Treespider's CHS - China Revisited - 1st look

[treespider]

Based on the discussion in the Level Bomber/Torpedo Bomber thread... I plan on modding my own scenario based on CHS Scen 155 v 2.08

The primary mission of this mod will be a drastic reduction in base sizes across the map....with that in mind I am considering two formulas at start:

Formula # 1 - applies to Base SPS - subtracting 5 from all base SPS with 0 as the lower limit.
Formula #2 - applies to At Start Base Size - :
1->1
2->2
3->2
4->3
5->3
6->4
7->5
8->6
9->7
10->10


Keep in mind according to coding every base can theoretically be developed into at least a size 3 airfield.

I'll consider other formulas....and intend on doing a comperehensive study of bases. Bases will not be sized because a particular aircraft operated from them. In the game as it stands now 2E and 4E bombers can operate from level 2 and level 3 fields albeit with penalties. Likewise players can base as many planes as they want at any base but they will not operate at peak efficiency.

Certain established bases will maintain there status as 10/10 bases however any base developed during the war will have a maximum SPS of 4 which can theoretically be expanded to a base size of 7.

Suggestions welcome.

One potential drawback that some have already mentioned is that bases may be more vulnerable to 'nuke' bombardments...I guess we'll just have to play it and see...

[bradfordkay]

Moved from the general discussion:

I like the idea, overall, though it will prove to be a map for PBEM only if you also adjust the port sizes. I believe that Mike Wood has already pointed out that certain bases were chosen to be main naval resupply depots for the AI and that ABs map has already reduced some of those below the level needed to resupply the ships.

It's one of the reasons I have finally started a PBEM. I love the CHS and ABs map, but the AI was bogging down and doing very little by April-May of '42.


It would take some work to figure out which bases should be at what level. In Bloody Shambles it is mentioned that B17s staged out of Namlea to attack Japanese forces at Manado. By this I am supposing that Namlea should start out 2(0)??

[treespider]

ORIGINAL: bradfordkay

It would take some work to figure out which bases should be at what level. In Bloody Shambles it is mentioned that B17s staged out of Namlea to attack Japanese forces at Manado. By this I am supposing that Namlea should start out 2(0)??

That's what I have in mind...

[Cathartes]

Exceptions to the "across the board" rule will make the difference. For example, there are base locations that did in fact represent multiple airfields. Rabaul is a perfect example of this, and large numbers of aircraft were capable of operating from this location, because there were some 5 airstrips and a seaplane base. Pearl Harbor is of course 9/10 probably not just because of the large runway length and developed tarmacs, but because multiple airfields are represented--Oahu makes perfect sense as a 9/10 base, as does SF. And what about airfields like this? This is the potential of Tinian fully realized.

[KDonovan]

nice pic of Tinian. I believe think the current level AF of 7(4) is accurate, based on that picture, but i would suggest perhaps lowering the port from 4(1) to 3(0). Based on my pic below you can see that the harbor would barely fit more than a couple ships

[treespider]

ORIGINAL: Cathartes

Exceptions to the "across the board" rule will make the difference. For example, there are base locations that did in fact represent multiple airfields. Rabaul is a perfect example of this, and large numbers of aircraft were capable of operating from this location, because there were some 5 airstrips and a seaplane base. Pearl Harbor is of course 9/10 probably not just because of the large runway length and developed tarmacs, but because multiple airfields are represented--Oahu makes perfect sense as a 9/10 base, as does SF. And what about airfields like this? This is the potential of Tinian fully realized.

Nice picture of Tinian...what is the date of the photo?

[treespider]

Actually the Tinian scenario is my primary concern right now...
 
Does anyone have data on the bombloads carried by the B-29's in operation? I know the stated max is 20,000lb but what impact would 20,000lb have on the max range?
 
In the game aircraft require a bombload of 6499lb or less to fly at extended range from a level 4, 12999lbs from a level 5, and 19499 from a level 6, and 25,999lbs from a level 7.
 
Tinian to Tokyo is 22 hexes. I think the B-29's normal range in CHS is 20...more calculating to do.

[treespider]

http://rwebs.net/dispatch/output.asp?ArticleID=13

Actually this website places the B-29's Normal bombload as 12,000lb, Max Load 20,000lbs...there is a note at the bottom that staes that Max load could only be carried for much shorter ranges.

