Rn vs IJN (1 Viewer)

[RCAFson]

WBK, regarding the Wellington figures, is that range or radius? If radius, that would put it with B-17 and B-24 which i find suspicious, but of course i could be wrong. But even the very rangy G4M could only do 880 nautical miles max.

According to Mason's The Secret Years:

"Wellington Mark III

The first Hercules-engined Wellington, L4251, was
delivered in May 1940 to the Armament Squadron, and
not, as was usual for a new version, to the Performance
Squadron. ....
On arrival in May 1941, P9238 started eighteen
months of tests by demonstrating a take-off run at 33,000
lb of only 440 yd-a considerable improvement on the
Pegasus-powered aircraft. This weight represented the
standard loading, and, with full fuel of 1,030 gal and 1,380
Ib of bombs, ideal range was 2,230 statute miles; with
maximum load of bombs, 6,750 Ib, range was reduced to 520 miles."

Ideal range was a no reserve figure and the practical range would have been about 1600-1700 miles with a combat radius of about 700 statute miles. For bomb loads above ~1400lb fuel had to be traded for range, so with a single 1650lb torpedo, deduct about 50IG of fuel for a radius of ~550nm.

 

[Wild_Bill_Kelso]

Yes, and I hold a different opinion. I think it could go either way. Both navies were very skilled. Both sides had some technical edges. And for what the Brits might bring to the Pac, you'd have to equally wonder which ships the Japanese retain in home/mandated waters due to an unfriendly America.

It could definitely go either way, but I think in the carrier battle, the IJN has a big advantage over the FAA which would be a severe problem for the British. Surface combat is more arguable, I lean toward IJN again here, at least initially, in large part due to the torpedoes, but it's certainly a closer match.

And that raid -- which is precisely what it was -- had no capacity for putting long-term pressure on British SLoCs. This is not a real answer to my point.

This is my major disagreement with you in this post. Yes, in the real world, this was a raid, albeit a powerful one. But that's only because they had to go back and contend with the USN. What did the British have to stop the Japanese from going further into the Indian Ocean, capturing Ceylon, and utlimately for example, bombing and sending in battleships and heavy cruisers to bombard ports on the coast of India itself?

Indeed I have. And I don't dismiss the Type 93s, I only pointed out that they didn't always represent the silver bullet. Of course they can be lethal. They could also miss.

Sure, but I don't think it was like 50/50. In most surface battles in the Pacific War they were major factor.

As for my state of bias, I struggle to take an equitable look at these historical discussions and consider all sides. I have already said I think it would be a close-run thing dependent upon when this war happens. That said, it's still possible that I'm biased. That's possible of anyone, after all. View attachment 733820

We all struggle with it, we all have biases, that's why we have long detailed debates about it. It's no biggy.

 

[Geoffrey Sinclair]

One engineering calculation I have seen showed that one battleship with nine 16" guns used enough material to build 50 destroyers. Perhaps twenty light cruisers ?

These are rough figures, the more expensive bits, I have never seen a breakdown of the costs to this level,
Fletcher class destroyer, 2,050 tons, 60,000 SHP, 1 fire control, no armour, 275 crew, 500 tons of fuel for 4,140 miles at 20 knots
Cleveland class cruiser, 10,000 tons, 100,000 SHP, 4 fire control, 1,470 tons armour, 992 crew, 2,200 tons fuel for 6,860 miles at 20 knots
Iowa class battleship, 45,000 tons, 212,000 SHP, 6 fire control, 10,175 tons armour, 1,921 crew, 7,900 tons fuel for 11,700 miles at 20 knots.

Bigger ship, less machinery per ton, less crew per ton, less miles per fuel ton, armour would add a lot of cost and I expect armour twice as thick would cost more than twice as much.

So 5 Fletcher class destroyers staying with a Cleveland class for 6,860 miles would need the same weight of material, 3 times the engines, 1 more fire control, about 400 extra crew and about twice the fuel.

22 Fletcher staying with an Iowa for 11,700 miles would need the same amount of material, 6 times the engines, 3.67 times the fire control, 3 times the number of crew and pushing three times the fuel.

While money has its limit as a measuring device, the attachment is total cost of ownership according to the RN in the late 1930's, note the destroyer costs are for 8 ships, in rough terms a destroyer and submarine cost about the same per year, a small cruiser 3.4 times a destroyer, a large cruiser 4.9 times and a battleship 10.7 times. Aircraft were expensive, making even a small aircraft carrier more costly than anything except a battleship, an airgroup of 36 made the carrier more expensive, an airgroup of 72 made the carrier nearly twice as expensive as a battleship.

If you just go for building costs, a small cruiser is 2.7 times the cost of a destroyer, large cruiser 4.4 times, battleship 16 times, small carrier 6.5 times, large carrier 8.1 times.

The navies all wanted a larger proportion of heavy ships during peace time, given build times and operating costs.

