Don.
Skizzenbuch page 419. I see you refer to the CO of U 995 as the holder of the Knight Cross (Ritterkreutz) which is correct, but yet a bit on the borderline. Hans Georg Hess being the youngest CO ever of a U- boat was on one of his last missions with U-995 February 1945 and sighted a Norwegian freighter S/S Iddefjord of 6300 DWT in the harbour of the Norwegian town Kirkenes, unloading supplies to the inhabitants. At that time the town was recaptured from the Germans by Soviet troops. Allthough his orders were to go after the Murmansk convoys he called in his officers and said: Gentlemen how about an attack a la Prien, suggesting the should sneak into the harbour of Kirkenes and sink the Iddefjord. So they did and they launched 3 torpedoes registered 3 explosions which they recorded as hits. However non of the torpedoes were hits they exploded in the nearby rocks and Iddefjord sailed unharmed a few days later. The sinking of Iddefjord was recorded by the high command and CO Hess got his Ritterkreutz. He was confronted with this some 50- 60 years later at a meeting with some Norwegian merchant naval gunners in Kiel and answered he had been convinced he had sunk the Iddefjord.
It is correct that 8th of May 1945 U-995 was at the yard in Trondheim installing Schnorchel that save her from operation Deadlight as she was unfit for passage to Scotland.
Page 421. U 480 2ND. warpatrol. The report is very interesting and correspond to my experience during a 28 days test schnorchelling with KNM Kaura ex. U 995. The underpressure could be a bit unpleasant possibly more that an overpressure. We expelled the garbage in the same way by the torpedo tube without a piston, however we did not use cans, but bags which sometime bursted and fouled up the torpedotube much to the torpedopeoples dismay.
I have put up a table in order to visualize the effect of the pressure fluctuations by showing the changes of water boiling temperatures. The yellow parts are the normal underpressure and the green part the normal overpressure. Red are the figures at normal atmospheric pressure.
Skizzenbuch checked up page 423.
Tore