Amphibious invasion of Pearl Harbor - results

[Bluebook]

ORIGINAL: Nikademus

ORIGINAL: Bluebook

Ok, this is going to be a somewhat long post because Im going to quote the combat report in relevant parts.

Couple of comments:

512 shell hits is "nothing"?

2nd: Where was the airforce and the navy?

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. So first a 3 inch battery would shoot and hit the PB, then a 6-inch, then a 12-inch, then a 16 inch, then a 12 inch mortar, then a RR gun, then a 155 gun... Nevermind that the PB was already sunk by the second hit. Then the next PB would appear and get the same treatment.

The navy is licking its wounds after having the KB linger around Pearl Harbor for the first week of war. Those ships that are combat worthy are either somewhere else, or they have been fighting the Japs during the battles for Midway, Wake, Johnston, and the rest of the Hawaiian islands.

The airforce... The 50 bombers I have outside CONUS (with experience in the 45-50-range) are right now on ground attack duty. I considered it to be utterly pointless to send those 30 B-17s and 20 B-18s/A-20s against the 80-Zero CAP only to have them drop their bombs harmlessly on or beside the 8 Jap BBs.

I have managed to reinforce Pearl with fighters though, and I think I can muster 150-something fighters to CAP right now.

[sfbaytf]

doesn't matter IMO. Just getting there is a major organizational accomplishment. Anyone who can plan, organize and carry out an invasion of Oahu has accomplished something big.

ORIGINAL: Chickenboy

ORIGINAL: sfbaytf
I'm waiting for the invasion of San Francisco AAR. Regardless of whether this is "gamey" or not you have to give credit for the audacity and the ability to plan and organize this feat.

Has the attack on Pearl Harbor / Oahu been successful? Did I miss an update indicating that the IJA forces have landed with supplies and have defeated the entrenched American forces?

Shall we see how this audacious enterprise unfolds with the infantry assault before we crown anyone's tactical or strategic genius or assault the game engine?

[Bullwinkle58]

Barber's Point would be my put-a-gun-to-my-head choice if I were a Japanese commander. But anywhere would be very difficult in winter.

[Smeulders]

ORIGINAL: Chickenboy

ORIGINAL: sfbaytf
I'm waiting for the invasion of San Francisco AAR. Regardless of whether this is "gamey" or not you have to give credit for the audacity and the ability to plan and organize this feat.

Has the attack on Pearl Harbor / Oahu been successful? Did I miss an update indicating that the IJA forces have landed with supplies and have defeated the entrenched American forces?

Shall we see how this audacious enterprise unfolds with the infantry assault before we crown anyone's tactical or strategic genius or assault the game engine?

What happens now to the land combat is completely irrelevant to whether or not the CD gun routine is wrong.

It seems that the main problem is the targeting of the CD guns. Instead of completely gutting the landing ships, which should probably be the priority when you're being invaded, they hit the PB ships. Another strange thing is that the PB ships don't sink during the combat. Looking at the size of the guns and the number of hits, nearly every PB should have sunk. They probably did, but only after the combat, leaving them to soak up a lot of damage that would have otherwise destroyed many a landing transport.

Another problem is of course the Japanese unloading bonus. I know it's necessary to let the Japanese do their early war expansion and it's probably not that unrealistic in the DEI/PI were there was almost no opposition on the landing beaches, but it isn't here. If the ships would have had to stay under those guns for multiple days to unload everything without the bonus, there wouldn't have been much left of the IJN.

[Nikademus]

ORIGINAL: Bluebook
512 shell hits is nothing since 80-90 percent of those hits were on the same 8-10 PBs.

Still, 512 shell hits shows that the coastal defenses were working. Thats alot of hits. In this case yes, the escorts took the brunt. I wish that were the case in the Joe/Nik game vs. the terrible Ozzers. In that particular, both escort and transports have taken fearsome damage from CD and army guns with far fewer hits.

