Amphibious invasion of Pearl Harbor - results

[stuman]

They were loaded to a TFs equal to their troop capacity about +20%. Thats a lot of ships but they unload in one go. That was a plan.

Do you mean that when loaded the transports had only 20 % of their load capacity utilized, and were thus 80 % empty ? Just curious.

That took a lot of planning [:)]

[Jim D Burns]

ORIGINAL: Bradley7735
Yes, some of the PG's could take several hits to sink,

Don't forget, in WitP one hit is not one shell. A Battleship has 9 shots, which represent how many hundreds of shells? So one or two "hits" should be more than sufficient to sink any small soft skinned ship in WitP terms, even if they are AP shell hits.

Showing a picture of a ship with less than a dozen holes in it doesn't even represent 1 hit in WitP terms. It seems players and design staff alike are forgetting one hit can mean 20-30 or more shell hits. So the problem seen here is far worse than some are thinking.

Jim

[MorningDew]

ORIGINAL: herwin
I doubt it can be fixed without a rewrite of the land combat model to support in-hex combat. That's not in the cards for now.

I disagree. Looking at things, I think adjustments to the CD targeting and adjustments to the Japanese early war benefits to not include places outside their historical sphere (i.e. whatever bonus they get for unloading) would mean this issue would have been resolved at sea, not on land.

[stuman]

.....ask your self why lighthouses have coded beams.....

bsq, being the landlubber that I am, what do you mean by " coded beams " ?

[MorningDew]

ORIGINAL: Bluebook
512 shell hits is nothing since 80-90 percent of those hits were on the same 8-10 PBs. I actually saw PBs obliterated by 16-inch gun hits only to be hit again and again by other guns after that. It seems that each escorting ship was engaged by all CD-guns at the same time, regardless of earlier hits.

They way I'm seeing it, this is the crux of the issue. Had the CDs engaged the troop ships after the PBs were obviously gone (as they would have IRL, if not before they were gone), then much of the force would have been destroy at sea.

The other issue in the combat reports I notice is that the number of CDs seem to drop dramatically each turn. What is destroying them? Blown out of the water PBs?

As I pointed out elsewhere, I don't see this as a land combat issue. It is a tweak to the CD logic.

[castor troy]

ORIGINAL: AndrewKurtz

ORIGINAL: Bluebook
512 shell hits is nothing since 80-90 percent of those hits were on the same 8-10 PBs. I actually saw PBs obliterated by 16-inch gun hits only to be hit again and again by other guns after that. It seems that each escorting ship was engaged by all CD-guns at the same time, regardless of earlier hits.

They way I'm seeing it, this is the crux of the issue. Had the CDs engaged the troop ships after the PBs were obviously gone (as they would have IRL, if not before they were gone), then much of the force would have been destroy at sea.

The other issue in the combat reports I notice is that the number of CDs seem to drop dramatically each turn. What is destroying them? Blown out of the water PBs?

As I pointed out elsewhere, I don't see this as a land combat issue. It is a tweak to the CD logic.

nothing is destroying them, the less ships, the less shells fired by the CD guns. Every have been like this. Send some ships and you see some shots, send many ships, see many shots. Strange but that´s how it is.

[witpqs]

ORIGINAL: treespider


And again i'm not saying that the routine is correct...just asking that we examine the reports more closely.

Give that man a cigar!

[Blackhorse]

ORIGINAL: AndrewKurtz

ORIGINAL: Bluebook
512 shell hits is nothing since 80-90 percent of those hits were on the same 8-10 PBs. I actually saw PBs obliterated by 16-inch gun hits only to be hit again and again by other guns after that. It seems that each escorting ship was engaged by all CD-guns at the same time, regardless of earlier hits.

They way I'm seeing it, this is the crux of the issue. Had the CDs engaged the troop ships after the PBs were obviously gone (as they would have IRL, if not before they were gone), then much of the force would have been destroy at sea.

The other issue in the combat reports I notice is that the number of CDs seem to drop dramatically each turn. What is destroying them? Blown out of the water PBs?

As I pointed out elsewhere, I don't see this as a land combat issue. It is a tweak to the CD logic.

I tend to agree. From the opening post we can see that every Harbor Defense gun fired at the PB Yodozu Maru, then every gun fired at the Ginyu Maru, then at the Tonon Maru, etc. etc.

