Anti-Destroyer Tactics
by Kofi Horberg

Read with great interest your advice on subsim tactics. Here an additional one that I developed on my own and tried with overwhelming success.

Upon attacking whomever, first to concentrate on the escorting watch destroyers. Go to periscope depth (never dive deep!) and proceed head on towards the closest one, accelerating my sub to flank speed when coming closer than 1,500 yds/mtrs. In such position the adversary will find it extremely difficult to make use of his asdic/sonar, because (a) I show him only my front profile, (b) on a target close to surface (periscope depth!) asdic/sonar was rather inefficient because of the shape of its ultrasonic beam, (c) he will be compelled to reduce his speed to meager 12 knots, if he wants to detect anything at all, say with his passive listening device (his active asdic/sonar he can forget for most of the time under such conditions). Hence, he may detect that something is in front of him, but he will find it hard to determine what is really going on there, where and how precisely. 

At an approach distance of 900 yds/mtrs I take a sharp turn of 70 degrees to one side, often to the side where the second-next destroyer is approaching, depending on his distance. There will be now a total of 3 alternative scenarios that will happen next: In each case, it will take at least 30-50 seconds before my adversary can detect that I was taking the sharp turn to one (which?) side. (This has confirmed technical reasons.) 

Scenario A: He will proceed straight ahead, ignoring my turn. After further 30 seconds or so he will then cross my sub's rear extended axis at a distance of about 500-600 yds/mtrs. In such position an air-powered torpedo from my stern tube will hit him without fail in about 18-20 seconds in the middle of his broadside and at an angle of said 70 degrees (whether it also detonates is another question). 

Scenario B: He will not ignore my turn. After he has discovered the same, he will follow my turn in a w i d e curve. After further 30 seconds or so he will thus cross my wake/keel water at a distance of about 300 yds/mtrs. Again, my torpedo from the stern tube hits him at the middle of his broadside after some 11-12 seconds and at a rectangular angle. 

Scenario C: He will follow my turn in a narrow curve, thus trying to intercept my course. In that case, I swing back more or less to my original heading, depending on how sharp he turns towards me, my sub can turn even sharper (that is so with subs!). As a result, he will inevitably cross my wake and receive the stern torpedo in the middle of his broadside and at the closest possible range. 

When thus attacking a whole group of destroyers, sinking them one after the other - I do that frequently and with great excitement - it can happen of course that my stern tube will be empty (not yet reloaded) for the next candidate (in SH this is not much of a problem, because most US-subs had 4 stern tubes and fair reloading reserves; in CAOD, with a type VIIB/C having only 1 stern tube and 1 reserve stern torpedo, the issue can become really exciting!). In such case I describe a full circle turn as narrow as possible with my sub so-to-speak a horizontal "Immelmann"-turn for subs - and thus get my candidate conveniently into the range of my front tubes, if his turn was not too sharp as well. If his turn was too sharp actually (really sharp destroyer turns will also result in further speed losses), the result will be that I come too close to him (below 250 yds/mtrs) to launch a bow torpedo. 

Not much of a problem: At such short distance, his asdic/sonar cannot detect anything at all, I show him in such situation only my front profile towards his broadside, and I can decide, according to the given circumstances, whether I turn away again sharply - not through his wake! - or dive through under him. Usually I prefer the former. 

My advantage is that my sub at 7 knots submerged can describe sharper turns than the much longer destroyer at his superior asdic/sonar-using speed of 12 knots, hence I can out-maneuver him with circle turns until I get him at minimum distance in front of my bow tubes or until my reserve stern torpedo is reloaded. One torpedo is usually enough to destroy a destroyer or at least to cripple him to such extent that he is no longer a menace for my sub. 

With this method I use to bottom usually whole destroyer groups, max. 6 so far with a Gato (SH), and 5 with a VIIc in CAOD. All readers are invited to try this method and to report your results on this site. I am quite curious to read how others will do with it. Would be interesting to know, what Capt. "Johnny" Walker on his HMS "Starling" would have done, if he and his successful "creeping attack" method on German subs would have been confronted with this counter-attack method before his support group could really unfold.

All tips and contents are
©2003 SUBSIM Review
Do not copy without permission.