Nighttime fights.

[Jack]

im not sure but is it possible that the AI do have no night time penalties? i normaly try to not fight in the night because i dont like it but this time my combat taskforce (2 south dakota class bbs and 3 CAs and 1 dd where left after the battle before) got attacked by an huge enemy taskforce with 2 bbs some CAs and some transports. i tried the battle 3 times and all 3 times the Kongo gets detected with its first salvo and then disappeared into the darkness again so my ships could not fight back even with radar active. they on the other hand could see my ships perfectly even the destroyer in a rainy night at about 12km distance. my ships got shot into pieces and i had to wait till they where at a range of between 2-3 km to spot them again. till then my lead BB was sunk, my other BB critical damage and heavy flooding, my DD was riped apart and my cruisers where also damaged or sunk. they managed to hit every shot. my ships had with radar an accuracy of 15-20% and managed to hit the enemy BB like 4 or 5 times till my last BB went down. thats why the question came up in me if the enemy does have no nighttime penalty or bad weather penalty? and if its so. when does this get fixed? nighttime battles are annoying enough. they dont need to be impossible

[cswiger]

US radar should have no trouble detecting a BB at medium range. If your ships had already fought a battle earlier, were they damaged or running low on ammo? In particular, were you using starshells to illuminate the enemy once detected?

Anyway, the AI's solution is subject to the same effects that the player receives. Note that Japan has an advantage to optics at night, just as the US has an advantage if using radar.

[Jack]

i tried using starshells but the kongo disappeared again to fast. the light cuisers i had in the taskforce ate most of the damage and got destroyed in the battle before. the atlanta class is made out of paper... but at her cost the rest came out with minor damage or no damage. ammo is kinda low. the DD is out of torps and the rest used about 60% i guess of its ammo. but ammo is not the problem if you cant even see the enemy. sure the starshells would give my ships a higher chance to hit but they where allready messed up and nearly gone at the time the enemies popped up on the map. gonna reinstall the game. maybe its a bug or something.

[cswiger]

Um. The USN Atlanta class is better armored than all of the IJN light cruisers and some of the heavy cruisers; Aoba class is comparable, and Myōkō or later would have better armor.

The notion that a damaged task force which has already fired off most of its ammo would have problems taking on a new undamaged enemy is normal, not a bug.

[CellNav]

@ Jack

To coin the phase ... It was as real as it gets. A BB vs BB at 20,000 yards can expect a 12% hit rate with MPI centered in the middle. The USN got chewed up at night despite radar (which was horrible during this period).

As a reminder, check the "efficiency" or your ships and the SOL (solution) %. There's a training exercise to demonstrate a CA firing on a maneuvering DD at 5,000 yards (SOL @ 60%, with radar it was 70%) in daylight. Note this was with the CA not moving so it would be much lower.

Also, the game seems to use "TBS" (talk between ships) for up to date target info. This means that you don't have to have the Kongo see you, they just need a smaller ship (DD) to spot for the Kongo .... which is like totally wrong IMO, but it is what it is.

[CellNav]

As much as I think night combat is modeled ok, I came across something that disturbs me greatly about RADAR in this game ... from the manual, page 33 :

Any Sea unit using radar may be detected at a distance up to 80% the sum of the surface radar strengths of the emitting unit and the receiving units.

I'm not seeing passive radar detection methods to pinpoint range/azimuth by the Japanese in this early stage of the war.

What's the purpose of this rule?

[cswiger]

Originally posted by CellNav:

I'm not seeing passive radar detection methods to pinpoint range/azimuth by the Japanese in this early stage of the war.

Turning the transmitter of an active radar set off results in a passive radar detection system.

Japan had prototypes of their H6 airborne radar on Kawanishi H6K Mavis, H8K Emily, and G4M Betty as of mid 1942, and were considered operational as of August 1942. The IJN started adding the 21-Go radar to carriers and battleships starting with the CV Shōkaku as of Sept 1942.

Either would have been able to detect the CXAM and SC radars used on various USN ships as they operated on the same VHF frequency band of ~ 150 - 200 MHz.

https://emmasplanes.com/index.php/japanese-radar/japanese-radar-h-6-type-3-ku-6-model-4/
https://en.wikipedia.org/wiki/List_of_Japanese_World_War_II_radars

[CellNav]

Originally posted by cswiger:

Turning the transmitter of an active radar set off results in a passive radar detection system.

It's the passive system that's not correct. The ships without radar (i.e. IJN) are pinpointing ships with radar when they shouldn't be doing that.

