Submarine Salvage Air

“Why is it impossible to bring oxygen and supply to a submarine lying on the bottom of the sea? Imagine a kind of umbilical cord.”

It’s not “impossible”: it was actually a design feature incorporated in many of the American submarines which served during the Second World War.

Before I continue, I must clarify: I have never set foot on an operational submarine; my experience in the matter stems from a fascination and scholarly effort on the subject. Therefore, my knowledge on this matter is purely academic – Timothy’s answer and the short discussion which followed offers a detailed description, and graciously I defer to his expertise on the matter.

It is fairly easy, in this day of digital archives, to find handy answers to such questions. The trick is, as with anything else, knowing where to start.

One of the best online resources on the old diesel boats comes from the San Francisco Maritime National Park Association, where Richard Pekelney has provided tons of scanned material for researchers, academicians, and insanely curious types.

In reference to the notion of surface-supplied air for submarines, one needs to venture no further than the description of the Salvage Air Section to learn the specifics and locations of every fitting needed for potential salvage operations.

Now, the actual salvage of submarines was a bit more different than what was theory. Starting in 1915 with the submarine F-4, the S-51 in 1925, and the S-4 in 1927, the successful methods of raising sunken subs was either a direct lift with cables (if the sub was small enough) or, more frequently, salvage pontoons and sealed/blown compartments.

As far as my own research has found, the only time that such salvage air fittings were used by Americans to provide external air to the main ballast and various fuel tanks was the raising of the USS Squalus in 1939. Other nations had similar problems with surface-supplied air alone – the HMS K-13 was the first use of compressed air to raise a submarine in 1917 and the HMS Truculent was raised in 1950 using cranes and air blown into her ballast tanks… Beyond these two examples, my research hasn’t proceeded much further. Whether or not all nations operating submarines have actually used such fittings – whether in training or in actual salvage attempts is something I will chew on for a while.