Other sites have said range in miles with a 10,000 lb bombload was 3250 miles.

Using the 12,000lb figure the B-29 could then operate from a Level 5 airfield at extended range...

More calculations coming.

[ctangus]

I think this is a very good idea for all the reasons you mentioned in the main forum.

There's still another advantage that you haven't mentioned - it should increase operational losses as well, which would IMO be a good thing. More ops losses would probably force players to rest there planes more often, leading to more realistic sortie rates.

I would, however, be careful of giving too many airfields an SPS 0. That would all but prohibit the Japanese from expanding the airfield. In game it took me 6-8 weeks to expand a 0(0) to a 1(0) using 6 or 7 Seabee units. That would certainly be fine for a field like Torokina (8 Seabee bns & a NZ engineer brigade took about 5 weeks to build the field IRL) but it wouldn't be correct for a field like Lunga (2 Japanese construction bns & rough equivalent in US forces took about 6 weeks to build it - those units would probably take 6 months in game to build up from a 0(0).)

A 0(1) or even a 2(1) would still require a significant engineering effort on the part of the Japanese to build to level 4, but it wouldn't be next-to-impossible either.

[herwin]

I'd rather use actual data. It should be available.

[treespider]

Currently in CHS Tinian has a SPS of 4 meaning it can be built to level 7. It is 22-24 hexes from most of Japan.

The B-29 in CHS has an endurance of 1125 and a cruise speed of 260 giving it an extended range of 27 and a normal range of 20. It also has a bombload of 20,000...meaning it requires a level 7 airfield to reach Japan which is at extended range.

Using figures from David Mondey the B-29 has a cruise speed of 230mph and a range of 3250 miles, this equates to WitP values of endurance  of 847.8 and a cruising speed in knots of 264.8 resulting in extended range of 20 hexes and normal range of 15 hexes... I assume this indicates a max bombload range.

So in order to get a B-29 to fly at extended bomb range from a smaller base will necessitate dropping the bombload. A number of sites I checked indicate that the normal bombload was 12,000 lb.. This would necessitate only a Level 5 airfield to fly at extended range.

Likewise a number of sites have indicated Max range is c.5800 miles. Averaging between 3250 and 5800 gives us 4525 miles. So using 4525... if I fudge and make it 4600 I give the B-29 a normal radius of 22 hexes assuming the cruising speed of 264 knots.

With a range of 22 hexes so long as Tinian is at least size 2, the B-29's can operate from Tinian and reach Japan.

Now depending on the bombload that was operationally carried - will we assign 12,000lbs or 20,000lbs. If 12,000lbs then Tinian can be given an SPS of 2 which could be expanded to 5 and B-29's could reach Japan with a full operational load. If 20,000lbs is assigned then Tinian would require a SPS of 4 which could be expanded to 7 to allow B-29's to reach Japan with a full load.

[treespider]

ORIGINAL: herwin

I'd rather use actual data. It should be available.

In terms of...

[KDonovan]

Now depending on the bombload that was operationally carried - will we assign 12,000lbs or 20,000lbs. If 12,000lbs then Tinian can be given an SPS of 2 which could be expanded to 5 and B-29's could reach Japan with a full operational load. If 20,000lbs is assigned then Tinian would require a SPS of 4 which could be expanded to 7 to allow B-29's to reach Japan with a full load.

correct me if i'm wrong, but adjusting the bombload of the B29, in order to operate at a lower AF level of 5 seems to open a can of worms. By that i mean, you wil then need to adjust the B17/24 for level 4 AF's, then B25/26's for level 3 AF's. Which won't solve any of the problems with the current base size's in the game.

[treespider]

Looking at historical data of Japanese development on Tinian...

According to the green books - The Japanese intended to place 4 airfields on Tinian each capable of accomodating 48 planes. However this construction plan seemed much too optimistic for the Japanese....

so in game terms assuming we gave Tinian an SPS of 4 the japanese could easily expand it to 4 allowing 4x50 planes to operate without penalty. However since historically Japanese had difficulty building this facility perhaps the SPS should should be rated as 1 allowing it to be built to 4 or even 2 allowing it to be built to 5.

