CARRIERS AT WAR: The Battle of the Coral Sea

[Tripoli]

I had an itch to play a carrier game this weekend.  Despite its age, SSG's CARRIERS AT WAR holds up well. It features a reasonable AI, weather effects, and erroneous sighting and combat reports which played such an important role in WWII naval operations.  The Coral Sea scenario comes with ten alternative scenarios, with hidden OOBs, increasing the "fog of war" for the player.  I'm playing "alternative 1" as the US.  Here is the situation at game start at 2000 on 03 May 1942:


US Forces

Mission: Prevent the Japanese from landing troops at Port Moresby, while inflicting disproportionate losses on Japanese forces, with an emphasis on crippling or sinking IJN carriers.

Naval
TG 17.3 USS CHICAGO and HMAS AUSTRALIA (Surface Action TG)
TG. 17.5 USS LEXINGTON, MINNEAPOLIS and NEW ORLEANS, 5 DDs, 70 aircraft (CV TG)
TG 17.2 USS YORKTOWN, CHESTER, PORTLAND, ASTORIA, 4 DDs, 68 aircraft (CV TG)
TG 17.6 USS TIPPECANOE, NEOSHO, 2 DDs (Replenishment TG)
USS S-42 is off Rabaul

Land based airbases at Townsend, AUS and Port Morsby

Land Based Air:
Townsville:
•    1 sqn of PBYs
•    1 sqn B-17D
•    2 sqn B-26B
•    1 Sqn B-25D
•    1 sqn Hudson
•    1 sqn P-39
•    1 sqn A24
Port Morsby
•    1 sqn of PBYs
•    1 sqn Kittyhawk
•    2 sqn P-400

Environmental: Dawn is at 0600. Sunset is at 1800.  Scattered Thunderstorms throughout the AO

Logistics: 20 days fuel @15 knts for YORKTOWN and LEXINGTON Task Groups, 17 days for the 17.3

Japanese Forces

I assume the IJN's goal is to land troops at Port Moresby, and/or sink any USN carriers.  The size and composition of the IJN forces are unknown, but historically the IJN had two CVs and one CVL in the operation.  I assume that the forces in this scenario are at least as large.  Major Japanese bases will be Rabaul, Law, Shortlands.  A recently constructed seaplane base on Tulagi can provide the Japanese with coverage into the SE part of the Coral Sea, while their base at Shortlands can provide coverage into the central part of the Coral Sea.  A significant number of fighter aircraft are likely at Lae, while LBA based in Rabaul will make the Solomon Sea to the area around the Louisaides (the islands off the SE tip of New Guinea) dangerous for USN assets.

CONOPS: In the historical battle, the USS YORTOWN raided Tulagi on 4 May.  While I considered replicating this raid, I decided against it because 1) USS LEXINGTON is too far away to participate so the USN strike will be diluted; 2) the USN mission is to protect Port Moresby and raiding Tulagi has a minimal impact on achieving that goal; 3) the time spent doing that mission risks putting USN forces out of position to oppose an IJN Port Moresby operation  if the scenario moves up the timeline compared to the historic IJN timeline; 4) The USN opeartion is far distant from land based recon and I don't have any information on IJN forces in the area, so the risk is fairly high. 
Consequentially, I have the USN forces move to a position in the center of the Coral Sea, sufficiently far enough from Japanese LBA, but within supporting range of Australia-based LBA.  From this position, USN assets should be able to intercept Japanese forces as they enter the Coral Sea enroute to Port Moresby.  Hopefully, this will allow me to somewhat mitigate the serious scouting disadvantage the shorter range USN carrier aircraft have compared to their IJN counterparts.  The slow replenishment forces (TG 17.6) will position itself closer to the protection of Australia, where it can sortie to refuel the USN forces if needed.




For reference, here is a chart of the historical Coral Sea battle:

[Jarhead0331]

Any nuances or problems running on a modern system?

[Tripoli]

Any nuances or problems running on a modern system?

No, it ran fine.  I'm using WIN 10, but I had no issues running it "out of the box". 

[Tripoli]

A couple of notes before proceeding: My "Battle Rhythm" for this scenario is to have begin arming my aircraft at 0400, so they will be ready to launch at daybreak.  Between nightfall and 0400, aircraft will be stowed, to minimize the chance of explosions in the event of a submarine attack.  But during daylight hours, a full strike will be spotted on the deck.  This is because in naval combat, the first effective attack usually wins the battle, so I don't want to lose time arming aircraft.  I will have a constant 30% of my fighter complement in CAP over the ship during daylight.  That sounds like a lot, but at this point in the Pacific war, the USN only had one fighter squadron onboard, so that is only 6 fighters on CAP. Port Moresby will similarly have 30% of their fighters airborne, as they will almost certainly get some love from the Japanese....

