Project 123, also called the P-4 or Komsomolets class, retained alloy construction but used a single-step hydroplaning form with a flush deck. Its resemblance to British Vosper boats suggests a possible influence without establishing that plans were copied or stolen. Adapting a form suited to timber into duralumin changes the engineering as well as the material. The flush deck gave the design more scope for mounting weapons than the cramped, swept forms of earlier Soviet boats. American Packard petrol engines supported a better service record, and later boats received diesel engines after the war. P-4s scored hits on the German destroyer Z34 without sinking it. Although work began before the war and accelerated in 1942, the replacement took years to reach useful numbers while the Baltic and Black Sea campaigns were already under way. Aluminium boats could work when maintained carefully, though controlling corrosion still took considerable effort.
Notable Point · 2:45:41-2:55:53
The P-4 Komsomolets: a more adaptable Soviet fast boat
The P-4 combined a flush deck and Packard engines with a more useful weapons layout, though its alloy hull still demanded intensive corrosion protection.