Dutch AVP Arend: Scenario 1 Exploits

[WEXF]

June 19 was another good day at Geraldton and the crew of Arend could easily see why. The base was not at 92% > level 3 and there were 5 US Army transports sitting on the runway that could be used to ferry troops between Geraldton and other bases. The Walrus II was now operational on Arend and the two pilots had rested, were fatigue free and ready to resume their training in ASW activities.

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However the biggest improvement noticed was the newly arrived artillery of the recently reformed North Sumatra KNIL Territory Regiment.

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When reformed the regiment had only 3 guns, all 12.7mm AAMG. They now had 9 guns. Added were another AAMG, 1 75mm Field Gun and most importantly 4 105mm Howitzers. Prior to the arrival of the 105s the only artillery at Geraldton were 5 25 Pdr Guns, a 3.7 Mtn Gun and some light mortars. The 105s had good numbers against armor (41), soft targets (26) and had a range of 12. This was about equal to the Japanese 10 cm T91 Howitzers and not that much poorer than the enemy's 15cm T96. It seems clear that the decision not to allow upgrades for the unit was the right decision.
In addition, 4 engineers and some support troops were added but the indications are that in 3 days more guns and engineers are likely to be added. Little by little the regiment was becoming a valuable part of the Geraldton defense.

[WEXF]

This turn was one that allows us to re-visit a discussion that started back in my July 7, 2023 posting talking about the process of converting Clemson Class DD to Clemson DM Class destroyer minelayer. The conversion process includes the addition of 40 MK6 mines on each converted DD. These mines do not come from the "pool". Production of MK6 mines is 35/month.
Once converted the DM can be upgraded in June 1942 and, as indicated in the earlier posts, any mines they had on board when the upgrade process started are automatically unloaded and sent to the pool.
DM Breese was upgraded at Auckland and has just completed the process. Its ship screen shows that there is a full load of 40 MK6 mines on board.

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These two screens show the number of mines in the MK6 pool for June 18-19 and the number of MK6 mines "used so far" as 370 in both cases.

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I was curious about whether the mines were loaded at the end of the refitting process or earlier.
This screen shows the 12 DMs that were being refitted on 18June. Notice that the number of days remaining ranges from 1-16. All of these ships currently have a full load of 40 MK6 mines and are fully fueled. DM Breese is one of those listed. So it is clear that the mines are loaded immediately. Since each ship has 40 mines the total for the 12 ships is 480 which exceeds the number shown as "used so far" confirming that the newly loaded mines could not have come from the pool.

I have said that one of the reasons I am doing this AAR is to learn how our game works and where there may be interesting opportunities. There are quite a few Clemson Class DD and they are not the best the US Navy will have, although at the start of the war they are certainly important. Converting them to APD is a frequent decision Allied players make, but going the DM path may be a better choice as it dramatically increases the number of MK6 mines available over time. The initial conversion adds 40 for each ship and the first upgrade adds another 40. There is a second upgrade that should add another 40. That is 120 MK6 mines per ship or 3.5 months of mine production.
It all depends on how much a player is using mines as a part of the game.
Food for thought!

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[WEXF]

June 20 found the port at Geraldton at 94%>level 3. In less than a week the submarine nets would be in place providing significant protection to ships in port.
From the looks of things it seemed to all that the next priority at Geraldton would be the expansion of the airfield. It was fairly small at AF2 but had the potential to be one of the largest airfields in Australia. Expansion to level 4 or 5 seemed certain as the number of aircraft based at Geraldton continued to grow.

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On the AF were the newly arrived Hurricane IIb Trop fighters of No. 14 Squadron RNZAF, part of 224 Group. These fighters were superior to the Dutch 75A Hawks and B339D fighters that were already on base. This squadron was well known to all at Geraldton. They had started as No. 488 Squadron RAF flying Buffalo I at Singapore and changed their designation on 24Apr. So far they had lost almost 2 dozen aircraft to enemy action along with 5 pilots KIA and 7 WIA. They had 41 kills to their credit.

