Amphibious invasion of Pearl Harbor - results

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RE: Amphibious invasion of Pearl Harbor - results

Post by Bullwinkle58 »

ORIGINAL: castor troy

That´s a whole different thing in AE now, there are only those "accidents" anymore. When I first saw those "accidents" I´ve thought wow, what a great new detail. Just to find out the rest of the "firing on the invasion" isn´t there at all anymore, changing my mind into: heck, what a damn crap. Please, noone take this offensive...

No, read the combat reports more closely. There are lines with "accident" in them, and there are other loss lines without, some from surf, some with just the loss reported. I'd always assumed that ones not clearly accidental were from enemy forces firing on the beach head. But, this is open to debate. The words could also mean the loss was accidental, but not said that way for artistic variety.

The text descriptions seem to only cover the destroyed squads and devices. Disrupted squads, the majority, are not detailed by cause. In the example below, I'd say that the enemy firing on the incoming landing craft, and the period after but before the attack phase, were very, very effective at rendering these troops and devices combat-ineffective for this phase. Which is historical for the USMC and USA. I can't name an invasion where landing operations were so bad that the first wave was paralllized on the beach for more than 12-hours. The survivors regrouped and got busy. I'm not familiar with ANZAC and British landings, but I'm sure that was true of them as well.

An example from my game:

Amphibious Assault at Eniwetok

TF 237 troops unloading over beach at Eniwetok, 127,108


Allied ground losses:
674 casualties reported
Squads: 1 destroyed, 192 disabled
Non Combat: 1 destroyed, 160 disabled
Engineers: 0 destroyed, 0 disabled
Guns lost 154 (0 destroyed, 154 disabled)
Vehicles lost 69 (0 destroyed, 69 disabled)


10 Support troops lost from landing craft during unload of 9th Marine Rgt
13 troops of a USA Rifle Squad 43 lost in surf during unload of 32nd Infantry Div /6

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RE: Amphibious invasion of Pearl Harbor - results

Post by Bullwinkle58 »

ORIGINAL: Mike Scholl


So what penninsula are you going to launch the daihatsu's from to land on Oahu?

Molokai?[:)]
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RE: Amphibious invasion of Pearl Harbor - results

Post by Cmdrcain »

ORIGINAL: Bullwinkle58

FWIW, in all this "the CD system doesn't work" talk I offer my recent experience taking that bastion of CD science--Wotje Island (huh?) I had the USS Pennsylvania, two CAs, and four DDs supporting a somewhat rambling invasion (hey, it's me, right?) I had two infantry regiments about 50% prepped, a Seabee unit, and a small, non-EAB combat engineer unit. Recon said there were about 5000 troops, about 30-ish guns, and no armor. I had been LBA and dive-bombing from three other islands for two weeks at a low but consistent rate, and had two fighter squadrons strafing daily for a week prior. My best info was there had been no re-supply of the island for about three months. I thought it was a simple mop up op. (Tarawa and Kwaj. hadn't had a whole lot of CD support.)

I got clocked. Two DDs sunk, both cruisers with 30-ish system damge and some float, the BB with 15 system and fires. There was counter-battery fire every phase from my ships, but it didn't put the CD OOC. In those phases I got the troops ashore with tough losses, including four xAKs and serious damage to eight other merchants, but zero, and I mean ZERO, supplies. Every LCU had a big red zero for supplies. I tried to use emergency barges from Mili to get supplies ashore, and lost about twelve, without landing even one ton of supplies.

For a second wave of resupply I used LSTs and DDs, and still couldn't get anything ashore. They got torn up too. (By now the BB and CAs had retired to lick their wounds.) Finally, out of anger more than anything, I ordered shock attacks without supplies, gambling that the Japanese were nearly out of supply. That worked in two attacks, and all three units (a Naval Guard, the Naval Fortress/CD unit, and a support unit) were wiped out.

Curious now, I re-loaded as Japanese and "peeked" at the remaining untaken islands nearby. A couple are CD farms just like Wotje. I may bypass them now that I know. This is, after all, a "learning" run-through game.

But I for one don't believe there's anything in the code that makes merchants immune while the AI focuses on small escorts.



Hummm mmmm


I cant find the old Report but my opponent, a ways back in our game send a surface fleet in trying get into Manila.


