"WW2 cruiser armament" Topic

Prior to WW2 there was considerable debate among designers as to the value of 6"guns over 8"guns. Usually a ship could carry more 6"guns and technically they have a higher rate of fire. Therefore a Brooklyn class cruiser could deliver a devastating volume of fire in a given time. However others argued that the heavy whack of an 8"shell was more damaging and only a few less guns were carried anyway.

By the beginning of WW2 the debate seems to have resolved itself into one that the 6" gun cruiser had a distinct advantage in close range actions, while the 8"gun cruiser was at the advantage in long range actions.

It seems to me after many years of research, that few battles were ever fought at long range anyway, which must surely have negated the 8"gun advantage. Yet actual rates of fire in action would seem to suggest that the number of shells fired per minute was nothing like the designers anticipated. As a result the rate of fire of both was fairly similar.

Has anyone ever looked at this aspect in detail???

Yes, somewhat.

There was never any definitive decision on which the US favored – the volume of fire from a 6" cruiser had the advantage of smothering a target, while the 8" had the advantage of being able to penetrate any known cruiser.

Part of the reason the US continued with heavy cruisers is it seemed like the Japanese were doing a lot of damage with theirs. The US was always in love with the 8" gun, and Savo Island looked like a good reason to continue with said hitting power. The second batch of Baltimores were authorized right around that time, and more 8" were authorized well after the last of the 8" duels (Komandorsky Islands)

One thing that was certain was the fifth turret on the Brooklyn type did not contribute enough advantage to warrant its weight, which is why subsequent cruisers dropped to four main turrets.

Britain was also strongly considering bringing them back in the late 30's, but could not arrive at a study that got them the hitting power, armor and speed they wanted for anything less than 17,000 tons.

At even the ranges favored by the ships packing 6" guns those with 8" have a flatter trajectory thus increasing the hit rate & damage potential. Backed by advances in fire-control definitly will give the advantage to the bigger shells.

For a better look on this trend look at the classes of cruisers after the Baltimores. The only small gun or light cruisers were the Spokane – with twelve 5" in six mounts & the Worcester class with twelve 6" guns also in twin mounts. Eight inch gunned vessels include the Oregon City class, DeMoine class, Wichita, etc. that is not to suggest the death of the lighter guns but a change in what they were purposed for. The newer cl's became "heavy" CLAA's providing the fleet with greater aircover from attacks by Kamakazi's, while the CA's now are tasked for bombardment duty of coastal installations. Becoming in effect the relief for the 'old' BB's.

From what I've read only the 8" gun had the range to do damage to the IJN cruisers before they launched their torpedos.

Later the navy considered the 8" gun the min. effective size for shore bombardment.

"From what I've read only the 8" gun had the range to do damage to the IJN cruisers before they launched their torpedos."

That's probably true. But war experience would seem to show that the extra range was rarely needed as actions tended to take place quite close.

The Worcester class were designed around the new automatic 6"gun with an incredible rate of fire. Their huge size for a light cruiser was partly to allow for the extra ammunition needed. But they became obsolete while under construction when it was found the same technology could be applied to the 8"guns later fitted to the Des Moines group.

I've never actually carried out a close research into the volume of fire used in real battles as opposed to the technical rate of fire possible. I've had a few short looks at it and it seems rate of fire rarely became applicable. But that's an imperfect observation that would require much more research in order to be conclusive.

"From what I've read only the 8" gun had the range to do damage to the IJN cruisers before they launched their torpedos."

The USN was not aware of the great range of the Long Lance until comparatively late in the war; they believed 6" guns could hit outside of torpedo range.

For a better look on this trend look at the classes of cruisers after the Baltimores. The only small gun or light cruisers were the Spokane – with twelve 5" in six mounts & the Worcester class with twelve 6" guns also in twin mounts.

