German Navy was permitted only six light cruisers. Article 190 limited new cruiser designs to and prohibited new construction until the vessel to be replaced was at least twenty years old. Since the six cruisers that German retained had been launched between 1899 and 1902, the oldest ships—, , , , and —could be replaced immediately. Design work on the first new light cruiser, ordered as "Ersatz Niobe", began in 1921. The Navy hoped to finish the ship as quickly as possible and to keep costs to a minimum, and so requested permission from the Naval Inter-Allied Commission of Control to use steam turbines, boilers, and conning towers from scrapped vessels to complete Ersatz Niobe. The NIACC rejected the request. The Navy also hoped to use an armament of four twin-gun turrets for the new ship. The NIACC rejected the twin-turret design, but allowed the use of guns from existing stocks of spare barrels. Nominally within the 6,000-ton limit of the Versailles Treaty, Emden in fact exceeded the restriction by almost fully loaded. In 1923, after work on Emden had already begun, the Germans proposed using the definition for standard displacement adopted in the Washington Naval Treaty of 1922, which was significantly less than full-load displacement. The Allied powers approved of the change, and thus Emden, which had a standard displacement of just under the 6,000-ton limit, was retroactively made legal. The ship was based on the blueprints from the late-war cruiser , primarily due to personnel shortages in the design staff and the closure of the Navy's Ship Testing Institute, and the blueprints for Karlsruhe were still available. Completed to a dated design, she proved to be something of a disappointment in service, primarily owing to her weak broadside of just six 15 cm guns. Nevertheless, the ship incorporated major advances over the earlier designs, including large-scale use of welding in her construction and a significantly more efficient propulsion system that gave her a cruising radius fifty percent larger than that of the older ships, which proved to be quite useful on the extended training cruises of the 1920s and 1930s. General characteristics Emden was long at the waterline and long overall. She had a beam of and a designed draft of ; at standard load, the draft was , and at combat load the draft increased to . Her designed displacement was , with standard and combat displacements.