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-   -   Realism mod (discussion) (https://www.subsim.com/radioroom/showthread.php?t=231759)

cj95 06-12-17 09:07 AM

Given the power of modern torpedoes and the great stresses modern sub hulls are under is there any "realistic" scenario where more than one torpedo would be needed to kill a sub?

(except maybe for a monster like a Typhoon)

I see videos of torps snapping destroyers in two and have to wonder how anything survives even a single hit.

(has there ever been a test of such a thing?)

FPSchazly 06-12-17 09:28 AM

Any major breach of a US pressure hull with explosives is pretty much game over. US subs can't survive flooding of any one compartment. The double-hull configuration of most Soviet subs gives them more reserve buoyancy, so they have a greater chance of surviving a torpedo hit. I have no data to back this up, however I don't think any smaller Russian SSN would survive a MK48 hit, that torpedo just has such a huge amount of explosives. Lightweight ASW torpedoes, yeah it would probably take more than one. Something big like an Oscar or Typhoon could definitely be a different story.

PL_Harpoon 06-12-17 10:39 AM

Quote:

Originally Posted by cj95 (Post 2490642)
I see videos of torps snapping destroyers in two and have to wonder how anything survives even a single hit.

(has there ever been a test of such a thing?)

Yeah, these videos got me thinking as well. However, the torpedo was able to snap it in half because it detonated below the ship. Direct impact would probably produce lesser results.
On the other hand it still has a powerful warhead and as far as I know it was like that from the start.
So, perhaps we should set player hull modifier at 0.6 and enemy at 1 or 0.8.


On another note, I did some testing regarding ship acceleration. And by testing I mean comparing CW to DW. Turns out it take almost twice as much time to reach flank speed in CW, than in DW. (LA class: 1:52' in Cold Waters vs 0:58' in DW). The problem is, it looks like CW doesn't take screw speed into consideration when calculating accelerations, so 0-5kn time is the same with 1/3 power as with full power.
Below is a comparison of various times done with a simple stopwatch:

http://oi68.tinypic.com/2mmwff9.jpg

FPSchazly 06-12-17 10:53 AM

Quote:

Originally Posted by PL_Harpoon (Post 2490671)
On another note, I did some testing regarding ship acceleration. And by testing I mean comparing CW to DW. Turns out it take almost twice as much time to reach flank speed in CW, than in DW. (LA class: 1:52' in Cold Waters vs 0:58' in DW). The problem is, it looks like CW doesn't take screw speed into consideration when calculating accelerations, so 0-5kn time is the same with 1/3 power as with full power.
Below is a comparison of various times done with a simple stopwatch:

http://oi68.tinypic.com/2mmwff9.jpg

That is a good point. Are there any real-world submariners out there that can comment on this? It's like driving a car. Cruising on the highway, you're using a certain throttle (making turns for that speed, as it were). If you were to accelerate to that speed using the cruising throttle, it would take forever (infinitely long in a mathematical sense). So, you use more throttle to accelerate to that cruising speed and then reduce throttle to maintain that speed once you attain it. I'm curious as to the distinction for this in naval turns. "Make turns for x knots" means (I would think) turn the propeller at the speed necessary to maintain x knots indicated. Would there be a situation where you apply more throttle to get to speed x more quickly and then reduce throttle?

Skwabie 06-12-17 12:48 PM

the reduced warhead weight on beta 1.01 is double edged.

it makes tactical game play more interesting.

it makes the player able to survive hits easier.

However. it makes campaign play harder. because player has to travel a lot more back to base for reloads and miss mission time windows.


considering the latter i've reverted to 1.00 weights. plus from the looks of data, the reduced weight is not "universal" i.e. only a few weapons got it. the Mk48 has almost the same warhead as MK37 in beta1.01 due to its warhead weight reduction, but in RL the mk37 is much lighter.

PL_Harpoon 06-12-17 12:59 PM

Quote:

Originally Posted by Skwabie (Post 2490712)
the reduced warhead weight on beta 1.01 is double edged.

it makes tactical game play more interesting.

it makes the player able to survive hits easier.

However. it makes campaign play harder. because player has to travel a lot more back to base for reloads and miss mission time windows.


considering the latter i've reverted to 1.00 weights. plus from the looks of data, the reduced weight is not "universal" i.e. only a few weapons got it. the Mk48 has almost the same warhead as MK37 in beta1.01 due to its warhead weight reduction, but in RL the mk37 is much lighter.

Yeah, Mk37 should have 149kg warhead, not 225, but that's easily fixable. Overall looking at the numbers the new warhead sizes are closer to real ones.

