Rn vs IJN

[Shortround6]

Destroyers Draw - Japanese destroyers clearly had the best torpedo's but the RN had more destroyers, were much better equipped with Radar and well trained

The question also gets into which destroyers and when.
Both sides tended to swap guns or torpedoes for AA.
The British guns fire a bit faster for gun duals. Max ranges given in most sources are for 30 degrees of elevation or more, pretty useless from a pitching, rolling destroyer deck,
You can also empty the magazines in 15-20 minutes at the best rate of fire (which you can't keep up due the manual labor) so getting into long range gunnery duals is not a good idea. Keep it short range and sharp.
Please note that US destroyers sometimes carried 2 -3 times the ammo per gun that the Japanese ships did (Fletchers carried 425rpg and later ships go more) so take that into account
when reading about the gun actions.
Tribals carried 200rpg SAP and 50rpg HE and 50 rounds per ship star shell.
British torpedoes were about 36kts at 10,500 yds to start, got better later.
A lot of the Japanese destroyers dropped down to 4 main guns to get better AA (more 25mm) while keeping their torpedo tubes. Japanese also had star shell/illuminating.
British 4 gun Destroyers may not be at much of a disadvantage if the RN (and RAF) can force the Japanese navy to upgrade the AA.

Submarines - RN Advantage as Japanese designs were very mixed and tactics very poor. Japanese submarines achieved very little

Japanese subs were pretty good for what they were designed for, which was long distances, high speed on the surface. Which meant they dive slow, don't turn well and are big targets for visual search, radar or sonar. The British boats are pretty much opposite. The American boats were sort of in-between, adjust expectations accordingly.

Escorts - Clear RN advantages in numbers, designs, equipment and training.

Something to consider here when looking at depth charge counts. The RN started with a 4 charges pattern, one off each side and two rolled off the stern. Then they went to a 7 charge pattern, then an 10 charge and in 1944 (?) they were using a standard 14 charge pattern.
Japanese destroyers started with 14-18 charges and went to 36 part way through the war, depth charge fit at the end???

 

[Thumpalumpacus]

I think I'd be timid too if I knew my torpedoes didn't work (and occasionally did really unpleasant things like circling back and hitting my sub and then deciding to work...)

But the USN culling bold sub skippers happened in the 30s, well before the war. Go to about 9:21 in this video for a discussion on the matter:


View: https://www.youtube.com/watch?v=LEtshZLnRTc

 

[Shortround6]

Regardless - I think 2 x 20mm plus two light machine guns is still heavier armament than one 20mm + one machine gun, though the ammution capacity is a limitation on the A6M2, and the hub mounted cannon are more accurate.

The Japanese short barreled 20mm guns fired at about 490-520 rpm, the shells were about 128-130 grams. The Russian 20mm gun fired at about 800rom and the shells were around 95-98 grams. The other thing is than the Japanese shells left the muzzle at around 600m/s (about what the MG FF did, not the MG FFM) while the Russian ammo was fired at 860m/s.
The higher velocity makes it easier to hit with, you don't have to lead as much.
We have been over this in the other thread.
The Soviets were not happy with their gun choice/s. Failure of the M-106 and M-107 engines forced them to keep using the M-105 and they sacrificed armament for performance.

 

[Glider]

But the USN culling bold sub skippers happened in the 30s, well before the war. Go to about 9:21 in this video for a discussion on the matter:


View: https://www.youtube.com/watch?v=LEtshZLnRTc

If you look at approx 11.00 it supports my view saying that when war started conservatism led to failure and they had to be replaced

 

[Shortround6]

But the USN culling bold sub skippers happened in the 30s, well before the war. Go to about 9:21 in this video for a discussion on the matter:


View: https://www.youtube.com/watch?v=LEtshZLnRTc

In the US Asiatic fleet (the 29 boats in the Philippines) two skippers were either relived or asked to be relieved in the first week or two. Six more had been relieved by the time the remaining boats made it to Australia. Critiques of the operations were many and while they knew about problems with the torpedoes (but didn't know how bad they were) a lot of the problems were lack of realistic training, lack of night training, lack of aggression in general, only 2 boats were on patrol on Dec 7th despite all the warnings.
Turns out the older MK 10 torpedoes used the S boats had a problem with depth keeping but didn't have any of the other problems. This contributed (?) to the S boats making, poor as it was, a significant contribution to the total score.