Without the full picture of how the other defenses were set up vs. those of the attacker its hard to comment further outside the fact that the CD's were firing but didn't give you the results desired.

[Bullwinkle58]

ORIGINAL: Smeulders


It seems that the main problem is the targeting of the CD guns. Instead of completely gutting the landing ships, which should probably be the priority when you're being invaded, they hit the PB ships. Another strange thing is that the PB ships don't sink during the combat. Looking at the size of the guns and the number of hits, nearly every PB should have sunk. They probably did, but only after the combat, leaving them to soak up a lot of damage that would have otherwise destroyed many a landing transport.

I don't kow if it's a "problem", but I think there's probably code in the attack routines to say "shoot at those whom are shooting at thee." How many times have we all seen surface engagements where a tough warship TF hits an anchored invasion TF containing two PBs and an E and twenty AKs, and the cruisers and destroyers plug away at the escorts and leave the fat boys alone?

On the other point, it's an interesting question of perception. Maybe some folks here think the combat replay is real-time, in sequence, and others don't? Do the ships really sink after the engagement, or is that only when it's reported? Are those different caliber shells hitting that PB in sequence, or are they only reported that way? Maybe they all hit at once, or were fired all at once, and it only looks like those dumb gun-bunnies were shooting perfectly good taxpayer-provided ammo at previously-obliterated ships. Who knows? The guys who can see the code of course![:)]

[sfbaytf]

One thing you could be sure of. After Dec7th all suitable landing sites were defended and barbed wire and obsticles emplaced. Don't know if they were mined, but if so that would have been a major problem. I suspect the beaches were mined and minefields laid offshore.
 
I do agree the CD targeting does appear to be screwey, but can't say if this is just a one off situation. In my current game my opponent invaded PM and I moved a CD battery there and it butchered the landing ships. My opponent didn't screen them with a lot of PB's so I can't say.

[Smeulders]

BTW, for anyone interested, there is another AAR on a Pearl Harbour invasion by undercovergeek (Bloody Pacific if I recall correctly), he also got a lot of troops ashore. Actually taking the island does seem to become a long term project, looking at the results from his first shock attack.

[Ketza]

Well they were french.

[8D]

[Mike Scholl]

ORIGINAL: John Lansford
Plus, how did the IJN unload troops in an amphibious landing?  They didn't have any specialized landing craft, so did they just load the troops in smaller boats and send them towards the shore?  Those two Army divisions plus Marine and Naval forces are going to slaughter them before they reach the beach, in addition to the CD guns still operating.  I don't remember the exact number of 155mm guns on Oahu at the time but think it was somewhere in the several dozen range. 

Four dozen mobile 155 guns, plus another dozen mobile 9.2"howitzers. All having a number of pre-sighted and surveyed positions (panama mounts) available depending on which area the threat developed from (all of which were tied into the fire control network). No matter where the landings were to take place, the fixed defenses could be reinforced by up to 60 6.1"+ guns in short order.

[Bluebook]

ORIGINAL: Nikademus

Still, 512 shell hits shows that the coastal defenses were working.

Yes, which means that if anything is wrong with the situation that the Japs can land 75 000 troops from 350+ ships at Pearl Harbor without losing more than 1000 troops and 15 PBs, it must be with something else. The coastal defences were firing alright, but at what and why?

Without the full picture of how the other defenses were set up vs. those of the attacker its hard to comment further outside the fact that the CD's were firing but didn't give you the results desired.

All of the units were in combat mode, fully rested and well supplied. They were completely unharmed by air or naval attack. What more do you want to know?

[mjk428]

ORIGINAL: Rob Brennan UK

Kudos on both players for having a really out of the box war ! Wippl for thinking this up ! and BlueBook for taking it on the chin and carrying on !

I hope you both continue to have a fun game (as thats why we play it after all)

Got to say i am v v curious about the next few turns.

