PDA

View Full Version : Bogus US carrier damage model.



ElAurens
06-19-2005, 09:10 PM
As we all know, USN carriers in WW2 had wooden decks. So why does it take so many direct hits with 250kg bombs to damage the deck? One hit with a 250kg bomb should put a hole in the deck. Period.

So much for reality.

Tater-SW-
06-19-2005, 09:30 PM
All ships should be easier to damage, and harder to sink.

The CVs in particular should have been given truely special attention since CV-based missions (coop/single/campaign) are the only types that have a braod representation from the start to the finish of the war (lack of maps with bases for both sides, etc).

The CVs (all ships, really, but the CVs in particular) shoudl have been dealt with as AI planes operating at sea level, with a DM comparable to a plane in terms of numbers of hit areas, etc, perhaps I'd go as far as to say a CV should have the DM of a 4-plane element of bombers. It'd be worth lowered numbers of AI planes you could run with decent FPS to have them have a "real" DM like the planes have.

Attacking ships in general, and CVs in particular, is one the salient features of a PTO flight sim, IMHO.

tater

Kernow
06-20-2005, 07:13 AM
Are the Illustrious class CVs from the game any tougher? Their armoured flight decks ought to make them better able to withstand bomb damage.

The Japanese carriers destroyed at Midway were hit by 2, 3 and 4 bombs, although one was fatally damaged by the first 1000 lber to hit. Although effectively destroyed by the fires started by the bombs, torpedos had to be used to finally send a couple of them to the bottom. In return Yorktown was rendered non-operational and brought to a stop by 3 250 kg bombs, although effective damage control got her back on-line and under way just before Kates hit her with 2 torpedos, which sealed her fate. It seems that, on average, it took about 2000 lbs of bombs to wreck these wooden decked carriers. Illustrious took 7 bomb hits and survived, but I'm not sure what size the bombs were - probably 250 kg.

Maybe I'll do some experiments to see if the CVs do have differing DMs.

stelr
06-20-2005, 11:31 AM
Originally posted by Kernow:
Are the Illustrious class CVs from the game any tougher? Their armoured flight decks ought to make them better able to withstand bomb damage.

The Japanese carriers destroyed at Midway were hit by 2, 3 and 4 bombs, although one was fatally damaged by the first 1000 lber to hit. Although effectively destroyed by the fires started by the bombs, torpedos had to be used to finally send a couple of them to the bottom. In return Yorktown was rendered non-operational and brought to a stop by 3 250 kg bombs, although effective damage control got her back on-line and under way just before Kates hit her with 2 torpedos, which sealed her fate. It seems that, on average, it took about 2000 lbs of bombs to wreck these wooden decked carriers. Illustrious took 7 bomb hits and survived, but I'm not sure what size the bombs were - probably 250 kg.

Currently at the office, so don't have the proper reference materiel, but the reason the Akagi, Kaga, Hiru and Soryu (sp?) went down so easily is that their decks were filled with bombs, torpedoes and fuel. They were caught right in the middle of rearming and refueling for an attack on the US CVs.

Also, keep in mind that the Yorktown had just been hastily patched up in 48 hrs after limping back to Pearl Harbor with substantial damaged received in the Coral Sea. And...it wasn't torpedoes from Kates that sealed her fate. She was underway on her own power with a skeleton crew to Pearl when a Japanese sub caught her and sent her to the bottom. In fact, I saw a Discovery Channel show that showed her being found and photographed. Pics were on a web site, but don't have the link anymore if they are even still up. Think it was the same guy that found the Titanic.

WWSensei
06-20-2005, 12:51 PM
steir is correct--it was a sub that did her in. Much of the credit of lasting as long as she did was that the damage control officer flooded all the fuel lines with CO2 after the first attack and took many other preventative actions.

For quite some time the Japanese thought they had sunk the Yorktown at Coral Sea, the Saratoga at Midway and a third carrier at Midway because they were certain the first attack sunk the York/Saratoga. It turns out the Yorktown was the carrier in all three cases but in the end she was finally overwhelmed.

The Japanese carriers were heavily damaged mainly because there were lots of fuel lines and excess ordinance laying around the deck when she was hit.

Kernow
06-20-2005, 01:03 PM
Yes, the IJN carriers I refered to above - Akagi, Kaga and Soryu - were particularly badly placed at the moment they were hit. But Hiryu also succumbed to 4 bomb hits and she had few enough aircraft left by then and they weren't being prepared for a strike. Whatever the situation, if any bomb came through the flight deck there were generally plenty of combustible items in the hangar.

The fire curtains on one of ther Japanese carriers were blown away and the fires then spread more easily. In contrast, the curtains on Yorktown held, allowing the damage control parties to avoid an inferno developing. No doubt luck played a part, but perhaps the greater blast from the US 1000 lbers, when compared to the IJN 250 kg bombs, was significant? (Actually I think the first SBDs to launch could only carry 500 lbers).

You're right that it was a sub which finally sunk Yorktown, but after the Kate attack it was felt she could capsize, so was abandoned - save for the skeleton crew (or did they go back later when she didn't capsize?).