The bataan/Manilia CD blew up 2 or maybe it was 3 BB's sinking his Fleet...


So maybe its that Pearl isn't a Designated "Fort" as is Bataan/Manilia and Singapore and some others where the CD guns deal extra damage...

Trying put any fleet into those port squares results in CD fire greater then normal Cd fire.

:)

My opponents not had a good time... we started with No Historic turn but dec 7 surprise on... he has the Extra help for japan Ahistoric option...
but On our turn 1 since not historic turn I was able sent my Pearl fleet to sea... well one surface group engaged his KB and FOUR of the KB carriers went down to BB guns :)

Then later his try into Manilia..


Its later in 1942 through and he nailed two of my Carriers so I've lost 2 he lost 4...


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RE: Amphibious invasion of Pearl Harbor - results

Post by Cmdrcain »

ORIGINAL: jwilkerson

I've been watching this thread with some interest. I have not yet had time to do any new testing on this - I did test the guns at PH and Manilla several times in early 2009 and bombardment fleets were 100% in all cases - these included multiple BBs, Cruisers, DDs.

On the one hand the example in the thread is complex because it exposes a number of very different issues: targeting of CD guns against large numbers of invading ships, damage caused by CD guns to ships in amphibious TFs, over saturation of shots against ships in amphibous TFs, overly rapid unloading of troops from amphbious TFs. Most of these issues have been with us since day-1 of WITP and are not new to AE.

But one fundamental point to make which is fairly simple, is that as with many if not most of the sub-systems within the game engine (both WITP and AE) if you scale things up far enough, you will be likely to break the sub-system. In WITP this was perhaps most glaringly true for the Air vs Air subsystem (the issue got called "Uber CAP"). We specifically targeted this issue for fixing in AE, and so far, it looks like this fix is holding. But many other sub-systems were not targeted for fixing, so there will still be scalability issues.

So, as to which, if any of these issues, we will ultimately address, we cannot say yet, this will require some testing to sort things out. In the mean time, just be aware that if you launch a very large Amphibous invasion as was done here, you will get outside the window were things work correctly.

And I might also add, that it still seems like to me that the defending base did not have any air force turned on and I haven't heard much about that - but I wonder what would be happening if PH had a large air force turned on during the landings - I would think that would have made a difference in the outcome - though I'm not actually sure what the out come is - I've missed some of the posts I'm sure.

But it is an interesting exercise in scaling things up beyond the engine's ability to handle, no doubt there.





Could it simply be that unlike Bataan/Manilia and Singapore, the hex is not, for PH, a Fortress hex so the PH CD don't defend like Bataan or singapores does... isn't there code in there that makes CD guns deadlier if the hex trying bombard or move into is a fortress hex?

My PBEM opponent made mistake of sending a surface bombard fleet ino Manilia... the 2-3 BB's
ended sunk, cruisers etc sunk or damaged

Pearl on map isn't a designated Fortress hex which would make a naval assault harder with CD guns doing more damage.

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RE: Amphibious invasion of Pearl Harbor - results

Post by castor troy »

ORIGINAL: Bullwinkle58

ORIGINAL: castor troy

D-day goes off and the landing sites aren´t defended by what they were in real life but some first line divisions with all their equipment they are supposed to have. D-day would not be shredded by two or three dozen medium - big calibre CD guns firing at the ships (if they would they would do damage too of course). The invasion would have been shredded by MGs, mortars and lots of divisional artillery. And it would be shredded on the landing sites and not on the open sea 15km off the beach.

Given that the Allies had total air supremacy over, in front of, near, and behind the landing breaches I think these divisions would have been chewed to hamburger if they'd been near enough to affect the landings. Even the troops in fixed emplacements were gone the first day.

Also, look at total day-1 casualties on Omaha beach, by far the worst. Even with anti-personnel emplacements--mines, wire, barriers, pillboxes--and years fro the Germans to prepare and train, they amounted to about 2400. Thirty-four thousand got ashore able to fight.

exactly!! And that´s my point. You have to do something before you invade, use your total air supremacy. If you can´t you have a problem, if you don´t do it, you have a problem. In AE, you never have a problem, because the soldiers coming ashore are NOT shot at... aren´t the people actually playing this game not watching any replays or looking at the combat reports?

