Why didn't an escort spend all day using active sonar?

GoldenRivet · 09-15-08, 06:44 PM

Why didn't Marine and Army patrols in Vietnam walk through the jungle screaming "Charlie! Where are you!?!?"

it broadcasts the position of the escort to the U-Boat, and it only effectively scans the area ahead of the escort on about a 45 degree arc.

banging away with active sonar wouldnt do you a great deal of good if the u-boat was 2500 yards off your port or starboard beam. and besides, unless he heard it on hydrophones, a u-boat crew wouldnt hear the pings with the naked ear except in certain situations. so a U-boat crew that heard a faint ping wouldnt jump into flank speed evasive mode automatically.

furthermore active sonar (depending on the time of the war) had varying degrees of effectiveness (consider thermal layers etc).

passive sonar (hydrophones) scans the entire area around the escort for any sounds of submerged prop beats. (except of course immediately behind the escort)

so...

hydrophones = broad focus to locate the u-boats approximate position directionally.

ASDIC = pinpointing the U-boat's position with a focused "beam"

09-15-08, 06:44 PM	#3
GoldenRivet Subsim Aviator Join Date: Mar 2007 Location: Texas Posts: 8,726 Downloads: 146 Uploads: 0	Why didn't Marine and Army patrols in Vietnam walk through the jungle screaming "Charlie! Where are you!?!?" it broadcasts the position of the escort to the U-Boat, and it only effectively scans the area ahead of the escort on about a 45 degree arc. banging away with active sonar wouldnt do you a great deal of good if the u-boat was 2500 yards off your port or starboard beam. and besides, unless he heard it on hydrophones, a u-boat crew wouldnt hear the pings with the naked ear except in certain situations. so a U-boat crew that heard a faint ping wouldnt jump into flank speed evasive mode automatically. furthermore active sonar (depending on the time of the war) had varying degrees of effectiveness (consider thermal layers etc). passive sonar (hydrophones) scans the entire area around the escort for any sounds of submerged prop beats. (except of course immediately behind the escort) so... hydrophones = broad focus to locate the u-boats approximate position directionally. ASDIC = pinpointing the U-boat's position with a focused "beam" __________________