Any evaluation of a new submarine feature must allow convoy escorts and anti-submarine forces to respond. Allied anti-submarine warfare and convoy protection would adapt to German improvements rather than remain frozen at an earlier standard. The manual's Type VII material provides a concrete look at the snorkel installation and the machinery it supported. The snorkel improved submerged endurance, but uneven performance and insufficient numbers meant that it could not reverse the Battle of the Atlantic by itself.
Chapter · 53:57-56:26
A technical owner's manual for wartime U-boats
A Haynes-style U-boat manual opens discussion of Type VII machinery, snorkels, and why late-war improvements could not overturn the adapting Allied anti-submarine system.