IJN Battleship availability chart

[spence]

I think there were some things going on at Samar are not well modeled in the game. For one thing visibility was poor that day as someone commented above and the Japanese depended on optical rangefinders. The quality of bunker sea in use was much worse than earlier in the war. The Japanese ended up in a stern chase which prevented them from bringing all guns into action.

I don't know for sure, but I suspect the BB crews' quality had also declined during the war. It was common in other navies to draw crew members away from established crews to serve on newly commissioned ships. The IJN expanded less than most other navies during the war, but they did commission a lot of smaller ships as well as a number of carriers. Even if the crews hadn't been drawn off, they may have just been rusty from years of inaction.

Bill

Did you look at the picture? The IJN cruiser is probably 7-8000 yards beyond Gambier Bay. The BB's were turned and fled USS Johnson's torpedo attack (turning away to comb the wakes rather than turning into). But the IJN cruisers got plenty close. Given the obvious visual conditions your argument about quality holds true for the IJN cruisers' failure to annihilate Taffy 3 but frankly the IJN BBs never displayed, in any of their actions any especial acumen. Even the 2 Kongo's action against USS Edsall can hardly be called a demonstration of their prowess.

If the US found it hard to send its old BBs to the South Pacific because it took too much fuel to operate there it seems pretty much for sure the IJN would have held them back for exactly the same reason (considering relative supplies of oil). If it is possible for the Japanese then something may well be wrong with the game mechanics that provide the IJN with way too much fuel. I've read that the Midway Operation used up a whole year of the fleet's supply of fuel...seems moving all those thirsty BBs cost the IJN plenty.

The IJN BB's for the most part did nothing during the entire length of the war. Their sole accomplishment seeems to have been shared between but 2 of their ships and was never repeated. Faced with someone who could shoot back about all they can claim is sinking a WWI retread DD.

[wdolson]

ORIGINAL: Symon

Just a teensy thought for all the IJ BB enthusiasts, out there. And a small take on why the IJN didn't use them

A rough run-in, in the Solomons by 8th Fleet. Rabaul to Guadalcanal is ~650 nm. That’s 2 days at nominal cruise speed; one-out, one-back.
2x BBs, 4x DDs = 880 + 280 = ~1160 tons of fuel at nominal cruise speed, and up to 6900 tons at full speed (although 4030 tons would be a better allowance assuming 50/50 cruise/full power fuel consumption).

A more robust run-in by elements of 4th Fleet. Truk to Guadalcanal is ~1350 nm. That’s 8 days out and back (4 days one way), at nominal cruise speed.
2x BBs, 4x DDs = 3520 + 1056 = ~4575 tons of fuel at nominal cruise speed. Allowing for a 1 day full power run-in and 1 day full power withdrawal that’s ~3450 tons at cruise, and 6850 tons at combat. That’s 10300 tons of fuel for a 2xBB bombardment mission. Of course Yamato used ~20% more fuel/day than the ‘typical’ IJ BB, so is it any surprise that she was used as a hotel and floating gas station?

Ciao. JWE.

They didn't have the fuel supply to support the BBs. Most of the BBs spent a lot of time in the SRA to be close to the fuel supply.

Bill

[wdolson]

I think there were some things going on at Samar are not well modeled in the game. For one thing visibility was poor that day as someone commented above and the Japanese depended on optical rangefinders. The quality of bunker sea in use was much worse than earlier in the war. The Japanese ended up in a stern chase which prevented them from bringing all guns into action.

I don't know for sure, but I suspect the BB crews' quality had also declined during the war. It was common in other navies to draw crew members away from established crews to serve on newly commissioned ships. The IJN expanded less than most other navies during the war, but they did commission a lot of smaller ships as well as a number of carriers. Even if the crews hadn't been drawn off, they may have just been rusty from years of inaction.