Here are the results of the testing I did. The numbers are the number of missiles to cause visible damage and the number needed to destroy in addition to that.

Torpedos - striking in line with the island:

Lexington, 4+2
Illustrious, 4+2
Akagi, 4+1

Skip bombing (1000 lb) - aimed as above:

Lexington, 4+1
Illustrious, 3+1
Akagi, 3+1

I repeated the test on Lexington another 2 times and got the same result each time. It seems Lexington is slightly more resistant to skip bombing for some reason. The next figures indicate she is no tougher against dive-bombing than Illustrious.

Having got a feel for the figs I tried some variations to see how repeatable the results were. For these dive attacks all bombs landed on the mid-third of the flight deck.

500 kg bombs (SC500):

Illustrious, 3+1 (same as skip bombing)

250 kg bombs (IJN):

Lexington, 6+2 (same tonnage as for Illustrious)

From this it looks like torpedos are marginally less effective than 1000 lbers, although I don't think that is always true. A destroyer will go down with one torpedo, but skipping 2 SC500s from a 110 into one only causes damage.

(Aside from the fact that Illustrious appears to be unarmoured.) The results aren't too unlike what happened at Midway from the 'tonnage to sink' point of view. What is lacking is a sophisticated DM and any sign of the infernos which broke out when any of the CVs were hit by the first bomb - even if the fires were subsequently put out.

I wonder if putting a train fuel tank inside a CV would recreate the IJN Midway scenario?

edit:

Yes it does. 8 fuel trucks cause damage to appear on Akagi after 2 1000 lb skip bombs (not 3). Although it still took another 2 to sink, I'm sure enough exploding objects would reduce the total required. Only possible in a DF of course.

AerialTarget
06-20-2005, 01:58 PM
Here (http://www.navweaps.com/index_tech/tech-030.htm) is a very interesting essay on the effectiveness of armoured carrier decks in World War Two. Apparently, it didn't really make that much of a difference, and was overall a bad idea because of the large reduction of the number of aircraft.

Talon8452
06-20-2005, 02:45 PM
Actually the lines were flooded with before the attack.It was lesson learned at Coral Sea after Lexington exploded from fumes much later after the attack.The fumes spread through the ship after they tried to ventilate it and a spark ignited it.

Kernow
06-21-2005, 06:04 AM
Originally posted by ElAurens:
As we all know, USN carriers in WW2 had wooden decks. So why does it take so many direct hits with 250kg bombs to damage the deck? One hit with a 250kg bomb should put a hole in the deck. Period.

So much for reality.

Getting back to the original point, it does seem that the way the DM works is the wrong way around. It seems hard to cause any real damage, but is then quite easy to sink the CVs. In RL it looks like a couple of bomb hits would cause damage and hinder operations, but it took much more to actually sink these ships, most of which proved to be very tough, sometimes needing to be finished by their own side.

ElAurens
06-21-2005, 10:33 AM
Thank you Kernow, my point exactly.

WholeHawg
06-21-2005, 01:58 PM
Bah!! who cares!!

Its called Pacific FIGHTERS!! Not Pacific Aircraft Carriers!!

Nimits
06-21-2005, 02:31 PM
Originally posted by WholeHawg:
Bah!! who cares!!

Its called Pacific FIGHTERS!! Not Pacific Aircraft Carriers!!

Because the current carrier damage model is like having a tank platoon that absorbs 4 500lb bombs with no damage, but on the fifth hit (no matter which tank) they all blow up simultaneously.

Carriers are fundemental to the Pacific air war and their correct modeling should have been a top priority. Besides, alot of us (mabye even a majority of us) like to fly bombers from time time, and correctly modeled carrier targets are most essential to that sort of mission (not to mention our ego . . .)

Tater-SW-
06-21-2005, 02:50 PM
A PTO sim that doesn't simulate ships very well in general, and CVs in particular, is like an Il-2 simulator that doesn;t allow ground attack ;-)

tater

WholeHawg
06-21-2005, 03:54 PM
Yeah what we need is a super sophisticated damage model and associated algorithm for every individual class and type of ship. That way when a hit is scored you computer comes to its processing knees calculating the result and rendering it in perfect detail.

I still say.... Bah!!! Fix my 50 cal tracers first.

johann63
06-21-2005, 05:12 PM
WholeHawg

I think there is breathing room between making it better and super sophisticated, that goes for damage modeling of ships and other elements

Tater-SW-
06-21-2005, 06:10 PM
WholeHawg,

You forget that right now the ship DM (for ANY ship) seems less sophisticated than the He111, TB3, or B-25J.

If a ship was modelled like a plane in terms of DM, it would be no more of a hit than an AI plane in a mission. I would sacrifice a handful of AI planes flying in a mission to have certain ships (notably the CVs) behave like real ships after a fashion (the ability to take some simple evasive action, for example--detect planes, hard rudder til they go away. Not rocket science). In terms of the DM, planes take all kinds of levels of damage. Somewhere between modelling every rivet, and what we have no for every single bomber would do nicely.

tater

WholeHawg
06-21-2005, 06:44 PM
Yeah so we beef up the D model then next week the post on this forum is ....