 

[Wild_Bill_Kelso]

WBK, regarding the Wellington figures, is that range or radius? If radius, that would put it with B-17 and B-24 which i find suspicious, but of course i could be wrong. But even the very rangy G4M could only do 880 nautical miles max.

Range for the Wellington is 2500 miles, (I've also seen 1,800 miles, 1500 miles and other ranges quoted. It would depend on the specific variant and loadout). I'm only guessing as to actual strike range. But the Wellington for example participated in strikes against Berlin from the UK which is close to 700 miles one way. Distance from Broome Australia to Surabaya on Java / Indonesia is 850 nautical miles.

The British had a knack for doing things like putting extra fuel tanks inside bombers and carrying a relatively light bomb load to extend the range. Wellington per spec carried a very large bomb load (of 4500 lbs) by Pacific War standards (especially compared to the Japanese bombers). Many Japanese port and airfield facilities were not that well defended from night attacks. I would also expect some infrastructure like oil facilities might be a particularly good target.

The Wellington was kind of ideally suited for maritime actions. It was slow but very lightly built while also being strong, and could trundle along for very long distances. It was also fairly heavily armed, enough that night fighters - if there were any, would have to be pretty careful and / or heavily armed themselves. Which many Japanese aircraft as we know, were not.

I know in some detail about the operational history of the Wellington in the Med, where they routinely reached farther than expected and dropped torpedoes into the water to sink Axis ships, particularly the more vulnerable commercial shipping and military supply ships. The Germans couldn't really come up with any answer for this, and I'm not sure, looking at the Japanese kit, they had a way to do it either. Maybe put guns on Ki-46s or something. They had a really hard time intercepting B-29s with even more incentive to do so, but that was partly due to the speed and altitude of the B-29. Probably they would have come up with some defense against Wellingtons and other possible Royal Air Force / Coastal Command long range bombers for the land bases, though i doubt every one of them... and I really doubt they could have protected ships out at sea.

 

[Thumpalumpacus]

It could definitely go either way, but I think in the carrier battle, the IJN has a big advantage over the FAA which would be a severe problem for the British. Surface combat is more arguable, I lean toward IJN again here, at least initially, in large part due to the torpedoes, but it's certainly a closer match.

Agreed that with limited capacity and inferior aircraft earlier in the war, British carriers have a tougher row to hoe.

This is my major disagreement with you in this post. Yes, in the real world, this was a raid, albeit a powerful one. But that's only because they had to go back and contend with the USN. What did the British have to stop the Japanese from going further into the Indian Ocean, capturing Ceylon, and utlimately for example, bombing and sending in battleships and heavy cruisers to bombard ports on the coast of India itself?

Bear in mind that 1) Japanese communications wend past the Philippines and will by their own doctrine require escort, and 2) without war in the Med, the Brits will have forces available to either escort or stultify such a move by IJN. If there's no war against Germany as well, that's an awful lot of ships available.

Sure, but I don't think it was like 50/50. In most surface battles in the Pacific War they were major factor.

They were definitely deadly. One question would be whether or not the RN would follow the Americans in the purblind denial of the capabilities Japanese torpedoes have, or made their peace with reality earlier.

We all struggle with it, we all have biases, that's why we have long detailed debates about it. It's no biggy.

Right, and we don't have to agree to enjoy the discussion and each others comments, so long as courtesy and good faith are involved.

 

[Wild_Bill_Kelso]

I really don't dislike most of your comments, except when you get real mad for reasons I can't fathom. Most of the regular posters here are fine once they learn to respect you a bit. Sometimes you have to fight a bit before that happens, in almost any walk of life. When somebody throws a punch at me, I punch back, that's how I was raised. But I don't necessarily keep a grudge. The only thing that really rubs me the wrong way on here is when sometimes the spin or advocacy clearly and intentionally crosses in front of the known data. Which I haven't seen you do, really.

But sometimes you don't really make sense to me. I can live with that & it doesn't bother me or cause me to dislike your posts.

 

[z42]

It is interesting that many of these entire classes of ships were built based on faulty intelligence. That kind of thing happened a lot in the 20th Century.

The MiG 25 was built to counter the (failed, aborted) B-70 Valkyrie double / triple supersonic fighter. Then the US, in a panic over how good the MiG 25 was (it being nowhere near as good as they thought, but it did make Mach 3), developed the F-15. So theoretically, a goof. But the F-15 ended up being an excellent fighter which was dominant in the Cold War for 20+ years and (in heavily upgraded form) is still considered somewhat viable more than 40 years after the first flight. They still fly over my neighborhood fairly often from the big nearby air base across the river from my house.

Sure, arms, and counters to them, are a never-ending race.

I would say from the operational history of the various battles, the heavy cruisers with the bigger guns did have a role. They seemed to punch Mike Tyson hard, and aside from the type 92 torpedoes and the battleships / battlecruisers, it seems to me that the 8" guns actually did most of the real damage in many of these battles. The shells seemed to be more accurate and a few, or even a single hit could wreck an enemy ship.

