Atoll invasion

[JocMeister]

So I invaded Canton Island. I kind of expected to fail but not get annihilated. So, what did I do wrong?
All troops were 100% prepped. Everything unloaded, no fragments. Best leaders.

Here is the combat report:

Ground combat at Canton Island (153,143)

Japanese Bombardment attack

Attacking force 4511 troops, 22 guns, 0 vehicles, Assault Value = 194

Defending force 7239 troops, 103 guns, 299 vehicles, Assault Value = 325

Japanese ground losses:
53 casualties reported
Squads: 0 destroyed, 5 disabled
Non Combat: 0 destroyed, 2 disabled
Engineers: 0 destroyed, 0 disabled



Assaulting units:
5th Armored Car Co
4th Garrison Unit
52nd Naval Guard Unit
53rd Construction Battalion
50th JNAF Coy

Defending units:
767th Tank Battalion
766th Tank Battalion
34th Combat Engineer Regiment
21st Marine Regiment


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

Ground combat at Canton Island (153,143)

Allied Shock attack

Attacking force 5919 troops, 100 guns, 271 vehicles, Assault Value = 325

Defending force 5407 troops, 26 guns, 31 vehicles, Assault Value = 190

Allied adjusted assault: 0

Japanese adjusted defense: 232

Allied assault odds: 1 to 99 (fort level 5)

Combat modifiers
Defender: forts(+), disruption(-), experience(-)
Attacker: shock(+), disruption(-)

Japanese ground losses:
32 casualties reported
Squads: 0 destroyed, 4 disabled
Non Combat: 1 destroyed, 1 disabled
Engineers: 0 destroyed, 0 disabled
Vehicles lost 14 (4 destroyed, 10 disabled)


Allied ground losses:
1819 casualties reported
Squads: 64 destroyed, 88 disabled
Non Combat: 92 destroyed, 56 disabled
Engineers: 5 destroyed, 9 disabled
Guns lost 57 (14 destroyed, 43 disabled)
Vehicles lost 258 (196 destroyed, 62 disabled)
Units destroyed 1


Assaulting units:
34th Combat Engineer Regiment
767th Tank Battalion
766th Tank Battalion
21st Marine Regiment

Defending units:
5th Armored Car Co
4th Garrison Unit
52nd Naval Guard Unit
53rd Construction Battalion
50th JNAF Coy

Its a pretty severe adjustment from 325 to 0?! [X(] One of the tank battalions are destroyed. The other one pretty much wiped out. The Marines took heavy disablements but are pretty okay given the adjusted AV. The engineers are completely UNTOUCHED? 3 disabled support and thats it?

So what went wrong? [X(]

[Bullwinkle58]

Offhand I'd say it was the Forts 5 in combo with not enough engineers and not nearly enough infantry to soak up the Shock mechanics. But mostly the Forts.

What was your prep like?

[btbw]

Sorry what tanks have Tank Battalions?

[JocMeister]

Bullwinkle, They were all 100% prepped!

btbw, I think they had light tanks. M5s.

This was my first ever attempt at an atoll invasion and I had read up on it using many tanks, engineer regiment. As AV heavy as possible so the speak. Didn´t seem to work out very well. Pretty shocked by the adjusted AV tbh!

[Puhis]

Also Japan had good amount of AV, thanks to 4th guard unit.

(I must wonder, why would anyone transport IJA Armored car company to Pacific? [&:] Any kind of infantry unit would be better...)

[Bullwinkle58]

ORIGINAL: JocMeister

Bullwinkle, They were all 100% prepped!

btbw, I think they had light tanks. M5s.

This was my first ever attempt at an atoll invasion and I had read up on it using many tanks, engineer regiment. As AV heavy as possible so the speak. Didn´t seem to work out very well. Pretty shocked by the adjusted AV tbh!

No, I meant island prep. Bombarment, air, etc.

[Crackaces]

ORIGINAL: Bullwinkle58

ORIGINAL: JocMeister

Bullwinkle, They were all 100% prepped!

btbw, I think they had light tanks. M5s.

This was my first ever attempt at an atoll invasion and I had read up on it using many tanks, engineer regiment. As AV heavy as possible so the speak. Didn´t seem to work out very well. Pretty shocked by the adjusted AV tbh!

No, I meant island prep. Bombarment, air, etc.

Dive bombers and BB's might not kill a lot of troops, but it will cause disruption .. this I believe disruption has a huge "hidden" affect on adjusted AV. I put hidden in quotes because we understand disabled squads which directly effects AV in ratio to numbers and types of troops, but disruption and fatigue in my observation have devastating effects in shock combat -- inlcuding the damaged doled out along with overall AV to hold a hex.