Not so. The planning for 6" cruisers continued right until the end of the ordering process in early 45. The first batch of 8 Baltimores and the first batch of 13 Clevelands were ordered simultaneously as part of the FY 40 program. Other than the 5" cruisers, the orders for ships that followed the original Baltimores and Clevelands, in order, are: another batch of 17 Clevelands, then another batch of 4 Clevelands and the first three Fargos which were re-ordered as 3 Clevelands, then a re-order of the first twelve Fargos, then 8 Oregon Citys, then 9 more Baltimores, then the first four Salems, then the first four Worchesters, then six more Salems, then six more Worchesters.

What it amounted to was the first Baltimores and Clevelands were built together, then there was a big run of 6" cruisers, then the Oregon Citys and the Fargos were to be built together, then the Salems and Worchesters were to be built together. The second batch of Baltimores was ordered when it was realized that it would be quicker to build and deploy them even after the Oregon Citys had been laid down. In other words, as an expediency rather than because they were preferred. They were ordered during a pause in 8" cruiser construct. More 6" cruisers were not ordered because there were still around 15 Clevelands under construction (some yet to be laid down even) and the Fargo program was already under way.

Wichita, BTW, predated all of these.

It seems to have been pretty much a toss up.

Both were able to sink cruisers, and neither were particularly effective against battleships.

One might suppose that the 6" cruisers were somewhat more effective against destroyers, giving them a bit of an advantage.
-Kle.

"One might suppose that the 6" cruisers were somewhat more effective against destroyers, giving them a bit of an advantage."

Right…that's the ground not covered in this discussion yet. While we can look at the battle of Empress Augusta Bay for a showdown of 8" vs. 6" cruisers, a lot of the justification for the Brooklyn class would be it's efficacy against DD's. It has been noted here that there weren't many long range gun duels, Komandorski Islands being the exception…and even there 6" cruisers participated in a meaningful way. BTW, that battle was fought in March 1943 and the range of the Type 93 was not appreciated then. Accurate reports of approaching torpedoes -- even when coming from bridge crew – were repeatedly dismissed as dolphins or other types of nonexplosive fish. One actually went under the Richmond's keel at a 90 degree angle but missed deep. Despite several spotters reporting it, the "brass" dismissed the possibility after the battle. (Source: THE BATTLE OF THE KOMANDORSKI ISLANDS by John A. Lorelli, p.87)

6" cruisers, a lot of the justification for the Brooklyn class would be it's efficacy against DD's

Not sure what you mean. The only clearcut case that I can think of, of a Brooklyn sinking a destroyer would be Helena and Honolulu sinking Niizuki at Kula Gulf. In the cases of Fubuki, Yudachi, Akatsuki, and Takanami, 8" cruisers may have had their hand in the fray.

I only meant to say that the discussion was being conducted in terms of CL vs. CA but a good rational for big, powerful CLs like the Brooklyn class is that they had enough throw weight to mix it up with CAs and absolutely devastate virtually unarmored Japanese CLs and DDs because of their "smothering" ROF.

But did the American light cruiser ever fulfill that promise? And if not was that because the theory was flawed, or simply for lack of opportunity, I thought is worth investigating so here is what I found so far:

CLs Helena and Boise were at Cape Esperance, an American victory. Helena kicked off the battle by pasting Aoba. Some combination of American ships set fire to Aoba, Furutaka and Fubuki, sinking both DDs eventually . OTOH, Boise took two 8" shells that crippled her.

Helena was at 1st Guadalcanal where she was one of 6 ships firing at DD Akatsuki which blew up and sank. Helena then fired "several full broadsides at Amatsukaze from close range and knocked her out of the action. The heavily damaged Amatsukaze escaped under cover of a smoke screen and while Helena was distracted by an attack by Asagumo, Murasame, and Samidare." link

No American CLs were at 2nd Guadalcanal.

Honolulu was a the Battle of Tassafaronga where she did fire on Japanese DDs, but apparently to largely negligible effect.