Well, you fight with what you have, not with what you wish you had. Or what some armchair admirals on the internet 80 years after the fact might think would have been a better force composition if history had played out slightly differently. In the end, heavy cruisers were relatively plentiful, and it was an easier decision to risk a cruiser than a BB. Committing BB's to the nighttime knife fights around Guadalcanal was a pretty ballsy (and rare!) move.

They also had a more punishing impact in bombardment.

For shooting at hardened targets, sure. For non-hardened area bombardment, arguably a 6" would be better. Lots of smaller bangs tend to be more efficient than a few bigger ones, that's why cluster munitions are considered so effective in modern times.

The battleships were also clearly very useful in the surface actions, and bombardment, and in air defense for the carriers. But they use such an incredible amount of resources (both in terms of building them, and operating them) that I would agree that it is arguable if they were cost effective.

A BB as an carrier air defense platform is wildly cost inefficient, but it did work. And the BB's did exist already, and didn't take slipway capacity away from some other sorely needed ship. All in all, probably a good way to utilize them given the situation at the time.

 

[Wild_Bill_Kelso]

Sure, arms, and counters to them, are a never-ending race.

And sometimes fixes to ephemeral or non existent problems turn out to be useful anyway...

Well, you fight with what you have, not with what you wish you had. Or what some armchair admirals on the internet 80 years after the fact might think would have been a better force composition if history had played out slightly differently. In the end, heavy cruisers were relatively plentiful, and it was an easier decision to risk a cruiser than a BB. Committing BB's to the nighttime knife fights around Guadalcanal was a pretty ballsy (and rare!) move.

Agreed. The more I learn about it, the more insane it seems.

For shooting at hardened targets, sure. For non-hardened area bombardment, arguably a 6" would be better. Lots of smaller bangs tend to be more efficient than a few bigger ones, that's why cluster munitions are considered so effective in modern times.

This I'm not sure about. Of all the bombardments in WW2, one of the most effective seems to have been the Japaense bombardment, by two battle-cruisers, against Henderson field. They almost knocked it out. There is really no bunker deep enough (almost) to protect against those big guns.

A BB as an carrier air defense platform is wildly cost inefficient, but it did work. And the BB's did exist already, and didn't take slipway capacity away from some other sorely needed ship. All in all, probably a good way to utilize them given the situation at the time.

Agreed. The other thing about the BBs is that they could take some bomb hits or even torpedo hits, while the CLs etc. were more likely to sink

 

[z42]

These are rough figures, the more expensive bits, I have never seen a breakdown of the costs to this level,
Fletcher class destroyer, 2,050 tons, 60,000 SHP, 1 fire control, no armour, 275 crew, 500 tons of fuel for 4,140 miles at 20 knots
Cleveland class cruiser, 10,000 tons, 100,000 SHP, 4 fire control, 1,470 tons armour, 992 crew, 2,200 tons fuel for 6,860 miles at 20 knots
Iowa class battleship, 45,000 tons, 212,000 SHP, 6 fire control, 10,175 tons armour, 1,921 crew, 7,900 tons fuel for 11,700 miles at 20 knots.

Bigger ship, less machinery per ton, less crew per ton, less miles per fuel ton, armour would add a lot of cost and I expect armour twice as thick would cost more than twice as much.

So 5 Fletcher class destroyers staying with a Cleveland class for 6,860 miles would need the same weight of material, 3 times the engines, 1 more fire control, about 400 extra crew and about twice the fuel.

22 Fletcher staying with an Iowa for 11,700 miles would need the same amount of material, 6 times the engines, 3.67 times the fire control, 3 times the number of crew and pushing three times the fuel.

While money has its limit as a measuring device, the attachment is total cost of ownership according to the RN in the late 1930's, note the destroyer costs are for 8 ships, in rough terms a destroyer and submarine cost about the same per year, a small cruiser 3.4 times a destroyer, a large cruiser 4.9 times and a battleship 10.7 times. Aircraft were expensive, making even a small aircraft carrier more costly than anything except a battleship, an airgroup of 36 made the carrier more expensive, an airgroup of 72 made the carrier nearly twice as expensive as a battleship.

If you just go for building costs, a small cruiser is 2.7 times the cost of a destroyer, large cruiser 4.4 times, battleship 16 times, small carrier 6.5 times, large carrier 8.1 times.

The navies all wanted a larger proportion of heavy ships during peace time, given build times and operating costs.

Good post!

I'll just add that AFAIU the longest lead time item when building a battleship was the gun barrels. Apparently manufacturing such a barrel literally took years, due to having to be heated or cooled very slowly, and similarly all boring etc. work had to be done very slowly to avoid damaging the barrel. So battleships had to be planned many years in advance, you couldn't just snap your fingers and have a big BB fleet next year. Cue the old joke about an infinite number of women not being able to produce a baby faster than 9 months. Contrast this e.g. with how fast the US was able to ramp up Essex construction.

