The conundrum of the Ki-48 II

[el cid again]

This is a difficult aircraft to classify properly in WITP game terms. Here I will review some of the issues and trade-offs involved - as we are about to freeze the RHS design base - and it will be a good deal less subject to changes (unless for cause) after that.

My first thought was "get rid of the beaste - we need Japanese slots - do we really need two different Ki-48s???"

This generated considerable opposition. The II actually is a better bomber than the I model - howevery you look at it.
Starting with its bomber mission: basically it carries twice the bomb load. [The design was for 8 x 100kg bombs - exactly the same as for Japanese "heavy" bombers of this era. The I model carried 8 x 50 kg bombs - the previous standard for JAAF bombers.] It actually carries twice the load slightly farther IRL - and slightly faster even in game terms. It has slightly upgraded defensive armament - a .50 vice a .30 top rear and provision for a side gun wholly absent in the I model. And it is armored. So theoretically it is a better plane. But in game terms, for reasons not even clear to programmers, it is also a very good ASW bomber. So players wanted it in.

My next move was to classify the II as a dive bomber. For the technical reason it WAS a dive bomber! To this Nemo objected vehemently - arguing in game terms that the way dive bombers work is completely different from horizontal bombers. He is right of course - a real Ki-48 II COULD dive bomb - but it could also bomb in a normal, horizontal sense. And the game code makes it take a lot more flak if it does the dive bombing profile. So I relented again - and put it back as a horizontal bomber.

Problem: A Ki-48 II is not clearly better than the Ki-21 II - an older design. In game terms it costs exactly as much to build as a Ki-21 II does. [IRL the cost ratio is 15.12 for the Ki-21 IIa to 11.32 for the Ki-48 II] [Later Ki-21 IIs cost 15.14 for the IIb and 14.572 for the IIc] The Ki-21 has more defensive guns and flies farther, but has no armor. Both have an RHS durability rating of 18. Why would a player spend 18 HI points to get a Ki-48 II when he could spend the same amount and get
a Ki-21 II?

Problem: IF we rate the Ki-48 II as a dive bomber, then dive bomer units (Ki=51 and Ki-36) can upgrade to it - but horizontal bombers cannot - except the Ki-48 I - which we can force to do it using the special upgrade field of an aircraft type. OTH if we rate it as a horizontal bomber, dive bomber units won't upgrade to it - and won't normally be allowed to do it. IF we rate the Ki-48 II as a horizontal bomber, then regular bombers can upgrade to it- but dive bomber units cannot.

Problem: The Ki-48 II, the Ki-45 II, the Ki-96, the Ki-102 and the Ki-108 are all designed by the same design team, and all used similar technology. Rating the Ki-48 II as a horizontal bomber - the rest are fighter bombers - tends to create an artificial distinction between essentially similar airframes - and many differences exist in the mission options and mission profiles in this case - which really would not be the case IRL.

Query: Should we leave the Ki-48 II as a horizontal bomber? Should we instead classify it as a dive bomber? Should we instead detete the type altogether?

[m10bob]

Many of the larger world bombers were intended as dive bombers before the war.because a good bomb sight had not really been "perfected" till the Norden came along.
Look at the Ju 88 , Dornier 17, Dornier 217, original He 111,and you will see they all had dive brakes.
(The entire tail of the Dorniers opened up clamshell wise), and the planes were very accurate bombers for this reason, yet over Britain, they were used as level bombers.
The simplest bombsight of WW 2 was likely Wallis' sights of 2 nails driven in a board, held in front of the bombardier, so when the nails lined up with the dam towers, it was release time..
If you make the plane a dive bomber, (historically accurate), it should in turn be more accurate in its' delivery..

[Dili]

Having dive brakes doesnt not necessarely means a dive bomber in a sense of Stuka or Val. A Ju88 the best of German bombers could not dive like a Stuka or a Val. It could dive but  more shallow way and at that is dificult distinguish from some fighter bombers .
 
