Coral Sea (Scenario 3) Human Allies v Hard AI

[tarkalak]

In my experience, it is very easy to kill the Japanese transports before their main carrier force arrives. They are just scripted that way.

However in my games the A.I. then sent Shokaku and Zuikaku on a wild voyage to Noumea and Australia to find and sink the US carriers.

Good luck with your Japanese game.

[Energisteron]

Hi tarkalak

It certainly seemed that way on my second attempt despite replaying it again on the 'hard' setting.

What was so remarkable for me was that I never got a proper identification of the Japanese Carriers. The 2 big CVs were probably lurking in the SE of the Solomon Sea and strayed too far from their principal objective. Did they get a false report that my small Surface Combat TF was in fact a Carrier TF? Meanwhile the CVL Shoho, which packs a fair CAP of Zeros was somewhere N or NE of Milne Bay, and yet it seemed to just disappear at the moment I attacked the Transports. They had no CAP that morning but did all the previous day as my Recon Aircraft watched their approach. Strangely my Escort fighters didn't arrive either so although no aerial combat was noted perhaps both sets of fighters met and fought an inconclusive engagement beyond the Transports?

In game one, having sunk my Carriers, the Japanese Carriers did attack coastal Australia, at Bundaberg I think, and caused some damage, leaving the Transports in the care of just CV Shoho. They won handsomely, so I'd caution other players not to think this game is a piece of cake!

[Energisteron]

OK, I'm dusting off my Admiral's Cap once more after dabbling in several other games and eras of history.

This time I will take, as earlier proposed, the Japanese side on exactly the same settings as last time, i.e. Hard, 1 day turns, and fixed arrival of reinforcements. As always I will be directing Sub Ops myself.

So, here's the IJN briefing and the historical overview for the Coral Sea scenario.

Essentially, the objectives are just as focussed on Port Moresby as for the Allied side, but I am tasked with maybe making something of Tulagi or at least not losing it also.

[Energisteron]

Game 3 - CORAL SEA scenario - Japanese Initial Assessment

I am not going to reveal all the initial Japanese Naval unit positions so as not to add an excess of spoilers for those who may yet wish to play this scenario from the Allied side.


Well, my primary objective is clear enough; take Port Moresby even at the risk of losses.

Secondary to this will be improving Tulagi, and damaging the Allied Carriers.

And thirdly, picking up a few unoccupied Allied bases along the way.

So, what have I got to complete this task?

Bases:-

Rabaul is my primary forward base with an appropriate defence force, supplies and fuel. It has a decent airfield (3) and port (3) and the Invasion Fleet is already fully loaded there and ready to sail. Here is our primary level bomber force, 27xNells, for an attack on Port Moresby, plus there are Zeros, Rufes as fighters and Mavis Transports.

Lae is a minor base already established on New Guinea's north coast only 160 air miles (200 mountain jungle miles by land!) from Port Moresby itself. It has a basic airstrip (1) and port (2) and is home to a base defence force and a large group of Zeros (x27).

Tulagi has been occupied recently by an Engineer Company. It has minimal port facilities (1) and no airfield. There's currently a Cargo TF there that's just completed unloading. It's a real mixed bag of Freighters and minor Escorts, the value of which for the coming operation is unclear.

Shortlands is probably in a worse state than Tulagi! It is perilously short on supplies, and only has a basic port (1), and again o airfield. There's a Battalion of Engineers supporting improvements plus a Squadron of 6x Mavis float planes which have the capacity to search as far west as the Great Barrier Reef, and Cooktown on the Australian coast, and as far south as Espiritu Santo. Needless to say, Port Moresby is well within their sphere!

Truk, way back in the rear of Rabaul by some 680 NM, has lots of supplies and fuel, adequate defences and no less than 4 air groups, Nells, Emilys, Bettys and Jakes as back-up. Judicious transfer of these air groups at just the right moment could be very helpful. I wouldn't want to overload Rabaul and hinder Ops there too soon.