 

[Wild_Bill_Kelso]

I was looking into more operational history for Spitfires in the East, other than the Darwin raids.

79 Sqn RAAF, stationed in New Guinea, were flying Spit Mk V engaged with some Japanese planes in June 1943 - claiming two Ki-61 and a Ki-46. They had some trouble intercepting enemy raids. Looks like they got Mk VIII in November 1944, but didn't get into any air to air combat with them.
85 Sqn RAAF started with Boomerangs but got Spitfire Mk V in Sept 1944, but never got any Mk VIII. They did not seem to able to intercept any enemy planes.
548 sqn RAAF got Spitfire Mk V in Dec 1943, considered as better interceptors than Kittyhawks. At some point they got Mk VIII. They did two fighter sweeps in Sept 1944 over Timor, but did not get into any air combat.
548 RAAF got Spitfire VIIIs in Oct 1945 but don't seem to have had any air to air action.

80 Wing RAAF (Made of 452 and was established in May 1944, with Spitfire VIII. Looks like they got a few victories after Darwin but not much. This unit was involved in the "Morotai Mutiny" due to being disgruntled at misuse by commanders, kept out of the fight and wasted on dangerous and pointless strikes against bypassed Japanese island positions, basically due to MacArthur if I understand the scenario correctly.

Spitfires seem to have gotten more action in India. MK VIII were used successfully in Burma / India (Kohim and Imphal valley) in early - mid 1944, and British units claimed 65 victories vs Ki-43 and Ki-44, for the loss of 3 Spitfires. They also did some CAS there, helping blunt a major JA offensive at Sittang bend in 1945.

 

[Shortround6]

I'm almost certain that with the absence of the naval treaties limiting cruiser tonnage, we wouldn't have seen the glass cannon 8" cruisers at 10000 tons. A decently well balanced 8" cruiser would probably clock in at around 15000 tons.

Well the actual glass cannon 8" cruisers were rather rare.
Remember that the 8" cruiser era lasted just over 30 years from the Hawkins to the Des Moines and closer to 20 years if you knock out these two extremes.

However a lot of that was the fact that 8" cruiser race was the first wide scale application of "standard" displacement and it took a while to sort out.
The Pensacola wound about 900 tons light and such was the pace of design and building that the 3rd class (Portland) was laid down days or weeks after the Pensacola commissioned with the six Northampton's in between. It made it hard to incorporate lessons learned as they looked for more balanced designs. The US did almost standardize on the size of the power plant and expected speed. So did the British.

The French and Italians were the most schizoid families of cruisers. The Japanese just flat out lied once they got by the Aoba class (only six guns).
The French Duquesne class (2 ships) used 120,000hp for 33.75 kts and only about 430 tons of armor. They could maintain 30kts on 1/2 power but they could only do 4500 miles at 15kts.
The Suffren's dropped the power to 90,000hp and speed to 31 kts but they got successively more armor. Suffren 951 tons, Colbert & Foch 1374 tons and Dupleix got 1533 tons. Range was little bit better.
The Algerie was a lot better, 84,000hp gave the same 31kts due to better hull form. Armor went to 2657 tons (?) and range went up about 2000 miles.

Italian Trento (2 ships) used 150,000hp for 36 kts. Trial, service seas speed was closer to 31 kts. Range at 16kts was 4160nm Armor was OK, not great.
Zara class (4 ships) were over weight-Around 11,500 tons ) and used less power, 95,000hp for 32 kts. Also only used two shafts (?). These were among the heaviest armor of the Treaty cruisers.
Balzano class (1 ship) sort of a repeat Trento class, 150,000hp=36 kts.

I would note that the Italian ships had a much better nominal AA battery than anybody else did with sixteen 4.7in guns in twin mounts. However in the late 30s the rear most twin 4.7in were removed and replaced by increased 37mm and 20mm AA guns.


The Baltimore's went a bit over 13,000tons.

 

[ThomasP]

Baltimore was (I think) ~14,500 tons Standard displacement as designed (it might be with her original AA as completed).

 

[Shortround6]

You are correct, Going by my increasing faulty memory.

The 8" cruisers disappeared from everybody's building programs except Germany and the US. (and Soviet 7.1" cruisers?)
The British drew plans but war work pretty much ended any chances.
British would have been better served by devoting such resources to more carriers.

We also need to take a look the "standard displacement' thing. The US cruisers had large fuel tanks. They also had more economical machinery. Their actually worked unlike the German machinery. The big (Pensacola) and newer ships were 'supposed' to do 10,000 miles at 15kts while the British ships did 8,000 at 10 knots and needed more fuel to do it.
The French and Italian ships were around 5000 miles at 15kts, they were built for the Med, not the Atlantic let alone the Pacific.