If each group of guns fired at a different vessel, then all the PBs would have been stripped away in the first couple of rounds, and more AKs would have been engaged.

If this is either a design-logic or a not working-as-designed issue, it it something to consider addressing in a future patch. I'd be interested to see more posts from players engaging CD defenses, large and small, to see if all the CD guns commonly fire at the same vessel each round.

There is also another factor. One of the limitations of the game engine is that all of the devices in each "weapons slot" fires at 1 target per round. Over half of the CD guns in the Oahu Harbor Defenses are 155mm M1A1 GPF (46 at start, expanding to 68). These are all in Weapons Slot #9. So they all fire at only 1 target.

The LCU for Oahu Harbor Defenses uses eighteen of the maximum possible 20 weapons slots. With the two available slots, the GPF guns could be split into three "batteries" (23 guns in one slot, 23 in a second, and 0 - expanding to 22, in the third). This would enable the 155s to engage three targets per round, instead of one. But this wouldn't make a difference if all the CD guns fire at only ship per round, anyway.

[bsq]

ORIGINAL: stuman

.....ask your self why lighthouses have coded beams.....

bsq, being the landlubber that I am, what do you mean by " coded beams " ?

Bit like morse code, the beams have published sequences of flashes so you can identify them (although the spacing is measured in seconds - a spacing might be 2.5 seconds, 7.5 seconds)

[witpqs]

ORIGINAL: stuman

.....ask your self why lighthouses have coded beams.....

bsq, being the landlubber that I am, what do you mean by " coded beams " ?

You might find this book interesting. It's published by the US government and is not under copyright. Find it here (government website) for free download.

American Practical Navigator

[bsq]

ORIGINAL: Blackhorse

ORIGINAL: AndrewKurtz

ORIGINAL: Bluebook
512 shell hits is nothing since 80-90 percent of those hits were on the same 8-10 PBs. I actually saw PBs obliterated by 16-inch gun hits only to be hit again and again by other guns after that. It seems that each escorting ship was engaged by all CD-guns at the same time, regardless of earlier hits.

They way I'm seeing it, this is the crux of the issue. Had the CDs engaged the troop ships after the PBs were obviously gone (as they would have IRL, if not before they were gone), then much of the force would have been destroy at sea.

The other issue in the combat reports I notice is that the number of CDs seem to drop dramatically each turn. What is destroying them? Blown out of the water PBs?

As I pointed out elsewhere, I don't see this as a land combat issue. It is a tweak to the CD logic.

I tend to agree. From the opening post we can see that every Harbor Defense gun fired at the PB Yodozu Maru, then every gun fired at the Ginyu Maru, then at the Tonon Maru, etc. etc.

If each group of guns fired at a different vessel, then all the PBs would have been stripped away in the first couple of rounds, and more AKs would have been engaged.

If this is either a design-logic or a not working-as-designed issue, it it something to consider addressing in a future patch. I'd be interested to see more posts from players engaging CD defenses, large and small, to see if all the CD guns commonly fire at the same vessel each round.

There is also another factor. One of the limitations of the game engine is that all of the devices in each "weapons slot" fires at 1 target per round. Over half of the CD guns in the Oahu Harbor Defenses are 155mm M1A1 GPF (46 at start, expanding to 68). These are all in Weapons Slot #9. So they all fire at only 1 target.

The LCU for Oahu Harbor Defenses uses eighteen of the maximum possible 20 weapons slots. With the two available slots, the GPF guns could be split into three "batteries" (23 guns in one slot, 23 in a second, and 0 - expanding to 22, in the third). This would enable the 155s to engage three targets per round, instead of one. But this wouldn't make a difference if all the CD guns fire at only ship per round, anyway.

Then perhaps the answer is to split these down into sub units for areas with complex CD emplacements. This way a more realistic pattern of fire might be achieved.

[witpqs]

ORIGINAL: Blackhorse

I tend to agree. From the opening post we can see that every Harbor Defense gun fired at the PB Yodozu Maru, then every gun fired at the Ginyu Maru, then at the Tonon Maru, etc. etc.

There are probably several of these kinds of issues in the game engine.

If each group of guns fired at a different vessel, then all the PBs would have been stripped away in the first couple of rounds, and more AKs would have been engaged.