Naval units:-

There's a mighty Air Combat TF (2xCV) at sea near Rabaul but out of position in my opinion.

A secondary Air Combat (Escort) TF (1xCVL) is further ahead, while the Invasion TF is as previously stated at Rabaul.

There's also 8x Submarines, but except for some already near Port Moresby, most seem to be hopelessly out of position also.


So, to plans.

Well, with just 10 days to complete the operation, there's certainly no time to lose! Yet I hesitate to rush the Transports too far ahead of the main CVs before I've identified the whereabouts of the enemy CVs and at least suppressed them.

So, our CVL will lead, heading for Milne Bay, while land-based bombers from Rabaul repeatedly attack Port Moresby supported by Zeros from Lae. I want to split the Invasion TF into two divisions, one trailing the other, but they will not move beyond land-based CAP from Rabaul until the big Carriers catch-up and can provide CAP themselves.

The main CVs will actually take up position near the Allied base at Buna to support the Transports on their final run-in to Port Moreby beyond Milne Bay. The Search Planes from Shortlands will provide observation to the SE of the Carriers' operational zone, and the empty Transports at Tulagi will go home.

Once the Transports close on Port Moresby, the Lae fighters will provide additional LRCAP.

Let's see how that works out!

[Energisteron]

Phase 2 of Plan Mo

If all has gone well, the Invasion force will be ashore and contesting Port Moresby. The Transports then need to get home. So after it leaves the LRCAP provided by Lae, CVL Shoho will take over CAP for the Transports, advancing close enough to Port Moresby to transfer its Zeros to the newly acquired airbase.

Meanwhile, moving SE approximately in parallel with the retiring Transports, the main Carrier TF will make a bold move into the Coral Sea to attempt an attack on the US Carriers.

The more astute of you will have realised there is just one TF at Rabaul in this diagram. It is undergoing reorganisation into two separate Amphibious TFs, according to load capacity and speed. The faster TF will set-off first at 18 knots, and (slight change of plan) the slower TF will follow close behind (not 24 hour behind, by a slightly shorter route) at a meagre 10 Knots. Near Woodlark Island the slower 10 knot vessels will be detached and loiter as a reserve to occupy Buna and the Russell Islands. The remainder of the Transports will then proceed at 14 knots to Port Moresby.

The Rufe float fighters from Rabaul will be transferred with a little aviation support to Tulagi or if operations are still confined to the western sector then they may go to newly captured Buna.

This first turn has taken quite a bit of setting up but I'm just about ready to go!

[adarbrauner]

[Energisteron]

Day 1 - May 04

The Outcome

The Invasion TFs (ultimately split into 3 divisions, not 2 as proposed) with maximum speeds of 18, 14 and 10 knots set out from Rabaul by the two pre-planned routes. The faster TFs going by route A and the slowest by route B. Immediately, they run the gauntlet of the Allied Submarine blockade around Rabaul. Several enemy Subs are spotted, but only one, US SS S-42, manages to make an attack. Four torpedoes just miss xAK Canberra Maru, and after a brief retaliatory depth charge attack the Sub escapes.

A hit would have been a serious blow since the Canberra carries over 4000 tons of supplies, and a Company of Engineers, and she could well have gone down. This does not auger well because she was in the fastest Transport TF! Even so, the attack put the fastest TF behind schedule and the medium speed TF now leads.

At sea, the rest of the day is uneventful. Only the retiring Transports leaving Tulagi are spotted by any Allied aircraft and no attack results. CVL Shoho moves boldly towards Woodlark Island as yet undetected, but the main Carrier TF is way behind and the Invasion TFs may have to loiter under Rabaul LRCAP to wait for them to catch up.

We make a reasonably successful daylight raid on Port Moresby. There is no CAP but in any case our Nells had an escort of Zeros from Lae. We take no combat losses, but a Rufe and a Zero are operational losses. The transport Mavis from Rabaul haul a few much needed supplies to Shortlands.