However since we know that B-29's operated from Tinian - so if we make the SPS a 2 then we can expand it to 5 allowing B-29's to operate from Tinian if we give the B-29's a normal bomb load of 12,000.

[treespider]

ORIGINAL: KDonovan

Now depending on the bombload that was operationally carried - will we assign 12,000lbs or 20,000lbs. If 12,000lbs then Tinian can be given an SPS of 2 which could be expanded to 5 and B-29's could reach Japan with a full operational load. If 20,000lbs is assigned then Tinian would require a SPS of 4 which could be expanded to 7 to allow B-29's to reach Japan with a full load.

correct me if i'm wrong, but adjusting the bombload of the B29, in order to operate at a lower AF level of 5 seems to open a can of worms. By that i mean, you wil then need to adjust the B17/24 for level 4 AF's, then B25/26's for level 3 AF's. Which won't solve any of the problems with the current base size's in the game.

I'm adjusting the bombload of the B-29 to allow for historical missions. See my previous post on historical Japanese capabilities at Tinian and how to reconcile them with B-29 capabilities from the same base.

I am merely trying to ensure that the B-29 will fly at extended range from a base from which it historically operated.

In the case of the B-17/B-24 in CHS they both only require a level 5 airfield to operate at extended range meaning a base with an SPS of 2. I don't see that as being a big issue in terms of where they will still be able to operate from.

The B-29 on the other hand with its huge load rating and range required some investigation...my reconciliation is to downgrade the bombload of the B-29 from 20,000 to 12,000.

[Cathartes]

The shot posted above in the thread is North Field (circles on tails for 313th Bomb Wing) and there was also a West Field. It's hard not to be impressed. There were 4 parallel runways at North Field at 8500' each (largest airfield in the world at the time?). West Field had two runways. If all aircraft were operating, between 350-450 B-29s could be launched within 90 minutes by summer 1945, based on the Bombardment wings based there. What Japanese player would allow such a violation of the stacking limits? Is it possible to accurately represent this in the game?

As most of you realize, Iwo Jima helped cut down B-29 OP losses dramatically. So maybe a 7 (4) does the trick just fine? Thing is, most B-29 raids on Japan were anemic until LeMay took on the job and concentrated on firebombing. Incendiaries changed the bombing game completely.


This is a nice site with some great shots of airfield and harbor at Tinian:
504th BG

[treespider]

Does anyone have any info on extend range missions flown by any other level bombers?

[treespider]

More Tininan considerations from Wiki -

Tinian was captured by the United States in July 1944 in the battle of Tinian. The island was transformed into the busiest airbase of the war, with two B-29 airfields (West and North) having six 8,500 foot (2700 m) runways. The Japanese had constructed three small fighter strips on Tinian but none were suitable for bomber operations.

Tinian becomes 1(3) expandable to 6(3).

Current CHS version 2.08 has Tinian rated as 3(4) which could become 7(4).

[Cpt Sherwood]

I like this idea but I don't think Tinnian is the problem. I see the largest problem being the large number of size 4+ bases available for the Japanese player to capture. These quickly allow Betty and Nell flights with Torpedeos. I don't see the problem with either side being able to build the bases over time, just make them expensive. I would like to see most bases with SPSs of 3 or less and starting with mostly level 0, 1 and 2 airfields with a few 3s and only major bases having 4+ starting sizes. I have no problem with a large number of SPS 0, 1 and 2 bases available throughout the Pacific, with most being 0 and 1. A SPS of 0 or 1 would not allow the Allied player to use B-17/B-24s at most island bases at full load or full range. They would be reserved for only a few bases that could support them.

[treespider]

ORIGINAL: spence

Here's a link to what appears to be a bunch of good maps of Pacific Islands and so forth at the end of the war:

http://www.lib.utexas.edu/maps/historic ... _1945.html

Very interesting. I have a series of questions. Basically:

1. What does a port size rating mean to the game engine?
2. How do you determine the port size in 1941?
3. What determines the potential port size?

Here, I'm thinking about some of the major ports developed by the USN during the war: Ulithi, the Admiralties, perhaps Samoa. I suspect manpower availability should be part of the model.