 

[Thumpalumpacus]

In the US Asiatic fleet (the 29 boats in the Philippines) two skippers were either relived or asked to be relieved in the first week or two. Six more had been relieved by the time the remaining boats made it to Australia. Critiques of the operations were many and while they knew about problems with the torpedoes (but didn't know how bad they were) a lot of the problems were lack of realistic training, lack of night training, lack of aggression in general, only 2 boats were on patrol on Dec 7th despite all the warnings.
Turns out the older MK 10 torpedoes used the S boats had a problem with depth keeping but didn't have any of the other problems. This contributed (?) to the S boats making, poor as it was, a significant contribution to the total score.

Rob is right, I think, in pointing to prewar training as a culprit in promoting cautious skippers to their stations.

 

[Wild_Bill_Kelso]

Even though it's often a bit frustrating to learn of all these mistakes and errors, I think these are some of the most useful data to come out of these discussions. It helps us see ahead to what kinds of problems we might face in the future. Hopefully they read this thread in the Army War College, Air Force Academy, Annapolis etc.

 

[Glider]

The question also gets into which destroyers and when.
Both sides tended to swap guns or torpedoes for AA.
The British guns fire a bit faster for gun duals. Max ranges given in most sources are for 30 degrees of elevation or more, pretty useless from a pitching, rolling destroyer deck,
You can also empty the magazines in 15-20 minutes at the best rate of fire (which you can't keep up due the manual labor) so getting into long range gunnery duals is not a good idea. Keep it short range and sharp.
Please note that US destroyers sometimes carried 2 -3 times the ammo per gun that the Japanese ships did (Fletchers carried 425rpg and later ships go more) so take that into account
when reading about the gun actions.
Tribals carried 200rpg SAP and 50rpg HE and 50 rounds per ship star shell.
British torpedoes were about 36kts at 10,500 yds to start, got better later.
A lot of the Japanese destroyers dropped down to 4 main guns to get better AA (more 25mm) while keeping their torpedo tubes. Japanese also had star shell/illuminating.
British 4 gun Destroyers may not be at much of a disadvantage if the RN (and RAF) can force the Japanese navy to upgrade the AA.

Japanese subs were pretty good for what they were designed for, which was long distances, high speed on the surface. Which meant they dive slow, don't turn well and are big targets for visual search, radar or sonar. The British boats are pretty much opposite. The American boats were sort of in-between, adjust expectations accordingly.

Something to consider here when looking at depth charge counts. The RN started with a 4 charges pattern, one off each side and two rolled off the stern. Then they went to a 7 charge pattern, then an 10 charge and in 1944 (?) they were using a standard 14 charge pattern.
Japanese destroyers started with 14-18 charges and went to 36 part way through the war, depth charge fit at the end???

As to who got what first when it comes to Radar would need a book all to itself. That said I think its a testimony to the RN that the first Type 271 surface search radar was fitted to a Flower class corvette in Feb 1941 and soon after 150 examples were ordered (some say 350 examples).

Type 273 fitted in BB's were introduced in 1941 and was the one used in the sinking of the Scharnhorst identifying her at a range of 45,000 yards

 

[Shortround6]

Well, just looking for some of the details for this I found somethings that are pretty obvious with hindsight.
In 1938 or 39 the US had only the 6 old S boats on station. The other 23 boats showed in a couple of batches in 1940 and 41. The Commander of one of the new flotillas was senor in seniority to the exiting flotilla commander and was appointed to submarine commander (can't remember the exact title). The previous commander had been the Philippines for a number of years. The new commander was in charge of training and all the administrative stuff, like deployments. I think he may have lasted until the end of Dec?
It took until Dec 11th to get 23 (21 plus the 2 boats already on patrol) boats out of the base, to be fair 3 of the boats were undergoing repairs, overhauls as of Dec 7th.

