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View Full Version : My own mk48 got me.


PieShade
07-05-17, 09:15 AM
Hello,

I was attacking two subs, when I was a bit too cautious/too passive, loitered a bit too long and an enemy detected me. He launched two torps at my current position, and shot one to the south, into my predicted escape path. I quickly snapshot two of my own towards him, on passive. One would eventually catch up with him and take him out. When I noticed he launched those torps, I immediately went flank and got out of the way before they activated.

The third torpedo (that was a pretty good prediction by the AI! or was it luck?) was going to be a bit of a problem, so I slowed down, launched a MOSS towards it to fool it. It worked.

http://i.imgur.com/J63h4WC.png (http://i.imgur.com/J63h4WC.png)

I immediately went flank again to create some distance, when I noticed one of the torpedoes I shot at the enemy sub came back for my own MOSS!

I quickly launched another MOSS to try and fool it, but it was only fooled momentarily. I went vertical as hard as I could, and even blasted up to the surface. Narrowly avoided the mk48, and it convincingly went for my MOSS after all.

http://i.imgur.com/5G7aj2P.png (http://i.imgur.com/5G7aj2P.png)

I was now on the surface, 0 kts, and the mk48 homing in on my MOSS 700 feet lower. When it caught up to the MOSS, it did another 180 and ... it picked me up. 700 feet up, stationary, a passive mk48 picked me up and blew me up.

Now my question is: HOW could this happen?!

Aktungbby
07-05-17, 09:20 AM
PieShade!:Kaleun_Salute: Nice diagrams!

Steiger
07-05-17, 02:59 PM
Yeah Mk48 seems a little too sensitive on passive homing. I want to say someone released a realism mod that addresses this.

snowmaninurface
07-07-17, 01:35 AM
Not 100% sure as to why except the sensitivity is turned way up or it's a game mechanic to help your torpedoes hit better at a lower difficulty (don't know what difficulty you have it on)? Can't say for sure though, I'm just guessing. But I do sympathize with you man, I torpedoed myself twice when I was learning how to play the game while driving my Narwhal :wah: once in the ass and the other in the face when I was trying to get to a higher depth.

Shadow
07-07-17, 07:19 AM
To mention a couple of stats, the Mk 48 has a very optimistic acquisition range (4,000 yards), and its acquisition cone is set to 80 degrees when the best Soviet torpedoes have 60. That's presumably horizontal acquisition, vertical is meant to be 15 degrees for all guided weapons, if I'm interpreting the files correctly.

Julhelm has mentioned they'll get around to addressing the Mk 48's omnipotence eventually.

For one, the 48 was ignoring the effect of anechoic coating and that's already fixed (not sure if in 1.05b), which should reduce the effective acquisition range against Soviet subs by as much as two thirds.

It used to be that the torpedoes were not taking anechoic coatings into account. They do now, which means practical acquisition range for the Mk48 against most Soviet subs should be around 2000yds. I have sources that indicate the tiles may be as efficient as 2/3 reduction vs an active pinger. When we get to overhauling them, though, they should become less godlike and more challenging to use.

PieShade
07-07-17, 12:41 PM
Good to hear it may not be just me then ...

I'm playing on Realistic, and I don't think that increases the sensitivity of the mk48.

I don't know if it's historical, but the mk48 really is easy-mode. If I fire a single mk48 relatively accurately at an enemy sub or surface vessel, it's pretty much always going to hit. The only time it doesn't, is when it moves around a decoy and picks up a wreck laying at the bottom of the ocean.

Shadriss
07-07-17, 03:45 PM
Sensitivity isn't the problem in this case - lack of realism is. MK48s have installed systems that are supposed to prevent them from attacking the firing craft (IE, YOU), and these are obviously not being modeled. Heavens, those safeties were in as early as the SCORPION era, and figure prominently in theories as to why the SCORPION was 180 degrees out from her expected course at the time she sank.

The weapons should be shutting down if they do anything more than a 120 degree turn prior to terminal homing, and they simply aren't.

max-peck
07-07-17, 03:52 PM
Sensitivity isn't the problem in this case - lack of realism is. MK48s have installed systems that are supposed to prevent them from attacking the firing craft (IE, YOU), and these are obviously not being modeled. Heavens, those safeties were in as early as the SCORPION era, and figure prominently in theories as to why the SCORPION was 180 degrees out from her expected course at the time she sank.

