HMS Dreadnought
U- 29
The sinking of the SS Glitra did much to change the Naval
Staff's perception of the value of a commerce war, particularly because all the
commerce-raiding cruisers had been sunk or captured by 1915. The Grand Fleet
had not behaved as the German planners had hoped (by refusing to risk a close
blockade of German harbours), and when it left harbour on one of its frequent
sweeps it was screened by destroyers. One such foray cost Weddigen his life in
the new U.29, when his periscope was sighted by a lookout aboard the battleship
HMS Dreadnought on 18 March 1915 in the Pentland Firth. In response to a rapid
helm order the 18,289-tonne (18,000-ton) ship wheeled out of line and sliced
the luckless U-boat in half. The ruthlessness with which the British enforced
the blockade also weakened any scruples entertained by the German Naval Staff
about breaches of International Law. For example, all foodstuffs were declared
contraband by the Allies, on the grounds that the German government had
commandeered all food supplies.
An unrestricted war against Allied shipping carried with it
a risk of losing the propaganda war. The torpedoing of the Belgian refugee ship
Amiral Ganteaume in October 1914 was just such an incident, labelled an
atrocity by Allied newspapers. Knowing how little a U-boat commander could
actually see through a periscope, it is likely that U.24 mistook the Amiral
Ganteaume for a troopship. With only a distorted image and only a few seconds
for a torpedo shot, the U-boat captain was supposed to count the number of
people on deck, guns, and even where the guns were mounted. Forward-mounted
guns indicated offensive armament, whereas aft-mounted guns counted as
defensive armament under the Prize Regulations. When U.20 first sighted the
liner Lusitania in April 1915, K/Lt Schwieger mistook her four funnels and
smoke for a flotilla of destroyers! Only when he returned to Germany did he
learn the name of the ship he had sunk. Despite the opinions of conspiracy
theorists, even if the German Naval Staff had an inventory of munitions carried
in the hold of the Lusitania, U.20 could never have identified an individual
ship with such precision.
Even without flouting their self-imposed restrictions, the
German Navy's U-boats were inflicting painful losses on the Allies: 32,513.6
tonnes (32,000 tons) of British and 16,155 tonnes (15,900 tons) of French and
neutral shipping sunk in January 1915 alone. By March the monthly total had
risen to 81,995 tonnes (80,700 tons), and by May the figure topped 187,969
tonnes (185,000 tons). Neutral opinion, particularly in the United States, was
outraged. The insatiable demands of the Allied war economies had opened a huge
new market to replace that cut off by the blockade. Neutral opinion was
inflamed by lurid tales of the rape of Belgium; the deaths of American citizens
at sea added fuel to the fire.
Ignoring the uproar, Germany announced on 4 February 1915
the existence of a War Zone around the British Isles, in which British and
French merchant ships would be sunk without warning. The declaration added
ominously that it would not always be possible to avoid attacks on neutral
ships. In other words, U-boats could 'sink at sight' unless they saw a neutral
flag. If the neutral maritime nations could have forbidden trade with the
Allies the German gamble might have paid off, but the tight British blockade
meant that a refusal to trade with the Allies would mean virtual bankruptcy for
most shipping companies. It was the same fact of maritime life which had
brought down Napoleon's Continental System, but in 1915 nobody seemed to pay
much attention to the lessons of history.