As we were driving to Maine today, we made a stop at the USS Albacore Museum in Portsmouth, New Hampshire. The Albacore (AGSS-569) was a small experimental submarine that entered service with the US Navy in 1953.
Submarine development proceeded rapidly during World War II, yet by the end of the war the majority of submarines still had hulls that were basically similar to that of a surface ship (for example, the USS Drum at Battleship Park, below):
This was in part due to the fact that submarines still spent most of their time on the surface because of the need for oxygen for their diesel engines. (They ran on batteries when submerged, but the range on batteries was very limited.) Unfortunately, the hydrodynamic requirements of surface ships and submerged ships are quite different, and most WWII submarines were much faster and more maneuverable on the surface than when submerged.
The Albacore was in part an experiment to test hull designs that were optimized for underwater performance, which would become especially important with the promise of nuclear power removing the submarine’s need for air to operate its diesel engines. Its hull shape was largely inspired by aircraft design, and in fact various hull designs were tested in aircraft wind tunnels.
The Albacore was a smashing success, and was easily the fastest submarine in the world when it entered service. It’s submerged speed on a given amount of power was actually about 3 times greater than a conventional-hulled submarine, and in fact it was faster submerged than most submarines were on the surface. The Albacore-hull became the basis for practically every combat submarine built since the 1950’s.
Of course, the Albacore’s success should not come as a shock to anyone familiar with marine mammals:
This body shape has been converged on by essentially every lineage of fast-swimming marine animal, including but not limited to cephalopods, bony and cartilaginous fish, placoderms, ichthyosaurs, pinnipeds, dugongs (which are amazingly fast), and of course cetaceans.
Perhaps the most stunning aspect of the Albacore story is that, as far as I can determine, marine mammals were not even looked at as a shape model when the Albacore was being designed. It seems that the only things the designers seriously considered were aircraft. Yet contemporary stories about the Albacore (copies were on exhibit at the Albacore Museum) almost invariably referred to it as “whale-like”. Apparently the Navy did eventually catch on to the biology angle, however; in the late 1950s they began a long-term program to study the hydrodynamics of dolphins in an attempt to coax even greater speed and maneuverability for submarines.