 

[Thumpalumpacus]

I really don't dislike most of your comments, except when you get real mad for reasons I can't fathom. Most of the regular posters here are fine once they learn to respect you a bit. Sometimes you have to fight a bit before that happens, in almost any walk of life. When somebody throws a punch at me, I punch back, that's how I was raised. But I don't necessarily keep a grudge. The only thing that really rubs me the wrong way on here is when sometimes the spin or advocacy clearly and intentionally crosses in front of the known data. Which I haven't seen you do, really.

But sometimes you don't really make sense to me. I can live with that & it doesn't bother me or cause me to dislike your posts.

I don't get "real mad" about anything here. I am not that emotionally invested. I'm unsure where I threw any "punch" at you. I disagree with some of what you've written. You will get that in any honest discussion, and that's what I'm giving you.

 

[ThomasP]

re the Churchill in the Far East

The UK and Australian armies performed comparison tests on New Guinea in mid- to late-1944 to decide what tank would perform best for the upcoming projected jungle war in the Far East, and to develop operational procedures ahead of time. They used the Matilda for the baseline as the Australians considered the Matilda quite good for the jungle war. The Australians were looking for a replacement for their Matildas and the UK looking to decide what tank they should send for their own troops as well as for Australia. The 2 alternative types were the Sherman (75mm) and the Churchill (75mm & 95mm).

This is a link to a video highlighting the tests, at the Australian War Memorial website "Churchill and Sherman tanks (Tank trials)"

I have run across the complete report in digital print online somewhere, but I do not remember where. I think it is a copy of what was sent back to the UK. The video does not present the conclusions (the Churchill was considered better than the Sherman) and IIRC there are a couple of minor inaccuracies in the video (ie statements that imply things the written report did not).

 

[RCAFson]

re the Churchill in the Far East

The UK and Australian armies performed comparison tests on New Guinea in mid- to late-1944 to decide what tank would perform best for the upcoming projected jungle war in the Far East, and to develop operational procedures ahead of time. They used the Matilda for the baseline as the Australians considered the Matilda quite good for the jungle war. The Australians were looking for a replacement for their Matildas and the UK looking to decide what tank they should send for their own troops as well as for Australia. The 2 alternative types were the Sherman (75mm) and the Churchill (75mm & 95mm).

This is a link to a video highlighting the tests, at the Australian War Memorial website "Churchill and Sherman tanks (Tank trials)"

I have run across the complete report in digital print online somewhere, but I do not remember where. I think it is a copy of what was sent back to the UK. The video does not present the conclusions (the Churchill was considered better than the Sherman) and IIRC there are a couple of minor inaccuracies in the video (ie statements that imply things the written report did not).

As an aside the 6pdr (57mm) had an HE round and the 6pdr was fitted to the Valentine and was standard on most Churchills prior to the ROF 75mm and, of course, the Canadian Ram II tank. Canada built about 6000 Valentines, Rams and Sextons (SP 25pdr on a Ram hull ), IIRC. Production numbers were low because Valentine and Ram production ended in 1943.

 

[z42]

This I'm not sure about.

We can approximate it as a simple geometry problem. The blast overpressure (or shrapnel density if you prefer) spreads out into space. Recall the formula for the surface area of a sphere, S = 4*pi*r^2. So e.g. at twice the distance from the explosion the blast pressure drops to a quarter. To cover an area target with at least a specific overpressure, you need much less explosive overall if you spread it out in multiple smaller explosions rather than one big explosion in the middle.

(Now reality is of course significantly more complex than the napkin calculation above, in that a shell doesn't explode exactly symmetrically, and also half the sphere volume is air and the other half is earth, where the earth partially focuses the blast wave along the ground and partially reflects it upwards. etc etc. But the basic conclusion holds, more efficient to use multiple smaller bangs than one big boom.)

Of course, to penetrate armor plate or destroy a deep underground bunker, sure, you need a massive enough projectile, and if you haven't got it you can keep pounding all week with little effect.

Of all the bombardments in WW2, one of the most effective seems to have been the Japaense bombardment, by two battle-cruisers, against Henderson field. They almost knocked it out. There is really no bunker deep enough (almost) to protect against those big guns.

AFAIU there were no deep bunkers on Henderson field. At that time wasn't it a pretty much makeshift recently constructed airstrip? They didn't even have revetments for the planes at the time IIUIC. I'm sure they had trenches for the personnel to hide in though. Not sure how fuel storage was handled, was it just a bunch of barrels stored on the perimeter of the field, or did they have trenches for the barrels/tanks etc.?