Battle Log
040600 May 42   Initial search aircraft are launching.  To hopefully mess up Japanese planning, I prepare a Strike on Lae from Townsville using the Hudsons and B-17.  With only 14 B-17's I have doubts that this will do much, but I would like to slow down the Japanese air attacks against Port Moresby that I am sure will be coming. 

040900 May 42  PBY from Port Moresby locates three auxiliaries. (Sighting ABLE).  I suspect this might be the invasion force coming from the major Japanese base at Rabaul.  While three auxiliaries is not a lot, sighting reports in the game are frequently wrong.



040905 May 42   Sighting ABLE is now reported as 2 carriers and 4 escorts

040905 May 42   A Coastwatcher makes sighting BAKER, reporting  a surface group of 8 heavy/medium ships and 6 escorts near Russel Island. [Note: I'm really not sure what this IJN force is doing.  It sounds like a surface action group, but I'm not sure what its purpose is at this location.  If it is part of the amphibious group, (which I doubt), my carriers are out of position, too far to east if this is part of the amphibious operation.  I would rather be south of tip of New Guinea to block the invasion.]



041005 May 42    Air Raid alert, Port Moresby, 191 bandits inbound.  40 interceptors are scrambled.
041015 May 42   Light damage to Port Moresby (3 hits).  12 attackers damaged, but the CAP loses 12 aircraft.
 
041030 May 42   Sighting BAKER appears to be moving WNW.    I consider attacking BAKER, but the long range means that only the SBD using a reduced bomb load can be used,  This means that damage will likely be light.  I decide not to attack BAKER because the surface ships are a secondary target, are unlikely to be seriously damaged and I don't want to give away fact that USN CVs are in area.

041145 May 42  Submarine S-42 reports a successful attack on an escort ship, sinking it.  The B-17/Hudson strike on Lae did no damage, but cost 3 B-17s and 7 Hudsons shot down.  I won't be doing that again....
041810 May 42 The IJN SAG appears to have changed course and is heading south.

[Tripoli]

05 May 1942

050600 May 42   Commence Flight Ops.  Port Moresby search aircraft are covering an arc 000-120 degrees, covering an arc from the Bismarck and Solomon Sea areas.  The USN carriers are covering an arc from 300-090, covering an arc from the exit from the southern coast of New Guinea to the Louisaides and to a point halfway to Tulagi.  Townsend aircraft are covering an arc from 030-120, covering the Coral Sea between Port Moresby and the SE entrance to the Coral Sea.

050910 May 42   PM aircraft report sighting ABLE.  Reported as two (2) CV and five (5) medium/heavy vessels located in Solomon Sea.  YORTOWN and LEXINGON are repositioned to the NNW to possibly launch a long-range strike.  They will be using a line of storms to hiding in, hopefully avoiding detection.

0910


051245 May 42  PM aircraft report an auxiliary near Woodlark Is.  I am thinking this might be part of the amphibious group?  Notably, the surface action group found yesterday seems to be gone.
051400 May 42  Search plane detected above YORKTOWN TF. YORKTOWN is operating at the edge of a thunderstorm, so it may not have been detected.  LEXINGTON is in the storm, so she is likely still undetected.
051525 May 42  Sighting ABLE is now reported as three (3) CVs.  While the SBDs are barely within range (red circle on the chart below), they  would not land until two hours after dark.  I think this is too risky for an uncoordinated strike without fighter escort.  This strike is scrubbed.

1545


051640 May 42   A submarine attack on TF 17.5 sinks USS DEWEY (DD-349).  Submarine is believed to possibly be sunk by LEXINGTON screen.

051840  May 42   Sighting BAKER now reported as two (2) CV.  I believe this report is in error, and may be a duplicate report for ABLE. It looks like weather is brewing to west of my current position.  I will try to reach it by dawn and use it to cover for an ambush.

1840

[Tripoli]

6 May 1942

060115 May 42 Sighting by coastwatcher off the southern tip of New Guinea.  Reported as one CV, 2 medium/heavy ships, 2 escorts. [Note: I have my doubts that this is a carrier, but is more likely part of the invasion convoy]

060600 May 42   Commence Flight Ops.  Port Moresby search aircraft are covering an arc 030-120 degrees, covering an arc from the Bismarck and Solomon Sea areas. I've narrowed it due to the localization of the IJN carriers yesterday.  The USN carriers are covering an arc from 030-090, covering an arc from the exit from the southern coast of New Guinea to the Louisaides and to a point halfway to Tulagi.  Townsend aircraft are covering an arc from 030-90, covering the Coral Sea between Port Moresby and the SE entrance to the Coral Sea.