My example of the SU not being in the war anymore is nuts of course so forget all about it. Say nation A puts three divisions into a 40 mile front to defend it against an invasion. Nation B invades, there are no CD guns, there has been not a single air attack and then it´s ok if the only "casualties" that happen are results of accidents? Sorry...

And your example from real life is definetely not what happened because not even the limited defenses of ther German were gone due to air attacks.
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RE: Amphibious invasion of Pearl Harbor - results

Post by castor troy »

ORIGINAL: Bullwinkle58

ORIGINAL: castor troy

That´s a whole different thing in AE now, there are only those "accidents" anymore. When I first saw those "accidents" I´ve thought wow, what a great new detail. Just to find out the rest of the "firing on the invasion" isn´t there at all anymore, changing my mind into: heck, what a damn crap. Please, noone take this offensive...

No, read the combat reports more closely. There are lines with "accident" in them, and there are other loss lines without, some from surf, some with just the loss reported. I'd always assumed that ones not clearly accidental were from enemy forces firing on the beach head. But, this is open to debate. The words could also mean the loss was accidental, but not said that way for artistic variety.

The text descriptions seem to only cover the destroyed squads and devices. Disrupted squads, the majority, are not detailed by cause. In the example below, I'd say that the enemy firing on the incoming landing craft, and the period after but before the attack phase, were very, very effective at rendering these troops and devices combat-ineffective for this phase. Which is historical for the USMC and USA. I can't name an invasion where landing operations were so bad that the first wave was paralllized on the beach for more than 12-hours. The survivors regrouped and got busy. I'm not familiar with ANZAC and British landings, but I'm sure that was true of them as well.

An example from my game:

Amphibious Assault at Eniwetok

TF 237 troops unloading over beach at Eniwetok, 127,108


Allied ground losses:
674 casualties reported
Squads: 1 destroyed, 192 disabled
Non Combat: 1 destroyed, 160 disabled
Engineers: 0 destroyed, 0 disabled
Guns lost 154 (0 destroyed, 154 disabled)
Vehicles lost 69 (0 destroyed, 69 disabled)


10 Support troops lost from landing craft during unload of 9th Marine Rgt
13 troops of a USA Rifle Squad 43 lost in surf during unload of 32nd Infantry Div /6



you are joking with this result, aren´t you? 1 squad destroyed? Wow, the attacker suffered a dozen soldiers dead. Now that was bloody. And now the most funny thing, because I AM LOOKING CLOSELY. Both the destroyed combat squad and the destroyed support squad were destroyed by the accident. Oh, what a bad Japanese shooting, they killed exactly NONE of the emeny troops.

But I guess I have enough problems with my own air thread already, have pointed out the flaws of the CD routine often enough at the beginning of this thread until there seems to have been some agreement anyway. So I´ll go over and fight through the other thread.
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RE: Amphibious invasion of Pearl Harbor - results

Post by Bullwinkle58 »

ORIGINAL: castor troy


In AE, you never have a problem, because the soldiers coming ashore are NOT shot at... aren´t the people actually playing this game not watching any replays or looking at the combat reports?

If soldiers coming ashore are not shot at, how did my guys on Eniwetok arrive massively disrupted?
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RE: Amphibious invasion of Pearl Harbor - results

Post by castor troy »

ORIGINAL: Bullwinkle58

ORIGINAL: castor troy


In AE, you never have a problem, because the soldiers coming ashore are NOT shot at... aren´t the people actually playing this game not watching any replays or looking at the combat reports?

If soldiers coming ashore are not shot at, how did my guys on Eniwetok arrive massively disrupted?


you seem to accept it as it is and I can´t point it out to you anymore anyway. NO ( N O ) dead... not one from a bullet... must have been a strange fight. We agree to disagree so let´s be it.
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RE: Amphibious invasion of Pearl Harbor - results

Post by EUBanana »

ORIGINAL: castor troy
you are joking with this result, aren´t you? 1 squad destroyed?

I assume a percentage of those in disabled squads are dead. disabled = hors de combat after all. And destroyed is, totally wiped out.