There were three Brooklyns at Kula Gulf and, as you say, the Japanese lost two DDs there, Niizuki surely to 6" gunfire, but OTOH Helena was victimized, taking 3 torpedo hits from the Japanese DDs and sinking.

There were no American cruisers at Vella Lavella.

Empress Augusta Bay matched the 4x 6" gunned Clevelands (w/ 8 Fletchers) against 2 CAs, 2 CLs and 6 DDs. The Japanese lost 1 CL (Sendai) and 1 DD, and generally got pretty well shot up. They had to turn back without accomplishing their mission. Of course, the efficient use of radar played a big part in this one sided victory but the 6" guns proved not to be no real disadvantage.

There were no Brooklyns or Clevelands at the Battle of the Komandorski Islands but the old Omaha class CL, Richmond did participate. There are arguments about whether Richmond or the SLC scored some of the hits on the 2 Japanese CLs and CAs. I think all the hits were 8" hits but Richmond was able to play an active role throughout the battle despite her almost obsolete 6" armament.

There were no American CLs at Java Sea.

At the Naval Battle of Casablanca the Brooklyn engaged and crippled French destroyers (Milan, Boulonnais) and a CL (Primauguet) impressing everybody with the sheer volume of fire put out, but the results are open to question as Augusta was along for the ride and definitely scored some 8" hits as well.

Brooklyn also silenced a shore battery. Morrison writes: "Equipped with the latest devices to keep main battery trained on a target while steering evasive courses at a speed of thirty-three knots, BROOKLYN delivered an amazing shower of projectiles, as she zigzagged and pirouetted, delivering 15 gun salvos and continuous rapid fire from her main battery, her appearance, with great bouquets of flame and smoke belching from her 6-inch guns, was a delight to the eye, if not the ear. BROOKLYN went far to prove, in this action, that the light cruiser is the most useful all around fighting ship. She expended almost 1700 rounds of 6-inch common and about 965 rounds of 6-inch high capacity, on this joyful day of battle, without a single misfire. OPERATIONS IN NORTH AFRICAN WATERS by Samuel Eliot Morison, p.112

I know the shore battery is off topic but Morrison's opinion about the usefulness of CLs is interesting. I hope others will add additional examples where American 6" CLs succeeded or failed.

OK.. I gotcha.

Here are some other US CL successes:

At Kolombangara Honolulu and St. Louis pasted Jintsu.

At Blacket Strait in 43, Denver, Cleveland and Montpelier and their DD's sank Minegumo and Murasame.

In '44 Denver, Columbia, Boise and Phoenix fired on Yamashiro and Mogami at Surigao strait.

3 US light cruisers ran down and crippled the Nowaki in the waning moments of Leyte.

Santa Fe, Birmingham and Mobile and their DD's knocked off Hatsuzuki around the same time.

Not to be left out – the 8" ships had their successes too:

Minneapolis and New Orleans caught and sank the Maikaze off Truk in '44

In raising this I did not mean to limit discussion to cruiser v's cruiser engagements. The battles of WW2 and indeed almost any war, rarely see the ships designed to fight each other, actually doing so.

But in the 1930's there was a strong debate about the value of the 6" cruiser and its supposed volume of fire, against the slower but heavier hitting 8". The RN came to the conclusion that except on some stations overseas, the majority of actions fought near Home Waters would be in relatively low visibility. Therefore volume of fire would be vital, and by amount delivered would be superior to the heavy cruiser.

Of course the first gun action was River Plate, where long range fire was important. Yet the light cruisers certainly harrassed the daylights out of Graf Spee, causing a lot of superficial damage that eventually proved rather more important that was thought during theoretical discussion based on armour penetration.

But from then on the actions became diverse. Ships of all kinds firing on ships of all kinds. Then of course a factor thrown in, and which was not part of the pre war debates, was radar gunnery control.