061005 May 42 Air raid on Port Moresby.  183 bandits inbound.  25 CAP launched.
061020 May 42 Air raid causes moderate damage (6 hits) to Port Moresby. Six CAP lost, 21 bandits reported shot down or damaged.
061230 May 42  Reported carrier TG is operating near East Is.  This is believable.  USN CVs are in a thunderstorm, so I may be able to get a bit closer undetected.  However, it is getting late in the day to launch and recover in daylight.

061300 May 42   Japanese search aircraft is over TF.  Although I am operating at the edge of a thunderstorm, I have to assume I've been spotted.  Order an immediate launch of 4 squadrons of unescorted SBDs at maximum range. [Note: this will be a nighttime recovery, so the USN may take heavy losses.  However, the importance of getting off an effective strike is so important, I'm willing to risk it.]

1300


061610 May 42 Airstrike hits the TF.  No carriers present.  4 CAs and escorting DDs.  This was likely the surface group detected two days ago.  It did have a CAP, which shot down 7 SBDs. This indicates that there is a CV somewhere in the area. The LEXINGTON's airgroup did a good job, claiming 4 hits on both a FURUTAKA and KINUGASA-class CA, both of which are reported as sunk. One reported hit on both an AOBA and a KAKO-class CA.  One hit on a DD.  Seven aircraft lost. [note: YORKTOWNs aircraft did not find the target]

061900 May 42 Airstrike recovers at night.  Three aircraft destroyed or damaged on landing.

[Tripoli]

07 May 1942

070215 May 1942  Coastwatcher reports 2 "Capital Ships" off SE tip of New Guinea. I have LEXINGTON and YORKTOWN position between this sighting and Port Moresby, using a weather front to hide their movements. [Note: I suspect this is the invasion convoy. I don't think any carriers are operating this close to the shoreline.  I am now in a bit of a quandary, as there is also at least two IJN carriers operating somewhere in the AO.  That means that I will have to divide my attention between two separate high-priority targets.  Further, I have lost approximately 25% of my dive bombers in the last attack.  I decide to emphasize hitting the carriers, and leaving attacking the transports to LBA.]



070530 May 42   Commence Flight Ops.  Port Moresby search aircraft are covering an arc 060-120 degrees, covering an arc from the Bismarck and Solomon Sea areas. I've narrowed it due to the localization of the IJN carriers yesterday.  The USN carriers are covering an arc from 060-120, covering an arc from the exit from the southern coast of New Guinea to the Louisaides.  Townsend aircraft are covering an arc from 030-90, covering the Coral Sea between Port Moresby and the SE entrance to the Coral Sea.

070555 May 42 Spotting aircraft spots four (4) IJN CVs 80 nm !!! from LEXINGTON and YORKTOWN. [Note: To say I was surprised by this sighting is an understatement.  I did not think that the IJN carriers would be operating this far inside the Coral Sea. A full complement strike, escorted by half the fighters is immediately ordered. A B-17 raid from Townsend is also ordered.

0555 May 1942


070700  May 42 Strike is very successful, claiming five (5) hits on ZUIKAKU.: three (3) hit HIYO, four (4) hits SHOKAKU.  LEXINGTON scores 3 bomb, 2 torpedo hits.  YORKTOWN scores 4 bomb and 3 torpedo hits. There is likely some exaggeration with these claims. The proof will be how big the retaliatory strike is. The  Losses are heavy:
•   VS-2 6 lost/2 damaged
•   VB-2 6 lost/2 damaged
•   VF-2 8 lost/1damaged
•   VT-5 1 lost/3 damaged
•   VS-5 5 lost/5 damaged
•   VB-5  2 lost/7 damaged
•   VF-42 6 lost/2 damaged

070855 May 42 A restrike on the IJN carrier task force is launched.  Thus far, their has been no Japanese strike, indicating that the initial USN strike crippled all the flight decks. A sighting report of a single Japanese carrier with a single escort detached from the main body indicates that at least one of the carriers is heavily damaged or sinking.

070930 May 42   An auxiliary and escort observed to North approaching Port Moresby.  This may be part of the invasion force.  However, the USN is unable to do anything about it right now, as the IJN carrier threat has to be neutralized.