Disabled squads take aaaages to recover, they may as well be dead, the only difference is they dont draw from your pools. I've always assumed disabled means heavy casualties, destroyed means gone completely.
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RE: Amphibious invasion of Pearl Harbor - results

Post by Bullwinkle58 »

ORIGINAL: castor troy
ORIGINAL: Bullwinkle58

ORIGINAL: castor troy

That´s a whole different thing in AE now, there are only those "accidents" anymore. When I first saw those "accidents" I´ve thought wow, what a great new detail. Just to find out the rest of the "firing on the invasion" isn´t there at all anymore, changing my mind into: heck, what a damn crap. Please, noone take this offensive...

No, read the combat reports more closely. There are lines with "accident" in them, and there are other loss lines without, some from surf, some with just the loss reported. I'd always assumed that ones not clearly accidental were from enemy forces firing on the beach head. But, this is open to debate. The words could also mean the loss was accidental, but not said that way for artistic variety.

The text descriptions seem to only cover the destroyed squads and devices. Disrupted squads, the majority, are not detailed by cause. In the example below, I'd say that the enemy firing on the incoming landing craft, and the period after but before the attack phase, were very, very effective at rendering these troops and devices combat-ineffective for this phase. Which is historical for the USMC and USA. I can't name an invasion where landing operations were so bad that the first wave was paralllized on the beach for more than 12-hours. The survivors regrouped and got busy. I'm not familiar with ANZAC and British landings, but I'm sure that was true of them as well.

An example from my game:

Amphibious Assault at Eniwetok

TF 237 troops unloading over beach at Eniwetok, 127,108


Allied ground losses:
674 casualties reported
Squads: 1 destroyed, 192 disabled
Non Combat: 1 destroyed, 160 disabled
Engineers: 0 destroyed, 0 disabled
Guns lost 154 (0 destroyed, 154 disabled)
Vehicles lost 69 (0 destroyed, 69 disabled)


10 Support troops lost from landing craft during unload of 9th Marine Rgt
13 troops of a USA Rifle Squad 43 lost in surf during unload of 32nd Infantry Div /6



you are joking with this result, aren´t you? 1 squad destroyed? Wow, the attacker suffered a dozen soldiers dead. Now that was bloody. And now the most funny thing, because I AM LOOKING CLOSELY. Both the destroyed combat squad and the destroyed support squad were destroyed by the accident. Oh, what a bad Japanese shooting, they killed exactly NONE of the emeny troops.

But I guess I have enough problems with my own air thread already, have pointed out the flaws of the CD routine often enough at the beginning of this thread until there seems to have been some agreement anyway. So I´ll go over and fight through the other thread.

I know English is not your native language, but I thought I had clearly made the point that, no, both of these squads are not stated to have been destroyed by accident. Only one was (maybe, it's not explicit.) The one lost unloading could have been shot while unloading, right? That's my point. The results sometimes state it was by accident, and other times do not. You can't assume.

Now, Eniwetok was held by three grandmothers and their dogs. It fell to the first shock attack the next day, wiping out the defenders. But even so, LOOK at the results, and stop obsessing on KIAs. EVERY artillery piece was useless. EVERY vehicle was useless. Massive disruption in both combat and support squads. THAT's the purpose of shooting at assault craft. Not only to kill, but also to take them out of the fight.
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RE: Amphibious invasion of Pearl Harbor - results

Post by aspqrz02 »

ORIGINAL: Brady
ORIGINAL: aspqrz

The "Type A" wasn't available until 1943-44 or later, as the sources cited elsewhere note ... the Handbook on Imperial Japanese Army produced by the War Department and similar pubs (where the illos are from, I presume) are very late war, and refer to the period 1943-44, not 41-early 42.

Phil McGregor

Thats incorect they were used in all the initial operations in some numbers, the links above sight thier presence at various landings.

See:

http://www3.plala.or.jp/takihome/toku-daihatsu.html

Example from Linked Thread above:

> How Many Landing craft were part of this operation?

30 Toku-Daihatsus, 175 Daihatsus, 175 Shohatsus, 30 motor-barges(‹@•täx�M) were used in the Java Campaign.


Taki

Actually, I misread. The cite I provided says "The Navy ordered 163 of these craft, but it is not known how many were actually completed (though at least 35 were built in 1943-44)" ... which I misread as "not produced" until those years. Still, my general point stands, the "average" Japanese landing craft was *not* of 120 man capacity, as it was *not* a Toku-Daihatsu ... your figures show this clearly.