When it comes down to it, it seems that the light cruisers ended up taking part in more decisive actions than the heavy cruisers, other than perhaps with the Japanese.

In the pre war debates, money was tight. So a lot of the discussion revolved around value for money on a ton for ton basis and fighting capability. As such, it might be argued that light cruisers did provide value for money. One of the hardest fighting class of the war were the British Dido's, which seem to have been everywhere and suffered heavy losses. Yet that they DID suffer such heavy losses is in itself an element of debate. Would a CA have survived where they could not? Yet the British reasoned they could build two Dido's for the cost of one Heavy Cruiser, and that too is an element for consideration.

"The RN came to the conclusion that except on some stations overseas, the majority of actions fought near Home Waters would be in relatively low visibility."

In retrospect that seems like it was an intelligent assumption…first, because very few battles were fought in conditions of excellent visibility, and second because when visibility was excellent air power tended to become a powerful and often crucial factor…hence the rise of carrier groups which gradually consigned cruisers to a secondary support (AAA) role.

"One of the hardest fighting class of the war were the British Dido's, which seem to have been everywhere and suffered heavy losses. Yet that they DID suffer such heavy losses is in itself an element of debate. Would a CA have survived where they could not? Yet the British reasoned they could build two Dido's for the cost of one Heavy Cruiser, and that too is an element for consideration."

This strikes me as a different question than you started out with and I am on even shakier ground attempting to answer it. The American Navy (it seems to me) was parsing platforms in an environment of relative prosperity while the Royal Navy was far more constrained in terms of men, material and maneuver room (in the Med.) Perhaps each chose wisely according to their relative situations? Even if so, what do we say about the IJN or the RM?

Virtualscratchbuilder,

Excellent list, most of which I know nothing about (Blacket Straight?)…but I will look them up.

"Not to be left out – the 8" ships had their successes too:"

For comparison purposes it would be fair/wise to construct a comprehensive list for all US CA successes…and it would be a long one indeed…but I haven't the energy right now.

(Blacket Straight?)

Blackett Strait. My bad.

When it comes down to it, it seems that the light cruisers ended up taking part in more decisive actions than the heavy cruisers, other than perhaps with the Japanese.

In the pre war debates, money was tight. So a lot of the discussion revolved around value for money on a ton for ton basis and fighting capability. As such, it might be argued that light cruisers did provide value for money. One of the hardest fighting class of the war were the British Dido's, which seem to have been everywhere and suffered heavy losses. Yet that they DID suffer such heavy losses is in itself an element of debate. Would a CA have survived where they could not? Yet the British reasoned they could build two Dido's for the cost of one Heavy Cruiser, and that too is an element for consideration.

Well, the very large numbers of British CLs sort of made a self-fulfilling prophecy of participating in more decisive actions…

A CA might well have survived damage that a Dido would succumb to, but probably not as much damage as would sink two of them. Besides, two torpedo hits would be pretty likely to sink or wreck either of them.

In any case, the UK really didn't have a choice – they had huge areas to patrol, and couldn't really afford enough CAs to cover them. Having a Dido on the scene was vastly superior to having nothing there instead.
-Kle.

The RN has always had the philosophy of numbers over absolute quality--The dozens of 6inch cruisers built just before and during the waswere all built to a similar design, were powerfull enough to be reasonably effective.Not only at the River Plate but also Barents Sea did 6inch cruisers prove themselves against 11inch Pocket battleships…

Remember its the men fighting the ship that mean more--During the Guadacanal battles the USN was often outfought by superior IJN nightfighting..
In the Med depite having old WW1 battleships versus modernized and powerfull Italian ships the RN usually hammered them…

"In the Med depite having old WW1 battleships versus modernized and powerfull Italian ships the RN usually hammered them…"

The Italians, French, British and even Americans all used overhauled WW1 dreadnoughts around Africa during WW2. Likewise they all employed ships built between the wars. To a large extent however, only the Americans and British kept pushing a lot of hulls into the water DURING WW2. And actually it was the smaller Italian escort vessels that tended to get "hammered" during WW2…the exceptions being Matapan, where their CAs were caught at night by British BBs and Taranto where Brit air power torpedoed them at anchor…using a superior technology: the aircraft carrier.