Ki 45 and Ki 48 similar airframes? maybe you are making confusion with  Ki-48 artwork that was a Ki-45.

[el cid again]

ORIGINAL: m10bob

Many of the larger world bombers were intended as dive bombers before the war.because a good bomb sight had not really been "perfected" till the Norden came along.
Look at the Ju 88 , Dornier 17, Dornier 217, original He 111,and you will see they all had dive brakes.
(The entire tail of the Dorniers opened up clamshell wise), and the planes were very accurate bombers for this reason, yet over Britain, they were used as level bombers.
The simplest bombsight of WW 2 was likely Wallis' sights of 2 nails driven in a board, held in front of the bombardier, so when the nails lined up with the dam towers, it was release time..
If you make the plane a dive bomber, (historically accurate), it should in turn be more accurate in its' delivery..

Surely the "simplest bombsight" of WWII was on the Beaufort (I think) - a British bomber with utterly no bombsight at all!
Pilots would "line up two rivits on the nose" that happened to be in a convenient location!

You are thinking as I did when I classified the 48 II as a dive bomber. But in that case:

Ki-48 II units will attrit much more than they otherwise would - they will take more flak on every mission;

other horizontal bombers won't be able to upgrade to the type

other dive bomber units will be able to upgrade to the type

meaning in this case a Ki-36 or a Ki-51 outfit can fly the Ki-48 II, but a Ki-30 / Ki-32 outfit could not
normall a KI-48 I also coult not - but

we can make a unit upgrade to anything one time

Nemo felt the effect on the pilot pools was unjustifiable.

It isn't like players have any control: a horizontal bomber ALWAYS bombs horizontally, a dive bomber ALWAYS dive bombs - no middle ground

[el cid again]

ORIGINAL: Dili

Having dive brakes doesnt not necessarely means a dive bomber in a sense of Stuka or Val. A Ju88 the best of German bombers could not dive like a Stuka or a Val. It could dive but  more shallow way and at that is dificult distinguish from some fighter bombers .

Ki 45 and Ki 48 similar airframes? maybe you are making confusion with  Ki-48 artwork that was a Ki-45.

Actually, I am quoting Francillon. The Ki-48 II was used to develop dive bombing technology - which then was applied to the later Ki-45 and its derivitives. Neither the original Ki-45 nor the original Ki-48 had the technology. So it is wholly unrelated to what they look like.

[Dili]

Neither were dive bombers like Val and Stukas. I think Ki-48 as a Bomber is correct, that's how they were used and they were representative of Japanese light bomb units, replacing them by Ki-21 cuts game immersion . Only a the need of a slot for an almost equal in importance plane would warrant its replacement IMO.

[el cid again]

Seems like some words are missing above. There is not really much difference between a Ki-48 II and a Ki-21 II - they have essentially the same load over a similar range. The 48 II has armor, the 21 II has better defensive guns, and both are rated at durability = 18. Speed is similar. IF there is a difference, it lies in the ability of a 48 to dive - but that difference is not apparent on its typical non-diving mission.

Mifune chimed in privately that "there are plenty of horizontal bombers" and he thinks the ability to upgrade dive bombers (Ki-51s carry almost nothing) is significant fairly early in the war.

I am not sure what you meant above, but before that you recommended going with the dive bomber, and that was also my view to start with. Why have essentially different flavors of the same thing? Different things are more interesting - and permit players more choices when they build/upgrade.

[Dili]

Well first of all 20% of weapon load difference isnt nothing.
 
Ki-48II  4550kg / 6750 kg>>cargo:2200kg =4 crew(400kg)+3x7.7MG(90kg)+800kg bombs>>Fuel=910kg 2x1150hp
 
Ki-21II  6070kg / 9710kg>>cargo:3640kg =7 crew(700kg)+4x7.7MG(120kg)1x12.7MG(55kg)+1000kg bombs>>Fuel=1750kg  2x1490hp 
 
 
So the Ki-21II have 20% more bombs, have more defensive armament and almost the double of fuel weight. If we include Radios the diference will be bigger.
 
