Dubbed as the “Silent Service,” submarines are considered the most survivable weapons-delivery platform. Submarine detection and monitoring was traditionally the exclusive domain of highly classified military units specializing in naval anti-submarine warfare (ASW). Military ASW employs technologies such as magnetic anomaly detectors (MAD), which detect tiny disturbances to Earth’s magnetic field caused by metallic submarine hulls, passive and active sonar sensors that use sound propagation to detect objects underwater, as well as radar and high-resolution satellite imagery to detect surfaced submarines. Recent advances in commercial tools and technologies now give open-source researchers some ability to monitor submarine fleets. With commercial satellite imagery, synthetic aperture radar (SAR), hydro-acoustic sensors, and even social media analysis, open-source researchers can better understand the size and composition of countries’ submarine fleets, monitor the construction of submarines and submarine bases, and potentially learn about patrol patterns and behaviors.
A submarine can be detected by a number of different sensors and methods.
Fort Drum, originally known as El Fraile Island, is a huge, now ruinous complex of concrete and steel that once guarded the southern entrance to Manila bay. It's construction and took years and for much of it's history, it was regarded as strange, unique oddity on the horizon of manila bay. For a brief few months amid the desperate defense of the Philippines during WWII, it proved to be a formidable and impervious foe.
0:00 - Introduction 1:37 - The Islands of Manila Bay 2:13 - El fraile Island & The Battle of Manila Bay 3:23 - Fort Drum - Early Proposals & Designs 6:02 - Fort Drum - Final Plans & Layout 7:40 - Naming Fort Drum 7:57 - Construction Begins 8:27 - Armament 11:11 - Construction Finishes 12:00 - Garrison & Early Troubles 13:53 - War Preparations Begin 15:32 - A Date That Shall live in Infamy 16:03 - Philippines Invaded 16:46 - Fort Drum's Strong Defenses 19:43 - The Fall of Bataan 20:05 - The Last Line of Defense 20:49 - The Fall of Corregidor 22:21 - Fort Drum Fights on? 24:11 - What Happened to the Garrison? 25:01 - Allies Retake the Philippines 25:22 - Fort Drum Abandoned? 26:24 - Fort Drum's Final Siege 30:25 - What Remains of Fort Drum Today? 31:54 - Outro & Waffling on a bit