How do I get inside a convoy?

[Fab]

I am playing in July 1941 in a type VIIC. I have sighted a nice convoy consisting 17 merchants and a Southhampton cruiser in the dead center, flanked by Flower Corvette, Tribal Destroyer, Black Swan Frigate, and something else I can't identify on the far side.

Now I have several questions. First, around the escorts there are rings and sectors on the F5 map (I'm playing with "God mode" turned on - I tried it with it off and I'm not good enough yet). What do they mean? There is a very small circle, and at the outside perimeter a very large circle. Then in between there's a sort of triangular sector in front with a medium-sized circle but with a triangular cut out at the back. I have yet to find what that means.

The reason I ask is once I was submerged waiting for escorts to pass me by, and I passed through the outer ring without detection and if I recall the middle ring (with the triangular sectors) but once that inner ring touched my boat he turned and came right at me at ramming speed. So in my effort to sneak into attack position on this convoy, I need to know what those circles mean and which ones I can enter safely and which I should avoid.

I am outside all the circles right now, and with the escorts darting around, I have no clue the best way to sneak past them to fire off my eels.

Last question I have is with the Southhampton inside the convoy in the dead center, and weighing in at 10,725 tons, it seems like an important target. But would a U-boot commander go after a capital ship or is merchant shipping my only authorized target? Even though I don't play with realism at 100%, I do try to conduct the game like a real WWII kaleu would do it. So should I go for the cruiser, or just take out a couple of the merchants before I'm swarmed by four escorts? (not looking forward to that)

[Boris]

I've never paid much attention to those rings...

Best way to get inside a convoy is to get way in front of it at a safe distance, then submerge and wait for it to sail over you.
Stay at slow speed and stop before it passes over you to make sure the destroyers don't hear you.
Then fire as many torps as possible before diving the hell outta there when those destroyers come.

I don't think BdU will give you a slap on the wrist for downing a cruiser, that's what I'd be going for. It's a judgement call real kaleuns would have to have made, and I'm sure most would have gone for an easy military target like that.

[Keelbuster]

Not sure about those rings - i imagine that the circles are passive acoustic detection, and that cone is his active asdic. Stay out of the cone, and, obviously the inner circle as well. But, really, you should turn those damned things off. You're ready - trust me.

In my mind you have two options:

1. Take a long shot with T2s on impact at your targets of choice and turn away from them, get distance, and be elsewhere when they hit. You might get a kill, or a cripple that separates from the convoy.

2. Leave. Flank ahead of the convoy. Come in on a diagonal at high speed - so that you're about 2km from the center course of the convoy. When you come within about 7km of the lead escort (5km at night) drop to PD and continue at 1/3. When the lead escort is 3km away, go silent (all schtop and let him pass). You want to have him at about 1.5km to your port or starboard. If he passes without detecting you, then you're in. Turn perpendicular to convoy course, and close the remaining 1 km to it's center line at silent. Then you take optimal shots abeam at the fat center column.

Kb

[Fab]

It was the inner ring that nailed me the one time. I was sumberged and completely stopped. I got unlucky that during one of his sweeps he came close enough for that inner ring to touch my boat. The response was immediate, swift, and fatal.

So now I'm trying to be more careful than that, knowing that one wrong move will have me avoiding DCs BEFORE I make my attack, not after. I hate being hounded by destroyers, but it's a lot easier to take if you inflict some pain on the convoy. If they nab you before you get close enough to shoot, it's very annoying.

Thanks for the advice, guys. I appreciate it. And as for the cruiser, it's dead center of the convoy, which tells me the British think it's the most important thing in there, so I think I'm going to go for it.

[zzsteven]

The outer circle is his visual range, the next circle with the wedge cut out of his aft is his passive listening range, the small pie shaped wedge in front of him is his active sonar range.

zz

[tycho102]

1. The outer most circle is visual detection distance. If you are running flank, with your "broadside" to the escort, on a perfectly calm day with noon sun, that outermost circle is the distance at which you will be spotted.

2. The next inner circle has a "baffle" at the rear of the boat. This is his hydrophone detection distance, again if you are running flank and perpendicular to his bearing.

3. The next circle in is active sonar (ASDIC) range. Again, maximum profile distance.

4. That last (innermost) circle is hedgehog distance. That is where he will be firing hedgehogs at you.

Keep in mind that if you are presenting minimum profile (pointing directly at, or away) and traveling at speeds less than flank, your detection distances will decrease. This is not reflected in the actual diameter of those circles; they are a static "guide" on each boat, and in no way reflect current conditions or your current sound profile.



You are in 1941, and a VIIc.