Gun data includes Amno.
 
 

[el cid again]

Actually the bomb load in game terms is identical: 8 x 100 kg bombs (or 16 x 50 kg bombs) = 800 kg.

In WITP we do NOT use maximum bomb load for many bombers - although you rarely see this in Japan - whose bombers usually have normal load = maximum load. The game code ONLY uses normal load - and also a reduced load (we say it is for "extended range"). There SHOULD be a third load - what I call maximum load - for a shorter range than normal range - but there is no such thing in our game system.

You will note this much more strongly in Allied bombers - where the normal load is usually much smaller than the maximum load.

Fighters and fighter bombers don't get an extended range (reduced load) and their "normal load" also is often their maximum load. Japanese light bombers are usually this way as well.

The tricky thing is this: the range with a normal load must be right in the data set. For some planes you can do this various ways - but you must be careful - as extended range is a function of what you set normal range to be. RHS is systematic and careful about bomber ranges in particular. In a vast number of cases these were not right when we started working. [Allied bombers in particular were under-rated in load and the range for even a bigger load] Anyway - in terms we can use - the normal load - the planes are virtually indistinguishable. The game cost is exactly the same (18 HI points). IRL the Ki-48 should be cheaper - and if we cared about the max load - the max load per cost point would still be virtually identical.

[jwilkerson]

ORIGINAL: el cid again

Actually the bomb load in game terms is identical: 8 x 100 kg bombs (or 16 x 50 kg bombs) = 800 kg.

In WITP we do NOT use maximum bomb load for many bombers - although you rarely see this in Japan - whose bombers usually have normal load = maximum load. The game code ONLY uses normal load - and also a reduced load (we say it is for "extended range"). There SHOULD be a third load - what I call maximum load - for a shorter range than normal range - but there is no such thing in our game system.

You will note this much more strongly in Allied bombers - where the normal load is usually much smaller than the maximum load.

Fighters and fighter bombers don't get an extended range (reduced load) and their "normal load" also is often their maximum load. Japanese light bombers are usually this way as well.

The tricky thing is this: the range with a normal load must be right in the data set. For some planes you can do this various ways - but you must be careful - as extended range is a function of what you set normal range to be. RHS is systematic and careful about bomber ranges in particular. In a vast number of cases these were not right when we started working. [Allied bombers in particular were under-rated in load and the range for even a bigger load] Anyway - in terms we can use - the normal load - the planes are virtually indistinguishable. The game cost is exactly the same (18 HI points). IRL the Ki-48 should be cheaper - and if we cared about the max load - the max load per cost point would still be virtually identical.

BTW just tossing in a potentially irrelevant group of data for your reading pleasure ... [:)]

In the Game (ITG) ... and let's say I'm talking "stock" here .. ITG the Lily is the best AF buster in the Japanese inventory. Since hitting "runway" and aircraft is dependent on # of bombs ... a Lily unit with EXP 80+ can start looking like a B-17 from the perspective of runway and ac damage. Now if you wanna hit the service, supply or LCUs .. in an AirField attack then better bring some Sally's along as well. But the Lily's can put a hurt on a runway with those 8x100KG bombs.

I bring this up because you might wanna consider the game impact of your changes while you're chatting about them.

In my game with Moses there is a recent (and quite rare) example of me making an air raid on Imphal (big British fytah base) and using a combo of Lily's and Sally's and getting decent results ... go check out my AAR if you wanna see a real game example, you might have to go back a page or so but it is recent.


Of course IRL I haven't found the sources which list out all the great Lily AF busting raids - but I'm still looking!!![;)][:D]

[jwilkerson]

ORIGINAL: Dili

Well first of all 20% of weapon load difference isnt nothing.

