Historical development of a subs bow
 

Have a question I hope some of you, can give an answer to.

The bow on Submarine from WWII, had almost form as a surface ship. If you take a look at a modern Sub, the bow is round bowl-form like.

When did this change take place ?

Markus

That's a good question! It all comes back to the fundamental difference between the submarines of WW2 and of the Cold War. The diesel electrics used in WW2 would primarily operate as surface ships, submerging only to attack or hide from danger. With the advent of nuclear power, however, it became apparent that submarines could be designed that would operate submerged almost constantly. And with this idea, people began to design submarines that sacrificed surface performance for submerged performance.

The actual shift begins in 1944, the Germans had pioneered a teardrop hull shape earlier with a prototype midget submarine. The prototype was lost in an accident and the concept abandoned.

It was revisited in 1949, when the United States launched a series of hydrodynamic studies to determine the best shape for a submarine's hull. A program within the US Bureau of Ships to design the best shape for a hull that would operate submerged for most of its operational lifetime. The David Taylor Model Basin tested these designs and came out with the best two. One with a single screw, and one with two, both with teardrop hulls.

Construction then began on an experimental submarine to test the new teardrop hull shape, the USS Albacore, AGSS-569. The Albacore's testing began in 1954 and, deedless to say, the tests were very successful. The teardrop hull shape is even now often known as an "Albacore Hull". The first production nuclear submarines to use the new hull shape were the Skipjack class, starting the USS Skipjack in 1956, and it's been pretty much the standard hull shape for submarines around the world ever since.

^ Thank you :salute::up:

Markus

One more thing to add to that excellent write-up. The Germans didn't stop with their experimentation with the failed midget sub. The Type XXI uboats had a heavily reworked shape meant to be more hydrodynamic than previous designs. It wasn't a teardrop shape like the albacore but was much lower drag and allowed for submerged speeds almost double what had been available before. This design was highly influential post war. The guppy conversions, Tang class, skate class and USS Nautilus all had type XXI type hulls. The Soviets also used that design for many of their early cold war designs, all of the SSKs through the Tangos used that hull type and several of the early missile boats like the Juliet also took inspiration from it. The albacore teardrop made it obsolete though. The USN adopted it fully and didn't look back and the Russians followed suit for the most part.

Note that first Soviet SSN used a "torpedo" like shape. While it may be argued that such a shape is not optimal and that "tear drop" is better, many modern SSNs use a simmilar shape (ie Virginias).