https://usacac.army.mil/cac2/cgsc/carl/docs/TM2160_20.pdf Training Manual TM 2160-20, "Submarine Mining," U.S. War Department, Washington, D.C., October 15, 1930], Sections XXIV–XXVI Each of these harbors also had on-shore facilities to store the mines (called "torpedo storehouses") and the TNT used to fill them, rail systems to load and transport the mines (which often weighed over 750 pounds each when loaded), and to test and repair the electrical cables.