Hello Maciek,

I must congratulate you on an excellent document on the U-boat torpedo tube functionality. I hope you don't mind, I printed it for a reference.

Below the Photo 9, There is the description of a torpedo surface firing sequence. You state the piston is not used because the water pressure is not great enough to return the launching piston back to the breech door when the torprdo is fired.

"That's why during surface attack torpedo was fired without using the pistom - compressed air was blown into the space between the piston and aft part of the torpedo pushing torpedo away and locking piston in the tube."

I have two questions:

Q1 - Photo 9 shows two holes in the torpedo tube. Are these holes the location where compressed air enters before and after the piston for submerged and surface firings?

Q2 - Was it always required to install the piston for a surface attack? Perhaps the piston was needed to allign the torpedo so the adjusting devices were mated properly?

Kind regards,
Don_

"A man's got to know his limitations..."
Harry Callahan, SFPD