Slitherine

quote:

ORIGINAL: poodlebrain

The more I look at this matter the more convinced I am that any Japanese invasion would have to be an attempted knock out blow aimed at achieving an autovictory. There is no real possibility of the forces committed surviving in the long-term, and withdrawing them would not be practical from a fuel use perspective. So any invasion is a one way mission resulting in Japanese victory or ultimate defeat since recovering from the losses would be impossible. Think of it as early kamikaze missions with land units. The VPs committed to the missions are as good as lost, it is the VPs that they can gain that will determine success or failure. The window of opportunity for such a knock out punch is pretty narrow. So it shouldn't be too difficult to plan your defense.

Can a Japanese invasion possibly succeed without capturing a port? It's not likely that he can secure the port of any of the critical bases with a direct assault landing. The existing coastal defense artillery would have a field day with the invasion fleet traveling at AP and AK speeds, and the Japanese simply do not have the forces to suppress the coastal defenses. The disruption to his LCUs would make a successful attack unlikely. So he will probably have to land at an adjacent base, without fixed coastal defenses, and secure the port before advancing to one of the critical bases. Looking at the geography and terrain, it would be difficult or impossible, to accomplish this anywhere except Los Angeles or San Diego. Los Angeles looks like a tougher nut to crack based on its terrain defensive value. So I would make defending San Diego my primary focus. Looking back, you already have 3ID at San Diego. It shouldn't take much more to get an adjusted AV of better than 3,500 for the defense.

What would it take in terms of forces for the Japanese to capture San Diego? A whole lot, in fact just about everything he has now and everything he can scrape together. That means just about everything that can sail to transport LCUs and supply. Protecting that much shipping will limit the role of the KB and surface combatants. Your naval forces should be able to pick and choose battles. His transports withdrawing from the assault landings should be especially vulnerable since they will be without CAP with the KB having to protect the troops on the ground. Conserving PT boats so you can create several squadrons for harassment purposes is an obvious ploy. Getting your carriers between the invasion force and Hawaii is another no-brainer. So having a few AO ready to allow them to patrol outside the reach of Hawaiian LBA and far enough from the WC that the KB would have to abandon covering the invasion forces makes sense. If you can get them to San Francisco, or one of the other nearby ports, you would be able to flank him from a relatively safe location. It would be nice to get the bulk of your surface combatants to San Diego and Los Angeles to give the KB something to worry about other than just supporting the land campaign.

You should hope for a Japanese invasion of the WC at this point. It is at best a long shot proposition for him, and a golden opportunity for you.

quote:

ORIGINAL: Lokasenna
IMO, with forts 6 at Noumea... you don't need to keep building them. Save your supplies. Not usually a sentence you see as the Allies, but it's hard enough for you to ship assets in, why make it harder by increasing the need?

I'd consider starting to build the airfield up a bit. At least to level 5, so that you can handle B-17s normally. Then maybe the port after that... if you know you're going to use the base, then there's no reason not to build it up now. With his force allocations as they are in India and NORPAC, there's no way he can come take a Forts 6 Noumea from you. So build it up. Start threatening places later this year.

quote:

ORIGINAL: Lokasenna
Another consideration is Noumea's VP multiplier for you . You may want that come 1/1/1943.

quote:

ORIGINAL: JocMeister

Good points and I certainly agree on that it would be for AV if he comes.

No turn from Jeff yet so I spent a good deal of time looking at the map and ship arrivals. As well as my defense...which is lacking. I simply donŽt have enough troops to cover everything so I have to rely on SIGINT to give me early warning. Whatever he does he has to prepp and that should hopefully give me some warning.

This is pretty much a two edged sword for me. I donŽt want to commit a huge amount of forces to defend WC against an invasion that most likely wonŽt come. So IŽll have to try and find some kind of middle ground here. And to be honest I think a WC invasion is quite unlikely. If he is coming why didnŽt he do so right away?

IŽll divert some engineers to building forts and let the forces currently on the WC stay there. IŽll push my subs out a bit to give some warning. I see three likely targets. SD/LA area, Portland/Seattle and SF/Alemeda. IŽll form a mobile reserve sitting at SF in stratmode.

If he comes my biggest allied will be his slow unloading. He will have to unload from xAKs/xAPs either in amphibious mode which is extremely slow or in strat mode on a very low level port which is equally slow. Couple that with SIGINT and I should have quite a bit of time to react.

EDIT: Does Japan even have the lift capacity to move the needed 10+ divisions? IŽm just thinking about my Moppo invasion against Erik (was probably around 10 IDs) which was problematic even for the Allies in 45.