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Four key aspects of the new fighters were impressive. They were faster, armored, had more than twice the defensive firepower of the other fighters on base and most importantly, they could carry 2 500 pound bombs.

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[WEXF]

June 21 started as everyone expected it would. The port was now 95%> level 3 and the activity related to potential airbase expansion continued. Aviation support at Geraldton had risen from 63+10 > 93+10 with the arrival of part of the NW Australian Aviation Regiment.

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On Arend, PO Caruthers saw his ASW skill rating go from 55>56.

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None of the crew on Arend could know that events about to be revealed in the morning intel report would make the day one that everyone would always remember. It was a single line from the 20June Operations report:

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48-143 was just 80 miles SW of Geraldton! No enemy submarine had ever been reported in the region much less so close to Geraldton. The report was not easily dismissed as an exaggeration. A specific submarine had been identified and the report was not just a "sighting" but that of an attack by Geraldton based air assets.
LCDR Goerk, like all the other officers at Geraldton quickly took out their reference manuals to get the details on SS I-20.

[WEXF]

SS I-20 was one of the most interesting Japanese submarines. It was C1 Class capable of carrying a Type A Midget submarine.

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I-20 was fast, could travel long distances, carried a sizable load of torpedoes and had decent deck guns. There were only a few of this class of submarines in the Japanese Navy.
The Midget sub was a pesky threat that had very limited range but carried 2 small torpedoes.
If the submarine attacked was I-20 there was no mention of it having been seen with a midget sub on board.
Lots of questions ran through the minds of everyone at Geraldton. Was the enemy sub really there? Was it really I-20? Was there a mini-sub near or already at Geraldton? Since I-20 could also carry Type 88 mines, was that their mission? Lots of questions but no answers!
Headquarters scheduled a detailed briefing for later in the day to explain to everyone what was known and what was not.
Everyone felt confident that the defenses at Geraldton were more than a match for a single enemy submarine. No one wanted to think that the mission of I-20 might just be to recon the area for an invasion!

[WEXF]

The intel briefing started with details on where the enemy submarine had been spotted and attacked. The proximity to Geraldton was obvious to everyone at the meeting.

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The friendly TF in the same hex as the enemy sub was TF382 containing 8 small cargo ships heading to Exmouth with 8000 supplies escorted by a minesweeper. If the attack by our aircraft did not damage or destroy the enemy sub it could well have prevented an attack on TF382.

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[WEXF]

Details on the unit and pilots involved in the sighting and attack were presented next.
W Flight RAF was a small squadron of just 6 Wirraway light level bombers. The unit was well known to most of the men at Geraldton as they had been in the war zone from the beginning. So far they had been able to avoid losing any pilots or airframes. The squadron commander was FLT Park, known as "promising and careful". His air and aggression ratings were quite low at 29 and 28. It could be expected that the men under his command would not take significant risks.

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On the day of the attack all 6 planes were serviceable but the squadron was set to only fly 70% of their planes on "naval search". If all "die rolls" were passed 4 planes would fly in the morning and afternoon phases. Altitude was set at 8000 feet with a maximum range of 4. Although it was normal for all aircraft to cover 160 miles (4 hexes) in all directions on search missions, arcs were set at 280/330 should normal procedure not be followed for some reason.

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All of the die rolls were passed and there were 8 missions flown by the squadron (helped no doubt by the large number of aviation support, adequate supply and the HQa presence at Geraldton). Two of the pilots (Wright, T, and Hazard) did not fly, 2 flew a single mission (Park and Bellamy) and 3 flew two missions each (Goodwin, Wright, V. and Holmes). This can be seen by examining the missions flown before and after the day of the attack. Pilot fatigue numbers also confirm which pilots flew missions. What cannot be determined is which pilot actually made the reported attack on the enemy submarine although it was likely one of the two that flew twice. Interestingly, while search skill numbers are fairly low ASW skills are quite respectable.

