SM U-73
Encyclopedia
SM U-73 was one of 329 submarine
s serving in the Imperial German Navy (Kaiserliche Marine
) in World War I
. She engaged in the commerce war
as part of the First Battle of the Atlantic
.
U-73 has the distinction of being responsible for sinking the largest ship sunk in World War I, the 48,758 ton hospital ship
Britannic, shortly after she laid the mine which Brittanic struck.
by Kapitänleutnant (Lieutenant
) Gustav Sieß. She joined the Kiel School, where she remained until February 1916, conducting trials and crew training. She then left for the North Sea and was attached to the 1st Half Flotilla, still under Her activities were monitored throughout the war by Room 40
, & most of her recorded movements are based on that information. Her first operational cruise began 1 April 1916, when she left Heligoland Bight
, bound for the Mediterranean
by way of the North Sea
. En route, she attacked one steamer in the Atlantic
and laid mine
s off Lisbon and Malta. On arriving Cattaro on about 1 May (the date is uncertain), she joined the Pola-Cattaro Flotilla.
The minelaying cruises of U-73 in the Mediterranean cannot be reconstructed. On 7 October 1916 she is reported to have left Pola, and the French put down to her the mine sunk off Cape Male on 12 October, as well as a minefield in the Gulf of Salonika, and mines in the Gulf of Athens on which two Greek ships were blown up. It seems certain U-73, still commanded by Sieß, laid the mine by which the hospital ship HMHS Britannic was sunk, one hour after it was laid. It is possible the hospital ship Braemaer Castle was also sunk by one of her mines. U-73 suffered from constant machinery trouble in common with her class. At the end of October 1918, now in the hands of Kpnlt. Fritz Saupe, she was scuttled
at Cattaro.
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...
s serving in the Imperial German Navy (Kaiserliche Marine
Kaiserliche Marine
The Imperial German Navy was the German Navy created at the time of the formation of the German Empire. It existed between 1871 and 1919, growing out of the small Prussian Navy and Norddeutsche Bundesmarine, which primarily had the mission of coastal defense. Kaiser Wilhelm II greatly expanded...
) in World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
. She engaged in the commerce war
Naval warfare of World War I
Naval warfare in World War I was mainly characterized by the efforts of the Allied Powers, with their larger fleets and surrounding position, to blockade the Central Powers by sea, and the efforts of the Central Powers to break that blockade or to establish an effective blockade of the United...
as part of the First Battle of the Atlantic
U-boat Campaign (World War I)
The U-boat Campaign from 1914 to 1918 was the World War I naval campaign fought by German U-boats against the trade routes of the Entente Powers...
.
U-73 has the distinction of being responsible for sinking the largest ship sunk in World War I, the 48,758 ton hospital ship
Hospital ship
A hospital ship is a ship designated for primary function as a floating medical treatment facility or hospital; most are operated by the military forces of various countries, as they are intended to be used in or near war zones....
Britannic, shortly after she laid the mine which Brittanic struck.
Operations
After completion at Danzig in November 1915, U-73 was commissionedShip commissioning
Ship commissioning is the act or ceremony of placing a ship in active service, and may be regarded as a particular application of the general concepts and practices of project commissioning. The term is most commonly applied to the placing of a warship in active duty with its country's military...
by Kapitänleutnant (Lieutenant
Lieutenant
A lieutenant is a junior commissioned officer in many nations' armed forces. Typically, the rank of lieutenant in naval usage, while still a junior officer rank, is senior to the army rank...
) Gustav Sieß. She joined the Kiel School, where she remained until February 1916, conducting trials and crew training. She then left for the North Sea and was attached to the 1st Half Flotilla, still under Her activities were monitored throughout the war by Room 40
Room 40
In the history of Cryptanalysis, Room 40 was the section in the Admiralty most identified with the British cryptoanalysis effort during the First World War.Room 40 was formed in October 1914, shortly after the start of the war...
, & most of her recorded movements are based on that information. Her first operational cruise began 1 April 1916, when she left Heligoland Bight
Heligoland Bight
The Heligoland Bight, also known as Helgoland Bight, is a bay which forms the southern part of the German Bight, itself a bay of the North Sea, located at the mouth of the Elbe river...
, bound for the Mediterranean
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
by way of the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...
. En route, she attacked one steamer in the Atlantic
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
and laid mine
Naval mine
A naval mine is a self-contained explosive device placed in water to destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, an enemy vessel...
s off Lisbon and Malta. On arriving Cattaro on about 1 May (the date is uncertain), she joined the Pola-Cattaro Flotilla.
The minelaying cruises of U-73 in the Mediterranean cannot be reconstructed. On 7 October 1916 she is reported to have left Pola, and the French put down to her the mine sunk off Cape Male on 12 October, as well as a minefield in the Gulf of Salonika, and mines in the Gulf of Athens on which two Greek ships were blown up. It seems certain U-73, still commanded by Sieß, laid the mine by which the hospital ship HMHS Britannic was sunk, one hour after it was laid. It is possible the hospital ship Braemaer Castle was also sunk by one of her mines. U-73 suffered from constant machinery trouble in common with her class. At the end of October 1918, now in the hands of Kpnlt. Fritz Saupe, she was scuttled
Scuttling
Scuttling is the act of deliberately sinking a ship by allowing water to flow into the hull.This can be achieved in several ways—valves or hatches can be opened to the sea, or holes may be ripped into the hull with brute force or with explosives...
at Cattaro.