IŽll make an update on the WC situation during the day. Home sick AGAIN.

quote:

ORIGINAL: Lokasenna
It isn't as hard as it sounds to land from xAPs and xAKs as Japan. The low load cost of their devices (relatively speaking) means more of them unload, and they also have a number of large AK, LSD, and AMC ships available that will all unload at accelerated rates. I landed 3+ divisions and a dozen (or more) supporting units without struggling for shipping in late 1942.

quote:

ORIGINAL: JocMeister

quote:

ORIGINAL: Lokasenna
It isn't as hard as it sounds to land from xAPs and xAKs as Japan. The low load cost of their devices (relatively speaking) means more of them unload, and they also have a number of large AK, LSD, and AMC ships available that will all unload at accelerated rates. I landed 3+ divisions and a dozen (or more) supporting units without struggling for shipping in late 1942.

Hmm, hadnŽt considered that...

An educated guess (if you dare! ). How many days would it take to unload 8-12 IDs as Japan over a bad port/amphibious? 3-5 days?

Could you even find enough transports for that?

PS. He lost 3 of the big AKs and 3 big AMCs.

quote:

ORIGINAL: Lokasenna

quote:

ORIGINAL: JocMeister

quote:

ORIGINAL: Lokasenna
It isn't as hard as it sounds to land from xAPs and xAKs as Japan. The low load cost of their devices (relatively speaking) means more of them unload, and they also have a number of large AK, LSD, and AMC ships available that will all unload at accelerated rates. I landed 3+ divisions and a dozen (or more) supporting units without struggling for shipping in late 1942.

Hmm, hadnŽt considered that...

An educated guess (if you dare! ). How many days would it take to unload 8-12 IDs as Japan over a bad port/amphibious? 3-5 days?

Could you even find enough transports for that?

PS. He lost 3 of the big AKs and 3 big AMCs.

1-2 days with a proper loading spread. A Yusen-A AKs has a capacity of ~5K for an amphibious max load of ~4K, so will fully unload in 7 phases (3.5 days), so if making sure that you have slightly more than enough capacity then it will unload in 3 days (up to 3600 load for 6 phases). Yusen-N class are roughly the same size, and Kyushu class are slightly smaller (around 4600). Husimi are around 4000.

If he has any Yusen-S, those are around 5500. This is before converting to AK-t, which drops the total load somewhat in favor of better troop loading.

The LSDs have the landing ship unload rate, which is 1750 per phase IIRC? Maybe it's 1250. There are 4 LSDs in the OOB.

There are 12 AMC's in the Scen 2 IJN OOB.

In my Scen 2 OOB, there are 134 total possible AKs (many start as xAKs and need converting to AKs).

quote:


6.3.3.3.2.1 OVER THE BEACH

This is for assault unloading over the beach.

» Beaching Craft. Beaching craft unload completely in one turn.
» Attack Amphibious Ships. (APA/AKA plus LSD, LSV and British equivalents)
in Amphibious TFs, unload at a Rate of 3000 points per ship, per turn.
» Regular Transport Ships. (Commissioned Naval AP/AK) in Amphibious
TFs, unload at a Rate of 600 points per ship per turn.
» Merchant Ships. (xAP/xAK) in Amphibious TFs, unload
at a Rate of 250 points per ship per turn.
» Special Japanese early war bonus of 1200 for all AP/AK and xAP/xAK types.

quote:

ORIGINAL: Canoerebel

Joc, I've mentioned before that I faced the possibility of a Japanese invasion of the West Coast in a game I played several years ago. The circumstances were different as I knew the threat had passed by late spring of '42, but I understand the issues you are evaluating. I have a few suggestions that you've probably already considered, but perhaps they may be of help:

1. I parceled out units to every base in North America to guard against paratroop assault. A small unit and a fort or two is generally sufficient to protect interior bases. It seemed funny to have the U.S. Marine patroopers garrisoning places like Regina and Wendover Field, but doing so provided alot of peace of mind.

2. Strat Mode was my friend. I placed my strongest units at critical junctions (even if in the interior) and left them in strat mode. That way, I could rail them in almost instantaneously to high-value targets. Thus, I had 32nd USA division at an interior base where it could react to an invasion of Prince Rupert or Seattle/Tacoma/Portland quickly. (This is assuming that strat-mode units can still rail into a hex in which the enemy has arrived but is still under Allied control.)

