We’ve fallen a little behind on our World War I series. Over the next few weeks/months, we’re going to work to get caught-up to the calendar.
German Chancellor Theobald von Bethmann-Hollweg was uneasy as he approached the podium in the Reichstag on January 31st, 1917. Despite having done more than perhaps any other figure in Europe to ensure the Great War, Bethmann-Hollweg’s support for the conflict had slowly dissipated. Only weeks earlier, the aging Chancellor had been forced to offer the outline of negotiations by rebellious German legislators eager to bring the bloodshed to an end.
Now, Bethmann-Hollweg was finding himself forced to announce a policy he had long fought against – the resumption of unrestricted submarine warfare. While the policy had done more to turn the tables of war in favor of Germany than any other action of their armies, Bethmann-Hollweg feared a continued policy of sinking any and all ships would eventually bring the United States into the conflict. Three weeks earlier, the leaders of Germany’s Navy had met with the Kaiser and implored Wilhelm II to restart submarine operations. The nation was starving to death and Berlin’s U-boats were the other weapon that could return the devastation of the blockade in-kind. The Kaiser agreed.
Bethmann-Hollweg told the assembled delegates that the U-boat campaign would renew the following day, February 1st, 1917. “We have been challenged to fight to the end,” the Chancellor intoned. “We accept the challenge. We stake everything, and we shall be victorious.”
For a weapon that nearly decided two World Wars, the Unterseeboot or U-boat was barely a consideration in Germany’s naval program.
German naval policy, crafted through a series of so-called “Naval Laws” that allocated resources to ship-building, had always been focused on creating a rival of the grand surface fleets of the British Royal Navy. While conceptually the submarine had existed since the American Revolution, it’s practical execution had yet to come into being, save for the CSS H.L. Hunley managing to sink a Union vessel during the American Civil War in 1864. Thus, it wasn’t until 1912 that Germany added submarines en masse to their fleet, designating them to the flotilla attachments of torpedo boats whose main purpose would be to harass the enemy. The submarine was intended to assist the High Seas Fleet, not conduct naval battles of their own.
The role of surface support for the U-boats wasn’t merely the result of policy, but also of technological limitation. The roughly 48 U-boats that Germany held at the start of the Great War were incredibly slow, awkward vessels that ran on noisy diesel engines. Only 29 of them were deemed seaworthy. Crews were lucky if they could get eight knots (9.2 mph) when the boats were on the surface, and even less when they submerged – which couldn’t be for long with the ship’s limited battery power. Most engagements would be on the surface, and with the ship’s deck gun, as torpedoes of the day were only effective at about 3,200 feet from their target.
Still, Berlin saw the potential of the U-boat as a relatively cheap weapon to even the numerical disadvantage of the German High Seas Fleet by engaging British capital ships. With little technology in place to combat, yet alone detect, submarines, the British would lose 4 cruisers to U-boats by late September of 1914 and a battleship by the end of the year. One German sub, U-19, would sink 3 British cruisers in less than an hour.
But the German use of submarines as capital ship destroyers would have a short life. The speed of the British ships, and inability of the German U-boats to remain submerged for long periods of time, gave the policy limited results. As more British warships embraced strategies as the “zig-zag” sailing formation and stripped paint to hide the direction of the ship, U-boats would have increased difficulty tracking a vessel’s bearing. Coupled with their slow speed, the ability for U-boats to sink major battleships would depend more on luck than skill. As anti sub-technology progressed, the U-boat’s days of being the hunter of British warships appeared to be coming to a close.
By the end of 1914, the U-boat had become a glorified mine-placement vessel, taking advantage of the sub’s biggest asset – it’s range of 4,000 miles – by dropping thousands of explosives along Allied shipping routes. The submarine’s wartime relevance had seemingly come and gone.
The first commercial ships sunk by German U-boats wouldn’t occur until late in October of 1914. And they weren’t intentionally targeted.
The role of commerce raiders had intended to be played by surface ships, whose speed would allow for faster pursuits than the U-boats could obtain. International naval law also dictated the submarine’s subordinate role against commerce. The “Prize Laws” that had effectively governed naval warfare since Hugo de Groot’s “Commentary on the Law of Prize and Booty” in 1604 had stated that the crews of unarmed commercial vessels would be warned before being fired upon, and allowed to depart their ships safely. In theory, warring nations would have to board a non-combatant ship from an enemy nation, search for military contraband, and if found, could sink the vessel only after accounting for the well-being of the crew.
The product of a more gentlemanly code of combat, the “Prize Laws” were wholly inadquate for the warfare of the 20th century. Radio technology allowed stopped ships to call for aid, and the British creation of “Q-ships” – commercial vessels with hidden guns – allowed for ambushes of any German surface raider or U-boat that attempted to abide by the “Prize Laws.” In response, German warships began firing on commercial shipping without a warning, including U-boats who now would fire their torpedoes without surfacing.
By February of 1915, the German Navy realized the U-boat was the only weapon in their arsenal that could effectively counter the British blockade without incurring substantial losses. Declaring the waters around Great Britain and Ireland a “war zone”, the German Navy made it clear that all vessels from all nations would endanger themselves if they sailed into British waters. Having occupied most of Belgium, German U-boats operating out of Ostend could now easily reach into the English Channel and Atlantic Ocean with a far shorter journey than their original bases in the North Sea.