We have to be careful about having the game engine ensure that 'everything goes right', because IRL it rarely does (nor did it in WWII). The effects of smoke (generated and from burning targets), range, confusion, etc. all would hinder efforts to methodically blast the AK's. But only hinder, not prevent.

The big CD guns probably should spend more time engaging AK's (depending on sighting conditions like smoke), while smaller guns would be the first to deal with the PB's. One thing that might be happening here is that the "AK is standing offshore" code might simply be a "AK is not a target" switch in the code (maybe that's why no AK's were hit at all?). If so, it instead should simply provide a range from shore. That way only CD guns with great enough range could target the AK's. Maybe at most landing they would be immune, but with guns like those described at Oahu they could be targeted by some serious firepower.

Back on the PB thing - It sounds like the PB are maybe a) a little too tough during the combat turn and b) getting too much gunfire even after they've been gutted. On the other hand, when a PB (or anything) makes it close enough to engage then it almost certainly should elicit a response. Suppose out of an escort a PB makes it close enough to engage a 16" gun - and the smaller shore guns are not knocking out the PB quickly enough - then I certainly can see the 16" taking on the PB. After all, 3" rounds flying in through openings or onto firing positions would be damaging and need to be dealt with.

[herwin]

ORIGINAL: castor troy

Guess a fast firing 6 inch gun firing HE shells is 1000 times more effective than a 16 inch gun slowly firing AP shells at a transport, which wouldn´t happen anyway I guess.

About twice as effective, to be exact.

[WITPPL]

EDIT: Actually you might be right. It might mean that they are mostly empty as I am only loading based on troop capacity of a ship and without supplies.

Loading routine as I have done pre PH Invasion:

- I never Load more than 1 LCU per TF. I do combine TFs later.
- If an LCU has troop load cost of ie 1000 I have choosen ships with 1100-1200 troop cap.
- I do not load supplies with troops.
- I do not load suplly ships up to their maximum.
All done in Amphibious mode.

If You do that, Forces will unload in one go, Anything from 1 impulse of a turn (as happened in PH) max 1 day. It works for every type of equipment, including 320 mm artillery pieces (which is BS IMHO [8|]).

It was 3rd invasion in this game like this regarding speedy unloading.

BTW: I think that historicaly, Japanese were able to unload in one night during a Malaya invasion so i think that a model might be right here. Im just unsure about the heaviest pieces.

ORIGINAL: stuman

They were loaded to a TFs equal to their troop capacity about +20%. Thats a lot of ships but they unload in one go. That was a plan.

Do you mean that when loaded the transports had only 20 % of their load capacity utilized, and were thus 80 % empty ? Just curious.

That took a lot of planning [:)]

[stuman]

"Doctor, the stress test killed the patient."
"No, nurse, it was the 145,000 cheeseburgers he ate over the last thirty years."

I will have to disagree with this example Bullwinkle58. At most I think it is reasonable to assume no more than 2 cheeseburgers per day. That comes out to 21,900 chesseburgers. 145,000 is just not realistic.

[John Lansford]

Since the rangefinders could detect ships out to 125,000 yds from Oahu, and the 16" guns could fire on targets within 35,000 yds, I'd say there's no place an invasion fleet's transports could unload the men and supplies without coming under fire from at least the largest guns.  Even at Normandy the transports were unloading their troops within 20,000 yds of the shore; several were fired upon by large caliber guns but none were hit.  USS Arkansas, OTOH, took several 11" shell hits while bombarding the positions.

[castor troy]

ORIGINAL: herwin

ORIGINAL: castor troy

Guess a fast firing 6 inch gun firing HE shells is 1000 times more effective than a 16 inch gun slowly firing AP shells at a transport, which wouldn´t happen anyway I guess.

About twice as effective, to be exact.

against a transport? What can a 16 inch gun achieve against an unarmored target if it fires AP? Not much I guess when I look at the LVPs of Treespider´s pic. The 6 inch HE shell would actually explode and the 16 inch AP would just pass through the target.

[Jim D Burns]

ORIGINAL: castor troy
against a transport? What can a 16 inch gun achieve against an unarmored target if it fires AP? Not much I guess when I look at the LVPs of Treespider´s pic. The 6 inch HE shell would actually explode and the 16 inch AP would just pass through the target.