3. The Allied position should be considerably stronger as the summer wanes and autumn begins.

4. Don't lose sight of high value bases that Lowpe might seize for AV purposes, but don't go out on a branch to defend them either. Noumea and Suva offer alot of points for him. Those are vulnerable even in late '42 if he wants them. So don't risk too much in an effort to keep them - you risk losing vast numbers of ground troops and naval assets if you create a situation in which you feel you have no choice but to maximize the effort to defend. You don't need Suva and Noumea to win the game.

quote:

ORIGINAL: Lokasenna

quote:

ORIGINAL: witpqs

quote:

ORIGINAL: JocMeister

quote:

ORIGINAL: Lokasenna

quote:

ORIGINAL: witpqs

Thanks guys!

So its reasonable to expect the 1st wave to come ashore on the 1st day which would be followed up by the rest in about 3 days (if no hiccups occur)? Add naval detection and movement of about 6 hexes/day and I could possibly have as much as 4-5 days from detection to the first IDs are landed. In 6-8 days he could have landed everything he needs.

Should give me plenty of time to react accordingly.

Since IŽm home from work IŽll look into the WC defense tomorrow. Going to read up on Japanese shipping too. CanŽt find any AKVs in the starting OOB. Assume Japan can convert some shipping into AKVs? How about Navsupport? Does Japan get any "boat and shore" units like the allies do in DBB?

quote:

ORIGINAL: Lokasenna

You can convert some to AKVs from the Lima and Aden class ships, of which there are relative multitudes... I'm not sure when the conversions are available (might not be until 06/1942). I also don't know the conversion time for them, but it's got to be less than the 120 and 180 days to convert to AVs. It might be 21 days? I'm not very confident in that guess but it's my best without looking in-game. The Lima class is big, 6475 tons and 12000 endurance. 14 knots. The aden class is 4875 tons, 9400 endurance, and 12 knots.

I should also point out that again, I'm reading both sides, so am trying to keep my comments technical and meta in nature in both. Let me know if I step over a line.

As mentioned, ops points burn and such can reduce the amount unloaded in a phase, and there are 2 phases per game day (exactly how this interacts with the 4 observed unloading/CD gunfire phases in the game, I don't know, but I have a guess there as well).

quote:

ORIGINAL: Lokasenna

quote:

ORIGINAL: JocMeister

quote:

ORIGINAL: Lokasenna

quote:

ORIGINAL: witpqs

Thanks guys!

So its reasonable to expect the 1st wave to come ashore on the 1st day which would be followed up by the rest in about 3 days (if no hiccups occur)? Add naval detection and movement of about 6 hexes/day and I could possibly have as much as 4-5 days from detection to the first IDs are landed. In 6-8 days he could have landed everything he needs.

Should give me plenty of time to react accordingly.

Since IŽm home from work IŽll look into the WC defense tomorrow. Going to read up on Japanese shipping too. CanŽt find any AKVs in the starting OOB. Assume Japan can convert some shipping into AKVs? How about Navsupport? Does Japan get any "boat and shore" units like the allies do in DBB?

You can convert some to AKVs from the Lima and Aden class ships, of which there are relative multitudes... I'm not sure when the conversions are available (might not be until 06/1942). I also don't know the conversion time for them, but it's got to be less than the 120 and 180 days to convert to AVs. It might be 21 days? I'm not very confident in that guess but it's my best without looking in-game. The Lima class is big, 6475 tons and 12000 endurance. 14 knots. The aden class is 4875 tons, 9400 endurance, and 12 knots.

I should also point out that again, I'm reading both sides, so am trying to keep my comments technical and meta in nature in both. Let me know if I step over a line.

As mentioned, ops points burn and such can reduce the amount unloaded in a phase, and there are 2 phases per game day (exactly how this interacts with the 4 observed unloading/CD gunfire phases in the game, I don't know, but I have a guess there as well).

quote:

ORIGINAL: JocMeister

....

In my game against Erik I perfected the art of unloading in just 2 phases. As you say a lot of things can effect unloading. A mine hit, some ship deciding to refuel, an unwanted reaction, sub attack etc etc...

...

quote:

ORIGINAL: JocMeister

quote:

ORIGINAL: Lokasenna

You can convert some to AKVs from the Lima and Aden class ships, of which there are relative multitudes... I'm not sure when the conversions are available (might not be until 06/1942). I also don't know the conversion time for them, but it's got to be less than the 120 and 180 days to convert to AVs. It might be 21 days? I'm not very confident in that guess but it's my best without looking in-game. The Lima class is big, 6475 tons and 12000 endurance. 14 knots. The aden class is 4875 tons, 9400 endurance, and 12 knots.

I should also point out that again, I'm reading both sides, so am trying to keep my comments technical and meta in nature in both. Let me know if I step over a line.

