SM U-17 demonstrated growing lethality by sinking merchant vessels, while U-19 survived being rammed by HMS Badger. The French submarine Archimède carried a complicated mixture of internal and external launchers intended to produce a heavy forward torpedo salvo. During the First World War it joined Anglo-French patrol lines guarding the Channel and Harwich approaches against German sorties. Because the High Seas Fleet did not attempt to cross those lines, its operational value cannot be reduced to a tally of ships sunk: the patrol may have contributed to deterrence without producing a visible engagement.
Notable Point · 40:14-47:32
Archimède and the operational value of an attack that never happens
French and German examples show both growing submarine lethality and the difficulty of measuring patrols that deterred an enemy without firing.