The weapons should be shutting down if they do anything more than a 120 degree turn prior to terminal homing, and they simply aren't.

In the game Mark 48's will not target own sub if the wire is attached
If the wire is broken they will target anything

Is this not the case in real life?

I am not doubting your knowledge Shadriss, it is a genuine question

I honestly do not know :06:

Berserker
07-07-17, 06:37 PM
Doesn't it make you wonder how they can put IFF on a fighter plane but they can't have the subs and torpedoes with the same?? Fighters and bomber cost millions but a sub costs billions and a lot more lives are at risk on a sub..:hmmm:

Shadriss
07-07-17, 07:22 PM
In the game Mark 48's will not target own sub if the wire is attached
If the wire is broken they will target anything

Is this not the case in real life?

No, they wouldn't. ACR (Anti-Circular Run) was made part of torpedo targeting logic a long time ago to prevent this very thing. USS TANG (IIRC) was a victim of her own torpedo during WWII with a dumb fire torpedo that had another issue, and she wasn't the only one. The ACR isn't wire-guide dependent, it's built into the torpedo's targeting and gyro logic. The 60* wire guide cone is another issue I have with the game, as it's far more restrictive than RL, though I won't go into that here for what I hope are obvious reasons.

Doesn't it make you wonder how they can put IFF on a fighter plane but they can't have the subs and torpedoes with the same?? Fighters and bomber cost millions but a sub costs billions and a lot more lives are at risk on a sub..:hmmm:

Simple, actually - IFF is radio based, and radio waves don't travel through water well. As in at all. This is why subs have to come to PD for radio traffic. The closest that we could get to this is to have every submarine's acoustic signature in the torpedo logic, and even that wouldn't work. Even in a given class of ship (say the 688's for this example), while a lot of the signature would be the same from ship to ship, loarge portions would also vary, so that wouldn't work either. NM the amount of memory and processing the torp would need to make it work.

No, ACR or any of the newer systems that prevent this issue would be the way to go with this.

Shadow
07-07-17, 07:26 PM
Doesn't it make you wonder how they can put IFF on a fighter plane but they can't have the subs and torpedoes with the same?? Fighters and bomber cost millions but a sub costs billions and a lot more lives are at risk on a sub..:hmmm:

IFF is radio-based, and radio waves don't travel very well underwater. Not to mention a submarine emitting signals makes it easier to detect, as well. It'd also give decoys another tool to spoof your torpedoes with.

EDIT: Damn, ninja'd.

No, they wouldn't. ACR (Anti-Circular Run) was made part of torpedo targeting logic a long time ago to prevent this very thing. USS TANG (IIRC) was a victim of her own torpedo during WWII with a dumb fire torpedo that had another issue, and she wasn't the only one. The ACR isn't wire-guide dependent, it's built into the torpedo's targeting and gyro logic. The 60* wire guide cone is another issue I have with the game, as it's far more restrictive than RL, though I won't go into that here for what I hope are obvious reasons.

Thing is, wouldn't ACR make a torpedo far easier to evade? All the target would have to do is force the fish to do more than a 180-degree turn, and then bam.

Shadriss
07-07-17, 07:36 PM
Thing is, wouldn't ACR make a torpedo far easier to evade? All the target would have to do is force the fish to do more than a 180-degree turn, and then bam.

In game, possibly. In reality, not a chance. You'll note I said earlier that ACR was only a valid cutout when it WASN'T in terminal homing. If it's in Terminal, it doesn't care what the gyro angle is - it knows exactly where the target is. If it were to lose track, ACR would then be a valid cutout again.

Thing is, in ASW combat, by the time you know a torp is on it's way, there is next to no chance to create the situation you describe. Standard evasions tactics is to put all your speed across the LOS (IE, put the weapon off your beam and floor it). Unlike the game, where you can create 'knuckles' (total BS, BTW) and noisemakers are very effective in the short term, modern torpedoes aren't going to lose their lock easily, and they certainly don't turn away they way the MK48s in the game do when they get fooled. That's how I got killed twice in this game so far - 10Kyds away, my weapon gets spoofed, turns 90*, and then SOMEHOW picks me up and homes in.

So yeah - ACR should be in here, but isn't, and now we're getting killed by something that even the NAVY figured out decades ago.