As mentioned, ops points burn and such can reduce the amount unloaded in a phase, and there are 2 phases per game day (exactly how this interacts with the 4 observed unloading/CD gunfire phases in the game, I don't know, but I have a guess there as well).

Thanks, IŽll look it up tomorrow. Will give me something to do to pass the time.

In my game against Erik I perfected the art of unloading in just 2 phases. As you say a lot of things can effect unloading. A mine hit, some ship deciding to refuel, an unwanted reaction, sub attack etc etc...

So I think my estimates are on the safe side. I would be amazed if he could unload 2-3 IDs in the first turn. I could do that with APA/AKAs but that was without any extra supply. But then again if the Japanese IDs are that much lighter...IŽll see if I can sandbox something tomorrow.

quote:

ORIGINAL: Uncivil Engineer

quote:

ORIGINAL: Lokasenna

quote:

ORIGINAL: JocMeister

quote:

ORIGINAL: Lokasenna

quote:

ORIGINAL: witpqs

Thanks guys!

So its reasonable to expect the 1st wave to come ashore on the 1st day which would be followed up by the rest in about 3 days (if no hiccups occur)? Add naval detection and movement of about 6 hexes/day and I could possibly have as much as 4-5 days from detection to the first IDs are landed. In 6-8 days he could have landed everything he needs.

Should give me plenty of time to react accordingly.

Since IŽm home from work IŽll look into the WC defense tomorrow. Going to read up on Japanese shipping too. CanŽt find any AKVs in the starting OOB. Assume Japan can convert some shipping into AKVs? How about Navsupport? Does Japan get any "boat and shore" units like the allies do in DBB?

You can convert some to AKVs from the Lima and Aden class ships, of which there are relative multitudes... I'm not sure when the conversions are available (might not be until 06/1942). I also don't know the conversion time for them, but it's got to be less than the 120 and 180 days to convert to AVs. It might be 21 days? I'm not very confident in that guess but it's my best without looking in-game. The Lima class is big, 6475 tons and 12000 endurance. 14 knots. The aden class is 4875 tons, 9400 endurance, and 12 knots.

I should also point out that again, I'm reading both sides, so am trying to keep my comments technical and meta in nature in both. Let me know if I step over a line.

As mentioned, ops points burn and such can reduce the amount unloaded in a phase, and there are 2 phases per game day (exactly how this interacts with the 4 observed unloading/CD gunfire phases in the game, I don't know, but I have a guess there as well).

Aden class xAK can convert to AKV starting April 42, takes 30 days in size 5 shipyard. There are > hundred Aden class.

Lima class xAK can convert to AKV starting February 42, takes 30 days in size 5 shipyard. These are not nearly as plentiful as Aden class.

Yusen A (AK) carries 385 troops (so quick unload), but can convert to -t and carry 1585 troops, which lengthens unload time. There are only a few of these.

Yusen S (AK) carries 410 troops, and can convert to -t and carry 1685. Very few available.

I haven't counted ships, or given much thought to a WC invasion, but in my experience playing Japan, it's conceivable to unload 3 divisions (~45000 troop load) in one day if every transport ship was available to that end. More than 3 divs would be questionable in my opinion. Most of the Aden class ships are usually tied up transporting resources, but that could easily be put on hold. They would need many days to transit the Pacific to pick up their new load, and SIGINT may give you a clue that that is happening.

quote:

ORIGINAL: richlove

quote:

ORIGINAL: JocMeister

....

In my game against Erik I perfected the art of unloading in just 2 phases. As you say a lot of things can effect unloading. A mine hit, some ship deciding to refuel, an unwanted reaction, sub attack etc etc...

...

Can we digress on this for a comment or two? What was your secret?

quote:

ORIGINAL: poodlebrain

If you are able to detect an invasion fleet 4-5 days out, then you should have no trouble interfering with his assault and unloading. PT boats to keep his escorts busy and burn their Op points. Then follow up sorties by heavier surface combatants to fight their way in among the transports. This should extend the unloading time, and leave his transports more vulnerable to attacks from air, sea and coastal defense.