Bill

ORIGINAL: spence
Did you look at the picture? The IJN cruiser is probably 7-8000 yards beyond Gambier Bay. The BB's were turned and fled USS Johnson's torpedo attack (turning away to comb the wakes rather than turning into). But the IJN cruisers got plenty close. Given the obvious visual conditions your argument about quality holds true for the IJN cruisers' failure to annihilate Taffy 3 but frankly the IJN BBs never displayed, in any of their actions any especial acumen. Even the 2 Kongo's action against USS Edsall can hardly be called a demonstration of their prowess.

If the US found it hard to send its old BBs to the South Pacific because it took too much fuel to operate there it seems pretty much for sure the IJN would have held them back for exactly the same reason (considering relative supplies of oil). If it is possible for the Japanese then something may well be wrong with the game mechanics that provide the IJN with way too much fuel. I've read that the Midway Operation used up a whole year of the fleet's supply of fuel...seems moving all those thirsty BBs cost the IJN plenty.

The IJN BB's for the most part did nothing during the entire length of the war. Their sole accomplishment seeems to have been shared between but 2 of their ships and was never repeated. Faced with someone who could shoot back about all they can claim is sinking a WWI retread DD.

From what I've read the order to turn away from the torpedoes instead of into them was a mistaken call by someone on the bridge and it was too late to change once given.

When did IJN battleships engage WW I era US DDs? At Guadalcanal I believe the DDs were ones built in the 30s and Taffy 3s screen were all war built ships. The carriers of Taffy 3 were built together. There are pictures of the Vancouver shipyard with all the carriers of Taffy 3 lined up side by side getting fitted out.

The aggressiveness of Taffy 3s screen really unnerved many. There were reports that the US DDs were actually CLs. The Johnston was especially bold. Commander Evans took them in so close the Kongo could not depress her guns low enough to shoot at them. They fired everything in the magazine at the Kongo including paint rounds.

On top of the aggressive screen, all the planes from all the CVEs were attacking the IJN ships. The Wildcats strafed until they were out of ammo and the TBFs made fake torpedo runs when their torpedoes were spent. It made Kurita think he was under attack by elements from the fast carriers and not just planes from the CVEs. He decided to scoot before the main attacks from the fast carriers showed up.

I believe the only ships to close the gap on the CVEs were the Tone and Chikuma which I don't believe had any experience in surface combat. Both had always been used with the carriers as scouting cruisers. Another problem the IJN had was they were mostly firing AP rounds which went right through the unarmored carriers. There were a number of rounds that hit the carriers and went through them before going off.

Samar happened because of a major strategic screw up on the part of Halsey, one that followed him the rest of his life. However the US commanders did everything right tactically to unnerve the Japanese and convince them that a much larger force was nearby than was actually there.

Bill

[spence]

If you had looked at the photo you would probably have recognized a Tone Class cruiser off on the horizon. Interestingly Tone, Chikuma, Hiei, Kirishima and Kido Butai's dive bombers won their fight against USS Edsall (a lone Clemson Class DD South of Java. I'll admit I was wrong. The IJN BBs can claim a tactical victory after all. I'm impressed[8|]

[Buckrock]

ORIGINAL: spence
Did you look at the picture? The IJN cruiser is probably 7-8000 yards beyond Gambier Bay. The BB's were turned and fled USS Johnson's torpedo attack (turning away to comb the wakes rather than turning into). But the IJN cruisers got plenty close. Given the obvious visual conditions your argument about quality holds true for the IJN cruisers' failure to annihilate Taffy 3 but frankly the IJN BBs never displayed, in any of their actions any especial acumen. Even the 2 Kongo's action against USS Edsall can hardly be called a demonstration of their prowess.

The Gambier Bay was initially slown (down to 11 knots) by damage from long range fire, likely from one or two of the Japanese BBs over 20,000yds away. As she drifted back and became the rear most carrier (replacing Kalinin Bay), Gambier Bay was then targeted and hit hard from beyond 10,000 yds away by a Japanese cruiser (Tone), the damage causing serious flooding and power loss.

