Don-
Snorting.
Schnorcheling is the German word for a Dutch system allthough known for many years before the dutch invention. In RN English the word used was snorting.
Q 1. The theoretical construction strength of a VIIC snort mast could take max. 6,5 knots I believe.
Q 2. We used the periscope while snorting.
Q 3. We were not completely blind, but one of the big disadvantages while snorting, regardless the speed, was the diesel engine noise and you could not use the passive sonar.
Q 4. You could run both diesels while snorting but limiting factors like underpressure, backpressure and speed would not give you much advantages of doing so.
Q 5. You could could go deeper while snorting shutting down the diesel immediately. and you would lower the mast while doing so.
Q 6. We mostly raised and lowered the mast while submerged, but you could do this surfaced as well.
A remark concerning my personal experience. We had an event before my submarine training course in UK, may be you recall the disaster of HMS Affray a British A class submarine. The training class 2 years ahead of mine was on board on a final snorting training in the English channel when she disappeared with all hands lost including the whole trainingclass, totalling 75 men. She was eventually found with the snortmast raised but broken. The discussion of the reason for the disaster was at my time still going on and in spite of the German snorting instructions I was a bit cautious as to pushing limits while snorting. One of the alternative snort propulsion, direct dieseldrive, we found a bit difficult to practise as the boat was no easy to handle, so we preferred electric propulsion running one diesel and generator as battery charger.
However as to HMS Affray I guess the conclusion was battery explosion and the broken snortmast was a secondary damage.
Tore
