat. 1,198 lost their lives in a dèbacle that compared unfavorably with the Titanic's demise only 3 years before. While 128 Americans died in the Lusitania disaster, most of the American people still opposed involvement in the European conflict, and U.S. diplomacy with Germany was remarkably mild at first. The post-Lusitania uproar in Britain and America pressured the Kaiser to restrict his subs temporarily; but the need to shorten the war soon prevailed and Germany resumed unrestricted submarine warfare in March 1917. The U-boats began hunting and killing with a vengeance, sinking scores of neutral American ships in the process. While the proximate cause of the United States' entering the war was the Zimmermann Telegram (in which Germany urged Mexico to join a war of conquest on the U.S. and share the spoils of victory), the Lusitania tragedy, the mounting losses in shipping, and repeated evidence of German bad faith all set the American climate for war. To this day, the U.S. State Department website erroneously cites unrestricted submarine warfare as America's sole cause for war with Germany in WWI.
Typically operating alone and far from base for weeks at a time, most German commerce-raiding subs at war's end were 240-foot, 820-ton models carrying a 4.1" gun and 16 torpedoes with 6 tubes for launching. They were sinking a steadily rising percentage of cargos inbound to Britain and France starting in February 1917, and threatening troop transports as well. At the start of the unrestricted submarine campaign in early 1917, U-boats were sinking more than 500,000 tons of shipping a month (versus 790,000 tons in total sunk between August 1914 and Sept. 1915). April 1917's monthly total topped 850,000 tons -- the wartime high. Because Lord Fisher had initiated an ill-advised crash capital ship construction program, British yards were unable to replace the tonnage destroyed. By 1918, Germany alone had 135 U-boats in commission; Austria-Hungary a further 40 subs (also called U-boats in the Austro-Hungarian K.u.K. Kriegsmarine). Only the convoy system devised by U.S. Admiral William S. Sims and Britain's First Sea Lord Sir John Jellicoe foiled the go-for-broke U-boat offensive in the final year of the War. Convoys served as magnets for hunting subs, luring them under concentrated formations of antisubmarine warships (ASW). Working in teams, destroyers and light escort vessels used primitive sonar ("hydrophones") and knowledge of their enemy's tactics to locate and destroy U-boats. Together they developed depth charges and techniques of ASW that stood the Allies in good stead when they faced an even more dire U-boat threat in WWII.
The moral issue of the U-boat war and Allied success in antisubmarine warfare (ASW) are touched on by this wartime poster touting war bonds. While the image is admirably composed, the artist has taken considerable liberties with the colors of the destroyer's dazzle-pattern camouflage paint -- an experimental anti-submarine measure adopted later in the War. Actual camouflage colors were shades of blue, grey and black, though many patterns were much more bizarre than that seen here. The big liner, too, would have been painted in dazzle colors during hostilities.
No essay on WWI submarining would be complete without a tip of the hat to the British submarine service. From The time of the Gallipoli invasion to the the Allied intervention in the Russian civil war, from the Black Sea to the Baltic, or to the Med, British submarine commanders compiled an admirable record in offensive warfare. Watch our site for a new page of British submariner's exploits in the Great War!
Whatever may be said about the morality of submarine sneak attack, it packed a wallop. Hear an American sailor, Ray Millholland, on the wreckage left behind by sinkings in the Mediterranean in 1918:
Everywhere on the surface . . . extending as far as the circular horizon, was mute evidence of the effectiveness of Germany's unrestricted submarine campaign. We were constantly shifting our zigzag course to avoid smashed lifeboats, drifting hatch gratings, and the odd clutter of gear that rises to the surface from a sunken ship. Occasionally a shapeless uhdulating mass buoyed by a cork life jacket would drift by, and a brine bleached face would stare with empty eye sockets at the glaring sun.
Rest in peace.
Relevant Weblinks:
MINE WARFARE
After the sub-launched torpedo, the straightforward, inexpensive mine proved the most lethal weapon at sea in WWI. At right, the brand-new superdreadnought Audacious gradually succumbs after striking a mine off Ireland in 1914. Floating explosive devices had a long history already by this time; river ironclads such as the USS Cairo were destroyed by primitive mines in the American Civil War, when they were called torpedoes: Adm. Farragut's famous line "Damn the torpedoes! Full speed ahead!" referred to the minefields at the entrance to Mobile Bay, after his monitor Tecumseh was sunk by one of the pesky devices. In the Russo-Japanese War, the Japanese lost 2 of their 6 battleships to Russian mines, while the Russians lost their best commander when Japanese mines blew up and sank his flagship Petropavlovsk in about 2 minutes flat. In the First World War, minelayers and minesweepers were busy from the North Sea to the Adriatic and the Dardanelles. Huge minefields in the Heligoland Bight protected the chief German base at Wilhelmshaven and the great British bases at Portsmouth and Scapa Flow. All sides also developed smaller submarines specifically designed for mining shipping lanes. Scores of warships and hundreds of merchant craft fell victim to mining in WWI. Perhaps the greatest massacre inflicted by mines was the ill-fated attempt by the Allies to force the Dardanelles on March 18, 1915. That day 3 pre-dreadnought battleships were sunk, 2 more seriously damaged, and the dreadnought battlecruiser Inflexible also badly damaged; the French battleship Bouvet sank in about 2 minutes with all hands. Mines were just as merciless to ships of the Central Powers: The dreadnought Goeben, transferred to the Turkish navy in 1914, had several episodes, most prominently her return from the attack on Imbros in 1918. Goeben spent some anxious days beached on a sandbar inside the Dardanelles (below left) for emergency patching before proceeding to Constantinople and safety; her consort, the light cruiser Breslau, was not so lucky, though most of the Breslau's uninjured crew escaped safely.
Mines continued their depradations in WWII and beyond. In fact, the official Soviet government story has it that a Nazi-laid mine in the Black Sea claimed one of their war prizes -- the battleship Novorossisk. This was the name with which Stalin dubbed the 1914 Italian dreadnought Giulio Cesare when she was assigned to the USSR as war reparations in 1946. The old vessel blew up and sank in her namesake port in 1954, placing her (with her sister Andrea Doria and the Turkish Yavuz, ex-Goeben) among the longest-lived WWI dreadnoughts. If true, the official Kremlin story would make this mine a wonder of surviving function -- it would have spent 11 or 12 years in seawater before devastating a warship that was also "of an age." Conspiracy theorists have an alternate explanation: In an act of vengeance for the Russians' taking their prized battleship, mysterious Italian frogmen sabotaged the ship's hull by dark of night, escaping before the time-activated explosives devastated the target. Italian frogmen indeed did just this with the Austrian battleships Viribus Unitis and Wien in WWI; repeating the feat against HMS Queen Elizabeth and Warspite in Alexandria Harbour during WWII. But hard evidence of an Italian caper in the USSR in 1954 is hard to come by. It is perhaps telling that no fresh information came out between the fall of the secretive, paranoid Soviet regime in 1991 and the rise of the secretive Putin regime after 2000.