It was only after this that Japanese warships closed to the ranges suggested in the photo to deliver the final hits to the Gambier Bay. From the accounts of the US CVE's involved, this final "close range" attack to finish off Gambier Bay appears to be the only time Japanese warships got to target the carriers that day from less than 10,000yds.

And just as an observation, the photo seems to have been somewhat enhanced from the original, likely to better show the (assumed) Japanese warship in the distance. I have zero experience with photographic interpretation but might the cropping and enhancement be giving the Japanese warship the perspective of being closer to the Gambier Bay than in the original photo?

As for the Edsall's demise, destroyers capable of evading would likely not expect to be hit by battleship gunfire from beyond 20,000yds. IMO, the only real indictment on the Japanese BBs that day was that they thought sending almost 300 14" shells toward a destroyer at that range was worth the effort.

I've read that the Midway Operation used up a whole year of the fleet's supply of fuel...seems moving all those thirsty BBs cost the IJN plenty.

The Japanese would have been in real trouble if this was true for their planned yearly wartime oil allocation. In fact, the Midway/Aleutians Operation used up four months worth. Luckily for the Japanese, this substantial expenditure of oil was countered in the second half of 1942 by the better than expected supply coming in from captured East Indies oil fields.

[Jorge_Stanbury]

The Japanese were in trouble!

according to HP Willmotts "Empires in Balance" I quote:

"With or without war and with or without the indies, the Japanese had problems -- if their calculations were accurate.
It almost goes without saying, however, that their figures were wildly inaccurate. The Japanese vastly overestimated their own potential and drastically underestimated their requirements. The notion of a single major engagement showed that the navy really had no inkling of the kind of war it was going to fight. In the first year of the war the navy used 60 percent more oil that it was allowed under any review or plan. Its operations consumed 30,520,000 barrels - 80 percent of the assessed national needs for 1941-1942. Its declining needs thereafter reflected its losses, not its commitments. The Indies maximum production was about 16,670,000 barrels in 1943, actually more than allowed for in the August review, but outflow to Japan fell 60 percent in 1944, mainly because of tanker losses and direct fueling of the navy in southern ports. Domestic production never exceeded 3,400,000 barrels in a year (1943)"

The plans he is referring are:
- Estimates done by the joint Army-Navy committee done in June 1941. This assumed a shortage of 4.4 million barrels in September 1944
- Navy revision done in August 1941: this saw a period of crisis - low reserve, no shortage - from September 1943 to September 1944.
The navy revision assumed significant increases in production in the 3rd year of war, for both the DEI (30,000,000 barrels) and domestic production (4,500,000 barrels). This estimates were very far away from reality

[Symon]

ORIGINAL: wdolson

ORIGINAL: Symon
Just a teensy thought for all the IJ BB enthusiasts, out there. And a small take on why the IJN didn't use them

A rough run-in, in the Solomons by 8th Fleet. Rabaul to Guadalcanal is ~650 nm. That’s 2 days at nominal cruise speed; one-out, one-back.
2x BBs, 4x DDs = 880 + 280 = ~1160 tons of fuel at nominal cruise speed, and up to 6900 tons at full speed (although 4030 tons would be a better allowance assuming 50/50 cruise/full power fuel consumption).

A more robust run-in by elements of 4th Fleet. Truk to Guadalcanal is ~1350 nm. That’s 8 days out and back (4 days one way), at nominal cruise speed.
2x BBs, 4x DDs = 3520 + 1056 = ~4575 tons of fuel at nominal cruise speed. Allowing for a 1 day full power run-in and 1 day full power withdrawal that’s ~3450 tons at cruise, and 6850 tons at combat. That’s 10300 tons of fuel for a 2xBB bombardment mission. Of course Yamato used ~20% more fuel/day than the ‘typical’ IJ BB, so is it any surprise that she was used as a hotel and floating gas station?