Not true, if the shell hits below the waterline then you've got major problems. And in reality the further offshore transports sit the higher the angle of the plunging fire, so at some point every hit passes through the ship and exits the ship below the water line. And each different caliber of shell has a different angle of plunging fire, so there is no sweet spot a transport could sit in to avoid this at extreme ranges. AP shells might also hit something solid in the ship causing it to slow enough to detonate within the ship.

Jim

[ADB123]

Here is a combat report from my game against the AI in which the AI attempted to move a number of multi-ship transport TFs past the guns at Bataan to Clark Field, which the AI had just captured. The mines and guns at Bataan didn't have much trouble with the small ships, and most were reported as being "obliterated" during the Combat Replay. The one MGB that got through to Clark tried to come out the next turn, and was sunk by a mine and more CD fire.

AFTER ACTION REPORTS FOR Jan 17, 42
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Naval Gun Fire at Bataan - Coastal Guns Fire Back!

3 Coastal gun shots fired in defense.

Japanese Ships
LB-116, Mine hits 2, heavy damage
LB-115, Mine hits 2, heavy damage
LB-114, Shell hits 1, Mine hits 1, heavy damage
LB-113, Mine hits 1, heavy damage



Manila Bay Defenses firing at LB-116
Manila Bay Defenses firing at LB-115
Manila Bay Defenses firing at LB-114
Manila Bay Defenses firing at LB-113

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Naval Gun Fire at Bataan - Coastal Guns Fire Back!

3 Coastal gun shots fired in defense.

Japanese Ships
LB-112, Mine hits 2, heavy damage
LB-111, Mine hits 1, heavy damage
LB-110, Mine hits 1, heavy damage
LB-109, Mine hits 2, heavy damage
LB-108, Shell hits 1, Mine hits 1, heavy damage
LB-107, Shell hits 1, Mine hits 2, heavy damage
LB-106, Shell hits 1, Mine hits 1, heavy damage
LB-105, Mine hits 2, heavy damage
LB-104, Mine hits 2, heavy damage
LB-103, Mine hits 1, heavy damage
LB-102, Mine hits 1, heavy damage
LB-101, Shell hits 1, Mine hits 1, heavy damage



Manila Bay Defenses firing at LB-112
Manila Bay Defenses firing at LB-111
Manila Bay Defenses firing at LB-110
Manila Bay Defenses firing at LB-109
Manila Bay Defenses firing at LB-108
Manila Bay Defenses firing at LB-107
Manila Bay Defenses firing at LB-106
Manila Bay Defenses firing at LB-105
Manila Bay Defenses firing at LB-104
Manila Bay Defenses firing at LB-103
Manila Bay Defenses firing at LB-102
Manila Bay Defenses firing at LB-101


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TF 413 encounters mine field at Bataan (78,77)

Japanese Ships
LB-112, Mine hits 2, heavy damage
LB-111, Mine hits 2, heavy damage
LB-110, Mine hits 2, heavy damage
LB-109, Mine hits 2, heavy damage
LB-108, Mine hits 1, heavy damage
LB-107, Mine hits 1, heavy damage
LB-106, Mine hits 1, heavy damage
LB-105, Mine hits 1, heavy damage
LB-104, Mine hits 1, heavy damage
LB-103, Mine hits 1, heavy damage
LB-102, Mine hits 1, heavy damage
LB-101, Mine hits 1, heavy damage



--------------------------------------------------------------------------------
Naval Gun Fire at Bataan - Coastal Guns Fire Back!

38 Coastal gun shots fired in defense.

Japanese Ships
LB-505, Mine hits 2, heavy damage
LB-504, Shell hits 1, Mine hits 2, heavy damage
LB-503, Shell hits 1, Mine hits 2, heavy damage
LB-502, Shell hits 1, Mine hits 2, heavy damage
LB-501, Shell hits 1, Mine hits 1, heavy damage
LB-135, Mine hits 1, heavy damage
LB-134, Shell hits 1, Mine hits 1, heavy damage
LB-133, Mine hits 2, heavy damage
MGB G-5
MGB G-4, Mine hits 2, heavy damage



Manila Bay Defenses firing at LB-505
Manila Bay Defenses firing at LB-504
Manila Bay Defenses firing at LB-503
Manila Bay Defenses firing at LB-502
Manila Bay Defenses firing at LB-501
Manila Bay Defenses firing at LB-135
Manila Bay Defenses firing at LB-134
Manila Bay Defenses firing at LB-133
Manila Bay Defenses firing at MGB G-5
Manila Bay Defenses firing at MGB G-4


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TF 349 encounters mine field at Bataan (78,77)

Japanese Ships
LB-505, Mine hits 1, heavy damage
LB-504, Mine hits 1, heavy damage
LB-503, Mine hits 1, heavy damage
LB-502, Mine hits 1, heavy damage





--------------------------------------------------------------------------------
Naval Gun Fire at Bataan - Coastal Guns Fire Back!