The game thinks those ships have radar switched off, when they don't even have radar installed. Passive systems during that period isn't going to plot a contact in real time like those have radar contacts. That's the problem I'm mentioning.

[MizuYuuki]

Originally posted by CellNav:

Originally posted by cswiger:

Turning the transmitter of an active radar set off results in a passive radar detection system.

It's the passive system that's not correct. The ships without radar (i.e. IJN) are pinpointing ships with radar when they shouldn't be doing that.

The game thinks those ships have radar switched off, when they don't even have radar installed. Passive systems during that period isn't going to plot a contact in real time like those have radar contacts. That's the problem I'm mentioning.

You are correct CellNav. This can be seen clearly in a Custom Battle Setup. I placed a Kongo and a Nagato 5000 yds from a USN North Carolina BB. I chose 21:00 hrs time; so it is dark, but clear with moonlight. Sea state is 5.

Without using radar or searchlights or star shells, the North Carolina achieves a 47% solution when targeting either the Kongo or Nagato while both Japanese ships achieve a 71% solution on the North Carolina. When the North Carolina turns its radar on, its solution on either of the Japanese ships rises to 69%, but the solution of the Japanese ships on the North Carolina also rises to 77% even though those two Japanese ships don't have radar.

If the North Carolina turns its radar off, it's solution drops to 57% on the current target. So the USN ship can gain 10 points on the current target by turning its radar on for a few seconds and then off. The Japanese ship's solution drops back to 71%. If the North Carolina changes targets, its solution on the new target goes back to 47% unless it cycles the radar on and off again.

It seems to me that it is definitely a bug for ships without radar to have an increase in solution it the target ship turns on its radar. Radio detection finders were in use at this time, but not radar detection finders.

[cswiger]

Originally posted by MizuYuuki:

You are correct CellNav. This can be seen clearly in a Custom Battle Setup. I placed a Kongo and a Nagato 5000 yds from a USN North Carolina BB.

All of the IJN battleships present in WoTS are listed as having Type 21 air-search radars.

If you want to test whether IJN ships without radar can detect radar emissions, you'll have actually select ships which the game does not list as having radar.

...even though those two Japanese ships don't have radar.

The Kongō got Type 22 surface radar in August 1942. Source:

https://en.wikipedia.org/wiki/Japanese_battleship_Kong%C5%8D#1942:_Pacific_War_service

Hiei and Kirishima were sunk in late 1942 before receiving a similar upgrade, but Haruna was upgraded with Type 21 and 22 radars, likely around March 1943 at Kure when she was refitted with upgraded AA guns.

-----

As for Nagato and Mutsu:

"As far as is known, no radars were installed aboard Mutsu before her loss. While in drydock in May 1943, a Type 21 air-search radar was installed aboard Nagato on the roof of the 10-meter rangefinder at the top of the pagoda mast. On 27 June 1944, two Type 22 surface-search radars were installed on the pagoda mast and two Type 13 early warning radars were fitted on her mainmast."

Source: https://en.wikipedia.org/wiki/Nagato-class_battleship#Nagato

[CellNav]

Originally posted by cswiger:

All of the IJN battleships present in WoTS are listed as having Type 21 air-search radars.

True but not surface search radar (in WoTS), a big difference. A USN example would be the SD air-search compared to the SC or SG surface-search, and none of those were used for director gunnery, which had it's own radar installed with the director.

WoTS simplified radar, which is fine, but the idea of any ship benefiting from being illuminated by a radar is not correct (either SOL or Contact position). Radar operating on or near another radar using the same frequency will result in negative effects, like interference.

While not usually caused by the enemy, interference can greatly impede the ability of an operator to track. Interference occurs when two radars in relatively close proximity (how close they need to be depends on the power of the radars) are operating on the same frequency. This will cause "running rabbits", a visual phenomenon that can severely clutter up a radar display scope with useless data.

Originally posted by cswiger:

If you want to test whether IJN ships without radar can detect radar emissions, you'll have actually select ships which the game does not list as having radar.

Yes, testing the non-radar ships need to be done, which (at the moment) is my other speculation about non-radar benefiting from radar.

[CellNav]

Originally posted by cswiger:

If you want to test whether IJN ships without radar can detect radar emissions, you'll have actually select ships which the game does not list as having radar.

I ran the test, a non-radar ship benefits by +10% SOL when illuminated by radar ... :(

The test was .... Furutaka vs Pensacola @ 15,000 yards on a Clear night with a Sea State of 0. Both ships were stationary, neither ships are firing.

The initial spotting results :

Furutake can spot the Pensacola at that range with a 4-6% SOL.
Pensacola could not spot the Furutaka with radar OFF. (SOL was 0%).

