Tactics when engaging convoys
 

Hey, I'm pretty new to this, so please bear with me :)

When you've found a convoy, how do you engage? Is there any point in killing destroyers or do you just go straight for the juicy targets? I'm not really sure what the best approach is. I'm unsure if it's worth blowing up destroyers... sometimes I've been able to avoid them easily, and other times I just can't shake them off.

If you are playing 100% realism, attacking destroyers is entirely pointless due to 2 reasons:

1.- You waste torpedoes in cheap vessels, not loaded with war material to help the enemy

2.- You will take on one, but probably be forced down by the second and/or third escort, effectively loosing any chance to get a real shot at the merchants

Those were also the two historic reasons why attacking a destroyer was an exception.

If you are playing less than 100% realism -specifically if you are using auto targeting and no torpedo duds- you can sometimes make a clean sweep of destroyers and then wipe the merchants away with little effort, collecting a huge bag.

The bottom line: Play irrealistically, and you will get irrealistic results. Play realistically and you *probably* will get realistic results.

Now I explained it, it's for you just a matter of deciding how you want to play:up:

All that Hitman has mentioned is true. Everybody who plays a subsim has a learning curve especially beginners. You develop your own tactics for attacking and then escaping. Sinking the destroyers first might work, but expending torpedoes on a DD which might take one hit and sink or it might require more and later you might see a nice big fate tanker come along that you could have used those torpedoes on instead of the destroyers.

In the Pacific war there actually was a president for sinking destroyers. It was late in the war, mid 1944. Just before the Battle of the Philippine Sea. The Silent Service had a priority list with which certain ships would be sunk first instead of other. Japanese capital ships were always high on that list. Tankers were another high priority target. Japanese destroyers were moved to the top of the list in mid '44 because of the destroyer shortage that the Imperial Navy experienced during that period.




cdrsubron7 ;)

If you want to go for the merchants, the first thing to do is close with them by sneaking inside the destroyer screen. Look at the diagram below (S is your sub, D are destroyers, M are merchants), showing a typical way I approach a convoy attack. In this example the convoy is travelling north ("up") and you are approaching from the northwest. The easiest way is to get between the destroyer in front and the one at the side, and attack the merchant in the upper left hand corner of the merchant grouping. Make sure you are fairly deep and running slow and quietly as you get past the destroyers. Then come up to periscope depth and carry out the attack.

.........D
...S

D ..M M M.. D
.....M M M

........D

After you've fired, I set for silient running, dive deep, and follow my torps to get under the convoy. The escorts tend to look for you "outside", not in and amongst the merchants. Depending on the escorts response, you can either come back up after a while and have another shot from the other side of the convoy (with stern tubes perhaps) or slink away and escape.:arrgh!:

I go for worthwhile targets only. That is anything over 4000 tonnes. The bigger the better. Destroyers I leave alone. The only time I've sunk (or tried to sink) DDs are when on the run and have a good firing solution from my stern tubes. Especially when it is coming right at me from dead astern this can be effective.

The problem I have with convoys now (after installing the TTM mod) is not being detected before the juicy targets are in good range and good bearing. Oh, and playing in early 43 btw. My previous careers have been in 42.

My traditional tactic was plotting a course that puts me roughly in the middle of a convoy. Then go silent and deep and just wait out the front DD screen to pass before floating up to peri-depth. I would then fire my fishes front and stern before slinking off again deep and silent. Worked wonders prior to installing the TTM mod. Now however, more often than not, I get detected by the front DD, and have to suffer through a lot of pain before getting away, if I do at all.

I'm trying various alternatives to this tactic. Usually I would have a 100'-80' angle on the trajectory of the convoy, thus presenting to the DDs a big long target for them to detect. Putting the sub more or less paralell to the trajectory of the convoy should present less of a target. Also I'm going to push down to more depth. Before I hovered from 75-90 meters (depending on sub), going down to 100-120 meters could help some. After the front DD pass, I could just float up doing 1 knot and change course back to the ideal 90' angle of target.

Failing that, I have to start attacking from some distance, either from just outside the flank merchant of a convoi (puts me between the front and flank DD. Distance from them might be a good thing. As opposed to my earlier tactic that often allows the front DD to pass right over me), or just a bit out from the flank DDs. Sucks getting detected, at least prematurely so. And speaking of premature, attacking from a distance will result in a lot of premature torpedo detonations. But that is better than getting spammed by DCs :D

Thanks for your helpful replies!

I intent to play at 100% realism, but atm I'm only on around 70%. I want to learn manual TDC, and obviously it's easier when you have map contacts and external view on :P

Back to the convoys... how do you avoid getting behind and eventually out of range? I just can't keep up with them when running silent.

