Attacking a Convoy in Silent Hunter 3

[GJO]

Originally Posted by Zosimus

Personally I have found that the best way to hit multiple targets is to set yourself between the rows of ships. That way you can fire at a promising target with your fore slavo and another target with your aft. This only works if you're at a 90º angle.

This is the only way to get the really juicy targets although not necessarily at 90 degrees. I prefer to get on a nearly parallel course as close to the centre of the convoy as possible - this makes it very easy to get an accurate measure of the convoy's speed - easy enough in the early years (even with a night attack on the surface) - even in later years it is possible to get into the middle of a slow convoy and play havoc.

After 1940 with armed merchants all around, surface attacks become very risky so this method is best used with a submerged attack on slow convoys and even then, too much time spent travelling with the periscope up or at anything faster than 1 Kt will attract the early attention of the escorts.

I rarely fire a torpedoe from within a convoy unless I am on a nearly parallel couse to the target at a distance of between 450 and 500 Metres - I have found that, after much practice, I can get the torpedoes to run at approximately 90 degrees to my course and score a crippling hit on the target. I know some regard this as 'firing from the hip' but I believe many of the more succseful WWII commanders used similar intuitive methods. In other words, many of their deliberations as to distance would have been the result of an inspired guess based on knowledge and experience.

It is essential to get the torpedoes out fast and then escape as quickly as possible - especially in the later years. Those targets that fail to sink are often crippled and can be found later well behind the main convoy to be finished off when the tubes have been reloaded.

[Zosimus]

That's great. So you can fire the torpedoes out the front tubes, have them curve a bit, and hit the ships.

But this doesn't let you use the aft tubes.

[Andrakis]

I've noticed that if you are firing for multiple targets in a convoy, that basing your firing order on the impact time can help mitigate the dodging effect.

That is to say. My further targets will have torpedoes fired at maximum speed, closer targets at slow. The ideal situation is having all of your volleys striking as simultaneously as possible.

That's easier said than done, however.

[GJO]

Originally Posted by Zosimus

That's great. So you can fire the torpedoes out the front tubes, have them curve a bit, and hit the ships.

But this doesn't let you use the aft tubes.

Yes that is how it was done in real life - the torpedoes are steered by a giro device and once set it will keep the torpedo on a straight course - AFAIK the giros were adjusted by the crew in the torpedo compartment as soon as the officer read out the calculated settings. If the torpedoes course is set to 90 degrees from the subs course, then the torpedo will follow a tight curve until the giro senses that it is going in the right direction. It works with all torpedoes including those in the stern tube(s) - in the game, I haven'y tried setting them up to run at an angle greater than 90 degrees but I can confirm that, at that angle they run nicely.

[GJO]

Don't set the torpedo speed too fast when the targets are within 500 metres!

I have had a few that have failed to detonate and my guess is that the game emulates real life in that each torp needs time to arm itself.

[Pisces]

There is also a bug with the torpedo speed settings when switching between a type 1 and type 2 torpedo. The TDC doesn't update the firing solution for the torpedo that has a different speed setting, so it goes the wrong way. Be mindfull of that and force the speed setting if you switch between types.

[Zosimus]

Originally Posted by GJO

Yes that is how it was done in real life - the torpedoes are steered by a giro device and once set it will keep the torpedo on a straight course - AFAIK the giros were adjusted by the crew in the torpedo compartment as soon as the officer read out the calculated settings. If the torpedoes course is set to 90 degrees from the subs course, then the torpedo will follow a tight curve until the giro senses that it is going in the right direction. It works with all torpedoes including those in the stern tube(s) - in the game, I haven'y tried setting them up to run at an angle greater than 90 degrees but I can confirm that, at that angle they run nicely.

Well, maybe you haven't explained yourself well, but I just don't see it.

Okay, you're inside the convoy between two rows and running parallel. You claim this lets you figure the speed of the convoy nicely. I say nonsense. If the convoy is going at 7 knots and you're going at 1 knot, then you have no way of "pacing" the convoy. You would need to go at 7 knots to pace a convoy going 7 knots. Whatever method you use to figure out its speed would work equally well at a 90º angle.

Second, I don't doubt that your self-admitted "shooting from the hip" works fine with the fore tubes. You have a ship roughly abreast of you, and you fire a torpedo (or two) out the fore tubes. The torpedoes race ahead of you while turning and smack the ship broadside. Perfect.

However, your aft tubes will be racing backward while the target is plodding foreward. That's going to be a problem. How exactly do you handle that? I suppose you must fire at ships that are substantially behind you. Sure, that's easy to figure out by just hitting F6 and looking at the torpedo trajectory and thinking, "That looks perfect." I wonder, however, whether the real u-boat commanders had F6 screens.

Finally, 90º shots have an advantage that parallel shots don't – it makes it far easier to hide under the cargo ships. Let's assume that you've worked your way into a big convoy and you see juicy targets fore and aft. You can easily fire a salvo at the fore, a salvo at the aft (or vice versa) and time them to hit at the same time. As you are waiting for them to hit, you can find another target and order your helm to turn to that angle.

Once the torpedoes hit, the convoy will react. Half of the time the third target will zig in a way that puts it broadside to you. If that happens, you can salvo that one too, and dive. If not, just dive anyway and kick up the speed. At this point you can easily position yourself under the row of ships as you go deep. The destroyers will need to wait till the ships get out of the way before depth charging. That will give you precious minutes you need to hit 200+ meters deep.

If the weather is decently bad, the destroyers will find it impossible to pick you up with sonar. You easily escape and go out and around to do it again.

[GJO]

Originally Posted by Zosimus

Well, maybe you haven't explained yourself well, but I just don't see it.