The impact was immediate. While Germany had only managed to sink 43,500 tons of shipping from August 1914 to January 1915, the new policy of unrestricted submarine warfare would result in an average of 100,000 tons of British shipping sunk per month – the equivalent of nearly 2 ships a day – all accomplished with only 20 U-boats. Over 168,000 tons would be sunk in August of 1915 alone. But the biggest casualty would be U.S./German relations.
American opinion had been strikingly sympathetic to the plight of German civilians affected by the British blockade. The British policy of declaring food stuffs as military contraband was accurately seen as a violation of international norms and an obvious attempt to attack civilians.
But what international goodwill Germany had developed by their suffering at the hands of the blockade was squandered by their efforts to combat it. By definition, the unrestricted U-boat campaign was indiscriminate. The sinking of the Belgian relief ship Harpalyce and the RMS Falaba, whose death toll included one American, began to inflame American passions against Berlin. With stories emerging from Belgium about the cruelties of the German occupation, the U-boat campaign was becoming part and parcel of a narrative (accurate or not) of German aggression. And with the sinking of the Lusitania in May of 1915, with 128 Americans among the nearly 1,200 dead, it appeared to American eyes that Germany’s aggression was crossing the Atlantic.
Eager to prevent the United States from entering the war, Bethmann-Hollweg and other German political leaders pressured the Kaiser to halt the unrestricted submarine campaign. Only once the Wilson administration threatened to cut off diplomatic relations in the summer of 1915, following the sinking of the SS Arabic and the loss of three more American lives at sea, did Germany relent. The U-boats would return to the North Sea in accordance to their original purpose in aiding the High Seas Fleet, over the objections of the German Navy.
In six months, the first U-boat campaign sunk over 750,000 tons of British commercial shipping. Yet, the British Merchant Marine had over 21 million tons of vessels and between captured Central Powers shipping and new construction, had equaled out the number of ships lost. Worse, the campaign had harmed Germany’s relations with most neutral nations and led to the internal belief that Germany’s political leaders were holding back the war effort. If only given more time and more U-boats, the officers of the German Navy complained, they could starve Britain out of the war.
For the next year, Germany’s U-boats would largely languish in the North Sea.
A brief unrestricted Atlantic campaign would occur in March and April of 1916 before once again being halted by Berlin due to American objections. But the abortive campaign’s results – 143 British ships lost to only 4 U-boats – begged the question: at what point could the U-boats out-sink British production? Renowned Magdeburg-based banking institute director Dr. Richard Fuss studied the question. At 630,000 tons per month, British industry would be incapable of replacing their losses. Dr. Fuss further theorized that within 5-6 months of such losses, London would be forced to sue for peace, regardless of whether or not the campaign led the United States into the war.
Bethmann-Hollweg was far from convinced, confiding in his journal that the plan “assumes that we will have England on her knees by the next harvest… Of course, it must be admitted that those prospects are not capable of being demonstrated by proof.” The objections of Berlin’s politicians were barely taken into consideration as Germany’s armed forces were desperate to find any solution. Newly appointed Chief of the General Staff Paul von Hindenburg advised the Kaiser that “the war must be brought to an end by whatever means as soon as possible.” Admiral Henning von Holtzendorff, an ardent supporter of Dr. Fuss’ conclusions, doubled-down on the recommendation, assuring the Kaiser that in the event of an American declaration of war, “I give your Majesty my word as an officer, that not one American will land on the Continent.”
Even if America did declare war, few in Germany’s military leadership trembled at the thought of the United States crossing the Atlantic. The General Staff believed “America’s assistance, in case she enters the war, will consist in the delivery of food supplies to England, financial support, delivery of airplanes and the dispatching of corps of volunteers,” Bethmann-Hollweg summarized in his journal, clearly disagreeing. It didn’t matter. The Kaiser was on board with unrestricted submarine warfare, meaning his Chancellor at least publicly had to be on board as well.
Armed with over 100 U-boats, the last unrestricted submarine campaign commenced on February 1st, 1917. Within the first seven months of the campaign, the U-boat were close to being on track for Dr. Fuss’ projections. Averaging over 612,000 tons a month of sunk commercial shipping, with over 860,000 tons in April alone, Britain struggled to replace their losses.
Dr. Fuss had been accurate about Germany’s ability to out-sink British production. He had been completely wrong about it’s impact on Britain’s ability to stay in the war. American and Brazilian shipping began to take the place of British vessels, and the development of the convoy system of sailing minimized Allied losses. Coupled with depth charges, mines and aircraft-based searches, U-boat losses were starting to mount at the rate of 5-10 per month. German industry was even less able to replace their U-boat losses than Britain’s Merchant Marine. By the summer of 1917, the tonnage lost to the U-boat campaign never rose above 500,000 tons per month.
1917 had cost the British 6 million tons of shipping, but it had brought the United States into the war, making those losses more than replaceable. Germany had lost 61 U-boats; more than half their fleet.
The final year of the Great War would see the U-boat campaign attempt to reach beyond the Atlantic.
Longer range U-boats had been developed to strike the American coast and into Allied possessions in Africa. Both campaigns would have success, including the shelling of Cape Cod, but with little overall impact to the war effort. The unrestricted campaigns would manage to sink over 12.5 million tons of shipping – over 5,000 vessels – for the loss of only 178 U-boats. Yet Germany would only flirt with it’s far-flung promises of blockading, and defeating, Britain.