Japanese Ships
LB-120, Shell hits 1, Mine hits 2, heavy damage
LB-119, Shell hits 1, heavy damage
LB-118, Mine hits 2, heavy damage
LB-117, Mine hits 1, heavy damage
LB-515, Mine hits 1, heavy damage
LB-514, Mine hits 2, heavy damage
LB-513, Mine hits 2, heavy damage
LB-510, Mine hits 2, heavy damage
LB-509, Shell hits 1, heavy damage
LB-508, Mine hits 1, heavy damage
LB-507, Mine hits 2, heavy damage
LB-506, Mine hits 1, heavy damage



Manila Bay Defenses firing at LB-120
Manila Bay Defenses firing at LB-119
Manila Bay Defenses firing at LB-118
Manila Bay Defenses firing at LB-117
Manila Bay Defenses firing at LB-515
Manila Bay Defenses firing at LB-514
Manila Bay Defenses firing at LB-513
Manila Bay Defenses firing at LB-510
Manila Bay Defenses firing at LB-509
Manila Bay Defenses firing at LB-508
Manila Bay Defenses firing at LB-507
Manila Bay Defenses firing at LB-506


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TF 389 encounters mine field at Bataan (78,77)

Japanese Ships
LB-119, Mine hits 1, heavy damage
LB-118, Mine hits 1, heavy damage
LB-117, Mine hits 1, heavy damage
LB-515, Mine hits 1, heavy damage
LB-514, Mine hits 1, heavy damage
LB-513, Mine hits 1, heavy damage
LB-510, Mine hits 1, heavy damage
LB-509, Mine hits 1, heavy damage
LB-508, Mine hits 1, heavy damage
LB-507, Mine hits 1, heavy damage





--------------------------------------------------------------------------------
Naval Gun Fire at Bataan - Coastal Guns Fire Back!

37 Coastal gun shots fired in defense.

Japanese Ships
LB-132, Shell hits 1, heavy damage
LB-131, Shell hits 1, Mine hits 1, heavy damage
LB-130, Shell hits 1, Mine hits 1, heavy damage
LB-129, Mine hits 2, heavy damage
LB-128, Shell hits 1, Mine hits 1, heavy damage
LB-127, Shell hits 1, Mine hits 1, heavy damage
LB-126, Shell hits 1, Mine hits 1, heavy damage
LB-125, Mine hits 2, heavy damage
LB-124, Mine hits 2, heavy damage
LB-123, Shell hits 1, Mine hits 1, heavy damage
LB-122, Mine hits 2, heavy damage
LB-121, Mine hits 2, heavy damage



Manila Bay Defenses firing at LB-132
Manila Bay Defenses firing at LB-131
Manila Bay Defenses firing at LB-130
Manila Bay Defenses firing at LB-129
Manila Bay Defenses firing at LB-128
Manila Bay Defenses firing at LB-127
Manila Bay Defenses firing at LB-126
Manila Bay Defenses firing at LB-125
Manila Bay Defenses firing at LB-124
Manila Bay Defenses firing at LB-123
Manila Bay Defenses firing at LB-122
Manila Bay Defenses firing at LB-121


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TF 392 encounters mine field at Bataan (78,77)

Japanese Ships
LB-132, Mine hits 2, heavy damage
LB-131, Mine hits 2, heavy damage
LB-130, Mine hits 2, heavy damage
LB-129, Mine hits 2, heavy damage
LB-128, Mine hits 1, heavy damage
LB-125, Mine hits 1, heavy damage
LB-124, Mine hits 1, heavy damage
LB-122, Mine hits 1, heavy damage
LB-121, Mine hits 1, heavy damage

[Mike Scholl]

Those were some interesting photos Castor Troy put into the discussion..., but does anyone have some photos of the Japanese Amphibious landings in Lingayen Gulf in 1941?  That was about the largest amphibious effort the Japs made during their offensives, so it should show their landing doctrine and equipment at the time.