The two most numerous LCs mentioned have capacities of 70 men and 35 men (14m D and Shohatsu), resspectively.

So, assuming optimum load always achieved ...

30 x TD = 3600 men
175 x D = 12250
175 x S = 6125
(Your guess is as good as mine as to what the capacity of the "Motor Barges" was)

Or c, 22000 men ... but you'd reasonably assume that they were carrying cargo ashore (heavy weapons, vehicles, ammo etc.) at least as often as not as they were carrying troops. All at 7.5 kts for maximum range (100 nm).

Doesn't compare to major allied efforts in the Pacific, which the invasion of Hawaii would surely equal in the real world, does it?

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RE: Amphibious invasion of Pearl Harbor - results

Post by oldman45 »

ORIGINAL: Don Bowen

ORIGINAL: oldman45

I think I would have a bigger problem with the results, if the defenders were aware of the invasion in advance, but it was pointed out the ships showed up and off loaded and the defenders really were asleep at the switch. One of Brady's pics does show all those transports sitting just off shore, now that would be called a target rich environment. [;)]

As previously written, there may not be a simple fix here, but to run out and make major changes would be bad and until we see the effects of a US led invasion with APA/AKA/LST's it would be dangerous to monkey with it.

Also, I think its fair to say the large caliber guns will be dueling with the combat ships, while the naval mortars and smaller guns would be attacking the transports. The guns supporting the local troops would engage the landing craft and troops on the beach. So unless there is a way to break down the phases even more I don't really see a solution. A fix could make defended beaches almost impossible for the Japanese to take and force the player to use the "attack them where the ain't" method. BTW wasn't that what they did historically?

Does some have detailed line-of-departure date for various amphibious invasions in the Pacific?

I am not sure what your looking for? When the convoys formed up or when the landing ramps came down on the beach? Is that what your looking for?
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RE: Amphibious invasion of Pearl Harbor - results

Post by Brady »

ORIGINAL: aspqrz



So, assuming optimum load always achieved ...

30 x TD = 3600 men
175 x D = 12250
175 x S = 6125
(Your guess is as good as mine as to what the capacity of the "Motor Barges" was)

Or c, 22000 men ... but you'd reasonably assume that they were carrying cargo ashore (heavy weapons, vehicles, ammo etc.) at least as often as not as they were carrying troops. All at 7.5 kts for maximum range (100 nm).

Doesn't compare to major allied efforts in the Pacific, which the invasion of Hawaii would surely equal in the real world, does it?

Phil


I came up with:

Toko Dihatsu- 180 x 30 = 5400
Dihatsu- 80 x 175 = 14000
Shohatsu- 30 x 175 = 5250

aprox 24650

So were not far enough off to realy wory about it, but again this is less than half the total Landing craft that Japan had at its disposal at wars start, in the SRA.

Japanese doctern dictated that the first wave which could be delevered in mass all at once would go in first and easly before dawn and would carry the fighting force, the men carried what they neaded for a few days rations. Suxceading waves would folow with suplys and heavy equipment, in some cases tanks would go in the first wave.

22K men is a lot by any standard, does it compare to the atempts the US made later in the war, no but the Japanese could easly Land an entire Divishion pluss on Hawaii in one wave using less than half their Landing craft assets, they could easly have more men at sea as well.

Since this all just for the sake of argument given the state of defenses on Hawaii in January of 42 I dont personaly see why it would not of been posable.

Waves could of cycled easly every two or three hours, even if it were 6 hour cycles they could of landed 100,000 men in a day....Say do to atration and the nead to move suplys they managed just 50,000 fighting men by Noon...


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RE: Amphibious invasion of Pearl Harbor - results

Post by WITPPL »

Results of first assault:
Everybody fully rested, organized and supplied.
No initial pre borbardment or shelling.

