LOGISTICAL BOTTLENECKS IN THE PACIFIC 1.3 

Simplified Production version:

+ only aircraft with specifications issued before 12/07/41 are in R&D > only 18 R&D facilities available
+ simplified Japanese engine prodcution > most planes use generic engine (like Allies)
 
Scenario info:
+ Afternoon of 7 December 1941 - 31 March 1946
+ based on DaBigBabes scen29 variant C (reduced shipping capacity)
+ for PBEM or H2H only - no AI files provided

Recommended Realism Options:
+ FOW: on
+ Advanced Weather: on
+ Allied Damage Control: on
+ PDU: on
+ Historical First Turn: off
+ December 7th Surprise: off

House Rules for scenario design reasons:
+  Scenario starts in the afternoon Dec 7th (meaning only 1 night and 1 day phase on turn 1), with initial air attacks on PH, PI, Malaysia and Wake already done. Kido Butai only naval attack allowed, no offensive missions for all Japanese / Allied air groups outside China except IJN air groups in Saigon allowed to fly Naval Attack. No restrictions on Search/CAP/Recon.
+ Strat movement restrictions concerning "constructible" resp. "damaged" railways (see documentation) - Require upgrading ports to lvl 6 before STRAT movement can be used. River crossings must be upgraded on BOTH sides. River crossings with Red X can never be 'fixed' during the game's time frame.

House Rules for realism reasons:
+ Full PP must be paid for restricted units to unrestrict and cross national borders, except Thai units and British / Indian units are allowed in Burma and Malaysia.
+ Sweeping is allowed max at the 2nd highest maneuver band altitude.
+ No fuel/oil transportation in xAK/AK/AKA types
+ Allies: no infantry unit transportation in xAK/xAKL unless for emergency evacuations (no such restriction for the Japanese since they were a lot tougher with their own men)
+ Allied 4E bombers no attacks below 10 000 feet except for SB-24 Liberator_ (attack bomber) squadrons & USN planes - see below.
+ Naval bombing by Level bombers at a minimum 2000 feet.
+ Naval & ground bombing by TB's and various level-bombing naval aircraft at a minimum 1000 feet. This includes US Navy 4E planes (Liberators, Privateers, Coronados) as these had a doctrine & were trained on low level NAV attacks. Same rule applies for CV capable bombers, regardless of CV or land based. 
+ Naval bombing attacks from 100' only allowed by the following classes: Fighters, F-B's, Attack bombers - denoted by the "_" at the type name, e.g. "PBJ-1D Mitchell_" or "KI-51a Guntei_" (AKA Sonia). Setting TB's to come in at wave top is allowed BUT you must have enough torps for the strike.
+ Night attacks on airfields and ports restricted to one squadron in 1941/42, two in 1943, three in 1944, four in 1945 - height restrictions for 4E heavies still apply. 
+ No industry bombing of Chinese-owned bases (manpower bombing ok)
+ Only one attack allowed using 'Doolitle Raiders' air group. Must be disbanded afterwards.
+ LBA Air group resizing via carriers is allowed, but the resulting squadron size is limited to max 36 planes / air group due to game engine limitation. Split the group into 1/3rds when going into battle. Ther eis also a hard cap on the number of pilots for the game duration, so don't push it!
+ No use of strategic movement on dashed railroads / roads (using LST's map) until repairs/construction has been done (to max standard port level along the line)
+ Hospital ship and its LCU must be together at the same hex, same for 'water distilling ships' (AW)
+ No full speed off-map movement.
+ On attack, armored formations are limited to one attacking tank unit for each attacking INF unit (not just Bombard!) except in CLEAR hex types. This is SE Asia, not the Kursk salient! Additional tank units can be set on Reserve/Pursuit to exploit a breakthrough.

