Sinking of the Lusitania 1915: Why Germany Torpedoed the Liner and What It Changed

The sinking of the RMS Lusitania on 7 May 1915 was the moment submarine warfare became a political weapon. A single torpedo from the German submarine U-20 hit the Cunard liner off the coast of Ireland, and the ship went down in about 18 minutes. Of the 1,959 people aboard, 1,198 died, including 128 Americans. The disaster did not bring the United States into the war immediately, but it turned American opinion against Germany and forced Berlin into a two-year debate over how far its U-boats could go.

This article explains what happened, why Germany attacked a passenger ship, what the liner really carried, and how the event led to the unrestricted submarine campaign of 1917.

What happened on 7 May 1915

The Lusitania was a British passenger liner, launched in 1906 and about 240 metres (787 ft) long, one of the fastest ships on the Atlantic with a top speed near 25 knots. On 1 May 1915 she left New York for Liverpool with 1,959 passengers and crew.

On 7 May she was approaching the south coast of Ireland, roughly 18 km (11 miles) from the Old Head of Kinsale. The U-20, commanded by Walther Schwieger, spotted her and fired one torpedo at about 14:10. A second, larger explosion followed inside the hull, and the ship listed so heavily that many lifeboats could not be launched. The Lusitania sank in about 18 minutes. The wreck lies in roughly 93 metres of water.

Of the 1,959 people on board, 761 survived and 1,198 died. Among the dead were 128 Americans, which is why the event echoed so loudly in the United States.

Why Germany attacked a passenger ship

Britain was blockading Germany with its surface fleet, and Germany answered with submarines. On 4 February 1915 Berlin declared the waters around the British Isles a war zone, and from 18 February enemy merchant ships there could be sunk without warning.

The German embassy in the United States even published a notice in American newspapers on 1 May 1915 warning travellers that ships flying the British flag were liable to destruction. Many passengers ignored it. For the German navy the logic was simple: a fast liner that carried war supplies was a legitimate target in a blockade war.

What the Lusitania was carrying

The ship's manifest listed about 173 tonnes of war material, including roughly 4.2 million rifle cartridges and shrapnel shells. Britain insisted that the cargo was legal and that passengers were not protected by it being on board. Germany pointed to it as proof that the liner was a military target. The second explosion has been debated for a century: a coal-dust blast, a boiler failure, or the munitions. Surveys of the wreck have not settled the question.

The honest summary is that both claims are partly true: the ship carried military cargo, and the attack killed more than a thousand civilians without any warning to those on board.

Consequences

Public outrage in Britain, the United States and neutral countries was immediate. President Woodrow Wilson sent a series of diplomatic notes, and Secretary of State William Jennings Bryan resigned in June 1915 because he thought the tone risked war. Germany backed down in stages: after the sinking of the liner Arabic in August, it pledged in September 1915 to stop attacking passenger ships without warning, and repeated a similar promise after the Sussex incident in 1916.

The restraint did not last. On 1 February 1917 Germany resumed unrestricted submarine warfare, hoping to starve Britain before American troops could arrive. The Zimmermann Telegram and the loss of more American ships followed, and the United States declared war on 6 April 1917. The Lusitania did not cause that decision, but it set the moral frame for it.

The Lusitania in numbers

• Sunk: 7 May 1915, about 14:10, after a single torpedo from U-20.
• Time to sink: about 18 minutes.
• People aboard: 1,959. Dead: 1,198. Survivors: 761.
• American victims: 128.
• Declared munitions: about 173 tonnes, including about 4.2 million rifle cartridges.
• Wreck depth: about 93 metres, roughly 18 km off Ireland.

What it teaches a strategy player

The Lusitania story is a lesson in the cost of a blockade. Cutting your opponent's supply lines is powerful, but every escalation creates a diplomatic price, and neutral players can become enemies. In a real-time grand strategy game this maps well to a simple rule: before you strike a target that touches a third party, ask who else you are about to bring into the war.

In Frontkrieg, a free browser strategy game about the First World War with 4,800 provinces and up to 500 players, that same logic runs through diplomacy and naval control. If you want the wider context, read about submarines and U-boats, the Battle of Jutland and the blockade, why the US entered the war, intelligence and codebreaking and WW1 propaganda. More articles are in the blog.

FAQ

Why was the Lusitania sunk?

Germany treated the waters around Britain as a war zone and considered the liner, which carried munitions, a legitimate target in its answer to the British blockade.

How many people died on the Lusitania?

1,198 of the 1,959 people aboard died, including 128 Americans.

Did the Lusitania bring the US into the war?

Not directly. The United States entered on 6 April 1917, nearly two years later, after Germany resumed unrestricted submarine warfare. The sinking did, however, harden American opinion against Germany.

Was the Lusitania carrying weapons?

Yes. Its manifest listed about 173 tonnes of war material, including roughly 4.2 million rifle cartridges, although it was also a passenger ship.

For a detailed neutral summary, see the Wikipedia article on RMS Lusitania.