--------------------------------------------------------------------------------

Ground combat at Pearl Harbor (180,107)

Japanese Deliberate attack

Attacking force 74149 troops, 767 guns, 145 vehicles, Assault Value = 2568

Defending force 50000 troops, 1130 guns, 1210 vehicles, Assault Value = 772

Japanese engineers reduce fortifications to 3

Japanese adjusted assault: 2046

Allied adjusted defense: 3169

Japanese assault odds: 1 to 2 (fort level 3)

Combat modifiers
Defender: terrain(+), forts(+), leaders(+), experience(-)
Attacker:

Japanese ground losses:
8693 casualties reported
Squads: 61 destroyed, 292 disabled
Non Combat: 89 destroyed, 471 disabled
Engineers: 25 destroyed, 137 disabled
Guns lost 6 (0 destroyed, 6 disabled)
Vehicles lost 7 (0 destroyed, 7 disabled)


Allied ground losses:
1864 casualties reported
Squads: 9 destroyed, 140 disabled
Non Combat: 12 destroyed, 297 disabled
Engineers: 0 destroyed, 29 disabled
Guns lost 3 (0 destroyed, 3 disabled)
Vehicles lost 122 (7 destroyed, 115 disabled)


Assaulting units:
20th Infantry Regiment
48th Engineer Regiment
1st Formosa Inf. Regiment
2nd Engineer Regiment
21st Division
33rd Division
4th Division
16th Infantry Regiment
4th Infantry Regiment
47th Infantry Regiment
16th Engineer Regiment
65th Brigade
9th Infantry Regiment
24th Infantry Regiment
15th Ind.Art.Mortar Battalion
2nd Ind.Art.Mortar Battalion
7th Air Defense AA Regiment
48th Field Artillery Regiment
1st Medium Field Artillery Regiment
16th Army
18th Mountain Gun Regiment
14th Ind.Art.Mortar Battalion
9th Ind.Hvy.Art. Battalion
2nd Field Artillery Regiment

Defending units:
27th Infantry Regiment
35th Infantry Regiment
19th Infantry Regiment
56th Coastal Artillery Regiment
21st Infantry Regiment
Oahu Harbor Defense
34th Infantry Regiment
2nd USMC Engineer Regiment
3rd Marine Defense Battalion
118th USAAF Base Force
251st Coast AA Regiment
119th USAAF Base Force
Seventh USAAF
198th Field Artillery Battalion
112th USA Base Force
97th Coast AA Regiment
804th Engineer Aviation Battalion
Pearl Harbor Base Force
Hawaiian Dept
64th Coast AA Regiment
VII US Bomber Cmnd
4th Marine Defense Battalion
Pacific Fleet
98th Coast AA Regiment
D Det USN Port Svc

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RE: Amphibious invasion of Pearl Harbor - results

Post by Blackhorse »

ORIGINAL: Brady

ORIGINAL: aspqrz



So, assuming optimum load always achieved ...

30 x TD = 3600 men
175 x D = 12250
175 x S = 6125
(Your guess is as good as mine as to what the capacity of the "Motor Barges" was)

Or c, 22000 men ... but you'd reasonably assume that they were carrying cargo ashore (heavy weapons, vehicles, ammo etc.) at least as often as not as they were carrying troops. All at 7.5 kts for maximum range (100 nm).

Doesn't compare to major allied efforts in the Pacific, which the invasion of Hawaii would surely equal in the real world, does it?

Phil


I came up with:

Toko Dihatsu- 180 x 30 = 5400
Dihatsu- 80 x 175 = 14000
Shohatsu- 30 x 175 = 5250

aprox 24650

So were not far enough off to realy wory about it, but again this is less than half the total Landing craft that Japan had at its disposal at wars start, in the SRA.

Japanese doctern dictated that the first wave which could be delevered in mass all at once would go in first and easly before dawn and would carry the fighting force, the men carried what they neaded for a few days rations. Suxceading waves would folow with suplys and heavy equipment, in some cases tanks would go in the first wave.

22K men is a lot by any standard, does it compare to the atempts the US made later in the war, no but the Japanese could easly Land an entire Divishion pluss on Hawaii in one wave using less than half their Landing craft assets, they could easly have more men at sea as well.

Since this all just for the sake of argument given the state of defenses on Hawaii in January of 42 I dont personaly see why it would not of been posable.

Waves could of cycled easly every two or three hours, even if it were 6 hour cycles they could of landed 100,000 men in a day....Say do to atration and the nead to move suplys they managed just 50,000 fighting men by Noon...