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[WEXF]

Some additional intel was presented that strengthened the likelihood that I-20, or possibly another sub, was in the area and attacked.
This screen shows the reported attack from the combat report. It shows the attack taking place in a hex that is both dark and light and therefore considered "shallow water", terrain that increases the ability to locate and attack subs. The weather was not great but not terrible either. From the report the attack took place in the afternoon phase. Since I-20 has a cruise speed of 4 hexes per phase it could be very close to Geraldton.

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From the screen shot presented earlier it can be seen that there is a detection level on TF382, in the same hex as the attack, of 4/4. None of the other TF or bases in the region show any detection levels. There have been some enemy recon on the north coast of Australia but nothing between Port Hedland and Perth. If TF382 was spotted by a sub that would increase the detection levels.
The fact that the detection level is 4/4 raises another possibility. If the sub was indeed I-20 it might not be carrying a midget sub. It has the capability of carrying a float plane, although it is not equipped with one at the start of the war. A recon flight by a float plane could have increased the detection levels as well even if the plane was not detected by the TF.
Command decided that the enemy was in fact in the area and a full alert would be called for. Orders were being issued to all units detailing the role they would play.
Arend and her sister AVP received orders to maintain the patrol planes. In addition 700 Squadron's Walrus II was ordered to fly an ASW Patrol at 2000 feet. It was expected that two such missions would be flown. Hopefully, all of the training received by the two pilots would pay off.

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The meeting ended to allow all the commanders to implement their orders but command scheduled an update to keep everyone up to date on the overall plan of defense.

[BBfanboy]

You have set the max range of your FP at 3. ASW Patrol cuts that in half so you only get an ASW search out to 1.5 hexes. If you up it to 4 in your settings your FP could reach the area where the I-20 was detected.

Also, if I-20 is shown as a FP carrier at game start, it could not be a midget sub carrier too. There is no FP hangar on a midget sub carrier - just a cradle for the midget sub. The detection level on your base indicates an enemy FP has been over the base. If it was sighted doing recon it will be mentioned in the Ops report.

[WEXF]

You have set the max range of your FP at 3. ASW Patrol cuts that in half so you only get an ASW search out to 1.5 hexes. If you up it to 4 in your settings your FP could reach the area where the I-20 was detected.

Also, if I-20 is shown as a FP carrier at game start, it could not be a midget sub carrier too. There is no FP hangar on a midget sub carrier - just a cradle for the midget sub. The detection level on your base indicates an enemy FP has been over the base. If it was sighted doing recon it will be mentioned in the Ops report.

Thanks for this posting. I have not been clear on the 50% rule for ASW searches.
I-20 is not listed as a FP capable sub in our game. In the editor it has no aircraft capability. My error.
The detection level of 4/4 is on the TF in the same hex as the reported attack. It is not on the base. There has never been a reported enemy aircraft over Geraldton or the TF, so the detection, I think, must be from the sub.
There is another possibility. The sub that was detected might not be I-20 but I-6 or any of the Glen carrying subs. FOW could have caused a mistake in the ID of the sub.
I-6 is the sub I was thinking about when I commented on it not starting with a FP but having the capability of carrying one.

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[BBfanboy]

OK, that clears up my confusion!

[WEXF]

The promised detailed intel meeting started with an overview of all of the air operations ordered to search for and hopefully destroy any enemy activity in the area. It was clear that assets from Perth (medium and heavy bombers) and bases to the north were part of the plan. Some aircraft were on "search" orders and others were on ASW patrols.

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Everyone was reminded that the port was not yet at level 3 so the sub nets were not yet in place. If an enemy sub were to attempt to enter the port it was the recently placed minefield that was the main line of defense. In addition a number of ASW TF were patrolling the region and should be able to detect and engage any midget or full size sub trying to enter Geraldton or one that was nearby either in shallow or deep water.
Goerk was especially interested in the details provided on ASW TF505. This group of 3 Thronycroft HDML were some of the smallest ships in the Allied force. This Commonwealth group, together with a 4th ship, started the war at Georgetown and despite numerous enemy air attacks made it safely to Australia.