Ki-48II  4550kg / 6750 kg>>cargo:2200kg =4 crew(400kg)+3x7.7MG(90kg)+800kg bombs>>Fuel=910kg 2x1150hp

Ki-21II  6070kg / 9710kg>>cargo:3640kg =7 crew(700kg)+4x7.7MG(120kg)1x12.7MG(55kg)+1000kg bombs>>Fuel=1750kg  2x1490hp 


So the Ki-21II have 20% more bombs, have more defensive armament and almost the double of fuel weight. If we include Radios the diference will be bigger.

Gun data includes Amno.

How were the bombs mounted on the aircraft? Were these all internal? Some internal, some external? Were they all one behind the other? Side by side? I can find the bombloads too but not the mounting data. I do have some real operational data from some Navy bombers (like what were actual operation bomb configurations) but not for the Army (still lookin).

[String]

ORIGINAL: Dili

Having dive brakes doesnt not necessarely means a dive bomber in a sense of Stuka or Val. A Ju88 the best of German bombers could not dive like a Stuka or a Val. It could dive but more shallow way and at that is dificult distinguish from some fighter bombers .

Ki 45 and Ki 48 similar airframes? maybe you are making confusion with Ki-48 artwork that was a Ki-45.

It's a bit OT but i've always understood that the Ju88 could and did do almost vertical dives, but the airframe couldn't really handle it and the wear was atrocious. So they banned vertical dives and changed it to more shallow approach.

[el cid again]

ORIGINAL: jwilkerson

ORIGINAL: Dili

Well first of all 20% of weapon load difference isnt nothing.

Ki-48II  4550kg / 6750 kg>>cargo:2200kg =4 crew(400kg)+3x7.7MG(90kg)+800kg bombs>>Fuel=910kg 2x1150hp

Ki-21II  6070kg / 9710kg>>cargo:3640kg =7 crew(700kg)+4x7.7MG(120kg)1x12.7MG(55kg)+1000kg bombs>>Fuel=1750kg  2x1490hp 


So the Ki-21II have 20% more bombs, have more defensive armament and almost the double of fuel weight. If we include Radios the diference will be bigger.

Gun data includes Amno.

How were the bombs mounted on the aircraft? Were these all internal? Some internal, some external? Were they all one behind the other? Side by side? I can find the bombloads too but not the mounting data. I do have some real operational data from some Navy bombers (like what were actual operation bomb configurations) but not for the Army (still lookin).

The Lily is actually a Japanese reply to the Soviet SB-2. They met that fast two engine tactical bomber in 1938 - and were impressed - so they designed what they thought would be a similar plane. In order to be fast and have a good range, it had to be clean, so it is a proper bomber: it has a true bomb bay. The earlier Japanese tactical bombers - Ki-30, Ki-32 and Ki-51 - all had entirely external bomb loads. [The Ki-51 is interesting in that it was proposed for the ARMY air force by a NAVY captain - it is derived from an ARMY bomber - but is smaller - armored - and fitted to dive - which the army bombers until then were not. So much for "there was no cooperation between Japanese services."]

The Sally - a relatively successful bomber in Japanese terms - never really replaced by its "replacement" Ki-49 (Helen) - also is clean and has a proper internal bomb bay. All JAAF "big" bombers are this way. Only fighters, fighter bombers and light bombers (or NAVY two engine bombers of the earlier sort) have external loads. [The Navy ones semi recessed the torpedo so it isn't internal but doesn't have the drag of an external weapon either]

[el cid again]

ORIGINAL: String

ORIGINAL: Dili

Having dive brakes doesnt not necessarely means a dive bomber in a sense of Stuka or Val. A Ju88 the best of German bombers could not dive like a Stuka or a Val. It could dive but more shallow way and at that is dificult distinguish from some fighter bombers .

Ki 45 and Ki 48 similar airframes? maybe you are making confusion with Ki-48 artwork that was a Ki-45.

It's a bit OT but i've always understood that the Ju88 could and did do almost vertical dives, but the airframe couldn't really handle it and the wear was atrocious. So they banned vertical dives and changed it to more shallow approach.