Anyway, from wikipedia Guadalcanal campaign - Wikipedia : "Over the next one hour and 23 minutes, the two battleships fired 973 14-inch (356 mm) shells ...", "Many of the shells were fragmentation shells, specifically designed to destroy land targets. The bombardment heavily damaged both runways, burned almost all of the available aviation fuel, destroyed 48 of the CAF's 90 aircraft, and killed 41 men, including six CAF pilots. "

So over 83 minutes they fired 973 shells, making for an average of 0.73 shells/minute/barrel, around half the maximum they would theoretically have been capable of (which makes sense considering it was a prolonged bombardment, time for spotting, switching aim points etc.). Going by Geoffrey Sinclair's figures above, a battleship cost between 3 and 6 times as much as a light cruiser (depending on whether you look at purchase or operating cost). If we take the middle value of 4.5, instead of those two battleships we could have 9 light cruisers. Using the figures for the Brooklyn class I calculated above (too lazy to look up values for Japanese light cruisers and guns, they might not have achieved the same rate of fire as the Americans), at half the maximum rate of fire, during those 83 minutes you'd have a rain of 9*15*9/2*83 = 50423 6" shells over Henderson field. More than enough to ruin your breakfast, I'm sure.

Though I'm quite sure no light cruiser had enough magazine capacity to go BRRRT for 83 minutes straight, so you'd have to settle for a shorter slightly less ridiculously overkill bombardment.

Alternatively, lets calculate the time it would take for the light cruiser squadron to deliver the same amount of HE to Henderson field. The 14" HE shell fired by the Kongos contained 29.5 kg HE Japan 36 cm/45 (14") 41st Year Type - NavWeaps , whereas per my previous post the American 6" HE contained 6.0 kg. So you need 973 * 29.5/6.0 = 4784 6" HE shells. Delivering those with 9 Brooklyns would take 4784/(9*15*9/2) = 8 minutes!

This also nicely demonstrates the previous point I made about being able to cram more HE into smaller shells. The 14" HE shell weighed 625 kg, so 29.5/625 = 4.7% HE content. For comparison, the 6" HE has 6.0/47.6 = 12.6% HE content.

 

[Geoffrey Sinclair]

The RAAF Squadron Histories books are online at the RAAF web site, after the Japanese went on the defensive the RAAF had few encounters with hostile aircraft in the air. It was hard enough for the allies to mount air operations in New Guinea and the Japanese supply situation was worse, then in 1944 their priority became the Central Pacific and points north.

79 Squadron, Spitfire V, to New Guinea in April 1943, ended up being fighter defence for the Admiralty Islands March 1944 until sent to the Darwin area in January 1945 and given mark VIII, to Morotai in the Molucca Islands in February
85 squadron, air defence of Perth Western Australia, Spitfire V started arriving in September 1944, replacing Boomerangs.
452 Squadron, Spitfire V, Darwin area January 1943, mark VIII in January 1944, Molucca Islands December 1944, Borneo June 1945.
457 Squadron, Spitfire V, Darwin area January 1943, mark VIII in July 1944, Molucca Islands February 1945, Borneo June 1945.
54 RAF, Spitfire V, Darwin area January 1943, mark VIII in May 1944
548 RAF, Spitfire VIII, Darwin area July 1944
549 RAF, Spitfire VIII, Darwin area July 1944

The RAAF confined the RAF units to defence of Darwin, under 1 Wing, while 80 wing took over command of the RAAF Spitfires going north.

The RAAF Mutiny of the Aces had a number of causes, the type of operations being done was a big one, so was the way the RAAF was doing them, the RAAF had followed the Army system of largely keeping the regulars in staff positions and using hostilities only people as combat commanders. In 1945 a number of regular officers were sent to the front for combat experience, but were way behind those who had been doing it for years. It did not work very well. Throw in Australians had alcohol and the Americans did not and air forces can be good at unofficially moving important supplies. MacArthur's wither on the vine required US and RAAF units to keep applying defoliant.

The Wellington came in so many versions ranges vary as do performance quotes for given models, end 1941 your choice was Ic being built since February 1940 (Pegasus), II built from October 1940 (Merlin), III built from May 1941 (Hercules), IV from December 1940 (Twin Wasp) and VIII from December 1940 (Pegasus). RAAF Official History, mark, still air range/bomb load,

Ic 2,250/1,000, 1,805/2,750, 1,200/4,500
II 2,445/1,150, 1,725/3,500
III 2,040/1,500, 1,200/4,500
IV 1,510/4,500
VIII 1,270/3,300, 1,580/2,700, 1,900/1,800

Initial prototypes of the mark II and III were flying in 1939

RAF performance report, Ic at 30,000 pounds at 195 mph, 1,055 miles with 4,500 pounds of bombs, 1,600 miles with 2,800 pounds of bombs, 2,255 miles with 500 pounds of bombs, at 165 mph, 1,805 miles with 2,800 pounds of bombs, 2,550 miles with 500 pounds of bombs. Mark II at 32,000 pounds at 195 mph, 1,273 miles/4,500 pounds bombs, 1,580 miles/3,500 pounds, 2,245 miles 1,150 pounds, at 175 mph, 1,725 miles/3,500 pounds, 2,445 miles/1,150 pounds. Ranges have 50 minutes allowance.

