SM U-9

She was one of 329 submarines serving in the Imperial German Navy, and engaged in commerce raiding (Handelskrieg) during World War I.

[3] U-9 was fitted with two Körting 8-cylinder plus two Körting 6-cylinder two-stroke petrol engines with a total of 1,000 metric horsepower (735 kW; 986 bhp) for use on the surface and two Siemens-Schuckert double-acting electric motors plus two electric motors with a total of 1,160 PS (853 kW; 1,144 shp) for underwater use.

Members of the Admiralty who had considered submarines mere toys no longer expressed that opinion after this event.

During this period, she sank 13 ships totalling 8,635 GRT: 10 small fishing vessels and three British steamers (Don, Queen Wilhelmina and Serbino).

U-9 and the raider SMS Emden were the only ships which Kaiser Wilhelm II awarded the Iron Cross.

Action of 22 September 1914
Illustration by Hans Bohrdt depicting the sinking of HMS Cressy , HMS Hogue and HMS Aboukir by U-9 on 22 September 1914 off the Dutch coast.
The men of U-9 .
Propaganda postcard depicting victories of U-9 .
The return of U-9 to Wilhelmshaven, Germany illustration by Willy Stöwer