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Yes these HDML motor launches were small and, in game terms, not worth much at only 1 point each, but in the situation at Geraldton they were a significant part of the defense plan. Each HDML had an ASW rating of 8. They were armed with a small 3 Pdr gun that had a range of 6000 yds. Not a match for the deck gun of a sub but big enough to do damage to any sub. Certainly, any sub commander would likely abort any surface attack upon sighting one of these motor launches. They also were not likely targets of subs. TF 505 was commanded by a young Ensign. The 4th HDML that started with the 3 in TF505 had been on duty at Perth but has been reassigned and is on the way to join TF505.

I just wanted to take this opportunity to make an editorial comment. Our game is great. What I really like about it is that it allows any player to go as deep as they want to find ways to have fun. I have seen many comments like "lost these ships but they are only 1 point each so no big deal". In game terms that is true but for me I look at our game as a way of putting myself in the middle of the action. Some players are only interested in big ships or intense air action. I am interested in finding ways to use every asset to the maximum of its capability or how many ATGs a Chinese unit may have remaining after several battles or maybe how many mines a particular ship might load in a turn. To each his own!

[WEXF]

Another day has passed and Geraldton is now at 97% of Port3. The sub nets will be fully in place in just a few days. Looking closely at the details in the base screen shows a number of small increases in the defense capability of the base. Guns have gone from 51>54, Artillery from 26>28, Flak from 3>4, engineers from 38>40.

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Looking a bit deeper into the ground units at the base the details are clear.
The 22 Australian Brigade added 2 Inf Sections and a Combat Engineer as well as one support. All of these had been expected as the previous unit screen had shown a "+" for these devices. Surprisingly, a 25 Pounder Gun was also added although there was no "+" on that device previously.

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This unit is really interesting as it originally started at Mersing, was destroyed on March 5 when Singapore fell. It returned in early April after being bought back, arrived in Sydney with only 1% of TOE. It is now still only at 24% TOE. It certainly was worth the few PP it cost to buy back.

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[WEXF]

Another unit accounted for the rest of the growth at Geraldton this turn. The North Sumatra Territory Regiment that had been recently reformed added another 105mm Howitzer, a 12.7mm AAMG, an engineer and 2 support (1 new support and another that had recovered from being disabled). Nothing major but every little bit helps. The unit is now at 29% of TOE and has the ability to add many more devices that are in the general pool. Unfortunately, the fighting power of the unit is limited, but it will be a solid support unit.

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The crew of Arend and everyone else at Geraldton anxiously awaited a briefing on the efforts to find and destroy enemy submarines that had been been spotted and attacked. Although all of the aircraft had returned from their search and ASW missions, none of the crews were boasting of any new attacks. There were some additional reports of "sightings", but everyone hoped that the intel officers would have some details.

[WEXF]

It turns out that the chief intel officer (ME) was having some difficulty understanding all of the reports that had been received. He needed some help from those who knew these reports better (all of you following this AAR).
Resolution of the 21Jun turn had this screen.

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In the box at the lower left (Combat Events) there is a listing of the sighting report by a B-26 Marauder of a Japanese submarine at 48-140, speed 16, moving NW. The map shows that sighting and location. The "combat event" line is in white and not blue like the one above it for the KIngfisher. It is well known by players of our game that lines in blue in the combat events box are unreliable. So being in white the line on the B-26 is at least to some degree credible. So far so good. All seems clear.
This screen is the "Combat Events" listing that is in the "save" file.

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It has the same information and also confirms that the sighting by the B-26 was reported in the AM Phase of air operations. No identification of the sub or report of any attack was made. There is also a report in the PM phase of a float plane at 64-127 near Derby by AMc Ceram. There are no other reports of a sub sighting on the west coast of Australia. All still seems clear.
This is the "Operations Report" for the same day.

