Convoy Tactics Question
 

I'm running SH3 commander and GWX3. Heading of for my second patrol in october '39 (already bagged 3 ships on my way in, not even at the patrol zone yet :3 ) But I'm curious as to how well ship visibility is modeled in this mod combo? Can I, for example, lie in wait for a convoy, let it slip around me and then surface in the middle and engage (much like the real thing), or will the merchantmen immediately spot me? Also, how well simulated is ASDIC- will destroyers hear me amongst the merchentmen? Can I wear one as a hat to confuse them? (certainly would prevent depth charging tehehehe ).

What are subsim's anti-convoy tactics?

Look at this link,if there are something,Otherwise, you can search the top right, in the search box on your ether after :yep:

http://www.subsim.com/radioroom/show...t=convoy+tctic

1: Visibility. As a rule of thumb, at anything less than 5000 meters, you should assume they can see you if you can see them. Over 5000, it depends on luck, the sun, haze, how fast you're moving, how choppy the seas are.

2: Lying in wait. It can work, but lying in wait off on one of the forward corners of the convoy, then going into the convoy after the lead escort has passed is safer and more forgiving.

3: Being spotted. The convoy reacts to any of the following. 1) your being spotted by any ship. 2) your torpedo being spotted by any warship (merchants don't notice). 3) a torpedo exploding. 4) your firing a deck gun. At that point, the convoy will begin to "snake" predictably and the escorts will try to attack. Warships in the convoy -- such as a BB or cruiser -- will snake like the merchants. And any armed ship (warships and, increasingly, merchants) will shoot at you.

4: Wearing a hat. It does not confuse them, as the AI ships do not hear one another (nor does seabed clutter confuse them). Nor does it keep them from getting at you, as the AI escorts think nothing of planting themselves in front of a merchant. The merchant stops on a dime, and you do not.

There is a good explanation of anti-convoy tactics toward the end of the GWX 3.0 manual... well worth a read.

I've found that detection range depends very much on weather conditions. Your own speed also has a noticeable effect, as does your aspect towards ships. Wether or not they are actively searching for you has a very big effect. Which means you can get close and not be detected, but once your torpedoes detonate, you may well be detected immediately.

In the worst possible visibility conditions: heavy fog, rain, visibility less than 1000 meters, you can, with some luck, sail on the surface between the rows of merchants in a convoy without them noticing you. Of course, in these conditions, getting inside the convoy without accidentally running into an escort or colliding with a merchant is a risk I'm not personally willing to take. Gathering the required torpedo data for a successful attack is also quite difficult.

I've found the most favorably weather conditions for a surface convoy attack to be moderate seas (6-10 m/s wind), light (possibly medium) fog, overcast, possibly light rain, and night of course, with a visibility of perhaps 4 - 8 km. In these conditions it is quite possible to penetrate a typical early war escort screen (front escort, one escort on each side, possible rear escort), especially if the side escort occasionally moves further from the convoy. Later on in the war, don't even dream about it.

Don't use higher than 1/3 speed, and consider approaching decks awash. You should be able to slip in between the front and side escorts without either of them getting closer than 2500 meters or so. Even so, it is possible they spot you, in which case you have to crash dive and abort the attack. Approaching decks awash makes diving a lot faster.

In these conditions, once you penetrate the escort screen, it is unlikely that the merchants will spot you unless you go closer than 1000 meters, at least until they know you're out there. This allows you to fire your torpedoes at choice targets from just outside the convoy.

After firing your torpedoes, you should try slipping out the rear of the convoy, especially if there is no rear escort. After all, the whole point of a surface attack is to retain the better speed and maneuverability you have on surface and to avoid being hunted alltogether. Be warned, this will not be easy.

Don't move too fast before your torpedoes detonate, as this will give you away. Once the torpedoes hit, the side escort will head straight towards the general position of your attack and everyone will try to spot you. If you had sufficient time to move away (slow torpedo speed, you didn't fire at the nearest ships, but chose juicy targets further inside the convoy instead), you might make it.

I've pulled this off a few times but also failed (had to dive) on several occasions. Pulling off a successful convoy surface attack without having to dive at all is one of the most gratifying achievements one can get with this game.

In better visibility conditions a submerged attack (using the same general attack plan and route) is usually the only option.

In general, they are slow to notice you but quick to pinpoint your exact location even when that's illogical (e.g. after a long-range shot under the keel)

There is a convoy tactics section in the manual that came with GWX.

Well, I trialed Otto Kretschmer's tactics of slipping in in the middle of the night between rows- and damn if it wasn't brilliant! I got within 400 meters of several boats, was able to sneak right up to the targets I wanted and align myself with them, fired 3 shots (2 forward to run under an ammunition ship in a self-set spread) and 1 stern to bend to a m31 at a bearing of 135-140ish, then crash dived just behind the merchant, slowed and ran silent at 70 meters with a target depth of DEEP - 130-140 meters. I'm still going down but the escorts have to weave and weave to get at me, with all the merchants around.... oh, and I scored a direct hit with one torp on the ammunition ship and it virtually exploded, loud explosions on the hydrophone, and immediate report of it sinking. About 45 seconds later I got a second impact report, I suspect on the stern shot.... 3 torps, 2 hits... that's bloody good for me. Now back to dodging these aimless destroyers, pics of my approach and the aftermath incoming when I shake 'em.

Surface attacks are fun and can be quite exhilarating, bear in mind you'll only be able to carry out surface attacks till 42' when escorts start getting equipped with radar on almost each (war)ship. Eventually your attacks will have to almost excusively be done while submerged; even then you have to be carefull as the war progresses radar improves to the point it detects your periscope if its too high up.