A lot of the boats were deployed to the wrong place/s, south and west of Luzon, a couple of hundred miles south of Manila and the opposite direction from where one would expect the invasion fleet to come from.
Once they got some of that straightened out they sent 3 boats (?) up to the North end of Luzon to join the two S boats to try to attack the invasion fleet leap frogging down the coast.
The S boats managed to pull it off but the 3 larger faster boats tried going in on the surface and were spotted and driven off, Water was too shallow to operate the bigger boats in.

Why they came up with that tactic instead of ambushing them in deep water?
Why no "patrols" off the coast of Formosa?
Why no patrols on the deep water between Formosa and Luzon?

There were a lot more Why's

 

[Thumpalumpacus]

This isn't true. RN torpedoes were good and there wasn't a wide margin between RN and UN Torpedoes.

"Good" is not the same as "the best", and I think that in hindsight all parties involved agreed that the Type 93 was indeed superlative. Warhead, speed, and range support this judgement.

Additionally, given American torpedo problems during the first two years of our involvement in the war, I'd call the RN torpedoes much better. It's true they too had magnetic issues, but they didn't have the contact-exploder issues that plagued the Mk 14.

 

[RCAFson]

"Good" is not the same as "the best", and I think that in hindsight all parties involved agreed that the Type 93 was indeed superlative. Warhead, speed, and range support this judgement.

Additionally, given American torpedo problems during the first two years of our involvement in the war, I'd call the RN torpedoes much better. It's true they too had magnetic issues, but they didn't have the contact-exploder issues that plagued the Mk 14.

I wasn't arguing with 'best' but rather the ' by a wide margin' statement. The IJN had a number of 21in armed ships and subs and there wasn't much difference at all in that size, ditto for aircraft torpedoes. The RN MkVIII**/IX** was a superlative design as well. There was only a few occasions when the longer range of the 24in IJN torpedo was used to advantage.

 

[Shortround6]

The range of the Japanese torpedoes is a bit of an illusion.
Not say they were lying, the torpedoes would go as far as claimed.
The problem was aiming them.
Atago Cruiser.

Now without radar how far can you see?
If you are 90 ft above the water (27.27 meters) you can see to 18.7km. But you don't need to see the enemy ships water line
Spotting plume of smoke and on a very clear day with the sun just right you might catch the top mast of enemy ship that might double the range. 37.7 km for a torpedo with a range of 40km. Except, all you know is that there is a ship out there and what direction it is.
You don't know if it is friendly or enemy (radio?), you don't know the course or speed so you do not have firing solution, the only way to do that, aside from having an aircraft go look, is to get closer to reveal more of the enemy ship. Like the upper part of the bridge and tops of the funnel/s. You may be able to ID the ship.

Three funnels is pretty distinctive for example.
But if you cannot see the hull is going towards you or away or parallel. How long have you got before they spot you and turn. You may have to get within 20km or even closer.
Actually single ship to single ship is pretty lousy odds.

The Japanese max range is for a mass torpedo launch at an enemy fleet (numerous battleships and cruisers) in a target area.
Which never happened (hindsight). The way they were used was fire from outside "normal" range and often without gunfire. Which basically means night time so the enemy doesn't spot the launching ships and change course and speed ruining the firing solution. Japanese don't have to wait for torpedoes to hit. They should wait long enough to give the target little time to react though. A judgement call. But because of the reduced visual range at night that might put the Japanese within range of the enemy torpedoes.
the actual engagements that were fought rarely had more than 4 cruisers in a group (hindsight) and to help making group maneuvers easy several destroyers would be strung out before and aft inline. Multiple parallel lines raised the risk of Collison in turns.
At closer range the type 93 could use more speed for reduced run time which is an advantage and even 20,000 meters range is an advantage. But the over 30,000 meter range is an illusion.

 

[Thumpalumpacus]

I wasn't arguing with 'best' but rather the ' by a wide margin' statement. The IJN had a number of 21in armed ships and subs and there wasn't much difference at all in that size, ditto for aircraft torpedoes. The RN MkVIII**/IX** was a superlative design as well. There was only a few occasions when the longer range of the 24in IJN torpedo was used to advantage.