If you beat the facts with a stick long enough, they'll confess anything. - Mark Twain

Using 290-380 invasion craft to put 100,000 men ashore in one day may pencil out on paper, but not IRL. By comparison, in 1944, with larger, purpose-built ships and craft, far better command and control, and the benefit of past experience, it took the Allies 3,500 landing craft to bring 175,000 men ashore in 24 hours at Normandy.

So, *if* the Japanese in early 1942 could operate with the same efficiency as the allies did in mid-1944, with a fleet of landing craft about 1/10th the size of what was used in Normandy, they might reasonable expect to unload about 17,500 men in a day, if losses to the landing craft are light.

At Normandy the Allies had 144 landing ships/craft sunk, and another 53 damaged. Those were trifiling losses for such a huge invasion fleet. But if the US coastal defenses on Oahu could have inflicted similar casualties, they would wiped out 1/2 to 2/3rds of the IJN's lift.
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Brady
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RE: Amphibious invasion of Pearl Harbor - results

Post by Brady »

ORIGINAL: Blackhorse



If you beat the facts with a stick long enough, they'll confess anything. - Mark Twain

Using 290-380 invasion craft to put 100,000 men ashore in one day may pencil out on paper, but not IRL. By comparison, in 1944, with larger, purpose-built ships and craft, far better command and control, and the benefit of past experience, it took the Allies 3,500 landing craft to bring 175,000 men ashore in 24 hours at Normandy.

So, *if* the Japanese in early 1942 could operate with the same efficiency as the allies did in mid-1944, with a fleet of landing craft about 1/10th the size of what was used in Normandy, they might reasonable expect to unload about 17,500 men in a day, if losses to the landing craft are light.

At Normandy the Allies had 144 landing ships/craft sunk, and another 53 damaged. Those were trifiling losses for such a huge invasion fleet. But if the US coastal defenses on Oahu could have inflicted similar casualties, they would wiped out 1/2 to 2/3rds of the IJN's lift.


Were both beating the facts I should think, At Normandy those landing craft were moving a lot more than just men.

And were just discusing the total potentail given perfect condations above.

............


2 Toku-Daihatsus, 17 Daihatsus, 15 Shohatsus were used to move 2,900 men of the Shoji Detachment ashore in 2 hours:

Order of Battle of the Shoji Detachment
Java Island, March 1942
Colonel Toshishige Shoji, commander of the Shoji Detachment
· 230th Infantry Regiment (minus 3rd Battalion)
· one Mountain Artillery Battalion (minus one battery)
· one Engineer Company (minus two platoons)
· one Anti-Tank Battalion (minus two batteries)
· one Light Tank Company
· one AA Battery
· two Independent Engineer Companies (minus three platoons)
· one platoon of the Bridge Material Company
· one Motor Transport Company
· part of the 40th Anchorage Headquarters
· part of the Airfield Battalion

from these ships:

Third Daigen Maru
Neiburu Maru
Calcutta Maru
Glasgow Maru
Suwa Maru
Kozan Maru
Yamatsuki Maru

The initial landing also included some Motor transpot and Tanks, The bulk of the equipment and the stores took 4 days to fully unload. with the above landing craft. Thats about 85 men per landing craft on average in the first wave, but again some had trucks and Tanks in them. So in practice It does not apear to far off to asume with the above mentioned landing craft that putting an entire Divishion ashore (or the fighting body of it) all before dawn would be at all unreasionable.

Refering to this alotment of landing craft for the Divishion argument:

Toko Dihatsu- 180 x 30 = 5400
Dihatsu- 80 x 175 = 14000
Shohatsu- 30 x 175 = 5250


Data from linked thread.

The argument also asumes a landing in early 42 with the existing CD weapons at wars start, whear most of Ohau's beaches were porely covered.
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Mike Scholl
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RE: Amphibious invasion of Pearl Harbor - results

Post by Mike Scholl »

ORIGINAL: Brady

Since this all just for the sake of argument given the state of defenses on Hawaii in January of 42 I don't personaly see why it would not of been possible.

Waves could of cycled easily every two or three hours, even if it were 6 hour cycles they could of landed 100,000 men in a day....Say do to attrition and the need to move supplies they managed just 50,000 fighting men by Noon...