Ciao. JWE.

They didn't have the fuel supply to support the BBs. Most of the BBs spent a lot of time in the SRA to be close to the fuel supply.

Bill

That was kinda sorta the point, Bill. Just thought I would do some simple numbers for folks that have difficulties with linguistic concepts [8D]

Ciao. JWE

[wdolson]

Sorry, didn't make it clear we were in agreement.

Bill

[Zorch]

ORIGINAL: wdolson

Sorry, didn't make it clear we were in agreement.

Bill

Agree with you both - besides the fuel issues, cruisers were the best ships for the Solomons campaign. I don't understand why Oi and Kitakami weren't used there. A broadside of 40 torpedoes at night would have been even more devastating than the historical ones.

[jamesjohns]

Thanks for the numbers showing the fuel issue Japan faced in WWII. I knew they had problems and the Yamato was a 1 way trip due to fuel but to see the numbers really sheds new light on it, hard to fathom the amount needed to move a ship, let alone a BB.

Any idea in US gallons how much it is?

[spence]

August - September 1942:
Kure and Yokosuka. KITAKAMI and OI are converted to fast transports. Their ten quadruple TT are reduced to six, for a total of 24 tubes. They are equipped with two Daihatsu barges and fitted with two triple mount Type 96 25-mm AA guns. Depth charge launching rails are also installed.

From TROMs of Oi and Kitikami at CombinedFleet.com

That explains that. Apparently the performance of Type 93 torpedoes in action up to that time (Java Sea) was not that impressive. Somebody figured it out: something of the order of low single digits up to then. Even at night they'd only sunk more Japanese ships (Oops) than Allied ones (Sunda Strait).

Those two CLs spent the time prior to their conversion as escorts to the Batdivs. As such they had done exactly nothing of note.

The photo is enhanced to show who was doing the shooting but anybody can find more than one photo showing both US carriers/desroyers off Samar with a Japanese CA on the horizon. One shot from USS Kitkun Bay shows Gambier Bay under fire from an IJN cruiser on the horizon - the Kitkun Bay is a good 2000 yds from Gambier Bay and the IJN cruiser is around 10000 yards beyond Gambier Bay. According to maps of the action that is about as close as they got before the IJN broke off. All that is irrelevant though. From my experience at sea the visibility was about as good as one has reason to expect at sea (admittedly my experience is all in the Atlantic). The horizon appears to be quite clear and that allows accurate celestial navigation (sun lines). The IJN BBs got exactly the "Decisive Battle" that they had practiced for. They blew it. Rating them as far more experienced than US BBs is just an IJN Fanboy wetdream and nothing more.

[Symon]

ORIGINAL: jamesjohns
Thanks for the numbers showing the fuel issue Japan faced in WWII. I knew they had problems and the Yamato was a 1 way trip due to fuel but to see the numbers really sheds new light on it, hard to fathom the amount needed to move a ship, let alone a BB.

Any idea in US gallons how much it is?

When talking about ships, the gallons don’t matter as much as the specific heat per unit mass. So tons of fuel is a true measure. It’s that ancient question; what weighs more, a pound of feathers or a pound of lead? But here’s some numbers for comparison.

#2 Residual Fuel Oil (as close to bunker-C as we come today) works out to 6.7 barrels per ton. Compare with Industrial Diesel Fuel at 7.5 barrels per ton. A barrel of petroleum is a volumetric containing 42 US gallons (liquid).

So 281.4 US gallons per ton, for Bunker-C equivalent fuel. 315 US gallons per ton, for industrial grade diesel fuel.

So looking at a minimum of 1.13M gallons for the short mission; 2.90M gallons for the longer one.

That's a lotta gas.[8D] Ciao. JWE

[wdolson]

ORIGINAL: wdolson

Sorry, didn't make it clear we were in agreement.