The 1940 crisis set back Australian Beaufort production, historically 10 built by end 1941, 28 by end March 1942 and 76 by end June 1942 against 1940 orders of 90 RAF, 90 RAAF, plus another 90 RAF ordered in 1941

Ship displacement/weight and ranges are very much like aircraft, context sensitive. The Baltimores were 13,600 design standard (treaty) displacement, and 14,970 tons design displacement. Norman Friedman quotes the Fletcher class ranges at miles/knots, design 6,500/15, trial 4,800/15, 4,150/20, War 4,900/12 4,490/15, 3,480/20, war was split plant condition, in other words keeping a sort of just in case reserve.

The Hawkins class was designed to deal with German WWI raiders, mostly the disguised merchant ships and were given good range and bigger guns than previous classes, this was carried through to the County class, they had ranges comparable to the US cruisers, once everyone had the heavy cruiser type the roles were recast to battle line not anti raider.

The RN did sea trials of 500 pounds/square inch 850 F machinery in the destroyer HMS Acheron, launched in 1930, there were many troubles coupled with a lack of resources to fix them which meant while other A class had 300 pounds/square inch 600 F machinery that was still the standard machinery during the war. Add the Southampton class were 9,100 tons which meant a cut in fuel capacity compared with the 10,000 ton USN types, the Fiji class were about 8,500 tons. And this is before the USN trying to build in more range, helped by the way the USN allowed water to enter the fuel tanks as the fuel was used while the RN did not. The USN Farragut class had 400 pounds/square inch 648 F, the Bensons 618 and 700-750.

The War Production Board Report, which starts in July 1940, 21 three gun 16 inch/45 turrets built, (18 needed) 3 in October 1940, 3 in June 1941, 3 in January, 6 in March and 3 in June 1942, 1 each in July, September and December 1942. There were 17 three gun 16 inch/50 built, the 6 Iowa class requiring 18, the 5 Montana class 20 turrets. Only 4 Iowa class completed, requiring 12 turrets. Production, 1 in November, 2 in December 1942, 2 in January, 1 in February, 1 in August, 1 in November, 1 in December 1943, 2 in January, 1 in February 1 in August and 1 in October 1944, 1 in April, 1 in June and 1 in July 1945.

The six 35,000 tons battleships were laid down October 1937 to February 1940, commissioned April 1941 to August 1942, the 4 completed Iowas February 1943 to June 1944. It certainly took time to build the heavy guns and their mountings, but for the US it was a few months longer than the time to launch the hull, which is what production scheduling would be trying to do. The first triple 6 inch/47 turrets were delivered in February 1942, the Cleveland class began launching in November 1941, the first triple 8 inch/55 turrets were delivered in December 1942, the first Baltimore launched in July 1942.

 

[Wild_Bill_Kelso]

We can approximate it as a simple geometry problem. The blast overpressure (or shrapnel density if you prefer) spreads out into space. Recall the formula for the surface area of a sphere, S = 4*pi*r^2. So e.g. at twice the distance from the explosion the blast pressure drops to a quarter. To cover an area target with at least a specific overpressure, you need much less explosive overall if you spread it out in multiple smaller explosions rather than one big explosion in the middle.

(Now reality is of course significantly more complex than the napkin calculation above, in that a shell doesn't explode exactly symmetrically, and also half the sphere volume is air and the other half is earth, where the earth partially focuses the blast wave along the ground and partially reflects it upwards. etc etc. But the basic conclusion holds, more efficient to use multiple smaller bangs than one big boom.)

Of course, to penetrate armor plate or destroy a deep underground bunker, sure, you need a massive enough projectile, and if you haven't got it you can keep pounding all week with little effect.



AFAIU there were no deep bunkers on Henderson field. At that time wasn't it a pretty much makeshift recently constructed airstrip? They didn't even have revetments for the planes at the time IIUIC. I'm sure they had trenches for the personnel to hide in though. Not sure how fuel storage was handled, was it just a bunch of barrels stored on the perimeter of the field, or did they have trenches for the barrels/tanks etc.?

Anyway, from wikipedia Guadalcanal campaign - Wikipedia : "Over the next one hour and 23 minutes, the two battleships fired 973 14-inch (356 mm) shells ...", "Many of the shells were fragmentation shells, specifically designed to destroy land targets. The bombardment heavily damaged both runways, burned almost all of the available aviation fuel, destroyed 48 of the CAF's 90 aircraft, and killed 41 men, including six CAF pilots. "

So over 83 minutes they fired 973 shells, making for an average of 0.73 shells/minute/barrel, around half the maximum they would theoretically have been capable of (which makes sense considering it was a prolonged bombardment, time for spotting, switching aim points etc.). Going by Geoffrey Sinclair's figures above, a battleship cost between 3 and 6 times as much as a light cruiser (depending on whether you look at purchase or operating cost). If we take the middle value of 4.5, instead of those two battleships we could have 9 light cruisers. Using the figures for the Brooklyn class I calculated above (too lazy to look up values for Japanese light cruisers and guns, they might not have achieved the same rate of fire as the Americans), at half the maximum rate of fire, during those 83 minutes you'd have a rain of 9*15*9/2*83 = 50423 6" shells over Henderson field. More than enough to ruin your breakfast, I'm sure.