Speaking of "waves" Brady..., the "Professional Big Wave Surfing Season" began January 13th on the North Shore of Oahu. Which suggests that the second wave or your invasion would be riding in on splinters, even without defending fire!
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Feinder
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RE: Amphibious invasion of Pearl Harbor - results

Post by Feinder »

Actually, Disabled is NOT dead (at least appearent in game terms). Destroyed is dead, and drains your pools. Disabled does NOT drain your pools, ie you are NOT drawing replacements. Disabled may mean anything from non-critical wound to loss of cohesion to scattered to unaccounted for. But if you put that unit same unit in a non-malaria base with an HQ, it actually regains fairly rapidly (at least in my experience). It might take 3 weeks, which in my opinion is a reasonable time.

I will say that while I do think the model is borked (by observation of these threads, that I am in no rush to begin PBEM in AE), if you do increase the destroyed squads results to be more realistic, you'd also have to adjust the replacement squad availability (which I have been reviewing to OBs, and replacement squads are certainly too anemic to begin with, much able to withstand an accurate combat model).

-F-
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Hoplosternum
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RE: Amphibious invasion of Pearl Harbor - results

Post by Hoplosternum »

The model does look to have some glitches to say the least.

I would hate to see an invasion of Pearl be impossible. But certainly the attack here seemed to be altogether too easy on the transports and troops. With the number of ships used I think the invasion should certainly have got most of the troops ashore and quickly. But more damage should have been done than was (how realistic this is would be a different question - it can be done in the game). The Pearl CD forces are some of the best in the game. Regardless of 'standing offshore', how many landing craft the Japanese had and firing on ships that fired on you the results just look wrong. The damage should have been greater or at least more spreadout.

The developer (jwilkerson) was quick to suggest that it might be due to the size of the task forces. The Japanese player used huge task forces for the invasion. 100+ in number. Most of us remember from WITP that strange thing happened to the model once numbers got too big. AE specifically resolved the problem with big air battles. But the Developer immeadiately suggested the issue was probably caused by the task force sizes.

I hope they look at that aspect.

But I hope they are cautious with any changes. CD should not make invasions competely ruinous. And from other AARs shown on this thread they are clearly pretty devestating at times. And making any hex 'safe' - be it Pearl or elsewhere will just lead to the defenders stripping the place of most mobile forces and using these to boost other places.

It would have been great to see the results of the invasion if WITPPL had tried a couple of test variations. Breaking those huge taskforces up in to either blocks of 50 (mixed transports and escorts) and then again with no TF being larger than 25. If the Developers hunch was correct that would change the outcome as each 'battle' would be of a more manageable size for the game system.
Allies vs Belphegor Jul 43 2.5:2.5 in CVs
Allies vs Drex Mar 43 0.5:3 down in CVs
Japan vs LtFghtr Jun 42 3:2 down in CVs
Allies vs LtFghtr Mar 42 0:1 down in CVs
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RE: Amphibious invasion of Pearl Harbor - results

Post by castor troy »

ORIGINAL: Feinder

Actually, Disabled is NOT dead (at least appearent in game terms). Destroyed is dead, and drains your pools. Disabled does NOT drain your pools, ie you are NOT drawing replacements. Disabled may mean anything from non-critical wound to loss of cohesion to scattered to unaccounted for. But if you put that unit same unit in a non-malaria base with an HQ, it actually regains fairly rapidly (at least in my experience). It might take 3 weeks, which in my opinion is a reasonable time.

I will say that while I do think the model is borked (by observation of these threads, that I am in no rush to begin PBEM in AE), if you do increase the destroyed squads results to be more realistic, you'd also have to adjust the replacement squad availability (which I have been reviewing to OBs, and replacement squads are certainly too anemic to begin with, much able to withstand an accurate combat model).

-F-


Feinder, there are now far more squads as replacements in AE than there were in WITP. Not because there are more replacements per se but due to the fact that if there are, let´s say, enough US combat squads 42 in the pool to upgrade one whole unit with it then the US combat squads go back into the pool and are upgraded to the US combat squads 42. So in fact the thing with having units with 1940 equipment in 45 that happened in WITP isn´t true anymore. At least that´s how I understood it and it seems this has been happening in my games so far.

AndyMac can give more precise information on this one.
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