Arguing about the exact positon/facing of any CD guns in the game is utterly pointless. We all know that CD guns are treated as units not as historically placed and covering each piece of potential landing space. so stop arguing whats actually impossible to model in game and if you feel its unrealistic then argue ways to improve it, not just cry foul.

If my car is broken I don't have to tell my mechanic how to fix it, I just tell him what the problem is.

I agree with the kudos to both players. Neither deserves to be criticized for exploiting the system or for bad play. The Japanese player should always have the option to put his troops on ships and send them anywhere on the map. The Allied player should reasonably expect that extensive forts and guns would slaughter any invasions without heavy surface support.

I don't know if this particular result is because of the amphib bonus or a bug with the coastal gun routine, probably a combination of both. The amphib bonus is fine when sending tiny units to the many undefended bases the IJN has to secure in the early months. It's ridiculous when it allows troops to instantly jump off ship in the middle of a fight. The Japs were capable of many things but walking on water was not one of them.

I've had Jap troops land fully supplied and capture a base even when I sunk the entire invasion TF (PBs and AKs) on arrival (AE 1.0). That's pure BS. The amphib bonus should evaporate when an invasion is contested.

[Smeulders]

ORIGINAL: Bullwinkle58

ORIGINAL: Smeulders


It seems that the main problem is the targeting of the CD guns. Instead of completely gutting the landing ships, which should probably be the priority when you're being invaded, they hit the PB ships. Another strange thing is that the PB ships don't sink during the combat. Looking at the size of the guns and the number of hits, nearly every PB should have sunk. They probably did, but only after the combat, leaving them to soak up a lot of damage that would have otherwise destroyed many a landing transport.

I don't kow if it's a "problem", but I think there's probably code in the attack routines to say "shoot at those whom are shooting at thee." How many times have we all seen surface engagements where a tough warship TF hits an anchored invasion TF containing two PBs and an E and twenty AKs, and the cruisers and destroyers plug away at the escorts and leave the fat boys alone?

On the other point, it's an interesting question of perception. Maybe some folks here think the combat replay is real-time, in sequence, and others don't? Do the ships really sink after the engagement, or is that only when it's reported? Are those different caliber shells hitting that PB in sequence, or are they only reported that way? Maybe they all hit at once, or were fired all at once, and it only looks like those dumb gun-bunnies were shooting perfectly good taxpayer-provided ammo at previously-obliterated ships. Who knows? The guys who can see the code of course![:)]

On the first point, that might be in the code and it would also explain why in smaller landing TF the transports do get hit. The CD guns aren't being attacked by many time their number in PB boats, so they have a chance to shoot at other ships as well. Anyone know what doctrine would be for the USA in this instance ? Shoot at the transports or the escorts. Another interesting thing in this regard is that these PB may have doubled as transport/escort, remember that they nearly all have cargo capacity.

As for the second, it's pretty unrealistic that all the CD guns shoot at the same time, I'd imagine that to unload this kind of force the TF should have been in range for several hours, so if the code would only give one 'round' of fire (even if this means several shells from every CD gun)then this could be modelled better to account for ships sinking during the engagement and thus no longer being a target. I'd indeed be interested to know the devs opinion on this.

[Bluebook]

I just checked my sunk ships screen. According to that one (and barring the fog of war, naturally) the Jap losses were:

On the day of the invasion:
1 CL and 2 DD to mines


The day after the invasion:
1 xAK and 1 xAKL to CD guns
2 DD to CD guns
1 DD to mines

[Bullwinkle58]

ORIGINAL: Mike Scholl

ORIGINAL: John Lansford
Plus, how did the IJN unload troops in an amphibious landing?  They didn't have any specialized landing craft, so did they just load the troops in smaller boats and send them towards the shore?  Those two Army divisions plus Marine and Naval forces are going to slaughter them before they reach the beach, in addition to the CD guns still operating.  I don't remember the exact number of 155mm guns on Oahu at the time but think it was somewhere in the several dozen range. 