Sure, but being more largely wakeless, and having larger warheads, as well as longer ranges which did come into play against the Americans in the Solomons for what that's worth ... says a bit. Remember too that USS North Carolina was hit by the same 21" submarine spread that sank USS Wasp -- some eight miles beyond the flattop.

RN torpedoes were damned good, but the Japanese were in a league of their own in this field.

 

[Thumpalumpacus]

The range of the Japanese torpedoes is a bit of an illusion.
Not say they were lying, the torpedoes would go as far as claimed.
The problem was aiming them.
Atago Cruiser.
View attachment 734339
Now without radar how far can you see?
If you are 90 ft above the water (27.27 meters) you can see to 18.7km. But you don't need to see the enemy ships water line
Spotting plume of smoke and on a very clear day with the sun just right you might catch the top mast of enemy ship that might double the range. 37.7 km for a torpedo with a range of 40km. Except, all you know is that there is a ship out there and what direction it is.
You don't know if it is friendly or enemy (radio?), you don't know the course or speed so you do not have firing solution, the only way to do that, aside from having an aircraft go look, is to get closer to reveal more of the enemy ship. Like the upper part of the bridge and tops of the funnel/s. You may be able to ID the ship.
View attachment 734340
Three funnels is pretty distinctive for example.
But if you cannot see the hull is going towards you or away or parallel. How long have you got before they spot you and turn. You may have to get within 20km or even closer.
Actually single ship to single ship is pretty lousy odds.

The Japanese max range is for a mass torpedo launch at an enemy fleet (numerous battleships and cruisers) in a target area.
Which never happened (hindsight). The way they were used was fire from outside "normal" range and often without gunfire. Which basically means night time so the enemy doesn't spot the launching ships and change course and speed ruining the firing solution. Japanese don't have to wait for torpedoes to hit. They should wait long enough to give the target little time to react though. A judgement call. But because of the reduced visual range at night that might put the Japanese within range of the enemy torpedoes.
the actual engagements that were fought rarely had more than 4 cruisers in a group (hindsight) and to help making group maneuvers easy several destroyers would be strung out before and aft inline. Multiple parallel lines raised the risk of Collison in turns.
At closer range the type 93 could use more speed for reduced run time which is an advantage and even 20,000 meters range is an advantage. But the over 30,000 meter range is an illusion.

Right -- but running at 49 kts on a short run allows little time for spotting and evasion. And -- their "short run" at 49 kts was about maximum range (9,000 yds or so) for Allied torpedoes chugging along at slower speeds for the same range. So Japanese torps were not only superior at range, but also in short-range melees.

Another thing: most Japanese ships, unlike most other ships of the time, carried torpedo reloads. Took about 30 minutes, as I've read, not sure how true that is. 4 cruisers plus, say, another four DDs, all with reloads, is a shit-ton of fish, all on ships designed to dash in and then dash out.

 

[SaparotRob]

The range of the Japanese torpedoes is a bit of an illusion.
Not say they were lying, the torpedoes would go as far as claimed.
The problem was aiming them.
Atago Cruiser.
View attachment 734339
Now without radar how far can you see?
If you are 90 ft above the water (27.27 meters) you can see to 18.7km. But you don't need to see the enemy ships water line
Spotting plume of smoke and on a very clear day with the sun just right you might catch the top mast of enemy ship that might double the range. 37.7 km for a torpedo with a range of 40km. Except, all you know is that there is a ship out there and what direction it is.
You don't know if it is friendly or enemy (radio?), you don't know the course or speed so you do not have firing solution, the only way to do that, aside from having an aircraft go look, is to get closer to reveal more of the enemy ship. Like the upper part of the bridge and tops of the funnel/s. You may be able to ID the ship.
View attachment 734340
Three funnels is pretty distinctive for example.
But if you cannot see the hull is going towards you or away or parallel. How long have you got before they spot you and turn. You may have to get within 20km or even closer.
Actually single ship to single ship is pretty lousy odds.