Close. The Ju-88 was an amazing airplane able to even play fighter with some success. Not your typical two engine bomber.

[el cid again]

I had some things wrong above:

a) The Ki-30 and Ki-32 had an internal bomb bay vice exterior bombs - although the Ki-51 did carry its load externally as I said.

b) The standard loadout for a Japanese light bomber (Ki-30/Ki-32/Ki-48) was 24 x 15 kg bombs - the 50 kg bomb could be carried but was not the normal case. I simulate the 15 kg bomb using 100 lb ICB clusters - where each cluster is considered to have 3 x 15 kg (33 pound) bombs. This loadout will be much more dangerous to soft targets - and not very dangerous at all to armored ships.

c) The standard loadout for a Ki-51 was half the above (i.e. 12 x 15 kg bombs). Again, the 50 kg weapon could be mounted, but was not the normal case. So here we have a clear difference between naval and land dive bombers: the land bombers carry many more, smaller bombs which won't do much to a big, armored naval target - but do considerable to a soft target.

d) The Ki-48 was principly a night bomber - mainly because it had poor survival chances if operated during daylight. That rendered it less effective as a bomber - yet it did score (almost as Joe did) in strategic counter air strikes. The Japanese would send in the Ki-48s at night - and the Ki-21s or Ki-49s by day.

e) Dili is right - the range data for a Ki-21 is with a 1000 kg bomb load - this in the form of 20 x 50 kg bombs. Its "normal" load is given as 15 x 50 kg bombs - and there is some room for confusion about which load is associated with the "normal" range? The 100 kg bomb could be carried - but usually was not. The 30 kg bomb would be mounted in its place for an extended range mission.

f) The Ki-49 had the very same loadout options as the Ki-21. It was a technically better aircraft - armored - better armed - but had (in its initial version) weaker engines than the later Ki-21 did - and performance suffered accordingly. When up engined it became a better performer - but by they it faced stiffer opposition.

g) The Ki-67 was not in this line of development - and its normal load was ten 50 kg bombs or five 100 kg bombs. Its alternative load was one 800 kg torpedo. It appears to have been strongly influenced by the Nell and Betty, but unlike them was armored. It traded payload for range however, just as they did.

[m10bob]

ORIGINAL: String

ORIGINAL: Dili

Having dive brakes doesnt not necessarely means a dive bomber in a sense of Stuka or Val. A Ju88 the best of German bombers could not dive like a Stuka or a Val. It could dive but more shallow way and at that is dificult distinguish from some fighter bombers .

Ki 45 and Ki 48 similar airframes? maybe you are making confusion with Ki-48 artwork that was a Ki-45.

It's a bit OT but i've always understood that the Ju88 could and did do almost vertical dives, but the airframe couldn't really handle it and the wear was atrocious. So they banned vertical dives and changed it to more shallow approach.

String, you are correct..I posted my reference to those German planes as I have films of them doing exactly that, and anybody with the stock filmstrip from Steel Panthers can see a JU 88 in an approx 70 degree dive over Poland.

[Dili]

It's a bit OT but i've always understood that the Ju88 could and did do almost vertical dives, but the airframe couldn't really handle it and the wear was atrocious. So they banned vertical dives and changed it to more shallow approach.

 
You are right. I was talking about comon operational use.
 

Since hitting "runway" and aircraft is dependent on # of bombs ... a Lily unit with EXP 80+ can start looking like a B-17 from the perspective of runway and ac damage.

 
Maybe 100kg bombs are too powerfull?
 
 

Actually the bomb load in game terms is identical: 8 x 100 kg bombs (or 16 x 50 kg bombs) = 800 kg

 
My data is 1000kg bombs for Ki21-II and 800kg for Ki 48-II.
 