"During the Guadacanal battles the USN was often outfought by superior IJN nightfighting"

True, but that training was coupled with a superior technology…the oxygen fueled Type 93 torpedo which tended to be decisive until the Americans learned how to exploit their numbers and a superior technology…radar. Kido Butai (the primary Japanese carrier group) can also be regarded as a superior technology…that included trained men as an integral component…giving the Japanese the run of the Pacific for 6 months. The ABDA forces fought and died bravely during that period, but despite being good men they did not win.

Maybe I'm mis-remembering, but wasn't the intitial stimulus for cruisers with lots of 6" guns the London Naval Treaty? Heavy cruisers (with 8" guns) were limited to 10,000 tons displacement. Despite much effort, no one found a way to build a good, all-around 8" gun cruiser on 10,000 tons. The treaty had done nothing to limit 6" gun cruisers, however, so the Japanese (Mogami class), Americans and British started experimenting with big-battery 6 gun cruisers. The Japanese gave up and re-armed the Mogami class with 8" guns, the Brits went with the 6" cruisers, and the Americans found they could afford to build both 6" and 8" gun cruisers.

No you are not mis-remembering Mserafin. That brought on the two definitions.

But I am talking about another issue. In the pre-war period there was a lot of debate about the value of both types and if in most actions it would come down to volume of fire, or weight of fire. Much theoretical discussion took place and as far as I know it was one of those things never really resolved to everyones satisfaction. What I am intrigued with is whether or not war experience proved one side or the other of the argument right.

What I am intrigued with is whether or not war experience proved one side or the other of the argument right.

I don't believe that there was a decisive victory for proponents of either gun size.
-Kle.

Although some see Empress Augusta Bay as answering the question, I agree with Klebert: there was no resolution and then the question became moot.

Yes….I guess it did become moot when the war ended!
Its interesting to note that after all that experience of war, the British were planning a heavy cruiser class when the war ended.

We actually built a few, here in the US. One of the ones with 8" machine guns (USS Salem) is preserved in Massachusetts.
-Kle.

Interesting discussion.

I think that 6" became the majority choice for a number of reasons.

6" were lighter with greater rate of fire, so better against relatively soft targets.
8" might be better shooting against another heavy cruiser or capital ship.

Now consider the roles of cruisers.

Leaders for DD flotillas (lighter QF gun is better).

Fighting other cruisers. Could be a 50/50 call here.

Screening/Scouting for capital ships. Again could be 50/50, though 6" might shade it as a better destroyer killer.

Stand in "capital ship" in quiet sector. 8" probably does the job here.

Shore bombardment. 8" may have an edge.

I think the point is that in a well endowed navy (RN, USN and Japanese prior to Midway), wherever an 8" beats a 6", you'll also have some BBs with 14-16" guns to do the same job.

8" may be more important where the capital ships aren't available.
Raiding situations and minor navies.

Trouble is by the end of WW2 the role of most ships -- including cruisers -- seemed to have devolved to protecting carriers from enemy aircraft. All of the roles you list were anticipated BEFORE and during the first half of the war, but I think there were all seriously eroded by carriers of various shapes and sizes. You could make an argument it was a moot choice by 1944-45 and it was really a function of what would be the best dual purpose gun available. And then missiles came along…reducing their role still further. Today, does any navy mount deck guns larger than ~5"? (No fair including those in mothballs.)

On paper the higher rate of fire of the 6" was a better choice when fighting other cruisers or lighter ships. Especially those which had only 1" armor on their cruiser's gun houses. But going by some of the anecdotal hits by 8" on battleships and battle-cruisers that did important damage would help their cause.