[Energisteron]

Day 2 - May 05

Planning

As can be seen from the graphic above, the main Carrier TF are not even on the map! The two CVs Shokaku and Zuikaku with an escort of 2xCA and 6xDD are routed to pass through the straight between the Feni and Green Islands (SE of Rabaul) during daylight today. Although they have a good screen of DDs we must surely step-up ASW patrols from Rabaul today. Thus the number of Nells striking Port Moresby will be reduced.

CVL Shoho will patrol about her current position with Naval Search aimed at the southern quadrant. Mavis from Shortlands will search further south and east of her. The Transport TFs will gather just north of Woodlark Island within range of Rabaul LRCAP and await the belated arrival of the Fleet Carriers.

Some small seaborne aviation support will be sent unescorted towards Shortlands.

Otherwise, pretty well as planned so far. Absolutely no sign of enemy Carriers or their aircraft as yet!

[Energisteron]

Day 2 - May 05

The Outcome

No hitches today. The enemy Subs are kept down as the Fleet Carriers pass through the straights without incident and all the TFs concentrate north of Woodlark Island as planned. Nells from Rabaul make an effective morning raid on Port Moresby which is followed up in the afternoon by a strike from the Fleet Carriers themselves as they come within range. Results are more than satisfactory. We lose 1x Val and 1x Kate to flak.

Despite Port Moresby airfield being in a bad way the Fleet Carriers are spotted by a Catalina. Catalinas also investigate Shortlands.

Two CLs are detached from the retiring Tulagi Transports to bolster the Invasion TFs, and aviation support is put into Shortlands. Extra supplies are flown in there again. The Fleet Oiler (unescorted) but with a LRCAP from Lae approaches Buna which will be a refuelling point.

Our Subs, hopelessly out of the picture begin to move into the Coral see and are fortunate enough to detect a small Surface Combat TF. Our spotters possible detect another enemy ship near Milne Bay. We estimate this is likely to be another Sub.

[BBfanboy]

Launching strikes against PM from your carriers is not wise because:
- enemy carriers could show up and find your carriers with your aircraft unable to strike at them
- you are using sorties that may be needed to fend off the Allied fleets
- your aircraft and pilots will suffer fatigue that may affect their availability or performance next turn or the one after. Three days continuous operations is about the limit for a carrier pilot without a rest period. Strikes on a fourth consecutive day will usually have a terrible performance for the numbers sent out, because of fatigue and morale issues.

[adarbrauner]

+, sending the all precious oiler in waters known being infected by aggressive subs without escorts does call in for disaster...

[Energisteron]

Hello to you both

Agreed. The air strike on Port Moresby was actually on the CV Commander's initiative, i.e. with what I hadn't held back for rest or CAP or Search. I will have to give stricter orders next time!

The Oiler does have LRCAP. Although everyone denies it, I seem to have found that aircraft of any type flying above deters Subs to some extent. However, I am woefully short of Escorts, as you will see once the Invasion TFs are attacked! I may even consider detaching a couple of the Escorts from the Fleet Carriers, such is the paucity of Escorts screening the Transports.

[Energisteron]

Day 3 - May 06 (corrected date)

Planning

Here's the current plotted positions.

The primary objective of the Fleet Carriers will be to engage enemy CVs if detected. They will also supplement the LRCAP for the Transports provided by CVL Shoho which will take up its intended target position today. It seems we've already established there's no significant air threat from Port Moresby itself. We just have to worry about the enemy Carriers!

So, now all TFs are in position the Invasion TFs will advance at their maximum speed to their target, the shoreline at Port Moresby.

Since there is no fighter opposition at Port Moresby, the Lae Zeros will be equipped with drop tanks and provide a LRCAP for Invasion TF 14 (the medium speed TF) which contains the bulk of the troops. Nells from Rabaul will hit the airstrip at Port Moresby again.

