The V80 Research Submarine

[LostCosmonaut]

Submarine technology is one of the few areas in which World War 2 Germany had any sort of advantage over the Allies. The Type XXI U-Boat is one of the most commonly known examples; it was one of the first (but not the first) submarines designed for sustained underwater performance; it was capable of 16-18 knots underwater, about double what other U-Boats could do. That they sank a grand total of zero Allied vessels during their career is more a symptom of German military incompetence and industrial issues than any severe problems with the concept. (Of course, it would take until 1955 for a ~*true*~ submarine to be built, but I digress).

 

Many other German U-Boat projects were developed at various points in the war that used exotic technologies or promised excellent performance. One of the less well known, but more successful of these was the V80 research submarine.

 

via http://uboat.net/types/v80.htm

 

Hellmuth Walter was a German engineer with interests in turbine propulsion and exotic propellants. One of the propellants he was especially interested in was hydrogen peroxide. While diluted hydrogen peroxide is commonly used as a disinfectant. However, in pure form, it is highly reactive, and decomposes into its component atoms with a large release of energy. It is currently used today as a torpedo fuel, as well as for niche applications in rocketry.

 

Walter hoped to develop full-scale U-Boats utilizing hydrogen peroxide turbines, however, the technology was still fairly immature as of 1939. He did manage to obtain funding to produce a small research submarine, with a displacement of about 80 tons (less than 1/10th of contemporary U-Boats). This was the V80.

 

V80 in drydock http://i276.photobucket.com/albums/kk27/MFR1964/Walther%20V80/v80kp3.jpg

 

The V80's shape was highly different from other U-Boats such as the Type VII or Type IX. More than anything else, this was its major innovation. Walter had the hull shape tested in a wind tunnel, and it was designed explicitly for submerged performance. The small size of the submarine meant that a crew of only four could be carried, although as V80 carried no weaponry or military equipment, this was not a problem. A Walter hydrogen peroxide fueled turbine output 2,500 horsepower, an excellent power to weight ratio for a 1940s submarine.

 

The V80 underwent trials in the Schlei inlet of the Baltic in 1940. There, it demonstrated exceptional performance, attained submerged speeds upward of 26 knots. This was far in excess of what other U-Boats were capable of, and would not be matched until the 1950s with the arrival of nuclear power. However, its range was very short, at only 50 miles. Maximum depth is unknown; as the V80 was only tested in confined coastal waters. It is probably roughly comparable to other U-Boats.

 

Trials of the V80 continued until 1942. Several submarines using Walter's hydrogen peroxide engines were ordered, of them, only the Type XVII managed to have a few units completed before the end of the war. While these boats also demonstrated very good submerged performance, there were also numerous mechanical issues with them, and they achieved little success. This again shows the challenges inherent in taking a concept demonstrator and scaling it up for actual use. A few of them were captured at the end of the war by the Allies, and used for testing. V80, on the other hand, was scuttled in March 1945. It is unknown if the wreck was ever located.

 

While the V80 and her hydrogen peroxide powered sisters were a very interesting technological development, they were not war-winning weapons by any means.  However, they could be seen as the spiritual ancestors of modern air-independent propulsion (AIP) submarines.

 

Sources:

 

http://uboat.net/types/v80.htm

http://www.walterwerke.co.uk/hw/wbiog.htm

http://uboat.net/types/xviia.htm

 

[Collimatrix]

What was the chemistry of the propulsion?  Just pure decomposition of H₂O₂?  I wonder if they ever looked at burning some kerosene with the O₂ to get more endurance.

[LostCosmonaut]

What was the chemistry of the propulsion?  Just pure decomposition of H₂O₂?  I wonder if they ever looked at burning some kerosene with the O₂ to get more endurance.

 

As far as I know it was just catalyzed peroxide decomposition. Wiki says that Walter thought about adding other fuel to burn with the oxygen produced, but I don't think V80 had any.

[Collimatrix]

I guess if you walk down that road, you start looking at oxidizers with the highest oxygen per liter.  I don't recall that H₂O₂ decomposition is particularly energy dense relative to burning hydrocarbons.