Four dozen mobile 155 guns, plus another dozen mobile 9.2"howitzers. All having a number of pre-sighted and surveyed positions (panama mounts) available depending on which area the threat developed from (all of which were tied into the fire control network). No matter where the landings were to take place, the fixed defenses could be reinforced by up to 60 6.1"+ guns in short order.

Well, yes and no.

This site http://www.northamericanforts.com/West/hi-north.html

shows a partial summary of some of Oahu's defenses, including Panama mounts. Many of them were either abandonned before the war began, or built sometime in 1942, but, for purposes of this thread's subject, not in January 1942. Lots of defenses were built on Oahu through 1944, and even into the late 1940s, but they didn't exist in the first months of the war.

[Smeulders]

Well, it looks like about every PB in that invasion fleet should have been lost as well, maybe WITPL can tell us something about this if he wants to.

[Mike Scholl]

As it is currently winter, I thought it would be interesting to check the current conditions for landing on Oahu

COASTAL HAZARD MESSAGE
NATIONAL WEATHER SERVICE HONOLULU HI
347 AM HST THU JAN 7 2010

HIZ001>003-006>008-012>014-016-017-019-020-023-026-080300-
/O.CON.PHFO.SU.W.0001.000000T0000Z-100108T1600Z/
NIIHAU-KAUAI WINDWARD-KAUAI LEEWARD-WAIANAE COAST-
OAHU NORTH SHORE-OAHU KOOLAU-MOLOKAI WINDWARD-MOLOKAI LEEWARD-
LANAI MAKAI-KAHOOLAWE-MAUI WINDWARD WEST-MAUI CENTRAL VALLEY-
WINDWARD HALEAKALA-KONA-KOHALA-
347 AM HST THU JAN 7 2010

...HIGH SURF WARNING REMAINS IN EFFECT UNTIL 6 AM HST FRIDAY...

SURF ALONG NORTH- AND WEST-FACING SHORES OF KAUAI AND NIIHAU WILL
RANGE FROM 25 TO 35 FEET WITH OCCASIONAL LARGER SETS TO 40 FEET
THROUGH TONIGHT.

SURF ALONG NORTH-FACING SHORES OF OAHU MOLOKAI AND MAUI WILL RANGE
FROM 25 TO 35 FEET THROUGH TONIGHT.

SURF ALONG WEST-FACING SHORES OF OAHU MOLOKAI LANAI KAHOOLAWE AND
THE BIG ISLAND WILL RANGE FROM 10 TO 20 FEET THROUGH TONIGHT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HIGH SURF WARNING MEANS THAT DANGEROUS...BATTERING WAVES WILL
POUND THE SHORELINE...PRODUCING EXTREMELY DANGEROUS SWIMMING
CONDITIONS AND DEADLY RIP CURRENTS.


20 to 40 foot waves along the West, North, and East shores. Yeah, a Japanese landing is going to be a real "cakewalk". The whole idea is a crock.

[Nikademus]

ORIGINAL: Bluebook

Yes, which means that if anything is wrong with the situation that the Japs can land 75 000 troops from 350+ ships at Pearl Harbor without losing more than 1000 troops and 15 PBs, it must be with something else. The coastal defences were firing alright, but at what and why?

Ultimately, bases and amphibious assaults are abstracted. The only differentiations are the strength of CD and army units that can fire back. The game also doesn't account for angles of fire and such. I keep hearing about Fortress Hawaii but i've been there. Its a big place. not all the CD's and guns can be everywhere fully effective. same for the troops. Ultimately its an abstraction and as such the game is impacted by randoms. My main point was to address the statement that "nothing happened" Something did happen, to the tune of 500+ shell hits. The escorts took the brunt in this case and yes, thats a pisser for you the defender, but not an indicator that something is broken by default. As mentioned, my own last amphib landing as Japan got shot to pieces by far weaker CD defenses. Bad rolls? perhaps. I'd even plastered the base beforehand and included surface TF's to bombard. Yet no "D-Day" occured and numerous Transport TF's got shot up badly and sunk. Game broken?

