Allied Forces Thread

[Fisherking]

Anyone have a sit-rep for me?

[King Kurt]

I have been chatting with Fischerking and we have a variation on our general tatics. It is to put one of our sloops - not the Stork - about 10 miles in front of the convoy to passively search for subs. This would be during daylight hours only. this forward picket would search for subs visually and with hydrophones. It would return to the convoy escort for the hours of darkness, but would attack any U boat it found. At best it would sink them, at worst drive them underwater, making it difficult for the sub to attack the convoy due to its slow speed underwater.

What do you think?

[Peasant Phill]

The U-boats will most likely be deployed in a straight line, like a net and converge when one of them sees anything. It's logical and a historical tactic. British research found that many smaller convoys were more vulnerable to this tactic than 1 big one. Being hard to find is our greatest advantage. By essentially making two groups, we just doubled our chances at being spotted. Is doubling the risk of being spotted worth the advantage of possibly sinking 1 U-boat? Is driving off 1 U-boat worth alerting every enemy vessel in the vicinity that at least one of our ships was there?
I know I'm being cautious here but I still see ourselves foremost as escorts/protectors. I only see a use for this tactic when we know they are somewhere in front of us and we need to find a way to avoid them, in other words when we are very close to Gibraltar and they have search a smaller area.

How far is our detection-radius compared to theirs? I know our spotters have a better and wider view by day and our technology is better than theirs but how does this translate in practice? Can we surprise them without breaking up our convoy?

Also, are we going anywhere near the mid-Atlantic gap?

[Fisherking]

Here is the advantage. The lead escort plays leapfrog with the convoy staying far enough a head to use passive sonar...which means rushing a head and then very slow.
If we use active pinging before we see the subs it give away our location.
The subs will pick up the sound of the convoy much quicker than that of a single ship and see the smoke before we see the sub if we don’t have something forward.

The lead ship is listening for submerged subs and looking on the surface and as an advanced radar picket. It is more advance warning than hunter and it only works during the day.

Subs can pick up a convoy by sound and hone in from about 20 miles. The preferred location would be in front of us. They won’t expect us to use passive sonar and they can not lay still in the water.

Does that sound riskier than holding positions and doing nothing?

No gap we go from here to England.

[Sarmatian]

Sorry guys, thought this was going to be a bit broader IH. I don't have the knowledge about such specific issue and technology and don't have the time to learn now. I'll have to withdraw from the game...

[Peasant Phill]

Sorry guys, thought this was going to be a bit broader IH. I don't have the knowledge about such specific issue and technology and don't have the time to learn now. I'll have to withdraw from the game...

I don't have the specific knowledge either. Just read a few wiki articles now and then and perhaps a few interesting websites. I can't say I have read much on this subject. Common sense and the inclination to ask questions is all it takes to be a worthwhile contributer as far as I'm concerned.

Subs can pick up a convoy by sound and hone in from about 20 miles. The preferred location would be in front of us. They won’t expect us to use passive sonar and they can not lay still in the water.

Unsurprisingly, after some further thought the plan appears to be sound. If subs can detect us from 20 miles away, from how far could we detect them?

[Fisherking]

By eye- maybe 12 mi.

By radar- in theory about 24 nautical mi (but subs are low in the water and choppy seas can hide them almost all together. Under normal conditions 1941, 6 to 10 N.mi.

Passive sonar- sub on surface using engines about 12 N. miles, submerged on electric motors but not silent running 3 to 5 nautical mi. It can tell direction but not range. Active sonar is needed to determine range.

These are only rough figures and conditions could make it much shorter ranges.

References that may help:
http://en.wikipedia.org/wiki/36th_Es...8Royal_Navy%29
http://en.wikipedia.org/wiki/Battle_...2%80%931945%29
http://www.uboat.net/index.html
http://www.convoyweb.org.uk/index.html

As to knowledge base; I know a lot more about subs than I do about escorts so don’t feel so alone.