Use the "dead stick" approach. Achieve a position ahead of the convoy and out of maximum visual range. You will need to get within 2000 meters of the convoy's base-course centerline. This centerline is where the lead escort will be, and you want to be just to the side of his course. Dive to periscope depth, and use your hydrophones to line yourself up.

Turn your boat so it is pointing toward the convoy's approach bearing, but slightly "diagonal" or askew from their exact reverse base-course. So if the convoy is heading 90 degrees, you will want to point your bow at 315 degrees, or 215 degrees.

All stop and quiet. Peek up with your periscope from time to time. When the lead escort shows up, you need to double check that you are about 1000 meters away from his base-line course. If you are, lower your periscope and just wait for him to pass.

Ideally, you want to be exactly between two rows of ships. This give you about 250 meters of perpendicular distance from them, so you will be shooting your torpedoes a little before they get to you.

Fire your foward tubes as soon as you get a tanker. If the seas are calm, fire magnetic detonators, and no more than two per boat. If seas are rough, use impactors and start off with two just behind the midline. With your rear tube, get whatever you can. An impact detonator at a C2, just behind the superstructure is a good place.

Soon as you've expended your tubes, ahead slow and dive. Turn your sub with the convoy's course if you are close to their center point, and back to 215/315 if you are towards the back of the convoy. If you turn with the convoy, it will give you several extra minutes of dive time before the rear escort catches up with you. If you are already too close, your best bet is to get outside his active sonar range.

As soon as you get outside their detection range, surface and reload with external tubes. Then run an "end around", and hit some more ships.

[don1reed]

Everything presented here, Fab, are "golden rules."

Every post has stolen my thunder :up:

Only thing left to add is get a copy of the UBoat Commander's Handbook Just about every situation for attacking, defending, escaping are on those pages.

When waiting at a safe distance in front of the convoy at periscope depth, when that lead escort shows up, turn your boat into their path (make as small a target as possible), go to silent running, dive to 60m. (Heading directly down their throat shortens the waiting time.)

When you/sonarman hears that lead escort off on either beam, begin your ascent to periscope depth, you are still about 4-5000m out in front of the oncoming convoy.

At PD, with scope awash, look to where you must try to maneuver between two columns, turn 90° toward the tankers/and/or big ship column. All stop, wait for your shots.

Escape: If still undetected, go deep as possible at silent running, trying to keep as narrow of a target as possible to the nearest escort, your sonarman will let you know.

Tactics: There as many of those as stars to navigate by...it's your choice.

cheers,

[DeepSix]

Everything presented here, Fab, are "golden rules."

Every post has stolen my thunder :up:
...

And thanks to don1reed, I don't even get to be the first to say that. :lol: Seriously, you've got the textbook in this thread.

Don't let that Southampton get away! :)

[Heibges]

The only thing I would add, and per the Uboat Commanders Handbook also, is that if all possible stay at PD so you can observe visually. Once you dive you are effectively blind, except for what you could guestimate with your hydrophones.

And take your time setting up for the attack. Figure out where all the escorts are, so you can decide which side is the best to attack. With 3 escorts, if you are lucky with your timing, there will be a huge space between the lead and the trailing escorts.

Also, if you want to be totally realistic, don't use all stop while submerged. 1kt minumum.

[Keelbuster]

The only thing I would add, and per the Uboat Commanders Handbook also, is that if all possible stay at PD so you can observe visually. Once you dive you are effectively blind, except for what you could guestimate with your hydrophones.
.

I fully agree - stay at PD as long as possible. Vision + surface noise makes it the best spot, strategically.

Kb

[Fab]

Wow, great replies. Thank you all so much. I picked up a copy of the U-Boat Commander's Handbook based on the suggestions here. I can't wait to read through it several times and develop my own tactics.

Plus, I don't think that fine manual would tell me what the rings were on the F5 view! Heh heh. Thanks for that info too.

[svenks]

Well, one other thing: While being at PD is a good idea most of the time, it isn't when the escort are very close to you. I find that they will hear you most of the time.
I usually approch a convoy from the from at an angle around 45 degrees and try to sneak in just behind the lead escort. I havely calculated a 'risk zone' of 1.5 km around my boat. If it seems like the escort is going to get closer than that, I'll go to 25m, silent running. Usually it is not necessary to stop engines, but I will do that if he stops for a listen. I will also try to keep my bow toward him. Once he has passed (for sure!) I go to 15m and open the tubes. Usually 15m is OK, even if one of the smaller ships passes over you, but be careful in rough weather.
For the shot, I normally don't go to PD, but set dept = 13m. The 'scope may be covered some of the time, but so will your tower :)

Good hunting!
Sven

[Torvald Von Mansee]

I got lucky w/a my first convoy, as I encountered it in October of '39 w/no escort. The my computer died, and a friend of mine is still working on it and I really really really want to get back to the game, but I have a feeling it will be a while until I will.