[Energisteron]

Day 3 - May 06

The Result:-

Surprisingly, there was absolutely no Allied intervention at all! Our Invasion TFs sailed around the Milne Bay bottleneck unmolested heavily guarded by LRCAP from Lae, and all 3 CVs. With drop tanks even Zeros from Rabaul could provide LRCAP right up to the approaches to Milne Bay.

The only action was another air raid on Port Moresby from Rabaul. The air strike caused little damage this time but we had no losses. We also transferred a group of Bettys from Truk into Rabaul which is well capable of handling the extra aircraft.

CVL Shoho got a lot of attention from Allied Search aircraft, including Carrier aircraft, but no attack resulted. While our own long-range land-based Search planes spotted what seems to be three Allied TF closely concentrated about 200 nm south of Rossel Island (same position as a Surface Combat TF yesterday). This sighting must surely include both US CVs?

[Energisteron]

Day 4 - May 07

The plot as we see it.

Sorry about the clutter in the diagram, there's a lot going on today!

So, the enemy Carriers seem to be out of position to launch an effective attack against our Invasion TFs. I'm so confident (war is war though!) that the Land Forces will reach the beachhead intact that I intend to relocate the main Carrier TF towards Woodlark Island with the intention of engaging the enemy Carriers. It was helpful to complete refuelling yesterday.

CVL Shoho will continue on to Port Moresby where its attendant Cruisers will assist with bombardment, meanwhile providing LRCAP for the Invasion TFs. Lae will also provide LRCAP especially over the beachhead.

The Invasion TFs are expected to commence unloading at their target tonight.

[EDIT] I've decided to turn the slow Invasion TF about, partly as a distraction, but principally to follow phase 2 of the plan, to occupy Buna.

The diagram indicates various other air support activities.

[Energisteron]

Needless to say it really does turn out to be a very busy day! I'll draw up a summary tomorrow.

Suffice to remark that unloading has commenced at Port Moresby and Buna. There are casualties inevitably including ship losses.

More to come. . .

[adarbrauner]

Ship losses amongst the landing party? Sounds like shell hits by shore batteries, which exsitence at PM I doubt;

or, from the US carrier embarked air force, which, in the picture you posted above, is perfectly posed to launch FIRST against all of your fleets, and probably it did also against your CVs but probably got burned by your CAP and AA and did not manage to plant any hit,

case in which the US-Allied is toasted, by loss of many airplanes, and is now your turn to destroy them, if he AI has not conveniently retired far from the theatre thing that the AI won't do.


Tell me I guessed right ?[:D]

[Energisteron]

Patience, adarbrauner! [:D]

The latest dispatch is imminent! [:)]

[Energisteron]

Day 4 - May 07

Just after midnight, US Sub SS Greenling encounters our Transports returning from Tulagi to Rabaul by a roundabout route specifically chosen to avoid the known cordon of enemy Subs south of Rabaul. In two attacks she launches no less than 12 torpedoes at a tiny coastal minesweeper, AMc Wa-1, eventually getting one hit. SS Greenling escapes unscathed.

At just 270 tons displacement, AMc Wa-1 understandably is heavily damaged. During the night the remainder of the convoy lose track of her and at dawn floating debris confirms her total loss with all hands.

It seems Sub Greenling wanted an excuse to go home! There seems no other reason to expend so much ammunition on such a trivial target.

Our Oiler, and other small TF in the vicinity fortunately encounter no enemy Subs.

[Energisteron]

Day 4 - May 07

In the early hours, well before dawn, our lead Invasion TF comprising an Assault Force of some 800 troops hits the beach at Port Moresby. A preliminary bombardment fails to suppress the shore batteries and we take losses to men and ships. Casualties amount to 12% of the men disembarked. xAK Canberra, a lucky survivor of a Sub attack on Day 1, takes 4 shell hits and she is badly damaged with fires out of control. Although her surviving troops have got away she still carries a considerable quantity of vital stores and supplies.

At this stage the invasion could have faltered so it was reassuring that the main Invasion TF was just 2 hours behind.

Other movements went as planned- see diagram.