One thing about disruption on an atoll given the inability to cause damage it provides the second chance to get most stuff ashore .. the enemy not being disurpted gives the enemy a chance at a bad die roll (from the attackers perspective) and wipe the invaders out ...

Just a thought ...

[Rainer]

Fort Level 5 is too high (needs softening by air and ship bombardement)
Net AV ratio 325:194 is too low, at least for me.
I prefer 3:1 if at all possible for an assault.
The combination of troops seems to be OK although I would prefer to have more Infantry (again, if at all possible).

[JocMeister]

I had a BB TF bombard during the night. No more prep in that regard though! I can see how that would effect the defenders adjusted AV but the attacker?

I´m a bit perplexed about the completely untouched Engineers regiment too. Its like they never did any combat. I just double checked. 3 disabled squads and that might just as well have been from the landing.

I just find the whole thing "odd". But that might just be because I don´t understand it.

ORIGINAL: Crackaces
One thing about disruption on an atoll given the inability to cause damage it provides the second chance to get most stuff ashore .. the enemy not being disurpted gives the enemy a chance at a bad die roll (from the attackers perspective) and wipe the invaders out ...
Just a thought ...

Sorry but I don´t understand!? [:)]

[Rainer]

I had a BB TF bombard during the night

How many BBs? Cruisers?
Did you set the spot planes to "recon" to help identify targets? More than a day so they have a chance to take some nice pictures?
A Bombardment TF can be quite ineffective if not prepared properly.
BTW, Cruisers and DDs can bombard more than once without ammo replenishment (BBs are out of ammo after one round of bombardment).

[GreyJoy]

ORIGINAL: Rainer

I had a BB TF bombard during the night

How many BBs? Cruisers?
Did you set the spot planes to "recon" to help identify targets? More than a day so they have a chance to take some nice pictures?
A Bombardment TF can be quite ineffective if not prepared properly.
BTW, Cruisers and DDs can bombard more than once without ammo replenishment (BBs are out of ammo after one round of bombardment).

Agree. Too little preparation. For an atoll you need to much much more air and naval bombings, for several days i'd say.

In late 1943 you cannot only count on surprise. Japs are everywhere dug in and you need to demolish them a lot before invading...just like in RL

How was your intel about his units on that atoll?

[Bullwinkle58]

ORIGINAL: JocMeister

I had a BB TF bombard during the night. No more prep in that regard though! I can see how that would effect the defenders adjusted AV but the attacker?

I´m a bit perplexed about the completely untouched Engineers regiment too. Its like they never did any combat. I just double checked. 3 disabled squads and that might just as well have been from the landing.

I just find the whole thing "odd". But that might just be because I don´t understand it.

ORIGINAL: Crackaces
One thing about disruption on an atoll given the inability to cause damage it provides the second chance to get most stuff ashore .. the enemy not being disurpted gives the enemy a chance at a bad die roll (from the attackers perspective) and wipe the invaders out ...
Just a thought ...

Sorry but I don´t understand!? [:)]

In addition to the disruption you should have achieved from pre-landing prep (air, bombardment) the general "recipe" for me is to land with a high number of infantry the first day, 3:1 or 4:1 if possible. Assume they're disrupted themselves and their main job on D-Day is to survive so they can collect themselves on D-Day +1, +2, +3 and win. Getting them this breathing room is the job of the tanks. They land, sit there, and take the hit. The anti-soft factors in the enemy are disabled, and Japanese atoll-type defenders usualy aren't rich in AT ratings. The infantry hides behind the tanks on the landing day. The engineers are there to knock down forts. It's not as important for them to land in the initial wave. Ditto arty, which can be very useful on Day +2.

Amphibious landings need waves, but the first one has to be the biggest, hairest one you have going in. If you don't have any tanks figure to increase the infantry to compensate, and use enough ships so they can all get ashore in one day. By 1943 you should have some dedicated landing ships. Use them. Don't be shy and don't skimp.

The second and third wave needs dedicated supply carrying TFs too. The first two days can eat your supplies down to nothing. You have to feed the beach like a starving puppy.

After Day +1 I often freeze the unload so I'm not forced into a shock attack a day. Sometimes I rest the beach for 3-4 days , bombarding, and let the infantry recover and get ready to push. It depends on what's going on at sea though. You have to have enough navy to keep the operating theater sanitary.

Atoll landings are the hardest thing to do in the game. The're even harder in 1943. You did fine for the first try. I've had the whole landing force wiped out before.

[crsutton]

Like every body said. 43 is a hard time to be hitting atolls because you don't have a lot of great ships. The best are the LCT, LCI, LCM type ships supported by LCIs carrying rockets. You really don't get these in numbers until mid 44.

