Factors in Amphibious Landings

[durnedwolf]

1. Exceptions: Amphibious TFs and Landing Craft TFs are presumed to have an amphibious assault Mission and have different unloading rules that are not bound by Port Size restrictions, but the exemption only applies for ships ( APA, AKA, and LCx/LSx) that have an “Amphibious Unload Bonus” capacity. Any TF can load, unload or refuel when not docked, but at a much slower rate.

2. Indications: The total tonnage of ships that may “Dock” at a Port is given in the Port Information Screen. The total tonnage that comprises a TF is given in the TF Information Screen. When the TF is larger than the allowable Port Dock Limit, a player should consider sub-dividing the TF into “Dockable” portions.

6.3.3.3.2.1 OVER THE BEACH (Pg127/128)
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.

6.3.3.3.2.2 FRIENDLY PORT (Pg 128)
For Amphibious docked at and unloading in a friendly port of Size 4 or less, the unload rate is slightly different for Troops and Cargo.
»» Beaching Craft. Troops unload at a Rate of 1000 points per ship per turn. Cargo unloads at a Rate of 750 points per ship per turn.
»» Attack Amphibs. Troops unload at a Rate of 1000 points per ship per turn. Cargo unloads at a Rate of 750 points per ship per turn.
»» Regular Amphibs. Troops unload at a Rate of 300 points per ship per turn. Cargo unloads at a Rate of 300 points per ship per turn.
»» Merchant Ships. Troops unload at a Rate of 125 points per ship per turn. Cargo unloads at a Rate of 125 points per ship per turn.
Amphibious TFs not docked at a friendly port unload at a different rate, depending on port size, amount of free dock space, and the types of ships in the TFs. Amphibious ship types, with attached landing craft, will unload faster than non-amphibious ships.

Note the rate of points per turn. The morew ships you assign to the amphibious TF, the smaller each each ship's load. Enough ships in a TF and you can basically unload all of your troops on day one of the attack.

[rustysi]

I don't recall what may have been said earlier. Did you have an amphibious HQ loaded on whatever ship it needs to be loaded on?

I've only played the Japanese, and they don't have these, but the Allies do.

[Hano]

Yes, I had an amphibious HQ in an AGC as well as a corps HQ that hit the beach with them, the five complete marine divisions were all up to strength and rested.

I'm going to do some research looking back and checking some of the possible factors, some things that come to mind are:

The length of time they were embarked
The level of training
Leaders
level of photo reconnaissance
Inability to put the whole force on the beach in one hit
Bombardment duration
Lack of preparatory bombing

[LargeSlowTarget]

ORIGINAL: Hano

Bombardment duration
Lack of preparatory bombing

Compare with RL:

Starting on 15 June 1944, the U.S. Navy and the U.S. Army Air Forces began naval bombardments and air raids against Iwo Jima, which would become the longest and most intense in the Pacific Theater. They would contain a combination of naval artillery shellings and aerial bombings that went on for nine months.

https://en.wikipedia.org/wiki/Battle_of_Iwo_Jima


Beginning on February 16, 1945, the pre-landing bombardments were conducted by Task Force 54, commanded by Rear Admiral Wiliam H.P. Blandy, USN. The six battleships in the force were USS Arkansas (BB-33), USS New York (BB-34), USS Texas (BB-35), USS Nevada (BB-36), USS Idaho (BB-42) and USS Tennessee (BB-34). The five cruisers were USS Pensacola (CA-24), USS Salt Lake City (CA-25), USS Chester (CA-27), USS Tuscaloosa (CA-37), and USS Vicksburg (CL-81). Despite the lack of time for support, visibility, and bombardment effectiveness, the warships worked closer to shore to concentrate on the landing beaches and adjacent heights. On D-Day, February 19, three more battleships were added. The battleships were USS North Carolina (BB-55), USS Washington (BB-56), and USS West Virginia (BB-48), along with three additional cruisers USS Indianapolis (CA-35), USS Santa Fe (CL-60), and USS Biloxi (Cl-80). With all the weapons materiel delivered, the naval-gunfire support greatly reduced the Japanese defeneses but many of the determined enemy survived and bitterly fought in the campaign which nearly lasted a month.

https://www.history.navy.mil/content/hi ... dment.html

[RangerJoe]

With that many defenders there, bypass it and go somewhere that is not as heavily defended. Use Iwo Jima as a training ground for bombers and ships crews.