Another problem I have is planes. I think the crew is excellent at blowing them out of the sky, but sometimes they get to finish their run. Should I just crash dive immediatly when they are spotted? I can't really figure out how to make the radar work, so it's generally too late when they are in visual range.

You need to get in position long before the convoy reaches you. Just plot the trajectory of the convoy once you get a radio message saying where it is or you make radar contact. Then make a course that will intercept this trajectory. Get there at full/flank speed whilst surfaced. Ideally the lead DD of the convoy should still be some 20-25km away when you are roughly in position. Then just dive deep, go silent, do final adjustments and turn off your engines. When the closest DD to you have passed, float up to peri depth and fire away.

I think there are some video tutorials floating around here somewhere.

Oh, and if the escorts do their job, you'll only have the one chance to fire at the convoy. When that is done, your priority should be getting away, not do another follow-up attack.

To get the radar to work properly, you need to install a mod that works around the currently bugged radar models in the stock v1.2 of the game. I'd reccomend the TTM mod.

Having a working Air-detection radar, you should avoid all aircraft like the plague. Detect one and immidiatly go down to at least 30 meters. You are _not_ safe at periscope depth, especially not if you got the peri up.

The best approach to use is the "dead stick" approach.

You get right out in front of the convoy's path, just off-center. Ideally you don't want the point escort to pass right over you. Dive as deep as possible and run silent. Cruise at 1kts toward the convoy.

After the point escort passes you and you're about halfway inbetween him and the first row of convoy ships, start climbing to periscope depth. You should also turn left or right so you are perpendicular to their base-course. You do this so you can fire bow and stern shots. Make sure a convoy column isn't going to pass right over you because they'll damage your boat a bit.

Wait for decent shots on both bow and stern tubes and let'em rip. Get all your depths, speeds, triggers, and torp doors open before you raise your periscope. You want your periscope up as absolutely little as possible. Peek up and get bearings and angles, put the scope down and get all your gyros set (if you're doing manual targetting), then pop back up and shoot. Tankers and troop transports should be main targets in merchant convoys -- task forces targets should be the biggest damn thing in there, with carriers before battleships.

Soon as you fire, lower your scope, ahead at 2kts, and dive as deep as possible. Turn so you're going out the rear flank (i.e. diagonal out the back) of the convoy -- not directly astern because there is usually an escort there. Make sure you're running silent until you get to your max depth, then consider whether to start reloading if it doesn't seem the escorts are very close.

Cruise at 2kts until you're out of range, then reload tubes and surface for air. Finish off any boats that are only damaged, then run an end-around and do the same thing again if there are still boats worth dropping.

Make sure your prioritize your targets well, firing at the furthest targets first to minimize the total salvo time, and individualize torp settings for each boat. Carriers go nicely (2 torps) if you get deep contact shots against the ammo and fuel storage holds. Tankers seem to go well with fairly shallow torps against the oil tanks. Regular cargo boats are best dropped with mags below the keel. Battleships, hell -- I haven't figured out what works best against them because they always seem to take a huge number of torps.

If you want maximum tonnage from every torpedo you carry, then using them on
low tonnage DDs is not the answer. If you remember the quote from the
Chief of the Boat to Burt Lancaster in "Run Silent, Run Deep", he said:
"I don't know of any time a shot like that was used except in desperation"
He was talking about the down the throat shot against the DD....

JIM

When positioned and awaiting a convoy to pass, I have never had any problem staying at periscope depth with periscope raised. If you are at 0 knots, the scope doesn't create a wake and is virtually undetectable, even during the day, even with the "better escorts" mod with more sensitive detection. (Note: I don't keep the scope fully raised, only high enough to just break the surface).

Personally, I need that time to match my solution to the observed target, particularly since the range finder is still a bit off using imperial measurements. Once I fire my torps, I keep my engines off and just drop-dive to 250, below the thermal layer, then I turn my engines on 1/3 and creep away. The destroyers rarely have a clue.

Hum, here's another example of unrealistic results as a result of more or less unrealistic physics...let me explain that.

Active Sonar can't detect a submarine at periscope depth (Reason: The node where the sound impulse comes from is below the bow of the destroyer and points slightly downwards), and passive sonar (hydrophones) can't either unless it is very close (Reason: Surface noise).