Once pattern running torpedoes become available they are great for causing distractions and diverting the escorts attention away from your primary targets. They can be (somewhat) aimed so that you hit a target on one of your flanks at the furthest distance possible (If you're positioned outside of column 1 you can potentially hit a ship in column 5) drawing the escorts completely away from you which can give you a considerable amount of time to dive deep and get out of their detection range.

Yeah, quite aware of the changes radar will make...
On the flip side, that run had me on the edge of my seat the whole time! Pity there was only two ships in the convoy worth taking (Heavy seas and the rest of the boats within any ease of access were under 3,000 tons)... But I'd heartily recommend night surface attacks right up the gut of them to anyone still in the early days :D

Glad to hear it worked for you!

Yesterday I decided to try, contrary to my own advice earlier in this thread, a surface convoy attack in bad weather - heavy fog, rain, 6 m/s wind and visibility of maybe 1000 meters. This was in December 1939. I had a good idea of convoy position, course and speed due to two earlier contact reports and a hydrophone check just before I reached the convoy.

All went well at first, and I finally spotted a merchant about 800 meters from me at bearing 30, aob 60, perfect for a nice 90 degree aob shot.

But then things started going wrong. I spotted another merchant heading straight towards me, much closer than the first one (maybe 400 meters?), forcing me to order full speed ahead to avoid being rammed. And in a few moments I was spotted, flashlights tore the fog, someone fired starshells and everyone started zigzagging.

I decided to look for targets anyway, believing that no ship was armed at this early date and that the destroyers were still far away. I fired a total of 3 torpedoes, missing with each one of them. Fully manual targetting is difficult when everyone, myself included, is turning, visibility is limited and estimating accurate distances is almost impossible.

Suddenly one of the merchants opened fire on me, and only seconds later, a destroyer emerged from the fog and likewise opened fire. Two shells from the destroyer hit me before I managed to crash dive, as did several smaller rounds from the merchant. I had flooding in 5 compartments, lost my radio, hydrophone, fore batteries (all of them destroyed) and half of my fuel, as well as got some minor repairable damage. Furthermore, the first depth charges took out one of my periscopes. I could dive no deeper than 85 meters without getting additional damage.

Lucky for me, no other destroyers joined the attack, and, possibly due to the bad weather, that one destroyer finally lost me beneath the convoy after four depth charge runs. I surfaced when the convoy had long passed and headed home. My hull integrity was 36%.

So, take this as a warning: do not attack on the surface in bad weather!

Usually when the weather is too bad to operate with precision, I'll get close to the convoy and fire a blind spread. Spray and pray....

Have had some success doing that, just usually not on the big high value targets. Though, some tonnage is better than zero...

One time I hit an escort, and it was satisfying to know that one of those buggers suffered the devils luck!

Hitting anything in a blind spread is pure luck & if you have done it several times, I would say you are having an amazingly good streak. There are just so many variables -- direction, speed, hull design, AOB, proximity. And, of course, the question of what to do when you only cripple one and it sails off into the murk.

Save your powder. There is always another day, and you have fuel enough to spend a long time at sea, even in a II-boat.

Luck? Absolutely. I won't deny that. However, I increased my luck by having a very good idea of where I was in relation to the convoy. Plotted good intercept courses, and used my hydrophones quite a bit.

It's not something I practice regularly, however I have had enough success with it as to not completely dismiss it as a last ditch move when I *absolutely* (out of sheer pride) must get some tonnage to my credit.

As far as risks go, I can handle being reprimanded by Uncle Karl. After all I can say "Yes, yes I know each torpedo is 40,000 marks but I sank more than that in allied war material with every one that didn't miss!"

:arrgh!:

Tom,

did you approach from behind? I managed to slip nicely in between two columns and only turned to make an attack run when I was right in there,

And I passed within 400 meters of more than one boat without them even bothering with me...

Until the ammunition ship in the middle of the convoy exploded of course :P

Circled in red is my tiny little boat, sneaking up.


http://i83.photobucket.com/albums/j2...voyattack1.jpg

And here, From the bridge (where the watch officer is in desperate need for a smoke, this is only our second patrol and our first convoy!)

http://i83.photobucket.com/albums/j2...voyattack3.jpg


And the aftermath. In red the ammunition ship that was my primary target, and behind it on the diagonal you can see smoke comming off a 3,500 tonner that snagged my stern shot

http://i83.photobucket.com/albums/j2...n/results1.jpg

The destroyers took a good 3 minutes at LEAST to get to me, given I was slap dash in the middle of the convoy (I fired from an AOB of 150 to stbd off the ammunition ship, range about 550). By that time I was 80 meters down and moving at a hard 90 from the speed and direction i fired from. They never even came close.

Both ships sank- the ammunition ship almost immediately, the merchant maybe 20 minutes later as I snuck away.

As there wasn't anything bigger in that convoy really (1 or 2 around the 5k mark), and I had only chanced across it, I sent a contact off to BdU and continued to my patrol grid.

No, not from the behind. From the convoy's point of view, I approached from the 10-11 o'clock direction, moving perpendicular to the course of the convoy in front and to the side of it.

My mistake was that I thought the convoy would be in front of me, and that the first ship I saw was in the outer column. Instead, I was in front of the convoy and the first ship I saw was in the second or third column, and one of the columns was heading straight at me (the second ship I saw.)

Actually that wasn't the real mistake. I made two real mistakes: I tried to attack in too poor visibility conditions and I tried to continue the attack even after being spotted.