Bill

ORIGINAL: Zorch
Agree with you both - besides the fuel issues, cruisers were the best ships for the Solomons campaign. I don't understand why Oi and Kitakami weren't used there. A broadside of 40 torpedoes at night would have been even more devastating than the historical ones.

The problem was they had a glass jaw. One 5 inch hit in the torpedo mounts and boom!

The problem with making torpedo runs is the ship doing it is fairly vulnerable on the run in.

Bill

[Veer]

ORIGINAL: spence

From TROMs of Oi and Kitikami at CombinedFleet.com

That explains that. Apparently the performance of Type 93 torpedoes in action up to that time (Java Sea) was not that impressive. Somebody figured it out: something of the order of low single digits up to then. Even at night they'd only sunk more Japanese ships (Oops) than Allied ones (Sunda Strait).

Those two CLs spent the time prior to their conversion as escorts to the Batdivs. As such they had done exactly nothing of note.

The photo is enhanced to show who was doing the shooting but anybody can find more than one photo showing both US carriers/desroyers off Samar with a Japanese CA on the horizon. One shot from USS Kitkun Bay shows Gambier Bay under fire from an IJN cruiser on the horizon - the Kitkun Bay is a good 2000 yds from Gambier Bay and the IJN cruiser is around 10000 yards beyond Gambier Bay. According to maps of the action that is about as close as they got before the IJN broke off. All that is irrelevant though. From my experience at sea the visibility was about as good as one has reason to expect at sea (admittedly my experience is all in the Atlantic). The horizon appears to be quite clear and that allows accurate celestial navigation (sun lines). The IJN BBs got exactly the "Decisive Battle" that they had practiced for. They blew it. Rating them as far more experienced than US BBs is just an IJN Fanboy wetdream and nothing more.

The problem is the game doesn't model experience degradation as occurred in history. Experience does not remain steady in the absence of action, it needs to be continually honed via training and drills (and shore rest/home leave because the South Pacific was fairly brutal weather wise). From 1941 onwards all were in short supply for the Japanese - for their infantry, air crews and ship crews. Many histories, even the Japanese high command, noted that veteran pilots no longer performed as well as they did by mid 1942 let alone 1944. The same would be true for their seamen.

The fact that the Japanese kept most of their capital ships in the South Pacific - where training facilities were close to nil, or in port due to a lack of oil and threat of subs, certainly didn't help.

edit: we saw a similar capability degradation in the German High Seas fleet during WW2. After being pretty much confined to port after Jutland, crack crews became bored, lazy and finally mutinous.

[jamesjohns]

Thanks Symon, huge amount of fuel no doubt

[Zorch]

ORIGINAL: wdolson

ORIGINAL: wdolson

Sorry, didn't make it clear we were in agreement.

Bill

ORIGINAL: Zorch
Agree with you both - besides the fuel issues, cruisers were the best ships for the Solomons campaign. I don't understand why Oi and Kitakami weren't used there. A broadside of 40 torpedoes at night would have been even more devastating than the historical ones.

The problem was they had a glass jaw. One 5 inch hit in the torpedo mounts and boom!

The problem with making torpedo runs is the ship doing it is fairly vulnerable on the run in.

Bill

The long lances had such a long range, and most of the battles being at night would mitigate that weakness. They should have been ordered to withdraw after firing their broadsides. The Tokyo Express could have benefited from them.

[wdolson]

Theoretical range and real world range are two different things. The Japanese never used the long lance at its maximum range. The problem with torpedoes of the 1940s was once they were in the water, their trajectory became known by the enemy and the further the torpedo had to travel, the more time the enemy had to get out of the way. So even if you have a torpedo with an extremely long range, you don't want to launch at max range unless it's an emergency. In ideal conditions you want to launch at the minimum range that would allow the torpedo to arm before reaching the target, though that could be suicidal against a strong enemy force, so in practice a compromise range is used that is not minimum range, but is relatively close.