Code: Select all

Size of Port
 - Influences	- Chance of being Targeted by enemy Air Strike.
 		- Additional damage to Ships in Base, due to existing Ships' damage.
 		- Amount of damage in enemy Air Strikes & Naval Bombardments.
 		- Port Facilites' damage repair time & Port expand time.
 		- Ship's Repair Time.
 		- Loading / Unloading Speed.
 		- Forts construction speed (combined with Airfield size).
 		- Garrison required in Chinese Bases (combined with Airfield size and production items in city).
 		- Reduction of LCU Fatigue (combined with Airfield size).
 		- Spoilage amount of Fuel / Supplies (combined with Airfield size).
 		- Victory Points for holding a Base (combined with Airfield size)
 - Size 1	- Barges & PT Boats can be activated (requires 10.000+ Supplies at Base).
 		- Fuel can be produced by HI & Oil centers in city.
 		- Ship Tenders (AD, AR, MLE...) can perform their duties.
 		- Can be Mined.
 - Size 3	- TFs can be disbanded - ships put At Anchor.
 		- PT Boats can reload Torpedoes. (requires 3.000+ Supplies at Base).
 		- Ships Docked /At Anchor  immune to Sub attacks.
 - Size 5	- Ship's systems (weapons, radars...) can be repaired.
 - Size 8	- Can be used for Auto Sub Ops (requires 10.000+ Supplies at Base).
 		- SS & Surface Ships can reload Torpedoes.
 - Size 9	- ML, DM & SS can reload Mines.

4. What does an airfield size rating mean to the game engine?
5. How do you determine the airfield size in 1941?
6. What determines the potential airfield size?

Here, I suspect buildable area, rock type, and manpower should be part of the model.

Code: Select all

Size of Airfield
 - Influences	- Operational Losses at take-off / landing.
 		- Chance of being Targeted by enemy Air Strike.
 		- Amount of damage in enemy Air Strikes & Naval Bombardments.
 		- Airfield Facilities' damage repair time & Airfield expand time.
 		- Chance to destroy / damage planes on ground.
 		- Level Bombers on Offensive Missions flying without penalties.
 		- What Missions planes can fly, when Airfield has sustained Runway Damage.
 		- Max. number of planes that can fly Missions.
 		- Max. number of Aviation Support in a main Base Force Unit in Base.
 		- Forts construction speed (combined with Port size).
 		- Garrison required in Chinese Bases (combined with Port size and production items in city).
 		- Reduction of LCU Fatigue (combined with Port size).
 		- Spoilage amount of Fuel / Supplies (combined with Port size).
 		- Victory Points for holding a Base (Combined with Port size).
 - Size 0	- Float Planes, Float Fighters or Patrol Planes can use - only if Costal hex.
 		- If SPS = 0, takes 10 * longer than normal to expand to Size 1.
 - Size 1	- Airfield / Port / Naval / Ground Attack and Sweep Missions can't be flown.
 		- Can be Targeted for Air Troop Transport.
 		- Ships' Air Units can transfer from their Ships.
 - Size 4	- Level Bombers with Bomb Load < 6,500 fly Offensive Missions without penalties.
 - Size 5	- Level Bombers with 6,500 < Bomb Load < 13,000 fly Offensive Missions without penalties.
 - Size 6	- Level Bombers with 13,000 < Bomb Load < 19,500 fly Offensive Missions without penalties.
 - Size 7	- Level Bombers with Bomb Load > 19.500 fly Offensive Missions without penalties.

If the game engine uses port and airfield size primarily to restrict the kinds of operations from a base, then we need to do a terrain analysis.

I wouldn't mind a version of CHS designed solely for PBEM that had accurate map data.

We can look at terrain to degree. Just because an area is currently well developed today and can accomodate commercial jetliners does not warrant it receiving a larger SPS value. I'm basing my SPS values on what was present at start as well as what was developed during the war. I will also likely give a minimum SPS value of 1 on any non-mountain continental or near continental type hex. In addition since I will be downgrading bombloads on the Superheavies (B-29, Lancaster Mk 1, and Lincoln) and perhaps other heavy bombers I am giving myself more flexibility to assign base values to ensure that these types of planes can still fly at extended range.