Pensacola turned on radar and spotted Furutaka @ 12-14% SOL.
Furutaka increased it's SOL to 14-16% when illuminated by radar.

Clearly, the Furutaka benefited with (VISUAL + RADAR) despite having NO radar on board.

Yeah, it's broken and I'm unsure if a mod can fix it for testing.

[MizuYuuki]

It's true that I assumed the Kongo didn't have radar, but it does have air radar and it was on during my test. The Nagato might have radar, but it's unclear because, while there is a radar button in the tactical grouping, there is no button on the command line below the tactical control panel. Also, the information on Nagato's radar lists both surface and air radar as having 0 nm range which is supposed to mean that the ship doesn't have radar despite having a button for it that you can switch on and off.

However, all that doesn't matter because, going back to the set up for my test, turning the Kongo's radar on and off makes no difference in the North Carolina's solution which remains at 47%. It also makes no difference in the Kongo's solution on the North Carolina because it's air radar not surface radar. This is also the case for the Nagato, but it's not clear if pressing the button does anything at all since the range listed is 0 nm for both air and surface radar.

What the game has modeled seems to be a simplistic: "Japanese ships have passive radar detection, but USN ships do not have passive radar detection.".

My advice for a USN player in a night engagement with IJN ships would be to use everything available to raise your solutions as much as possible, i.e. radar, star shells and searchlights, or alternatively try to slip away without engaging using smoke or sacrifice a couple of destroyers while the rest of your task force makes a run for it.

[cswiger]

Originally posted by MizuYuuki:

Also, the information on Nagato's radar lists both surface and air radar as having 0 nm range which is supposed to mean that the ship doesn't have radar despite having a button for it that you can switch on and off.

Have you modded your ships? I see Nagato having 100 km air radar:

https://steamcommunity.com/sharedfiles/filedetails/?id=3120269411

...which means a Type 21 radar which is also capable of detecting large ships up to 20 km away.

However, all that doesn't matter because, going back to the set up for my test, turning the Kongo's radar on and off makes no difference in the North Carolina's solution which remains at 47%.

A US ship which is already using radar to detect Japanese surface ships isn't going to gain further benefit from detecting any radar emitted by those same IJN ships. Likewise, the few IJN ships with radar are probably not going to gain a solution benefit from detecting US radar either, if they already have spotted the US ships via their own radar.

It also makes no difference in the Kongo's solution on the North Carolina because it's air radar not surface radar.

This conclusion is wrong.

Both Type 21 and Type 22 IJN radars were capable of detecting battleships at almost the same range. The Type 21 was described as an air search radar because it had a much longer detection range (~ 3x) for planes compared to the Type 22, whereas the Type 22 could detect enemy BBs up to 24 km away.

Source: http://pwencycl.kgbudge.com/R/a/Radar.htm#mozTocId70488

What the game has modeled seems to be a simplistic: "Japanese ships have passive radar detection, but USN ships do not have passive radar detection.".

IJN ships without radar gain some benefit from detecting US radar, but that benefit is generally smaller than what the US gains from using radar.

Sure-- IJN ships didn't have particularly good radar detection capabilities in 1942, but the claim that they had no capability is disprovable by reviewing primary documents:

https://apps.dtic.mil/sti/tr/pdf/AD0895891.pdf

[Killerfish Games]

Great discussion!
Repeated the tests with Furutaka and Pensacola and got the same results.

Looked over the code for solution calculations and as tests indicate, a vessel without radar can indeed pick up emissions from an ship using radar.

Suggested fix:
a) only apply the tmaRadarBonus to a solution if the observer has surfaceRadarStrength > 0 or airRadarStrength > 0, namely an observing ship must have radar to detect the emissions of another ship

OR

b) add new variable to each ship_data.txt file "passiveRadarDetection":true that allows the detection of emissions on a per ship basis. This could then flag any ship with radar as able to detect emissions as well as emulate passive detection capabilities on ships without radar

[Killerfish Games]

Originally posted by MizuYuuki:

What the game has modeled seems to be a simplistic: "Japanese ships have passive radar detection, but USN ships do not have passive radar detection.".

USN should...

15,000m Sea State 0 at midnight
Pensacola and Northampton cannot detect each other initially.
Pensacola turns on radar and gets 8% SOL on Northampton, but Northampton fails to detect Pensacola

10,000m Sea State 0 at midnight
Pensacola and Northampton see each other at 14% SOL
Pensacola turns on radar and gets 34% SOL on Northampton, Northampton increases detection of Pensacola to 22%

So Northampton is benefiting from passive detection of Pensacola's radar emission.