This is also the reason B-17s dropping from altitude couldn't hit a moving ship in the real world. No matter how good the bomb sight, it took time for the bomb to fall from altitude and gave all but the slowest moving ships plenty of time to get out of the way.

I suggest reading this article:

http://www.navweaps.com/index_tech/tech-067.htm

It examines every time the long lance was used and its effectiveness in the real world. If anything, the game overrates them.

Bill

[Buckrock]

ORIGINAL: Jorge_Stanbury

The Japanese were in trouble!

according to HP Willmotts "Empires in Balance" I quote:

"With or without war and with or without the indies, the Japanese had problems -- if their calculations were accurate.
It almost goes without saying, however, that their figures were wildly inaccurate. The Japanese vastly overestimated their own potential and drastically underestimated their requirements. The notion of a single major engagement showed that the navy really had no inkling of the kind of war it was going to fight. In the first year of the war the navy used 60 percent more oil that it was allowed under any review or plan. Its operations consumed 30,520,000 barrels - 80 percent of the assessed national needs for 1941-1942. Its declining needs thereafter reflected its losses, not its commitments. The Indies maximum production was about 16,670,000 barrels in 1943, actually more than allowed for in the August review, but outflow to Japan fell 60 percent in 1944, mainly because of tanker losses and direct fueling of the navy in southern ports. Domestic production never exceeded 3,400,000 barrels in a year (1943)"

The plans he is referring are:
- Estimates done by the joint Army-Navy committee done in June 1941. This assumed a shortage of 4.4 million barrels in September 1944
- Navy revision done in August 1941: this saw a period of crisis - low reserve, no shortage - from September 1943 to September 1944.
The navy revision assumed significant increases in production in the 3rd year of war, for both the DEI (30,000,000 barrels) and domestic production (4,500,000 barrels). This estimates were very far away from reality

I was only addressing the relative fuel oil cost of conducting the Midway/Aleutian operation in relation to Japan's actual 1942 supply (including the better than planned early output from the East Indies).

Willmott's figures though are a good guide as to Japan's problems in getting through a war they expected might take up to three years.

Even before the war they had recognized a "slight" problem if it went into a third year. It's little surprise then if they were prepared to ignore their oil budget during 1942 in the hope that some decisive victory against the USN might be gained early.

[Buckrock]

ORIGINAL: wdolson
I suggest reading this article:

http://www.navweaps.com/index_tech/tech-067.htm

It examines every time the long lance was used and its effectiveness in the real world. If anything, the game overrates them.

Bill

Are you referring to them being over-rated due to their accuracy (in the database) or their performance in the game? Just curious as I
tend to gain few decisive results with them in surface combats during games against the Allied AI.

[Zorch]

ORIGINAL: wdolson

Theoretical range and real world range are two different things. The Japanese never used the long lance at its maximum range. The problem with torpedoes of the 1940s was once they were in the water, their trajectory became known by the enemy and the further the torpedo had to travel, the more time the enemy had to get out of the way. So even if you have a torpedo with an extremely long range, you don't want to launch at max range unless it's an emergency. In ideal conditions you want to launch at the minimum range that would allow the torpedo to arm before reaching the target, though that could be suicidal against a strong enemy force, so in practice a compromise range is used that is not minimum range, but is relatively close.

This is also the reason B-17s dropping from altitude couldn't hit a moving ship in the real world. No matter how good the bomb sight, it took time for the bomb to fall from altitude and gave all but the slowest moving ships plenty of time to get out of the way.

I suggest reading this article:

http://www.navweaps.com/index_tech/tech-067.htm

It examines every time the long lance was used and its effectiveness in the real world. If anything, the game overrates them.

Bill

Thank you. It has the very interesting observation that torpedo speed may have been more important than range.
A good book on the technical aspects is Torpedo: The Complete History of the World's Most Revolutionary Weapon by Roger Branfill-Cook.