[HansBolter]

The real issue here is the ability of the Japanese defender to station a force on an island that the historical Japanese could never have afforded to do.

Solitaire play against an Ironman AI results in the same thing. The ironman AI over defends historical objectives to a degree that makes taking them impossible. I typically see 12-16 units defending Lunga in mid-42 and it just gets worse from there.

You can take a 6,000 capacity atoll defended by a brigade plus by landing a full division plus artillery, tanks and combat engineers, but you must immediately reload the division after taking the objective or overstacking will cause it to suffer tremendously.

You cannot hope to take an atoll, even a 30,000 capacity one that is overdefended, unless you isolate it, cut off and drain all supply and bomb and bombard it back into the stone age. All of this can take as long as six months to accomplish.

I play with stacking limits everywhere, that the AI ignores, but I cannot. This means there are quite a few overdefended locales that plan to bypass.

What is the strategic need in your game for you to take this insignificant fly speck of an island? Likely none, beyond historical nostalgia. If that is the case ditch the historical nostalgia because your opponent already did.

BYPASS, BYPASS, BYPASS!!!

[rustysi]

From the point of view of a Japanese player, I can tell you when places like this are so heavily defended someplace is that much worse off.

So, hit 'em where they ain't.[8D]

[Hano]

Thanks for the information and food for thought.
My strategy has been to aim to split Japan from its conquered territories as early as possible taking the minimum amount of territory and aiming to reduce/eliminate the flow of supply by sea and eliminate the Japanese military’s ability to interfere with this.
In practice this has meant that the British/Australians/Indians with US support have taken Thailand/Indochina, with the Japanese pushed back to South of Victoria Point and East of Haiphong, large airbases are being built so they can range over the Phillipine Sea .
In the Pacific - New Guinea, the Solomons and Phillipines have been bypassed, with key bases held at Milne Bay, Rabaul, Truk, Guam, Wake Island and Marcus Island, the remaining areas largely Japanese held but with little movement between them and no supply, where there are significant airbases, they are raided daily to keep them degraded.
The plan is to take Iwo Jima, Okinawa and Formosa to enable US forces in the PAO to link up with the Brits in SE Asia and enable secure supply, build up airbases to dominate the South China Sea and to base B29's on Formosa to raid the home islands use other aircraft and naval units, surface & submarine to enforce the blockade and degrade Japanese industry/military to prepare for a ground invasion of Japan.
So far I’m in Aug 44, I have destroyed 8 CV & 5 CVL and 10 BB leaving only Yamato & Yamashiro, for the loss of one CV & 2 CVE plus seven BB although I have a couple being panel beaten as we speak.

[Ian R]

... the Japanese pushed back to South of Victoria Point and East of Haiphong, large airbases are being built so they can range over the Phillipine Sea .

The supply movement down the tracks from Moulmein, and across from Victoria Point, will not likely feed enough supply into Vietnam to support a B-29 campaign to bomb down the oil soyrces, & shut down the big airbases on the PI. You need to get down to at least Alor Star, which is only a small port, but it is on the railway and you can put hundreds of nav support in there. Likewise Georgetown, which can be built to a 6 level port, and has a primary road link to Taiping and the rail line.

Really though, you need to push all the way to Singapore, which not only allows you to land massive supplies, interdict shipping to Palembang/Oosthaven, gets you a repair shipyard in a 9 port, and threatens the IJ hold on the NEI, but is also worth 2430 VP.

[Hano]

ORIGINAL: LargeSlowTarget

ORIGINAL: Hano

Bombardment duration
Lack of preparatory bombing

Compare with RL:

Starting on 15 June 1944, the U.S. Navy and the U.S. Army Air Forces began naval bombardments and air raids against Iwo Jima, which would become the longest and most intense in the Pacific Theater. They would contain a combination of naval artillery shellings and aerial bombings that went on for nine months.

