The reason they used the influence over contact was for under the keel shots. Most targets, mostly warships were weakest at the bottom, the keel. It also has more effect than just a side contact explosion. Usually the ship would lift due to the explosion underneath..what goe's up must come down, so the lift would help break the ship, but it also came back down breaking again, sort of a double break effect...giving us...the "breaking of the back". This often split ships in half.

Game wise...maybe not as much, but still works. Much depends on the damage zones and mods may differ. I haven't checked, but in reality the keel should be weaker and it appears so in the game.

However, as in real life the influence settings were flawed. Before 1943 the M14 influence settings caused many problems and many skippers switched to contact...against orders. In the game and most mods do this, if you use influence, you will get more prematures, but less duds. If you use contact only, you'll get less prematures, but more duds.

Obvious the goal in using influence settings, you want to set the torp deep to pass under the keel. Here's the bigger problem, the M14's run much deeper than set. Until they're fixed in late 43, you set them to run below the keel, they will go about another 9ft or more deeper and not go off, so you have to judge your settings. If a ship has a 20 ft keel, I usually set my depth at 12 ft.

Your best bet if you use M14 with most mods is to shoot so they impact at an angle and use the slower speeds early war and run them shallow on contact. I do this until they're fixed...cept sometimes I use the fast settings during the day in calm water.

With mods...you're gonna see a lot of failed torps. If it bothers you, carry some M10's...not as powerful, but they work 90% of the time.

The idea of a keel shot is to break the back of a ship. The initial explosion of a torpedo directly underneath the keel will create a breach in the hull and also drive water up through that breach, causing catastrophic damage. Here's a video: http://www.youtube.com/watch?v=BSBNG7IFyKU

Now obviously that's with modern equipment, but you can get the idea of how it works. The first, smaller explosion you see is the actual torpedo detonation. The second blast is the water being explosively driven through the ship by the force of the payload. Someone contradict me if I've got any of this wrong.

My understanding, and from reading about the development of the magnetic influence pistols was related to putting the largest amount of explosive force onto the target.

Torpedoes detonating on the side of the hull were expending less destructive force onto the target versus a torpedo that exploded under the target.

That in my mind and from my reading is what prompted the research into magnetic influence pistols or triggers.

As to the physical damage done to a ship by said detonation its hard to find specifics in the literature. Merchant ship construction offered a lot of variety in the 20's, 30's and 40's and none of these ships were built with the idea that they would become targets in a war. From the record we can undesrtand that they sank rather well in the Pacific as in the Atlantic.

so what do you all use? magnetic or contact.

if i set the torp to magnetic, will it still explode correctly if it come in contact with the ship? because what if i set the depth settign wrong and it turns out to be a little too high that it "wont" pass under the keel, if like you guys said it's based on magnetic sensing of the ship, will it still explode if it makes contact with the ship?

what's best for convoys? it seems for the initial attack, detonate on impact works best for me. i also find that if you set the torp's depth just right at the exact lowest keel, the detonate on impact method can still sink a T3 tanker effectively with one shot. what troubles me is after the initial attack when the remaining fleet start to change bearing irratically, the impact method doesn't work so well anymore after that. i then will have to rely on homing torpedos, even then, it's sometimes ineffective against warships.

I'm a history freak, so I use the settings they used historically. In 1939-1940 for U-boats and 1941-1943 for US Fleet Boats I leave the magnetic on (by default it is always set for both), since even though that was when they were having all the problems with it the captains didn't know that. From late 1940 to mid-1942 for U-boats I use impact only, as that's what they did. From mid-1942 for U-boats and late 1943 for Fleet Boats the problems were fixed.

In real life they didn't have a switch to turn it on and off. The Germans had one or the other, and they were interchangable but it took time to do it. The Americans had both systems built into the torpedo, and it couldn't be messed with. Actually some enterprising captains allowed their torpedo chiefs to disassemble the heads and disable the magnetic pistols, but that was rare. Another problem was that if the torpedo ran deeper than set (and they did) then they wouldn't go off, and nobody knew that was happening. If it did run at impact depth there was a chance the magnetic detonator would explode before it reached the target. Either way, you lose.

The game models the duds well, but no how the systems related to everyday use by the crews.

It makes more sense after I read the video description; Seems the water itself isn't being propelled upwards by the detonation, but instead, the warhead causes a massive cavitation under the target. In this particular case, a hull's ability to redirect an explosion causes even more damage, because less of the blast goes into the hull itself; instead, most of that explosive power contributes to making the giant cavity. The real damage comes into play with all of the fluid pressure from the water around that cavity rushing in to fill it again.

Can see it in action a bit better in this video. Notice how the bulk of the eye candy happens moments after the visible explosion, when fluid pressure comes over to play. :D

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Back on-topic, though, you don't have to choose between impact and magnetic as a US skipper; in fact, there is no setting available for magnetic only. The magnetic option is for "Contact + Influence" meaning your fish will still kaboom if they hit dead-on. Like Steve said, though, the mags did historically cause more premature detonations, though I truly can't say whether this ever modelled into SH4. I never noticed significantly more torps jumping the gun with them on than off, and I almost always start early war campaigns, but I always stand to be corrected.

Rough sea's can cause the magnetic influence to go off :nope: and it's modded very well. Rotten geyser alerts your target then the DC's start raining :damn:

Don't mean to laugh but the first post, the anger in his words, reminded me of when i first played SH 4 lol, this game caused many fits before the issues were corrected.

Thing is, I stuck with it, upgraded and learned things, then went to the mods, which saved this game.Well worth sticking it out:salute:

I'm gonna do some speculating here based on my corrupted save experience. What I did at first, save1, save2, save3, and so on, when I got up to half a dozen or so I would start overwriting previous saves. That triggered the "do you want to overwrite" message, say yes and now that file is corrupted?! Since I figured that one out, if I want to save, for example, "save5" and there's already one in there, I delete "save5", then save a NEW file named "save5" and I've had no further corruption problems since. So if you're overwriting previous saves, don't. Try deleting the previous saves then save with a new name.

As for magnetic torpedoes, the backbone of a ship is the keel, break the keel and you break the ship. Water (for all practical purposes) is incompressible, and explosion at the waterline would vent half its force upwards into the air outside the hull. An explosion directly under the keel will send most of its force toward the area of least resistance, the ship being hollow and full of air instead of water most of the force goes thataway.

The theory is sound, any iron object distorts the earth's magnetic field, that's how magnetic anomaly detectors work to find submarines. Problem they hadn't reckoned on when they designed magnetic mines and torpedo triggers is that the magnetic disturbance around a ship varies with the distance from the magnetic pole - so closer to the equator the lines are wider, causing more premature detonations. It also varies with direction, a ship heading north or south will have a narrower magnetic field than one heading east or west. MAD (magnetic anomaly detector) sensors are adjustable and tunable for that reason, the magnetic exploders in WWII torpedoes were not, which is why they failed so often for all the navies that tried them.