I think I would try to get as much of the U.S. Navy as possible to the San Francisco Bay bases while the KB is not on station off the WC. From the SF area your navy would be in position to support the defense of any likely invasion site. I doubt the Japanese will seek a pre-invasion decisive naval battle while your fleet is under the protection of air power in superior numbers. You could operate your carrier air units from the land bases, and disband your carriers at Mare Island or Alameda depending on the IJN's approach vector. This would require the Japanese to make a port strike into the teeth of 3 mutually supporting airfields to attack your valuable ships. That is not a winning proposition at this point in the game unless the Japanese can achieve a Pearl Harbor type surprise.

quote:

ORIGINAL: JocMeister

CanŽt move the USN to the WC as I canŽt cover them from the KB for more then 2-3 days before KB sweeps would have blasted away my CAP and completely drained my pools. Any ships still on the WC after that would be easy pickings for the KB.

quote:

ORIGINAL: Lokasenna

quote:

ORIGINAL: Uncivil Engineer

quote:

ORIGINAL: Lokasenna

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ORIGINAL: JocMeister

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ORIGINAL: Lokasenna

quote:

ORIGINAL: witpqs

Thanks guys!

So its reasonable to expect the 1st wave to come ashore on the 1st day which would be followed up by the rest in about 3 days (if no hiccups occur)? Add naval detection and movement of about 6 hexes/day and I could possibly have as much as 4-5 days from detection to the first IDs are landed. In 6-8 days he could have landed everything he needs.

Should give me plenty of time to react accordingly.

Since IŽm home from work IŽll look into the WC defense tomorrow. Going to read up on Japanese shipping too. CanŽt find any AKVs in the starting OOB. Assume Japan can convert some shipping into AKVs? How about Navsupport? Does Japan get any "boat and shore" units like the allies do in DBB?

You can convert some to AKVs from the Lima and Aden class ships, of which there are relative multitudes... I'm not sure when the conversions are available (might not be until 06/1942). I also don't know the conversion time for them, but it's got to be less than the 120 and 180 days to convert to AVs. It might be 21 days? I'm not very confident in that guess but it's my best without looking in-game. The Lima class is big, 6475 tons and 12000 endurance. 14 knots. The aden class is 4875 tons, 9400 endurance, and 12 knots.

I should also point out that again, I'm reading both sides, so am trying to keep my comments technical and meta in nature in both. Let me know if I step over a line.

As mentioned, ops points burn and such can reduce the amount unloaded in a phase, and there are 2 phases per game day (exactly how this interacts with the 4 observed unloading/CD gunfire phases in the game, I don't know, but I have a guess there as well).

Aden class xAK can convert to AKV starting April 42, takes 30 days in size 5 shipyard. There are > hundred Aden class.

Lima class xAK can convert to AKV starting February 42, takes 30 days in size 5 shipyard. These are not nearly as plentiful as Aden class.

Yusen A (AK) carries 385 troops (so quick unload), but can convert to -t and carry 1585 troops, which lengthens unload time. There are only a few of these.

Yusen S (AK) carries 410 troops, and can convert to -t and carry 1685. Very few available.

I haven't counted ships, or given much thought to a WC invasion, but in my experience playing Japan, it's conceivable to unload 3 divisions (~45000 troop load) in one day if every transport ship was available to that end. More than 3 divs would be questionable in my opinion. Most of the Aden class ships are usually tied up transporting resources, but that could easily be put on hold. They would need many days to transit the Pacific to pick up their new load, and SIGINT may give you a clue that that is happening.

Keep in mind that the Japanese have favorable troops-in-cargo-space calculations... with 130 or so AK-t's, you can unload a ton of troops. Way more than 45,000.

quote:

ORIGINAL: JocMeister

Uncivil Engineer, Loka

Thanks for the input. Looks like shipping per see wouldnŽt be a problem. So 3 IDs on the first wave seems pretty reasonable to expect. The rest would have to come by xAK/xAPs.

This probably means landing right on the intended target is very unlikely. Which would buy me more time.

quote:

ORIGINAL: Bullwinkle58
True to an extent, but there are a lot of ports to hide them in. I doubt he has the assets to recon every port every day, or even every week. But I do think DDs are you friend here. I'd leave the cruisers somewhere safer.

quote:

ORIGINAL: Uncivil Engineer
The vast majority will be on xAK or xAP - there are not enough AK or AP to carry much more than 1 division.
As I mentioned in the previous post, 122 Aden class xAK are required to unload 3 divisions in one day (after the early war bonus). Converting them to -t allows more troops to be carried, but lengthens the unload time.

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ORIGINAL: JocMeister

Probably not. But if he knew they bulk of the USN was disbanded in port(s) somewhere close by he would probably do what he could to find them!

quote:

ORIGINAL: Bullwinkle58

quote:

ORIGINAL: JocMeister

Probably not. But if he knew they bulk of the USN was disbanded in port(s) somewhere close by he would probably do what he could to find them!

Fixed it.

Every port foray he mounts is one less strat bombing mission. A DD is 10 VPs.