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G7eT2 · 02-14-10, 09:20 PM

I knew I should have panicked.

Still my batteries are not dead yet so the battle continues...

My first post came from one of a series of threads, on the uboat.net Technology and Operations forum, initiated by someone called Phil Gollin. He was trying to argue that escorts used active sonar only (he was accused of trolling for this). I disagree as did everyone on the forum. That is why there are multiple entries on that page supporting the use of passive sonar by escorts.

My suggestion is that escorts used both passive and active sonar/asdic 24/7. In your first quote an average detection distance of a uboat of 1350 metres is given. I think that with enough escorts operating at 2-4 kms from the convoy with this detection range, it would be very difficult for a uboat to close to within their preferred firing range of less than 1000 m.

It also mentions Panoramic sonar available from 1943 with a range of up to 3000m in all directions simultaneously. That would really ruin a Kaleun's day.
Please don't bring this to GWX's attention.(Too late Jimbuna is GWX !

)

With regard to the use of active sonar by escorts giving away the convoy's position :

-from the same page as your second quote -
6. Conclusion

In WW2 active sonar (Asdic) was fitted on a surface ships. It was so because the surface ships didn't care if submarines knew for their presence or not. Even better, presence of surface ship (a destroyer or a patrol craft, for example) caused giving up of submarine attack. Also, with the active sonar (Asdic) it was possible to determine range between the surface ship and submarine.

- further to your case from this link http://maritime.org/fleetsub/sonar/chap5.htm
Reporting enemy echo-ranging Sometimes a ship's pinging can be picked up before you can hear its screws. Any ship that is pinging is out searching for submarines. Merchant vessels are not equipped for echo-ranging.
(my underlining)

- further to my case from a few pages later in the same link http://maritime.org/fleetsub/sonar/chap6.htm

Why submarines do not echo-range continuously

Since the speed of surface escort ships produces a noise level too high for efficient listening, they depend heavily on echo-ranging to detect submarines. In fact, surface escorts echo-range continuously. But submarines hardly ever echo-range, because a submarine has to keep its location secret from the enemy. Continuous pinging would be a dead giveaway.

Torplexed - I agree totally with your analogy but think it refers more to subs than escorts.

Can I surface now ?

02-14-10, 09:20 PM	#24
G7eT2 Watch Join Date: Jan 2010 Posts: 23 Downloads: 70 Uploads: 2	I knew I should have panicked. Still my batteries are not dead yet so the battle continues... My first post came from one of a series of threads, on the uboat.net Technology and Operations forum, initiated by someone called Phil Gollin. He was trying to argue that escorts used active sonar only (he was accused of trolling for this). I disagree as did everyone on the forum. That is why there are multiple entries on that page supporting the use of passive sonar by escorts. My suggestion is that escorts used both passive and active sonar/asdic 24/7. In your first quote an average detection distance of a uboat of 1350 metres is given. I think that with enough escorts operating at 2-4 kms from the convoy with this detection range, it would be very difficult for a uboat to close to within their preferred firing range of less than 1000 m. It also mentions Panoramic sonar available from 1943 with a range of up to 3000m in all directions simultaneously. That would really ruin a Kaleun's day. Please don't bring this to GWX's attention.(Too late Jimbuna is GWX !) With regard to the use of active sonar by escorts giving away the convoy's position : -from the same page as your second quote - 6. Conclusion In WW2 active sonar (Asdic) was fitted on a surface ships. It was so because the surface ships didn't care if submarines knew for their presence or not. Even better, presence of surface ship (a destroyer or a patrol craft, for example) caused giving up of submarine attack. Also, with the active sonar (Asdic) it was possible to determine range between the surface ship and submarine. - further to your case from this link http://maritime.org/fleetsub/sonar/chap5.htm Reporting enemy echo-ranging Sometimes a ship's pinging can be picked up before you can hear its screws. Any ship that is pinging is out searching for submarines. Merchant vessels are not equipped for echo-ranging. (my underlining) - further to my case from a few pages later in the same link http://maritime.org/fleetsub/sonar/chap6.htm Why submarines do not echo-range continuously Since the speed of surface escort ships produces a noise level too high for efficient listening, they depend heavily on echo-ranging to detect submarines. In fact, surface escorts echo-range continuously. But submarines hardly ever echo-range, because a submarine has to keep its location secret from the enemy. Continuous pinging would be a dead giveaway. Torplexed - I agree totally with your analogy but think it refers more to subs than escorts. Can I surface now ?