I always like to analise aircrafts by weights, engine power, it tells much. If the Ki-21 have only 800kg bomb payload then it has more fuel. I have saw at least in a Website that 800kg was for Kamikaze missions but i cant confirm that. Certainly more power from new Engines would warrant more weapon load tough the weapon load duplicated but engine power not increased enough. As can be seen by weight data i doubt that Ki-48-II could fly with 800kg bombs as normal payload. A 700kg increase in all up weight i doubt it translates to 400kg more bomb payload and only 300kg for "slightly lengthened fuselage, improved engines (Nakajima Ha-115s with a two-stage blower), some fuel-tank protection, and some armour for the crew, including a 12.5mm plate behind the bombardier's seat, a 6.5mm plate under the pilot's seat, 16.5mm armour behind the pilot's seat, and 16.5mm plates to protect the dorsal and ventral ammunition boxes." All that without increasing the fuel load despite increased weight and power to mantain same range. There is no miracles in engineering.
 
http://www.century-of-flight.freeola.com/Aviation%20history/photo_albums/timeline/ww2/Kawasaki%20Ki%2048%20Lily.htm
 
Btw this site says "normal payload"  of Ki-48-I was 6x110lb or 24x33lb bombs.
 
 
We will need to know the data on Engines and Drag for a proper research but i doubt that Ki-21 needs 2xFuel of Ki-48 to have same range.
 
 

[el cid again]

ORIGINAL: Dili

It's a bit OT but i've always understood that the Ju88 could and did do almost vertical dives, but the airframe couldn't really handle it and the wear was atrocious. So they banned vertical dives and changed it to more shallow approach.

You are right. I was talking about comon operational use.

Since hitting "runway" and aircraft is dependent on # of bombs ... a Lily unit with EXP 80+ can start looking like a B-17 from the perspective of runway and ac damage.

Maybe 100kg bombs are too powerfull?

I hope not! I just made em de facto 15 kg bombs. Too powerful or otherwise, that was the actual normal load for a 48 I.
I just made ALL JAAF light bombers de facto 15 kg bomb loadouts - using the 100 pound cluster to simulate them (= 3 15 kg bombs per device). This creates a real distinction between JAAF and JNAF light bombers. The Val carries a heavy AP bomb - the Ki-30/32, Ki-51 and Ki-48 I (and Ki-36) carry numerous small bombs with no AP value worth mention.

[el cid again]

The Ki-48 and Ki-21 should not be directly compared engineering wise: I compare them as a player or operational user has to pick which to buy.

The Ki-48 is a Kawasaki product by the designer of the Ki-45 - a second priority to the Ki-45 (which delays its development) - and it is nearly a fighter - bomber.

The Ki-21 is an older Mitsubishi product by a completely different designer - done to a completely different specification in competition with a comparable Ki-19 project.

The Ki-21 II weights about 50% more (empty) than a Ki-48 - explaining that there is room for more defensive weapons, crew and payload.

The Ki-21 is slower than the Ki-48 - explaining why it is somewhat less fuel efficient. [Slower and lighter, the Ki-48 is able to be more fuel/range efficient]

In modern (c 1960) Pentagonese, the cost effectiveness of a Ki-21 is better than a Ki-48 - that was my point. It was able to function as a day bomber - giving its not much greater bombs much better hit probability - while the Ki-48 was always relegated to night bombing - because it was not fast enough to avoid interception. Modeled on a SB-2 - it took too long to develop - and by the time it appeared - fighters were faster. The game situation is a bit artificial: the cost of a Ki-48 is inflated over reality - due to a simplified production system it costs as much as the better armed, slightly more bomb efficient Ki-21. Nevertheless - it is available in numbers - and players should use it until they can upgrade it. They even should build some - to insure units don't run out of them - and because the Ki-48 is better than a Ki-30 or 32 - so you want to phase them out in favor of it. If the Ki-48 II is a dive bomber - then the Ki-51 should phase into that.

[jwilkerson]

What was different about Betty/Nell that they could only carry 3x250KG whereas Sally could carry 4x250KG? There seems to be some asymmetry in there somehwere ... and the math guy is wonderin' ...