0930


070940 May 42   Restrike claims three (3) torpedo hits on SHOKAKU, four (4) hits on a CA and one (1) bomb hit on a DD.  [Note: While these claims are likely exaggerated, the SHOKAKU is reported as likely sunk. While HIYO was seen burning in the formation, she is also evaluated as likely sinking. There was no sign of the ZUIKAKU, indicating that she was the unit spotted earlier as detached and heading to the east.]

071100  May 42 Strike is launched on the possible amphibious TF. [Note: With the likely sinking of HIYO and SHOKAKU, and the crippling of ZUIKAKU, I believe it is safe to neutralize the invasion convoy.  I do not have a current position on  ZUIKAKU, leading me to believe it has already sunk. If it hasn't, search aircraft should be able to pick it up and allow one more strike before nightfall.]

071230 May 42 Strike is unable to locate the possible amphibious task group. {Note: this indicates it may have been a bad report].  The strike diverts to attack the remainder of carrier task force.  It reports sinking two destroyers. TG 17.3 is detached to engage in a surface action against the surviving surface units.

071340 May 42 A reported sighting or 3 carriers near Woodlark Island has me mildly concerned.  I don't think it is a accurate ID.  However, this is a random scenario, and it is possible the  Kidō Butai is out here.  My two carriers do not have the capability to fight 3 fresh carriers.  TG17.3 is recalled, and I begin withdrawing towards Australia. Still no confirmed reports of ZUIKAKU.

1340


071440 May 42 Still no confirmed reports of ZUIKAKU.  With dusk approaching, a final strike against the remainder of the CVTF.  LEXINGTON reports sinking a destroyer and damaging a cruiser. YORKTOWN aircraft miss the target.

[Staggerwing]

Which version are you playing? The 1984 Commodore/Apple II using Emulation, the 1992 one for DOS (or its final compilation version, Complete Carriers at War), or the 2007 Matrix remake?

[Tripoli]

Which version are you playing? The 1984 Commodore/Apple II using Emulation, the 1992 one for DOS (or its final compilation version, Complete Carriers at War), or the 2007 Matrix remake?

I'm using the Matrix remake. 

[Tripoli]

8-12 May

The scenario lasted for five more days, but not much of significance happened during those days.  The survivors of the Japanese carrier task force withdrew back to Rabaul, managing to avoid serious contact with a USN surface action group that tried to intercept.  The USN SAG was attacked by Japanese Betty bombers when they strayed too close to the Louisaides.  However, the damage to the SAG was minimal, with the Japanese scoring a single hit on the HMAS HOBART.  I then withdrew the SAG back to the safety of the Coral Sea.  The ZUIKAKU was not seen during the remainder of the game, and I was confident it had been sunk.

The end of the game victory screen  showed the USN had scored a decisive victory. While the Japanese had lightly damaged the USS CHICAGO, HMAS HOBART and USS PERKINS, they had sunk only the USS DEWEY.  In contrast, the Japanese lost the carriers SHOKAKU and HIYO, the cruisers HAGURO and KINGASA and the destroyers SHIGURE and YUGURE.  Three other cruisers, three destroyers were also damaged.  The carrier ZUIKAKU was moderately damaged, but in fact managed to slip away to fight another day. The Japanese also lost 130 naval aircraft and 17 land based fighters and 28 land based bombers.  This compared to US losses of 55 carrier aircraft, and 40 landbased fighters and 12 land based bombers.

[Tripoli]

After Action Review

I think my strategy of remaining in the central Coral Sea was the proper course of action.  This allowed me to negate the Japanese LBA.  Taking advantage of the numerous storms further improved the US chance of getting off a first strike.  Additionally, By placing the USN between in the central Coral Sea, the US only had to search an approximately 60 degree arc to the SE of Port Moresby to locate the important invasion and carrier TFs, which were draw towards Port Moresby and the ambushing US carriers.  This search arc could be largely covered with US LBA.  In contrast, the Japanese were forced to search 180 degree arc with their carrier aircraft, as the US would be out of range of the Japanese LBA.  This diluted Japanese striking power.

My most notable failure was my inability to locate and sink the damaged ZUIKAKU.  I'm not really sure how I missed it.  With it beginning its withdrawal only 80 nm from my carriers, I was confident it would be discovered in my searches.  I also assumed that since it was detached from the Japanese task force, it was badly damaged and moving slowly.  In fact, its damage was probably largely limited to its flight deck, so it was likely able to still sail at, or nearly full speed.   In retrospect, I suspect it used a combination of high speed and hiding in rain clouds to escape, while I was focused on restriking the SHOKAKU/HIYO task group and hitting what I thought might be the amphibious task force.