"Well everyone knows the Akagi had a deck made 187.25mm of northern Honshu Oak with a tensile strenght of 57 MPa. So a 500lb Armor Piercing bomb would have to be dropped from above 5275 feet to achieve terminal velocity and penetrate the deck. Well last night I ran 3 trials and guess what!?! I drilled straight thought the deck between bulk heads 16 and 17 from 4900 feet!! I mean how unrealistic is THAT!!" What was Oleg thinking when he created this FLIGHT SIM!?!?"

I am all for making this a better sim but in my opinion certain compromises have to be made and I think the efforts of the Devlopment team will be better spent working on BoB or getting the Mosi flying or fixing my 50 Cal tracers!!

So I still say Bah!!, to all you mud movers!!

Nimits
06-21-2005, 06:59 PM
Shoot, even a simple hitbox DM, dividing the large ships into 2 or 3 componants plus maybe 1 or 2 critical subcomponents (engine, magazine/AVGAS line) would be better than what we have now. For example, a carrier could have maybe 6 "hit boxes," such as forward flight deck, aft flight deck forward hull, aft hull magazine, and engine room. Bombs would damge the flight deck (which would take only a couple of hits to destroy) but have only marginal effect on the other four boxes, while torpedoes would have more chance of damaging the hull and engine room boxes. Boxes could display appropriate damage textures at, say 50% damage (which should be only 1-2 hits on an exterior box). When a hull or magazine box is destroyed, the ship sinks, when a flight deck box is destroyed, that section of the flight deck is rendered more or less unusable, and when the engine room box is desroyed, the ship goes dead in the water. Obviously this is not ideal, and maybe IL-2 already does this a little already, but it is certainly not visually apparent, and that is the crux of the matter. Also, I can't imagine that it would kill the game to add a simple defensive AI to the ships, such as "Enemy planes xxx meters from ship; Begin defensive zig zag/circle; Enemey planes not xxx meters; head to next waypoint". I am admittedly no programmer, but if a good system can handle the AI of 30 or 40 bombers and fighters at once, surely it could handle a simple dm and defensive AI for 8 or 10 ships as well.

FritzGryphon
06-21-2005, 08:02 PM
Currently, the ships are divided into external parts. The problem is that, destroying most of these parts has no effect on the functioning of the ship.

Hull/deck is in 3 parts, fore medium and aft. Only one of these has to be destroyed to sink the ship, so you should try and concentrate your hits in the same spot. If you spread out hits, it will just take more.

If a carrier hull section is damaged, the deck will show holes on it, which will destroy planes that drive over them.

Superstructure is usually 2 parts, fore and aft. Destroying superstructure has no effect, as far as I know (in some ships, destoying superstructure will eliminate the flak located on it). You should avoid superstructure at all costs, as it doesn't help to sink the ship. This is why skip bombing is good.

This is kinda realistic, as superstructure does act like a bomb-soak in real life too. But, in real life, you can use delayed fuse bombs to get around this.

Stacks are seperate. For example, in Ward you can destroy each stack seperately. No effect, AFAIK.

Radar/rangefinder arrays. Its possible these increase accuracy, like searchlights do, but as far as I know, they have no effect.

Lifeboats, yachts, etc. Most boats can be destroyed seperately. But this doesn't accomplish anything.

And of course, each gun turret and AA gun can be destroyed seperately.

While it wouldn't be practical to have DM completely like planes, it would be nice to have the damage actually affect things, like Nimits said.

ElAurens
06-21-2005, 08:37 PM
WholeHawg,

1. They are not your .50 Browings.

2. Ground attack wins wars, contrary to what all the fighter jocks will tell you.

3. The ability to deny your enemy his assets is what air power is all about. Damaging a carrier deck, or cratering an airfield is an absolutely essential element of force projection and denial of assets. This is what wins wars.

Nimits
06-21-2005, 08:42 PM
Originally posted by WholeHawg:
Yeah so we beef up the D model then next week the post on this forum is ....

"Well everyone knows the Akagi had a deck made 187.25mm of northern Honshu Oak with a tensile strenght of 57 MPa. So a 500lb Armor Piercing bomb would have to be dropped from above 5275 feet to achieve terminal velocity and penetrate the deck. Well last night I ran 3 trials and guess what!?! I drilled straight thought the deck between bulk heads 16 and 17 from 4900 feet!! I mean how unrealistic is THAT!!" What was Oleg thinking when he created this FLIGHT SIM!?!?"

I am all for making this a better sim but in my opinion certain compromises have to be made and I think the efforts of the Devlopment team will be better spent working on BoB or getting the Mosi flying or fixing my 50 Cal tracers!!

So I still say Bah!!, to all you mud movers!!

We understand its not a Naval sim, a hyper accurate DM is overkill. It would just be nice if ships had a some defensive AI and reacted (visually) to bomb and torpedo damage in a more realistic way. Having ships go from no damage to damaged to slipping beneath the waves, all the while blithely driving in a straight line, rather ruins suspension of disbelief . . .

WholeHawg
06-21-2005, 10:04 PM
They are to my 50 Cal Browings, I bought them with my PF simulated tax dollars.

And anyone with a brain knows the P-51 won the war!!