Okay, you're inside the convoy between two rows and running parallel. You claim this lets you figure the speed of the convoy nicely. I say nonsense. If the convoy is going at 7 knots and you're going at 1 knot, then you have no way of "pacing" the convoy. You would need to go at 7 knots to pace a convoy going 7 knots. Whatever method you use to figure out its speed would work equally well at a 90º angle.

Second, I don't doubt that your self-admitted "shooting from the hip" works fine with the fore tubes. You have a ship roughly abreast of you, and you fire a torpedo (or two) out the fore tubes. The torpedoes race ahead of you while turning and smack the ship broadside. Perfect.

However, your aft tubes will be racing backward while the target is plodding foreward. That's going to be a problem. How exactly do you handle that? I suppose you must fire at ships that are substantially behind you. Sure, that's easy to figure out by just hitting F6 and looking at the torpedo trajectory and thinking, "That looks perfect." I wonder, however, whether the real u-boat commanders had F6 screens.

Finally, 90º shots have an advantage that parallel shots don't – it makes it far easier to hide under the cargo ships. Let's assume that you've worked your way into a big convoy and you see juicy targets fore and aft. You can easily fire a salvo at the fore, a salvo at the aft (or vice versa) and time them to hit at the same time. As you are waiting for them to hit, you can find another target and order your helm to turn to that angle.

Once the torpedoes hit, the convoy will react. Half of the time the third target will zig in a way that puts it broadside to you. If that happens, you can salvo that one too, and dive. If not, just dive anyway and kick up the speed. At this point you can easily position yourself under the row of ships as you go deep. The destroyers will need to wait till the ships get out of the way before depth charging. That will give you precious minutes you need to hit 200+ meters deep.

If the weather is decently bad, the destroyers will find it impossible to pick you up with sonar. You easily escape and go out and around to do it again.

That is all correct - when running approximately parallel, I find it very easy to judge the speed of adjacent targets - it is a bit like walking in a crowd - they are either slightly faster or slightly slower and with slow convoys you can often adjust your own speed to match theirs - the other advantage is that whilst on a parallel course there is more time available to make sure that all is correct. Obviously the stern tubes could only be used for a target that is astern of the 90 degree line - a succesful method here is to discharge the bow tubes first then reduce speed and fire the stern tubes as the target comes into the intended path of the torpedo. I am not sure that it is always easy to escape - I play GWX and the escorts with this mod are very good at locating submarines. I have found that the most effective means of escape is to change direction and then run silently away going as deep as possible . . .

[Zosimus]

As I said, if the weather is sufficiently bad then escape is not a problem. If the wind speed is 0 m/s then you're not escaping no matter what you do.

[GT182]

Originally Posted by Zosimus

That's great. So you can fire the torpedoes out the front tubes, have them curve a bit, and hit the ships.

But this doesn't let you use the aft tubes.

Yes you can use the aft tubes. Make it quick to pick up a target and fire off a torpedo. If you have a Type IX sub you'll have two of them to fire. Once the tubes are clear dive fast, go silent, and get out of there. Don't even think of reloading while you're being hunted.

The convoy ships and explosions will mask your departure for a bit. But when the escorts start their hunt.... go deep, go silent, and stay silent. They will give up and leave but it might not be for a long long time.

I'm not sure if doing a game "Save" while submerged is ok now, but it used to be you wanted to be on the surface to do a Save.

[Bosje]

there, see? Can of worms

seriously though, read up on the many many guides there are here, both on convoy attack and manual targeting.
90 degree is not always the best. early in the war it's asking for duds, and yes if you want to be at 90 on torpedo-firing-time, then you have to be at another angle when you start the run-up.

oh i could go on for hours and hours, but i seem to remember my most fun times with this game were learning it all by experience

edit: look into GWX and read the GWX manual. it's only about 400 pages

[RustySubmarine]

Finding convoys are sometimes a matter of being in the right place at the right time. But for most of the time, it is just luck that a convoy appears within your range. When and if it does, try and get inside the convoy if you can, rather than be outside. This gives you more chance of not being attacked by any escorts. Try and run with the convoy and choose your targets well. Choose larger ships if you can and try not to get too close to your targets. Try to let loose your fish in salvoes from your bow tubes and keep your stern tubes full for anything that might come into range from behind you. Once you have released your fish, stay at periscope depth and engage silent running, try to stay within the convoy and see the carnage and what any escorts do. If things turn for the worse. Then dive deep and try to avoid detection, keep in silent running. If any escorts pick you up they will hound you with depth charges so you need to vary your depth and try to avoid them, but will eventually give up searching after a while, you just need to try and out fox and manoeuvre them. I find this quite a challenge and usually manage to shake them off. When you think you are pretty safe, return to periscope depth to see the situation. By this time, you might be well out of range of the convoy, but at least you will have scored a few hits and still be alive to tell the tale.

[Andrakis]

Has anyone had any success shadowing inside of a convoy after an attack? Let the escorts sniff around but hide near a convoy ship's hull and slowly ride it out, then dive and wait for the convoy to pass by overhead. After the escorts give up, of course.

[RustySubmarine]

Originally Posted by Andrakis

Has anyone had any success shadowing inside of a convoy after an attack? Let the escorts sniff around but hide near a convoy ship's hull and slowly ride it out, then dive and wait for the convoy to pass by overhead. After the escorts give up, of course.

I encountered a convoy at night (grid BF14) and managed to sink five merchants plus a Flower class corvette. I managed to stay within in the convoy whilst being stalked with two more destroyers. I dived to 90 metres on silent running before coming back to periscope depth after three hours. I had sustained some damage but not enough to render me unplayable. After repairing most of the damage I managed to limp home on one engine and both deck guns out of action. An Iron Cross was presented and promotion to some of my crew. I had survived my 12th patrol since 1939 qnd it was now December 1941. It was the luckiest escape I have had so far.