All of the units were in combat mode, fully rested and well supplied. They were completely unharmed by air or naval attack. What more do you want to know?

Full layout of all defenses including naval and air, how much air search, how much naval attack was allocated. Status of naval warships. Sub deployment etc. It looks like your opponent sailed in undeteted and unopposed. I saw no surface bombardments or air attacks. If thats the case he indeed got off lucky given the # of hits scored on the transports but is also indicative that he planned and planned very well for this attack. Was Pearl reinforced with more troops and planes? Where are the US carriers? Did intel give a hint to target. Those kinds of things. Again the "hint" is that your opponent planned a very intricate offensive.....but what of the defense? The argument i'm seeing repeatedly revolves around the CD's alone and what people think or assume they should have done (which suggests instant anhilation)

As to the size of the invasion...thats the game. Been that way, and will probably remain so. Either side, its easy to stage massive assaults and troop movements. There's no representation of the exponential impact logistically or administratively on invasions that exceed divisional size. With the amphib bonus, it is easier initially for the Japan side to do this quickly without full prep which is very helpful. The Adak invasion i staged with two divisions was badly hurt by lack of full prep.

Yet for all that....unless i'm mistaken...he hasn't actually taken Oahu yet right?

[John Lansford]

Mike,
 
Thanks for the exact numbers.  My book on the history of Oahu coast defenses mentioned the 155mm mobile guns and the preselected mount locations but I'd forgotten just how many were there.  Sixty 155mm guns firing from all angles at both the men on shore and the ships offshore would have been a complete nightmare, not even taking into account the 5", 6", 8", 12", 14" and 16" guns firing too, plus divisional artillery and any ships damaged but still operational in the harbor itself.
 
Bullwinkle,
 
The IJN will have charts but no way to take sightings on where they are once they get to Hawaii.  Do you think the navigational lights and lighthouses will be operating?  They will have errors in their positions and even a small error means they aren't shooting accurately at anything at night.  Please show me where any navy managed to disable fixed fortifications by shooting at them during night time.  The USN certainly didn't attempt it in the Pacific, and IIRC the French CD guns were engaged in the early morning when there was light to see them by.  Gunnery standards in the IJN, especially in their big units, was not all that good due to lack of practice.  It was certainly nowhere near the USN's standard and they bombarded in the day, not the night for lack of accuracy.
 
BTW, Barber's Point is in range of nearly every single fixed gun position on the south side of Oahu.  Good luck with having your fleet sitting offshore at that location.

[Bullwinkle58]

ORIGINAL: Smeulders
As for the second, it's pretty unrealistic that all the CD guns shoot at the same time, I'd imagine that to unload this kind of force the TF should have been in range for several hours, so if the code would only give one 'round' of fire (even if this means several shells from every CD gun)then this could be modelled better to account for ships sinking during the engagement and thus no longer being a target. I'd indeed be interested to know the devs opinion on this.

I'm sympathetic (increasingly so as I learn more about the game's finer points) to the dev's challenges though. A phase is 12-hours. Do you do one 12-hour "chunk" of calculations? Three 4s? One hour layers? Do you consider that some of the (sometimes hundreds) of ships in range of the CD guns move during those 12-hours? How often and where to/from? Is weather a factor? How often do you do a check on CD supplies? If they run out in the middle of the 12-hours, how do you handle that? How about time-to-sink? Do CD gunners still shoot at a Monty Python-esque damaged ship ("I'm getting better!") or do they look elsewhere? How do they know the damage over there, 12,000 yards away? And on and on. Hundreds of questions we all could pose onto what is only one, pretty small part of the total code base. And, once you make all these trade-offs, how do you present the results so they're clear, actionable, but still concise enough that anyone will read them?