Changelog May 25, 2023:
LST's changes:

- corrected duplicate B-17 slots
- fixed recombine error of NZ division
- corrections / minor changes to road network in Malaya
- a few localised tweaks to base sizes / supply caps
- Singers now light urban to reduce defensive terrain bonus
- fixed withdrawal date error for AK Betelgeuse
- corrected Mine Mark 18 not being produced because set to 'can build - no' by error
- Mine Mark 6 set to produce 300 per month for the duration of the war - historic starting pool was 59.000 (!) and it remained in the USN inventory until 1985
- Upped loading capacity of Daihatsu barges to be able to transport motorized support and light / medium tanks
- Increased Oil well output to 15, Refinery input the same and refinery output to 12 fuel points. Japan's issue historically was more in hull availability & the oil/fuel being in the wrong places than not having it. Higher output per point means any damage will affect production more. (JS + LST)

JS Changes:

- Made Chungking port size 3 to allow rearming of the Chinese river boats
- All AT guns for both sides (except Soviet) changed to 'Naval Gun' type. This allows them to engage ships during invasions or naval bombardments if these ships come too close to the shore, to simulate gun emplacements close to the shoreline. These devices only have a range of 2, at the most 3 so unloading TF's will only be targeted if they come too close to the shore (dice roll). They should, however, directly engage mortar and rocket armed Landing support craft! Early war yolo-invasions should also come with a bit more attrition on the participants. Based on testing, land combat results do not appear to be affected. 
- IJA 70mm T92 Bn Gun - changed the SNLF & NAV Guard units to use a 'Naval Gun' type (New device - 683). This is a VERY short ranged weapon (3k), so it is reasonable to expect these to be deployed in direct fire role for shore defence. The original 'Army version' (device 745) remains in use by IJA.
- IJA 10cm T92 Gun and 75mm T90 Field Gun changed to Naval Gun type & reduced PEN to 65 - these are 'high-performance' guns, very capable in direct-fire role, but they still should not be able to penetrate a CA's armor. They are also quite rare in the OOB at start, later on the 75mm T90 will replace the T95 and T38 field guns for IJA field divisions. There are 4 regiments using the 10cm T92. 
- IJA 15cm T89 Gun changed to Naval Gun type & reduced PEN to 124; there are ~5 regiments of 8 guns + the Hong Kong Def Force CD unit is using these.

All other values, including accuracy, remained unchanged so these weapons will still be of limited use compared to dedicated CD units. As an example, the 15cm T89 gun has an accuracy of 4, compared to 47 for the 15cm 41YT CD Gun (used in many Naval Fortress units, including Truk & Saipan).

Design Note: The idea is that invading a shoreline defended by a full, unsuppressed and well supplied IJA division should incur costs for the ships taking part in it. There was a reason why operations like Cartwheel or any of the major invasions were executed the way they were, instead of just tossing out a couple-three Marine divisions & a bunch of tank units directly onto the enemy's main base & ROFLStomping the defenders. Japan could do the same in the early war to a large extent, so now they may face a bunch of 2pdr AT guns taking potshots at the unloading ships! 

IMO the Allied doctrine did not really have a need for 'regular', or 'field' units to perform shore defence; there are plenty of dedicated CD units with 155mm guns in the USN OOB, many Royal Navy base forces carry 6" CD guns. There is also a game engine rule that only DP or naval guns with a range of 15k and above can participate in the Bombardment land combat phase so I could not just 'turn it on' for all light guns without affecting the land combat balance.

- Allowed ToE upgrades for the 1 and 2 battalion sized SNLF Naval Guard units to stronger coastal defense formations with 12cm guns that also makes them static units if triggered. The number of SNLF squads remains the same so they are still not enough to hold against a couple of US regiments byt themselves. The upgrade takes place from 5/42 and does not affect 'assault' type SNLF units (the ones that come with Armored Cars), nor the smaller, company-sized formations.
- Reduced loading cost of Motorized Support from 12 to 11, to be in-between Regular Support (10) and Engineering Vehicle (12). Normal trucks should be a bit easier to move than dozers.