Though I'm quite sure no light cruiser had enough magazine capacity to go BRRRT for 83 minutes straight, so you'd have to settle for a shorter slightly less ridiculously overkill bombardment.

Alternatively, lets calculate the time it would take for the light cruiser squadron to deliver the same amount of HE to Henderson field. The 14" HE shell fired by the Kongos contained 29.5 kg HE Japan 36 cm/45 (14") 41st Year Type - NavWeaps , whereas per my previous post the American 6" HE contained 6.0 kg. So you need 973 * 29.5/6.0 = 4784 6" HE shells. Delivering those with 9 Brooklyns would take 4784/(9*15*9/2) = 8 minutes!

This also nicely demonstrates the previous point I made about being able to cram more HE into smaller shells. The 14" HE shell weighed 625 kg, so 29.5/625 = 4.7% HE content. For comparison, the 6" HE has 6.0/47.6 = 12.6% HE content.

All that sounds pretty impressive, but the thing is, they bombarded Henderson field multiple times. Mostly with smaller ships firing smaller guns. Only the heavy bombardment with the 14" guns really came close to shutting it down.

I don't think they had deep underground shelters there but IIRC they eventually got some bulldozers there so they did have revetments for planes and fuel etc., they had bunkers made out of sandbags, and of course the ubiquitous slit trenches. The big shells just wrecked everything regardless. Smaller shells just didn't seem to do as much. The same applied for the American bombardments on several of the islands (i.e. the battleships, and aircraft, seemed to do the real damage), that is one reasons why the Japanese eventually did make the super deep bunkers and cave lairs.

I think the 5" etc. guns were plenty lethal if you had a spotter directing them, mind you. Even a 60mm mortar is pretty dangerous if you know what you are shooting at. But shooting 'blind' as was often the case in these bombardments, the heavier guns are much more likely to wreck the place.

 

[Wild_Bill_Kelso]

The RAAF confined the RAF units to defence of Darwin, under 1 Wing, while 80 wing took over command of the RAAF Spitfires going north.

The RAAF Mutiny of the Aces had a number of causes, the type of operations being done was a big one, so was the way the RAAF was doing them, the RAAF had followed the Army system of largely keeping the regulars in staff positions and using hostilities only people as combat commanders. In 1945 a number of regular officers were sent to the front for combat experience, but were way behind those who had been doing it for years. It did not work very well. Throw in Australians had alcohol and the Americans did not and air forces can be good at unofficially moving important supplies. MacArthur's wither on the vine required US and RAAF units to keep applying defoliant.

IIRC Clive Caldwell traded some smuggled booze for a bulldozer and well digging gear to get his guys out of the malarial mud puddle they had been put in

The Wellington came in so many versions ranges vary as do performance quotes for given models, end 1941 your choice was Ic being built since February 1940 (Pegasus), II built from October 1940 (Merlin), III built from May 1941 (Hercules), IV from December 1940 (Twin Wasp) and VIII from December 1940 (Pegasus). RAAF Official History, mark, still air range/bomb load,

Ic 2,250/1,000, 1,805/2,750, 1,200/4,500
II 2,445/1,150, 1,725/3,500
III 2,040/1,500, 1,200/4,500
IV 1,510/4,500
VIII 1,270/3,300, 1,580/2,700, 1,900/1,800

Initial prototypes of the mark II and III were flying in 1939

RAF performance report, Ic at 30,000 pounds at 195 mph, 1,055 miles with 4,500 pounds of bombs, 1,600 miles with 2,800 pounds of bombs, 2,255 miles with 500 pounds of bombs, at 165 mph, 1,805 miles with 2,800 pounds of bombs, 2,550 miles with 500 pounds of bombs. Mark II at 32,000 pounds at 195 mph, 1,273 miles/4,500 pounds bombs, 1,580 miles/3,500 pounds, 2,245 miles 1,150 pounds, at 175 mph, 1,725 miles/3,500 pounds, 2,445 miles/1,150 pounds. Ranges have 50 minutes allowance.

Yeah so this is exactly what I'm talking about. You put two 250 lb bombs on a Wellington, and probably half of the bomb bay has an extra fuel tank put in it. You send about 30 of those to bomb the docks in Batavia or Surbaya, or oil facilities somewhere on Java, striking at about 3:00 am... two or three times a week for a couple of months. The bombs may be light but the damage will be telling, I suspect.