Propulsion Machinery of the “Koeln” Class Escort Frigates With Special Consideration of Gas Turbine Propulsion

The Koeln Class escort frigates represents the first larger type of vessel built for the German Federal Navy. The design work dates back as far as 1955–1956. In view of the planned operational use of the ships an extremely light construction of the propulsion machinery with a long operating range was required. Furthermore, combat safety required an appropriate space structure of the propulsion machinery. For this purpose various propulsion systems were examined at the time, e.g., steam-turbine and diesel-engine propulsion, and a comparison was made between direct and electrical output transmissions. The advanced development of gas-turbine technique in connection with the introduction of high pressure-charged, high-speed diesel engines together with the development of high-performance, variable-pitch propellers led to a design which, compared with other types of propulsion, proved to be extremely advantageous not only with regard to the standard displacement of the vessel but, because of the low fuel consumption, also to the displacement of the fully equipped ship (1, 2).