For 43. Follow all of the advice above. and

And 1.Make sure your Amphib TF has a good naval leader
Use an amphibious support ship with an Amphibious force HQ aboard. (these do not land).
If using AK AP AKA APA types use more than you need to allow all your troops to land on the first impulse.
Station your invasion one hex off the day before so that you will use up all your OP landing troops on the invasion day.
I always have a pure supply LST invasion force unloading at the same time as the troops. You can't get enough supply ashore on the
first impulse
Use veteran units. Don't throw 55 experienced units at beachheads.
Combat engineers. More is better.
Recon, recon and more recon so that your air and naval bombardments will have a greater effect.

I would have to say that my worst mistakes have been going in on a budget. Overkill is not a bad thing when hitting an atoll. You do have to be aware of the stacking limit.

Wait till you get to late 44. You get such overwhelming force and if you use pure landing craft assault forces supported by rocket carrying LCIs it is just a breeze getting ashore. That is, if you do it right.

[Wally Wilson]

I concur with BullWinkle58. Recon the heck out of the island. Bombard the crap out of it. Have at least 3-1 in overall troops on hand, but keep 1/3rd in reserve. Have plenty of supply. Have transport on hand to get overstacked troops off the island ASAP. Have a base in reserve to land on the island (if you are going to use it for staging or air).

[CaptBeefheart]

It looks like you had a lot of guys disrupted on landing which brought your AV to 0. Perhaps you could share that information? Also, I think it's best to land with at least one Inf or Marine division, preferably two, anywhere that has close to 6000 defenders, especially if it's later in the game and thus you know forts are high. Overstacking is no problem if you have enough ships in your Amph TF that are only carrying supplies (and you have a spare supply TF which can offload on subsequent days). Once you win, pull the invasion troops back on the TF and take them back to Pearl or wherever. Also, to get your troops to land quickly, it helps to have some naval support/shore parties (in DBB) in the invasion force in addition to the AGC/amph force mentioned.

Further, I don't think Naval skill is important, but rather Ground skill for the Amph TF leader (there's a leader chart somewhere in this forum--I have it bookmarked at home). Softening up is of course quite important as mentioned by most people.

EDIT: A corps HQ in the invasion also helps if you have one handy.

Cheers,
CC

[btbw]

Sorry if i missed it - how long your troops sit on transports? May be they had alot of fatique/disruption from it?
P.S. leaders
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[witpqs]

Lot's of good stuff in this thread.

Amplifying what the Antlered-One wrote, you need a second wave. You must pay attention to stacking limits or else supply usage will kill you. And, very often (not always) one infantry unit in the first wave will get the snot beaten out of it. So, (using your case as an example) have a second regiment ready to go in on the second day. Note that you will simultaneously load up the first, battered regiment. That means you must have enough empty ships available on day two, as ships with even 1 supply point left on board will not load troops (AFAIK). Second day landings are never as bad as first day landings in my experience.

Second is supply, already mentioned above. If you do choose to over stack by a large degree, you might see all supply vanish by the end of the turn. You can still deal with that. The key is that the supply penalty is assessed after land combat. That means that any supply you land during the turn is available for land combat, you just don't see it when you are giving orders. Make sure you have enough supply laden ships to land adequate supply each and every turn.

[Bullwinkle58]

All true re supply. I would only add to be aware of the organic supply levels in each LCU as well. Have them fat when they land. Don't send half-starved units from island to island. Let them regenerate and re-load their in-unit supply stocks.

[Chickenboy]

I was wondering about the disruption shown here too. For the Allies, what sort of disruptive influences impacted the fight? What was the nature of their stowage aboard ship? What sort of assault ships delivered them? How long were they at sea? Were they 'overstacked' at sea or did you have sufficient extra shipboard space for supply and comfortable stowage?

Agree with the other observations: aerial and naval bombardment, unit prep, supplies, 3-4:1 assault superiority, follow-up waves, denial of / interdiction of enemy supplies, disruption of enemy fortifications prep, etc. These are all important considerations.

This assault went in at just 1:1 and was adjusted downwards. Understrength against a tenacious defender.

I'd recommend extricating them before they're destroyed on the beach. "Issue in doubt. Issue in doubt."

[Chickenboy]

ORIGINAL: Puhis
(I must wonder, why would anyone transport IJA Armored car company to Pacific? [&:] Any kind of infantry unit would be better...)

Weren't there some armored car / armored units at Guadalcanal, Iwo, Saipan and Okinawa? My preference would be for the RF gun battalions in defense.