https://en.wikipedia.org/wiki/Battle_of_Iwo_Jima


Beginning on February 16, 1945, the pre-landing bombardments were conducted by Task Force 54, commanded by Rear Admiral Wiliam H.P. Blandy, USN. The six battleships in the force were USS Arkansas (BB-33), USS New York (BB-34), USS Texas (BB-35), USS Nevada (BB-36), USS Idaho (BB-42) and USS Tennessee (BB-34). The five cruisers were USS Pensacola (CA-24), USS Salt Lake City (CA-25), USS Chester (CA-27), USS Tuscaloosa (CA-37), and USS Vicksburg (CL-81). Despite the lack of time for support, visibility, and bombardment effectiveness, the warships worked closer to shore to concentrate on the landing beaches and adjacent heights. On D-Day, February 19, three more battleships were added. The battleships were USS North Carolina (BB-55), USS Washington (BB-56), and USS West Virginia (BB-48), along with three additional cruisers USS Indianapolis (CA-35), USS Santa Fe (CL-60), and USS Biloxi (Cl-80). With all the weapons materiel delivered, the naval-gunfire support greatly reduced the Japanese defeneses but many of the determined enemy survived and bitterly fought in the campaign which nearly lasted a month.

https://www.history.navy.mil/content/hi ... dment.html

Its really interesting, I get very frustrated that we cant do this in WIP AE, if I'm bombarding IJ - in 24hrs I expend 90% of main armourment and have two days steaming to Guam to reload, realistically bombardment becomes a five day cycle making it impossible to maintain a constant naval bombarment. I'm not a naval officer, never have been, never will be, but I cant believe that the respective navies where incapable of replening Main Armourment at sea until 1945?

[Hano]

Hi Ian,

Thanks, the plan is to open up Bangkok, Saigon & Cam Ranh Bay and by securing Formosa to allow direct supply from the US via Bonins, Okinawa and Formosa, which is why IJ was key to supporting ops against Okinawa, with Okinawa supporting ops against Formosa.

I was considering forcing a 200 000 unit of supply convoy with significant carrier escort into Bankok/Saigon/Cam Ranh Bay to give me the supply to get air power established there to supress air units in the Phillipines/Chinese mainland.

I'm considering parking my game and going back six months to see what effect different actions have on IJ, I must confess I had become complacent having walkovers at Truk, Wake, Marcus Islands & Guam

[Ian R]

What you want is 500,000 supply convoys of Sam & Fort ships from Aden to Saigon/Hong Kong, sailing under fighter cover along the east Asian Coast. Once you have Singapore this is much easier than pushing across the Pacific.

[Hano]

Interesting you say that...my other option or option in conjunction was to run a similar sized convoy through from the Indian Ocean, but probably running West of Sumatra and popping between Osthaven/Batavia and then running between Malaya & Borneo. The big if about this is th Yamato that was operating out of Singapore, I managed to damage her earlier in the year, extent unknown. I have five CV (incl 2 x Essex Class), two CVL and five CVE operating with three BB and a BC out of Colombo and I'm desperate to try an Operation Pedestal and put a couple of 100 K of supply into Bankok, but I need to do a lot of recce before I'm ready to commit to it.

[RangerJoe]

Stockpile supplies in Australia and go up the Eastern DEI to interdict from there. You can move into the Philippines where there should be islands with no defenders or only lightly defended. You can also take bases on the north side of Borneo and the west side of New Guinea to support this.

[rustysi]

but I cant believe that the respective navies where incapable of replening Main Armourment at sea until 1945?

Could be a constraint put in by the Dev's for any number of reasons.

[GetAssista]

ORIGINAL: Hano
... but I cant believe that the respective navies where incapable of replening Main Armourment at sea until 1945?

https://www.history.navy.mil/content/hi ... e-sea.html

"On 23 February 1945, the USS Shasta (AE-6) conducted the first underway ammunition replenishment"

[RangerJoe]

How fast can you move a 1 ton artillery shell between ships that are moving up and down as well as sideways in respect to each other?

[jmalter]

For any phib assault, *especially* against an atoll, you must bring LOTS of supply. Include cargo transports loaded only w/ supply in the initial wave as well as the 2nd-wave TF. Of course you want to banjo the defenders w/ max Assault Value, but they have no combat value if they have no supply. Your initial assault will overload the the target's stacking limit, & the game engine will penalize you by removing your units' supply.
On the 2nd day of the assault, you must be unloading supply into the target hex, in advance of the next ground combat phase.