The Japanese max range is for a mass torpedo launch at an enemy fleet (numerous battleships and cruisers) in a target area.
Which never happened (hindsight). The way they were used was fire from outside "normal" range and often without gunfire. Which basically means night time so the enemy doesn't spot the launching ships and change course and speed ruining the firing solution. Japanese don't have to wait for torpedoes to hit. They should wait long enough to give the target little time to react though. A judgement call. But because of the reduced visual range at night that might put the Japanese within range of the enemy torpedoes.
the actual engagements that were fought rarely had more than 4 cruisers in a group (hindsight) and to help making group maneuvers easy several destroyers would be strung out before and aft inline. Multiple parallel lines raised the risk of Collison in turns.
At closer range the type 93 could use more speed for reduced run time which is an advantage and even 20,000 meters range is an advantage. But the over 30,000 meter range is an illusion.

Wow. Atago is pretty impressive for only 9850 tons.

 

[Alan Stevens]

Two, apparently, which is more than the HMS Prince of Wales did.

Prince of Wales hit Bismarck with 15-inch fire three times and damaged a fuel tank and caused enough damage that Bismarck had to abandon its mission and attempt to return to port.

Bismarck was down somewhat by the bow and trailed an oil slick and lost 2 knots of speed. The incident that crippled the ship enough that it was vulnerable to further attacks which led to its sinking.

 

[Shortround6]

Wow. Atago is pretty impressive for only 9850 tons.

They lied....................................big time.

 

[Alan Stevens]

Again, what navy fighter was better than the A6M prior to the Hellcat?

The F4F Wildcat fought it to a draw in the very beginning and better than even after more IJN pilots were killed.

 

[Wild_Bill_Kelso]

The range of the Japanese torpedoes is a bit of an illusion.
Not say they were lying, the torpedoes would go as far as claimed.
The problem was aiming them.
Atago Cruiser.
View attachment 734339
Now without radar how far can you see?
If you are 90 ft above the water (27.27 meters) you can see to 18.7km. But you don't need to see the enemy ships water line
Spotting plume of smoke and on a very clear day with the sun just right you might catch the top mast of enemy ship that might double the range. 37.7 km for a torpedo with a range of 40km. Except, all you know is that there is a ship out there and what direction it is.
You don't know if it is friendly or enemy (radio?), you don't know the course or speed so you do not have firing solution, the only way to do that, aside from having an aircraft go look, is to get closer to reveal more of the enemy ship. Like the upper part of the bridge and tops of the funnel/s. You may be able to ID the ship.
View attachment 734340
Three funnels is pretty distinctive for example.
But if you cannot see the hull is going towards you or away or parallel. How long have you got before they spot you and turn. You may have to get within 20km or even closer.
Actually single ship to single ship is pretty lousy odds.

That is what the E13, E7, E8, F1M etc. spotter planes were for. Apparently these were used even at night in some battles in 1942-43.

The Japanese max range is for a mass torpedo launch at an enemy fleet (numerous battleships and cruisers) in a target area.
Which never happened (hindsight). The way they were used was fire from outside "normal" range and often without gunfire. Which basically means night time so the enemy doesn't spot the launching ships and change course and speed ruining the firing solution. Japanese don't have to wait for torpedoes to hit. They should wait long enough to give the target little time to react though. A judgement call. But because of the reduced visual range at night that might put the Japanese within range of the enemy torpedoes.
the actual engagements that were fought rarely had more than 4 cruisers in a group (hindsight) and to help making group maneuvers easy several destroyers would be strung out before and aft inline. Multiple parallel lines raised the risk of Collison in turns.
At closer range the type 93 could use more speed for reduced run time which is an advantage and even 20,000 meters range is an advantage. But the over 30,000 meter range is an illusion.

I think the torpedoes were all almost always used at less than maximum range, which sometimes allowed higher speed. The thing that shorter range for the type 93 was sometimes around 20,000 yards and they did get hits at that range.

 

[Wild_Bill_Kelso]

Prince of Wales hit Bismarck with 15-inch fire three times and damaged a fuel tank and caused enough damage that Bismarck had to abandon its mission and attempt to return to port.

Bismarck was down somewhat by the bow and trailed an oil slick and lost 2 knots of speed. The incident that crippled the ship enough that it was vulnerable to further attacks which led to its sinking.

2 knots isn't 'crippled', and light damage (at the cost of one battleship blown to bits and another heavily damaged) isn't a "kill"