Technology and Operations
This forum is for discussing technological & operational matters pertaining to U-boats.
Re: Depth Charges and ASDIC/Sonar
Posted by:
ROBERT M.
()
Date: August 14, 2002 12:40AM
Ken du:
Germany had developed a variety of schemes for fooling both echo-ranging and listen-only torpedoes, among them were the following:
The PILLENWERFER, a chemical compound that, like an Alka-seltzer tablet, caused the water to foam. The substance (containing largely calcium hydride)
would be ejected from the side of a U-boat, then, remaining suspended at just under a hundred feet, it would release hydrogen bubbles for some twenty minutes.
The flood of bubbles should confuse an accoustic torpedo--and to sonar (ASDIC)
it would look like a solid surface.
SIEGLINDE, a decoy, also ejected from a chamber in the U-boat's side.
Running on electric motors, it rose, sank. and, to a certain extent, sounded like a submarine.
ALBERICH, an anechoic (sound absorbing) coating of synthetic rubber holding a multitude of air bubbles, used on the Type XXI U-boat design. It was developed to
reduce the echo return from both sonar and radar. A freshly-applied coat was effective, but it quickly became less so as the bubbles collapsed, and tended to rip away from a hull at high speeds. The name came from a legendary German dwarf
who wore a helmet that rendered him invisible.
Regards,
ROBERT M.
Germany had developed a variety of schemes for fooling both echo-ranging and listen-only torpedoes, among them were the following:
The PILLENWERFER, a chemical compound that, like an Alka-seltzer tablet, caused the water to foam. The substance (containing largely calcium hydride)
would be ejected from the side of a U-boat, then, remaining suspended at just under a hundred feet, it would release hydrogen bubbles for some twenty minutes.
The flood of bubbles should confuse an accoustic torpedo--and to sonar (ASDIC)
it would look like a solid surface.
SIEGLINDE, a decoy, also ejected from a chamber in the U-boat's side.
Running on electric motors, it rose, sank. and, to a certain extent, sounded like a submarine.
ALBERICH, an anechoic (sound absorbing) coating of synthetic rubber holding a multitude of air bubbles, used on the Type XXI U-boat design. It was developed to
reduce the echo return from both sonar and radar. A freshly-applied coat was effective, but it quickly became less so as the bubbles collapsed, and tended to rip away from a hull at high speeds. The name came from a legendary German dwarf
who wore a helmet that rendered him invisible.
Regards,
ROBERT M.
