Why were midget submarines such a failure?

[Felix C]

Their loss rate was heavy and results were minimal?

Was the issue too many tasks for the crew or crewman to do?

Navigation related? Sea condition related?
Poor visibility?

[thaddeus_c]

thought the first series were a learning curve (and to a certain extent almost suicide craft, human torpedoes?)

the one considered fully developed , the Seehund http://en.wikipedia.org/wiki/Seehund , arrived very, very late in the war and not in the numbers intended.

[wibble]

Assume only refers to German WW2 efforts.. my take (abridged)in no particular order

a) wrong employment, even Seehund
b) torpedo as weapon of choice
c) bad design (sorry! serious)
d) training and crew selection
e) navigation
f) no toilets
g) advancing allies forced bases to keep moving and to be sub-optimal
h) more....

Sorry in a bit of a rush today

[flakbait]

As a rushed into production craft, most designs suffered from construction and material defects that appalled the few assigned veteran U-boat crewmen whom flat out refused to man them; rightfully deciding their familiar "iron coffins' stood a much greater chance of survival. Plus all were considered underpowered as well as pathetically short ranged. And their initial deployment with the Allied naval antisubmarine tactics and numbers of platforms plus all but total aerial dominance approaching it`s full might didn`t do a single thing to allow their operators anything faintly resembling a learning curve; rather it was almost always deploy on their 1st sortie, get quickly detected and then die under a barrage of well placed depth charges...very few even damaged an Allied ship, perhaps 2 actually sank an Allied ship, and doubt any of their crewmen made 5 roundtrip sorties...

[wibble]

Have had the good fortune of briefly corresponding with a former Seehund Captain who survived two missions. He knew that his chances of living where slim (less than 50% probably) but like a lot of young men he never thought it would happen to him. He was right. Seehunds were crewed by more professional crews who did get practice. Still, the odds were against them.


Not sure I agree that they were all considered underpowered or too short ranged. But maybe we are thinking of different types or measuring by different standards.

[flakbait]

Will allow that some crews DID get the `luxury` of the full training period, most did not due to ever tightening fuel and supply shortages, Allied fighter bomber attacks and even having to repeatedly relocate their operating bases due to the Allied ground advance. As far as being shorter ranged and slower than designed, would imagine this less than optimum performance became more pronounced as the war progressed due in no small measure to exactly these reasons as well as a scarcity of skilled mechanics and techs to continue to service them; keep in mind that the Luftwaffe at this time was experiencing exactly the same type of problems except on a more massive scale...would imagine the mortality rate was crippling too.

[wibble]

Re short range etc, some of the Seehunds demonstrated incredible range reaching East Anglia. But midget submarines are inherently short ranged due to the crew endurance. The British had equivalent types and we know from their trials that something equivalent to the Biber has a human capability of about 12 hours.

The Biber had a tendency to kill its crew through suffocation before then anyway.

[flakbait]

Looking at several websites came up with the following info as to design vs actual operational ranges: Neger manned torpedoes: Designed range and speed was 20- 25 miles at 3kts. Approx. 200 built, actual range was 18-20 nm @3kt. Very heavy losses operationally while sinking 1 Allied cruiser, and destroyer and several smaller craft.. Molch: 50 mile @5 kt designed range with 2 G7e torpedoes could travel submerged only. Actual range was 40 miles @ 5kt. 362 built, 102 operational sorties with 70+ craft lost. Surviving craft used for training only afterwards. Hecth: Designed range was to be 80 miles @ 5kts surfaced and 50 miles at 7 kts submerged; actual was approx. 78 miles @ 3kts surfaced but 40 miles at 6 kts submerged. 53 built, but due to extremely poor maneuverability was only used for training. Biber: designed speed and range was 150 miles @7 kts surfaced and 20 miles @ 5 kts underwater; actual was 130 miles @ 6 kts surfaced but only 8.6 @ 5 kts submerged. Unable to launch torpedoes while submerged. Dive depth 65` 324 built, 102 combat sorties with 70+ loses against 7 small Allied ships sunk for 491 tons and 2 damaged for 15,000 tons. Seehund: Designed range and speed was 325 km @7 kts surfaced and 70 miles @3kts submerged vs 300 km @ 7 kts surfaced and 60+ miles @ 3kts submerged. 50 were modified with larger fuel tanks allowing a loaded combat range in excess of 340 miles. Diving depth was 160 fow. 285 built, 138 commissioned. 142 sorties, 35 lost, but 70+% had enemy contact while 90% survived their 1st sortie. Sank 8 ships of 17, 301 tons including Free French destroyer "LA COMBATTANTE" and further damaged 3 more ships of 18,000 tons...Uboat.net, Wiki and Axis submarines of WW2.