Skwabie 06-12-17 02:07 PM

Quote:

Originally Posted by PL_Harpoon (Post 2490716)
Yeah, Mk37 should have 149kg warhead, not 225, but that's easily fixable. Overall looking at the numbers the new warhead sizes are closer to real ones.

MK48 v1.00 550, b1.01 295
MK37 v1.00 225, b1.01 225

something disconnects here, why MK48 ~halved and MK37 same (along with many others unchanged between 1.00 and 1.01)?

http://www.navweaps.com/Weapons/WTUS_PostWWII.php

Mk37 real: 150kg HBX -> 225 kg TNT equivalent (assuming HBX = 1.5 TNT)
Mk48 real: 292.5 kg PBXN-103 -> 544 kg TNT equivalent as noted

Since they posted the warhead weight being TNT weight, the 1.00 numbers should be closer RL values. i think they are changed for more interesting gameplay reasons.
For how many torps it takes to sink a ship, personally i think the 1.00 warheads is spot on. destroyers and attack subs, 1 hit is enough. shoot at the SSG/BNs, or Kirov or Kiev, it takes anywhere from 2-4. big ships are just rarely encountered due to the in-game battles setup more against small ships.
More importantly, the weak warheads makes campaign mode.. will so far a bit ridiculous. It is doable, but a lot harder. like one battle later it's return port to re-arm for 3 dayz. - Maybe also double the loadout capacity of player subs, then halve the reload in-port time of weapons. Anyway thankfully this is all moddable lol.

Haukka81 06-12-17 03:44 PM

I hope that they boos weapons back, double loadout would be just stupid move to too arcade style game.

I hope that this is not sing of end, i mean that many games are ruined when devs lose their orginal "red line" or goal. :oops:


-

PL_Harpoon 06-12-17 04:02 PM

Quote:

Originally Posted by Skwabie (Post 2490734)
MK48 v1.00 550, b1.01 295
MK37 v1.00 225, b1.01 225

something disconnects here, why MK48 ~halved and MK37 same (along with many others unchanged between 1.00 and 1.01)?

http://www.navweaps.com/Weapons/WTUS_PostWWII.php

Mk37 real: 150kg HBX -> 225 kg TNT equivalent (assuming HBX = 1.5 TNT)
Mk48 real: 292.5 kg PBXN-103 -> 544 kg TNT equivalent as noted

Since they posted the warhead weight being TNT weight, the 1.00 numbers should be closer RL values. i think they are changed for more interesting gameplay reasons.
For how many torps it takes to sink a ship, personally i think the 1.00 warheads is spot on. destroyers and attack subs, 1 hit is enough. shoot at the SSG/BNs, or Kirov or Kiev, it takes anywhere from 2-4. big ships are just rarely encountered due to the in-game battles setup more against small ships.
More importantly, the weak warheads makes campaign mode.. will so far a bit ridiculous. It is doable, but a lot harder. like one battle later it's return port to re-arm for 3 dayz. - Maybe also double the loadout capacity of player subs, then halve the reload in-port time of weapons. Anyway thankfully this is all moddable lol.

Well, looks like you're right. Too bad there's no info about what type of explosive the Soviets used in their torpedoes. Cause I doubt it was TNT.

In that case we'd have to set US warheads to their 1.0 values and use some sort of multiplier for Soviet ones. Unless someone will provide info on the type of explosive used in their torps.

Julhelm 06-12-17 04:35 PM

I think they got changed back because people complained about one hit killing cruisers with Mk48s = too easy.

PL_Harpoon 06-12-17 04:50 PM

Perhaps make surface ships more durable in general? Or add a variable, like "hull strength" to ships (from what I tested it seems to be based on ship displacement), so that it's possible to tweak it for individual vessels.

I'm not an expert here but I do think that surface ships should be harder to kill that subs.

Haukka81 06-12-17 05:06 PM

Ships should use decoys, towed etc.. but yes , 1-2 direct hits should make ships go down (least cruisers) and 1 direct hit should sink sub about 98% time. But i hope that dev's will tune this more.


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jenrick 06-12-17 05:34 PM

I'm by no means an expert in naval architecture, torpedo design, or the physics of underwater explosions.

I thought that one of the major advantages of the post WW2 US torpedo design with the Mk48 was that it would automatically attempt to detonate under the keel of a vessel, versus going for an impact against the hull. As we know from WW2, even a single well placed torpedo had a decent chance of doing non-survivable damage to pretty much anything smaller then a cruiser. That was also to ships built to a very sturdy design standard, that was moved away from by most of the worlds military's over the years. The MK48 has a warhead that is slightly more powerful then MK14 mod 3 torpedo of WW2 (approximately 1200 lb TNT equivalent to 1000 lb TNT equivalent). So I think the effectiveness of a MK48 detonating under a ships keel or on contact should be equivalent roughly to what was seen in WW2 at a minimum.

