Type 423 Oste class are purpose built SIGINT/ELINT and reconnaissance

Reconnaissance

Reconnaissance is the military term for exploring beyond the area occupied by friendly forces to gain information about enemy forces or features of the environment....

 ships of the German Navy

German Navy

The German Navy is the navy of Germany and is part of the unified Bundeswehr .The German Navy traces its roots back to the Imperial Fleet of the revolutionary era of 1848 – 52 and more directly to the Prussian Navy, which later evolved into the Northern German Federal Navy...

. Officially designated as fleet service ships, they replaced the Type 422 class.

Accommodation for the crew was designed to civil standards, and the Oste class offers much more comfort for the crew than other ships in the German Navy.

List of ships

Ship	Pennant number Pennant number In the modern Royal Navy, and other navies of Europe and the Commonwealth, ships are identified by pennant numbers...	Call sign Call sign In broadcasting and radio communications, a call sign is a unique designation for a transmitting station. In North America they are used as names for broadcasting stations...	Launched	Commissioned
Oste	A52	DRHH		July 30, 1988
Oker	A53	DRHG		November 10, 1988
Alster Alster (A 50) The Alster is an intelligence ship of the German Navy. She is the lead ship of the German Navy's Type 423.The Alster is a reconnaissance ship, which was originally intended to gather data on Soviet ships. She has a wide array of modern electromagnetic, hydroacoustic, and electro-optic sensors for...	A50	DRHF	November 14, 1988	October 5, 1989

The ships were built at Flensburger Schiffbau-Gesellschaft

Flensburger Schiffbau-Gesellschaft

Flensburger Schiffbau-Gesellschaft is a German shipbuilding company located in Flensburg. The company is trading as Flensburger and commonly abbrevated FSG.-History:...

 in Flensburg

Flensburg

Flensburg is an independent town in the north of the German state of Schleswig-Holstein. Flensburg is the centre of the region of Southern Schleswig...

.

All ships are currently based in Eckernförde

Eckernförde

Eckernförde is a German city in Schleswig-Holstein, Kreis Rendsburg-Eckernförde at the Baltic Sea near Kiel. The population is about 23,000.All German submarines are stationed in Eckernförde....

 and belong to the 1st submarine

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...

squadron stationed in Eckernförde. The vessels got the same name and pennant numbers as the three Type 422 class vessels they replaced. To avoid the confusion, the ship names are sometimes suffixed with II.