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It lists the same report by AMc Ceram, which we know was in the PM Phase. There is no listing of the report by the B-26. There are 3 reports by PBY-5, Do-24K-1 and Vildebeest aircraft of indications of a sub at the 48-140 location. None of these were included in the "Combat Events" listings.
My question for all who follow this AAR is: What can you tell me about the way our game reports events between the "operations Report" and the "Combat Events" report? I have always took the OR to be what pilots reported back after missions. I would have expected that the B-26 pilot would have reported his sighting, but it was not in the OR.
Thanks in advance for any help on this.

[BBfanboy]

Not sure. Your AOperations report cuts off at the bottom - was there anything beyond that?
FOW is always in reports if you have it ON. That is to account for false reports and other goof-ups that can happen. One of those goof-ups could be reports not being sent or not being taken seriously by the operations center. Your job is to scan the various reports (including SIGINT) for corroborating info. You have enough from the other three aircraft to be sure there was a sub in that hex during the turn. Hint - the blue text on that sighting in the Aleutians means it is bogus - a whale or something.

[WEXF]

Not sure. Your AOperations report cuts off at the bottom - was there anything beyond that?
FOW is always in reports if you have it ON. That is to account for false reports and other goof-ups that can happen. One of those goof-ups could be reports not being sent or not being taken seriously by the operations center. Your job is to scan the various reports (including SIGINT) for corroborating info. You have enough from the other three aircraft to be sure there was a sub in that hex during the turn. Hint - the blue text on that sighting in the Aleutians means it is bogus - a whale or something.

Thanks for your response. The OR does have more info but nothing that is likely related to the enemy sub sightings. I expect the best way to use the combat events, OP report and other intel is to look at everything together and decide if a response is necessary. I try to consider everything in two different contexts. The first is the best way for playing the game turn. The second is how the situation might have played out in RL.

[WEXF]

As the intel briefing started, Goerk and the crew of Arend had some idea of what had happened during the previous day. They knew that PO Caruthers had flown 2 missions. They also had heard from the pilots of the patrol planes they supported that additional sub sightings had been made at 48-140 about 80 miles NW of Geralton. All together there had been 4 different air groups reporting sightings and some believed that there could be a second sub at the location.

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It was reported that the efforts of the previous day had been successful in preventing any attacks by the possible enemy subs that were thought to be in the area. However, no enemy subs were actually attacked and it appeared that at least one sub was still nearby.
The concern was for TF 382 (yellow arrow near enemy sub) consisting of a minesweeper and 8 small cargo ships heading to Exmouth and TF 210 (red arrow N of Carnarvon) heading to Geraldton from Exmouth that consisted of a single xAP and an escort. Both of these TF were in the likely path of the enemy. There was a single DD patrolling deep water W of Carnarvon (yellow arrow) that could be in position to intercept an enemy sub in the region.

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New orders were issued for all of the air assets in an effort to maximize the likelihood of attacking or at least forcing the enemy to decide that attacking our shipping was too risky. Time will tell.

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[BBfanboy]

You can help that APD/xAP TF by setting them to "Coastal" routing. Subs don't like shallow water - easier to detect them and attacks are more likely to be effective in shallow water.

Full speed can also help if the TF is close enough to destination - if it gets to the hex next to the destination in the night phase it should enter port in the day phase. And subs are less likely to get a shot if the TF is moving faster.

[WEXF]

You can help that APD/xAP TF by setting them to "Coastal" routing. Subs don't like shallow water - easier to detect them and attacks are more likely to be effective in shallow water.

Full speed can also help if the TF is close enough to destination - if it gets to the hex next to the destination in the night phase it should enter port in the day phase. And subs are less likely to get a shot if the TF is moving faster.

Good points. The TF is actually set at "full speed". It was not set at "coastal" but that would have been smart. Even at "coastal" the TF would have to pass one deep water hex (47-135), but the time in deep water would be much less than it is as I set the orders.
Thanks for the advice.
WEXF