[Khayman]

Well, one other thing: While being at PD is a good idea most of the time, it isn't when the escort are very close to you. I find that they will hear you most of the time.


They sure can, and they sure do. Then they'll ram you and drop depth charges right on top of you. Cue end of mission on account of being dead. So try not to let them get too near....says K who's now starting a new career after being rammed then blown to bits. :)

[Keelbuster]

Well, one other thing: While being at PD is a good idea most of the time, it isn't when the escort are very close to you. I find that they will hear you most of the time.


They sure can, and they sure do. Then they'll ram you and drop depth charges right on top of you. Cue end of mission on account of being dead. So try not to let them get too near....says K who's now starting a new career after being rammed then blown to bits. :)

It depends. In very still water, if a DD sails by you at 300m, yer probably busted. This may not hold for rough water. I've seen some close calls with all schtop and silent where the DD didn't smell a thing.
As a rule of thumb, keep the lead escort 1km or more away from you at all times.

Here's another trick I've learned that works like 50% of the time.

If the lead DD gets suspicious and starts doing his snake search, you can actually use that to your benefit. Turn against the convoy, and wait. If yer lucky, and close enough to his base course (i.e. 500m), his snake pattern will have him pass very close to you (i.e. between you and convoy) before turning and going back the other way in another run (like a FaT torpedo). When he turns to go back, you're in his baffles. Go to ahead 1/3, and try to get past him so that in his next snake pass back towards you, you're allready beyond him and closer to the convoy. In this situation, if you stay put, yer dead because he will see you on his next run. But if yer lukcy, you'll get past him and into the convoy undetected. This is really great because after a while he's totalyly convinced that the convoy is safe, and really you just deeked him and are lining up for multiple kills.

Kb

[bsalyers]

I was once waiting in the path of a convoy in - I want to say 1941 - with engines off at periscope depth. As the lead escort drew nearer and nearer, I ordered silence. My hydrophone man whispered that the destroyer was closing at short range. In this game, short range means really close. I knew then we would be killed; I just wanted to watch it happen. On a whim, I put up my scope; not all the way so it broke the surface, just enough to see the cans when they were dropped. Within seconds I actually saw the hull of the destoyer pass over my bow. We were probably less than 2 meters under him. He never detected me. BTW, I was playing at full realism.
I don't know if this is remotely authentic, but in the world of the game, "silent running" seems to make a huge difference. I've used it ever since, not just when evading, but when lying in wait just before my attack, too.

[Heibges]

I agree with Keelbuster. I have had some destoyers pass extremely close to me at PD and not hear me. It's all a matter of nerve. And by observing them you are able to determine instantly if they suddenly steam full speed at you, or steam off full speed in the other direction. A really delightful game of cat and mouse.

One time, on the surface, in the middle of the Atlantic, with medium fog and heavy seas, I had a destroyer cross my stern at 450m. It just came out of nowhere. I sat there watching it, but it just kept right on steaming. We were the proverbial, 2 ships that passed in the night.

[Keelbuster]

Yea - I'm pretty sure that their passive ASDIC sensitivity scales by their level of suspicion - if they know yer about, they'll detect you <1km. If they have no idea, then they're not looking for you and you can get away with some close action.

Kb

[Fab]

Well, I tried the advice listed here and got into position without being detected. I launched four eels at the Southhampton and my aft tube at a large cargo. Three of my four hit the cruiser and it was already sinking before I had a chance to submerge. The large cargo was hit aft but did not cripple her. I submerged and managed to evade two escorts (the other two luckily stayed with the convoy).

When I came back up, the cargo ship was hurt bad but steaming ahead at 4 kts (the rest of the convoy was at 5 kts). I managed to sneak out the back of the convoy then tried to run up along the side, hoping once the convoy finally outdistanced the crippled ship I could come in for another go but to my delight the convoy zagged (which I thought was heading 315° turned out to be heading 360° and was in the zig part of their zig zag). They turned themselves to 45° which put me instantly right in line to submerge and take a second pass.

I'll take another crack at that cargo, and probably another ship before calling this convoy finished (I'll be out of all eels but one in the aft after this attack).

Thanks for the advice, everyone. So far so good.

[Kilamon]

I often hide underneath a crippled boat while reloading, or under one that's moving a la Down Periscope. Works great in the game but I doubt it could be done for a real tactic.

As others have done, I too have sat in the front of the convoy watching that lead destroy zig-zag his way towards me. In one instance, I had a type iv acoustic loaded aft and as soon as he'd gone past me, I started lining him up for a shot. I managed to sink 2 tankers, a liberty and cripple a C2 while the acoustic @^#% DESTROYED the DD (massive explosion! MASSIVE! Must have hit the ammo). :o Diving down to evade the retaliation, it always seems like it takes forever to reload. Those DDs were pissed at me too because they kept tracking me for 2 hours while I kept popping decoys and moving away.

