Science, Time, and Spirit

  Submarine Proliferation · Export Controls · Marine Diesel The Second German Diesel A Wisconsin factory made the Junkers architecture American and won the Pacific War. Eighty years later, a Friedrichshafen factory still decides which navies can buy diesel submarines—and which cannot. The diesel engine remains the unforgiving arbiter of conventional undersea power. By Stephen L Pendergast, LT USNR · Contributing Analyst ·  Companion to “The Iron Heart of the Silent Service” —— BLUF —— The dominant conventional submarine export platform of the past fifty-five years is the German Type 209, a diesel-electric attack submarine designed for export by Howaldtswerke-Deutsche Werft and Ingenieurkontor Lübeck, commissioned in 1971 and still being built. Sixty-eight Type 209s have been delivered to fifteen navies across Latin America, the Mediterranean, the Gulf, South Asia, and East Asia, with additional Type 214 and 218SG variants ext...

They Doubted His Engine — Until It Powered Every U.S. Submarine in the Pacific ! - YouTube Naval Institute Style · Historical Engineering Feature Vol. LXXXII Annapolis · Independent Forum No. IV Submarine Force · Propulsion Engineering How a condemned German aero-diesel, resurrected by a Wisconsin scale-maker, powered the campaign that strangled Imperial Japan—and why the Navy still buys the same engine today. By Stephen L Pendergast, LT USNR · Contributing Analyst —— BLUF —— Between 1938 and 1945 the U.S. Navy acquired a two-stroke, twin-crankshaft, cylinder-headless diesel of German pedigree—the Fairbanks-Morse Model 38D8⅛—and installed it as main propulsion in roughly half of the Gato-, Balao-, and Tench-class fleet submarines that conducted the Pacific guerre de course. Those submarines sank an estimated 54.7 percent of all Japanese merchant tonnage and roughly 30 percent of Imperial Japanese Navy tonnage...

Why is the Ocean Water Salty ? - YouTube How the Three-Dimensional Distribution of Ocean Salinity Affects Sonar Propagation, Range Prediction, and ASW By Stephen — April 2026 Bottom Line Up Front Ocean salinity—its spatial distribution across latitude, depth, and proximity to geological and hydrological features—is a critical but underappreciated variable in naval acoustic propagation modeling. While temperature and pressure have long dominated sound velocity profile calculations, salinity is the decisive variable precisely where it matters most: at the axis of the deep sound channel, where temperature is nearly constant and pressure is linear, leaving salinity as the only factor that can shift the channel geometry on which SOSUS, its successors, and long-range low-frequency sonar systems depend. Salinity gradients produced by differential evaporation, freshwater inflows, hydrothermal venting, water mass intrusions, and climate-driven changes to thermohaline ...