One of the major issues in CW is that a ship is either in fighting trim (I'm have no clue if they are degraded when damaged, but they are certainly not out of the fight) or they are sinking. I have yet to see a propulsion casualty, a ship break off and run after being torpedoed etc. There also isn't the slow death of a ship, where you spend 30 mins to a couple of hours waiting for it to slow down and slowly sink that historically was pretty common. If a ship sustains enough damage, it simply sinks right then and there.

I think the ideal answer would be to have a mechanism for the degradation of the ship when damaged, and it's sinking be based on the nature of damage etc (if only wishes were fishes.....). However based on the current binary (alive, firing, and driving or sunk) conditions of ships, I think it works out. Would a cruiser be headed to the bottom within 30 seconds after impact by a single torpedo that detonates near the bow? Probably not, but it might be after 3-4 hours. As a player I'd love to have the longer sinking time as it keeps me guessing if it's still in the fight, but the end result is still a sunk ship.

TLDR: With the current surface ship damage modeling, the 1.0 torpedo damage levels provide the correct result. However due to the limitations of the game, the graphical representation appears to be off.

-Jenrick

PL_Harpoon 06-12-17 05:53 PM

Quote:

Originally Posted by jenrick (Post 2490791)
...Would a cruiser be headed to the bottom within 30 seconds after impact by a single torpedo that detonates near the bow? Probably not, but it might be after 3-4 hours. As a player I'd love to have the longer sinking time as it keeps me guessing if it's still in the fight, but the end result is still a sunk ship....

I agree on that one. Subs have damage modelling and flooding, surface ships should have those things as well.
Then, unless the ship gets destroyed on impact the explosion would damage the hull and create flooding, just like in subs and the ship would be registered as sunk only after its hull passes below water. Such ships would not be firing, cause all available hands would be busy trying to keep it afloat or preparing lifeboats.

Similar thing could be applied to subs (playable ones included) only that they would be marked as sunk after they hit the ground with no way of going up or reaching crush depth.

But, as you said, so far 1.0 values are our best option.

FPSchazly 06-12-17 06:39 PM

Quote:

Originally Posted by jenrick (Post 2490791)
I'm by no means an expert in naval architecture, torpedo design, or the physics of underwater explosions.

I thought that one of the major advantages of the post WW2 US torpedo design with the Mk48 was that it would automatically attempt to detonate under the keel of a vessel, versus going for an impact against the hull. As we know from WW2, even a single well placed torpedo had a decent chance of doing non-survivable damage to pretty much anything smaller then a cruiser. That was also to ships built to a very sturdy design standard, that was moved away from by most of the worlds military's over the years. The MK48 has a warhead that is slightly more powerful then MK14 mod 3 torpedo of WW2 (approximately 1200 lb TNT equivalent to 1000 lb TNT equivalent). So I think the effectiveness of a MK48 detonating under a ships keel or on contact should be equivalent roughly to what was seen in WW2 at a minimum.

One of the major issues in CW is that a ship is either in fighting trim (I'm have no clue if they are degraded when damaged, but they are certainly not out of the fight) or they are sinking. I have yet to see a propulsion casualty, a ship break off and run after being torpedoed etc. There also isn't the slow death of a ship, where you spend 30 mins to a couple of hours waiting for it to slow down and slowly sink that historically was pretty common. If a ship sustains enough damage, it simply sinks right then and there.

I think the ideal answer would be to have a mechanism for the degradation of the ship when damaged, and it's sinking be based on the nature of damage etc (if only wishes were fishes.....). However based on the current binary (alive, firing, and driving or sunk) conditions of ships, I think it works out. Would a cruiser be headed to the bottom within 30 seconds after impact by a single torpedo that detonates near the bow? Probably not, but it might be after 3-4 hours. As a player I'd love to have the longer sinking time as it keeps me guessing if it's still in the fight, but the end result is still a sunk ship.

TLDR: With the current surface ship damage modeling, the 1.0 torpedo damage levels provide the correct result. However due to the limitations of the game, the graphical representation appears to be off.

-Jenrick

I have had ships break contact. If I attack a landing force, I've had the escorts come after me while the LSTs disengage. Also, I've hit a Kirov with one torpedo to have it disengage while the escorts come after me.

I've also experienced ships being "killed" but staying afloat and burning for the remainder of the match.


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