Don't forget to use your recognition manual! I've only learned of it's importance recently and getting critical hits to a boat can save your neck.

[Ducimus]

>>How do I get inside a convoy?

It's all about accurate plotting, and alot of breif periscope observations, and being able to accuratly place yourself ahead, and just to the side of a convoy.

Dont get DIRECTLY ahead of the convoy. The lead escort has a high likelyhood of detecting you. Try to get yourself about 3000 (give or take) meters ahead and to the side (or less, depending on situation and position of lead escort). Point your bow at aruond a 15 degre angle towards the convoy. Ive found that direct 90 degree shots are hard to make accuratly unless your at an extreme range - but extreme range means you have a high likleyhood of missing.

The reason for angling your bow towards the convoy instead of a stright 90 degree shot against the side of ships is because the gyro angle, and the speed of the targets, its hard to shoot a spread, and have them all impact around the same time frame. A long delay between your first two fish, and your second two fish, means that the second salvo will most likely miss because the targets have changed course when alerted by your first spread. So by angling your boat, you can shoot at two targets much quicker. Beward, too much angle and a contact pistol is useless, and you'll have to use magnetic, and if the seas are rough this isnt desierable, so you'll have to be be careful not to use too much angle.

Anyway, get 3000-4000 (or less, it dpends on the situation) meters from where you expect the convoy to pass, and let the lead escort cross your bow. The instant he's crossed your bow, hes a little more blind to you. Move at 2-3 kt, NOW, before the side escort catches up. You need to move quickly (but not loudly) if you expect to get in between two colums, or at the least, to get some distance from the side guarding escort before he reaches your vacinity.

Getting in the middle of a convoy is hard to do if theres a lead escort, but getting inbetween the first two columns of ships on the side of the convoy is much more feasible.

Angle the bow about 15 degrees (or less, give or take) towards the 2nd inner column, take your bow shots first, by now your stern tube should have a good gyro angle on the outter column, shoot those quickly. You wont have much time becuase your bow spreads are giving you away.

Then set your dive planes to normal dive and change course so you dont go under the ships from your first bow spreads. Avoid crash diving if you can, once escorts get that tip off in late war, its VERY hard to shake them.

On a side note, in a VII boat, i woudlnt try very hard to get inside a convoy if using manual targeting. Primarly because that 1 stern tube, to me, doesnt really make it worth the effort. Its great as a coup de grace shot, but your chances of sinking a ship with it arent as great as if you had two sterm tubes. All depends on you SOP really, i use manual targeting (hence no silver bullet torpedo's) , so my SOP is two fish per target if it's more then 2000-3000 tons. Your milage may vary.

[Dowly]

My method is to get ahead of the convoy and then turn straight towards it. When I reach the convoy, I turn my boat back to the way the convoy is headed.

I tend to go at slow speed and in 100+ depth. As long as I´m not detected before reaching the convoy, I´m safe. When inside of the convoy, you can even reload your external tubes (Works best with the VII boats, as they turn better than IX), without troubles from the DD´s.

Good Hunting! :up:

[Fab]

When inside of the convoy, you can even reload your external tubes (Works best with the VII boats, as they turn better than IX), without troubles from the DD´s.

You surface in a VII inside a convoy and spend an hour loading your external stores into your tubes? I must be mis-reading something, or I'm doing something very wrong, or else you have the largest, brassiest cojones of anyone I've ever encountered.

[Seminole]

Getting in is not that much of a problems as I'm sure has been already explained adequately above.

The big problem is getting out again. :yep:

[Dowly]

When inside of the convoy, you can even reload your external tubes (Works best with the VII boats, as they turn better than IX), without troubles from the DD´s.

You surface in a VII inside a convoy and spend an hour loading your external stores into your tubes? I must be mis-reading something, or I'm doing something very wrong, or else you have the largest, brassiest cojones of anyone I've ever encountered.

Before the merchants get guns it´s easy. Just have to maneuver my boat behind merchant, when the DD´s start blasting with their guns. :)

I rarely do that, but it´s a nice maneuver training. Have to be changing direction all the time. :rotfl:

[Ducimus]

Getting in is not that much of a problems as I'm sure has been already explained adequately above.

The big problem is getting out again. :yep:

You have to resist the urge to crash dive, AND resist the urge to watch your torpedo's hit. Instant you shoot your fish, start going deep.





Before the merchants get guns it´s easy.

I was about to say, you'd HAVE to be doing that early war, no way in hell youd be doing that later on :D