For most other nations the leap to nuclear power for submarines was out of the question, because of the absence of the necessary industrial and scientific infrastructure, its great expense, and, in some instances, political obstacles. Instead, they exploited the elektroboote technologies to produce a new first generation of Western, conventionally powered fast submarines.
The second generation of postwar diesel-electric boats represented a substantial advance on the earlier types. Three elements combined to create these new boats: great strides in battery technology, new hull forms inspired by the Albacore design, and advances in reducing acoustic and magnetic signatures. New battery designs not only generated more power for the same space and weight but also recharged much faster, enabling submarines to operate fully submerged for longer periods and use their snorkel on a much more limited scale. New hull forms, and advances in metallurgy, endowed these boats with higher speed, greater maneuverability, and deeper diving capabilities. Reduced magnetism came from using nonmagnetic, high-tensile steel or active demagnetizing. The biggest asset, however, that these later-generation diesel-electric boats possessed was quietness and, therefore, stealth. Rafted machinery, slow-speed motors, advanced propeller designs, sophisticated streamlining, and anechoic hull coatings all dramatically reduced their acoustic signatures. When combined with their small size, especially relative to nuclear-powered submarines, and thus an ability to operate in confined waters, this stealth made later diesel-electric boats very difficult targets for aerial, surface, and subsurface antisubmarine forces.
Several producers of advanced conventional boats were able to turn these assets into lucrative export production. Beginning in the 1970s, France, Sweden, and above all Germany began to dominate the market for advanced conventionally powered submarines worldwide. The most successful by far is the family of German Type 209 submarines, of which almost 60 have been delivered or are on order for 15 nations. Moreover, since many of these export boats were ordered by fleets without solid experience of modern submarine operations, lucrative training and support contracts often accompany the orders for the hardware, and contribute to the spread of a remarkably uniform ethos of operation.