Shadow
07-07-17, 08:15 PM
In game, possibly. In reality, not a chance. You'll note I said earlier that ACR was only a valid cutout when it WASN'T in terminal homing. If it's in Terminal, it doesn't care what the gyro angle is - it knows exactly where the target is. If it were to lose track, ACR would then be a valid cutout again.

Thing is, in ASW combat, by the time you know a torp is on it's way, there is next to no chance to create the situation you describe. Standard evasions tactics is to put all your speed across the LOS (IE, put the weapon off your beam and floor it). Unlike the game, where you can create 'knuckles' (total BS, BTW) and noisemakers are very effective in the short term, modern torpedoes aren't going to lose their lock easily, and they certainly don't turn away they way the MK48s in the game do when they get fooled. That's how I got killed twice in this game so far - 10Kyds away, my weapon gets spoofed, turns 90*, and then SOMEHOW picks me up and homes in.

So yeah - ACR should be in here, but isn't, and now we're getting killed by something that even the NAVY figured out decades ago.
Yes, I read the terminal homing bit. Thing is, if the target sub were to escape the torpedo's LOS, wouldn't the reenabled ACR prevent it from searching anywhere but (say 180º ish) forward? Are seekers smart enough to guess which direction you disappeared off to and orient the fish that way, in order to quickly reenter terminal phase?

Shadriss
07-07-17, 11:58 PM
Gyro angle is gyro angle, and the limits were set at launch. Going into terminal homing would only remove that cutout from the logic. Once homing was lost, the original gyro cutout limits would still exist, and it would shutdown based on that.

Despite what a lot of sub games show, detection ranges in a sub-on-sub situation, assuming two modern and upkept ships, is extremely short range. If what the games show is a street brawl, then sub-on-sub is a knife fight in a dark alley wearing a blindfold. The torpedoes are designed with those ranges and setups in mind.

Julhelm
07-08-17, 03:56 AM
Doesn't ACR makes the reattack patterns and circle search patterns as such moot?

Shadriss
07-08-17, 01:02 PM
MK48s don't use circle search patterns for that reason. As for Re-Attack, that's part of re-aquisition, which basically means it hasn't gone back into the full search mode yet, hence ACR is still cutout.

Now I should note here, before others do, that I am referring to standard MK48s here. ADCAPs use VERY different Own-Ship protection methods that I'm not gonna even touch here. Ones that don't deal with gyro angles at all, and hence have search patterns and such that allow them to come back towards the firing ship in such a way as they STILL would not attack it's firing platform.

Julhelm
07-08-17, 03:19 PM
Well, ingame I'm pretty sure 100% of the occasions where people get killed by their own torp is when they fire at a close contact, torpedo gets decoyed and goes into reattack and acquires the firing ship. If ACR is cutout during the reacquisition phase, isn't this a feasible scenario?

jenrick
07-09-17, 12:37 AM
Based on what our service/prior folks are saying there are significant safeguards in place to prevent that very occurrence. A simple hypothetical way the safety might function (again I have no clue how it actually works), a 30 degree cone in the direction of ownship is a no go. So if you fire on a contact on heading 000, even if the torpedo goes into search mode, anything it picks up on a true bearing of 165-195 it wouldn't pick up. Now there are certainly limitations to something as simple as this. What if you change course and are at 164 for instance? If you know that this is how the ACR protection works, you would work VERY hard to stay in this 30 degree cone.

I'd be willing to believe that our navy came up with a way to solve this problem, even if it involves some tactical procedures we are not privy too.

-Jenrick

shipkiller1
07-09-17, 08:06 AM
Where's my popcorn....

Shadriss
07-10-17, 05:41 PM
Regardless of how it's done RL, the real point here is that any more advanced weapon like the MK48 should not be homing in on it's firing platform... certainly not as often as it has been in the games I've played. There's a lot to like in this game, but the weapon performance is much to arcade-y for my tastes at the moment.

609_Avatar
07-11-17, 12:20 PM
I've had this happen and it sucked. But this morning before heading into work I was playing a little and heading back to base to rearm and refuel. got jumped by 3 subs and I'm unarmed... the first guy ended up killing himself! (Was able to run away for the other two...)https://s6.postimg.org/g15h4g3w1/Cold_Waters_2017-07-11_12-16-13-41.jpg