Since SH2 I have seen people develop irrealistic tactics that consisted essentially in submerging very deep, then coming up for the shot. That is not historically correct as far as I know, no sub commander would do that for several reasons:

1.- All the time you are below periscope depth you are virtually blind and your only means of knowing what the target is doing is hydrophones. The convoy might well zig zag away and you would never notice it until it is too late

2.- You can't collect aditional critical data through visual observation to set up a fire solution: AOB, distance, speed

3.- The amount of time required for a sub to go down and then up is enough to ruin any decent attempt of positioning yourself well for the attack.

4.- There were in real life much more chances of being detected at medium or deep depth (Where active sonar reaches well and passive is not distorted by surface noise ) than at periscope depth, except in two cases: A) A heavy termal duct at shallow depth, which you can position your sub below, and B) Broad daylight in an aircraft covered zone, as you can be detected submerged at periscope depth by a plane visually.

The irrealistic tactics describe above have been more than often the result of the use of auto targeting in SH2/3/4, where you get "magically" the perfect fire solution with just a click of the mouse. Sometines in conjunction with astonishing manouvers like "blow ballast" to climb faster, then level at periscope depth :o . A real submarine would go out of control when blowing ballast heavily, and surface uncontrolled:down:

In real life the destroyers patrolled all around the convoy perimeter continuously with a stop and sprint tactic not for fun, but because the only means of detecting a submerged submarine at periscope depth was mainly listening or casually stumbling upon her. If you submerge deep and enter the area where their active sonar reaches more and their passive is more effective, you are losing an advantage. You have already a big speed disadvantage when submerged. If you worsen it by going into the area where escort sensors are more effective and you are blind for not being able to use the periscope, the result is obvious.

Unfortunately, SH2/3/4 have not always simulated well the escort sensors, and some mods have been allowing them also to be operational at periscope depth, which is not correct. While that probably might have been done to compensate other flaws, it has lead to the use of historically incorrect tactics in some cases.

In real life commanders would hunt on surface by night, and only attack at periscope depth if a target of oportunity is found at broad daylight and no alternative (Following it) is possible. The US submarines doctrine at the start of the war was exactly the opposite (Submerge all day and attack at sonar depth, with no visual aim) at the beginning of the war, and the results were a plain disaster. The germans employed the oposite tactics and had incredible results.

When things changed later with the adition of radar, air cover, and convoy escort screens grew thicker, the only means of attack for submarines was submerged, be it day or night, which didn't necessarily mean "go deep and come up when the convoy is above you". Instead, just the fact of being unable to do anything else than moving at 2 knots at periscope depth when the convoy was already 20 miles away was enough to ruin any decent firing solution. How would you be able to position yourself properly at 2 knots when you are engaging a convoy who is moving at 8 knots and zig-zagging?? That's what killed the success of the german u-boots, and not the improved ASDIC. The improved active sonar helped hunting and destrying them once located, but the real reason they were no longer able to closen the enemy convoys enough to fire a torpedo (With a run length of some 2000-3000 metres at most if you want to hit anything) is that they were forced down by aircraft and surface radar.

:roll:

Unfortunately the game sometimes dictates unrealistic behavior to get the best results.


Any suggestions for modding the AI sensors to make them more realistic? (I mean specific parameters to change and values?)

I've installed the mentioned mod and it works great... it's nice to have a working radar :D.

I think I got the basics pretty covered up, thanks all, it's very helpful.

I was suspecting that this idea would come out sooner or later :roll: I have yet to write a long and throughout essay on the "realism" matter, and I really wish I will some day be able to, but suffice for now saying that essentially no game can be perfect and complete in terms of simulation. Humans have an ability to find "weak spots" in everything and using them to their advantage. That's unavoidable. So when you play in the constraints of a computer simulation it is a given that sooner or later you or other will find how to trick it and get better results with unrealistic tactics (i.e. tactics that in the simulated "real life" would not have paid off ) . Thus the question is not if you can do unrealistic things to get better results, but instead what results do you get when playing realistically. I have to laugh when I see posts like "Look, I engaged a Battleship in a gun battle and won! Bug! Unrealistic!". That's nonesense. Why on earth would a submarine commander in real life engage a BB on a surface duel? And there you have dozens of modders now worried in changing that and ensuring that the next kid who has the idea of doing an unrealistic action is inmediately blown off by the BB:doh:.

Game code is limited, simulations have severe constraints. The only thing we can aim at, is to getting rewarding results and experiences from using historical tactics, but as soon as you step aside and say "I'm going the wild goose chase route. I get better results", you are obviously the first element in an unrealistic gameplay. And the most important one, to be more precise. Voluntarily abandoning historic tactics might give you better results, but don't claim then that they are irrelastic. Sure they are, as was the gameplay input that made the game code generate the results you received.:down:

Would the game credit you for sinking that ship?
I think that you have to visualy see the ship sinking...