London & Washington era Heavy vs. Light Cruisers

[17thfabn]

If I understand correctly most of the cruisers built during the treaty era were around 10,000 tones. Or at least had claimed tonnage of around 10,000 tones.

The typically "heavy" cruiser had eight to nine 8" guns. 

The typically "light" cruiser had twelve  6" guns. A few had fifteen "6" guns. 

I'm leaving out the odd ball small British cruisers and the U.S.N. Atlanta class with 5" main armament and the RN Dido class with 5.25" guns and similar.

I would guess that  it wouldn't happen too often that  a light and heavy cruiser would have a one on one shoot out due to most naval actions being a team sport. But there could be actions where a light and heavy cruiser traded shots during an engagement. 

How would a light cruiser fare against a heavy cruiser. The heavy has the advantage of bigger shell with better penetration. The light has the advantage of more guns and higher rate of fire. 

[sunday]

Battle of the River Plate could be good for having some guesses, I think. 

[17thfabn]

Graf Spee  was a much bigger ship mounting much bigger guns than a heavy cruiser. 

[RichTO90]

5 hours ago, 17thfabn said:

If I understand correctly most of the cruisers built during the treaty era were around 10,000 tones. Or at least had claimed tonnage of around 10,000 tones.

The typically "heavy" cruiser had eight to nine 8" guns. 

The typically "light" cruiser had twelve  6" guns. A few had fifteen "6" guns. 

I'm leaving out the odd ball small British cruisers and the U.S.N. Atlanta class with 5" main armament and the RN Dido class with 5.25" guns and similar.

I would guess that  it wouldn't happen too often that  a light and heavy cruiser would have a one on one shoot out due to most naval actions being a team sport. But there could be actions where a light and heavy cruiser traded shots during an engagement. 

How would a light cruiser fare against a heavy cruiser. The heavy has the advantage of bigger shell with better penetration. The light has the advantage of more guns and higher rate of fire. 

The Washington Naval Treaty defined cruisers and established tonnage allocations of the type by nation. They were limited as ships to 10,000 tons and maximum 8" guns.

The London Treaty defined a difference between light and heavy cruisers and established tonnage allocations of each type by nation. The light cruiser was also limited to 10,000 tons, but a maximum 6" gun.

Which pissed off the Japanese since such a light cruiser didn't fit into their doctrine. So they built heavy cruiser hulls, put 6" guns on them, and called them light cruisers, then when they abrogated the treaty refit them with 8" guns. Rather than cry foul, the USN did much the same - the Brooklyn class were essentially heavy cruisers with 6" armament as well.

It all comes down to what kind of light cruiser and what kind of heavy cruiser. Most of the actual Japanese light cruisers like Yubari were destroyer leaders with very light hulls and armament. A Brooklyn or Cleveland was a much different animal. The weight of fire and penetration of the 6" Mark 16 using the "super heavy" AP Mark 35 meant that the only real disadvantage they had versus 8" gun cruisers was range.

[R011]

On 12/4/2023 at 10:33 PM, 17thfabn said:

Graf Spee  was a much bigger ship mounting much bigger guns than a heavy cruiser. 

Only slightly bigger than the 10K ton CAs and smaller than the later German and WW2 American heavy cruisers laid down after it.  Arguable whether six 28 cm and a few 15 and 10.5 cm are better than nine 203 mm and several 127 mm.

Of course what it needed to be a lot better against six 203mm and sixteen 152 mm than she proved to be and was lucky not to meet six 15 inch and even more 203 and 152 mm plus destroyer torpedoes.

Edited December 6, 2023 by R011

[17thfabn]

11 hours ago, R011 said:

Only slightly bigger than the 10K ton CAs and smaller than the later German and WW2 American heavy cruisers laid down after it.  Arguable whether six 28 cm and a few 15 and 10.5 cm are better than nine 203 mm and several 127 mm.

Graf Spee was almost 15,000 tons.   HMS Exeter 8,400 tons. Graf Spee had a 50% weight advantage.

[Yama]

On 12/5/2023 at 9:06 AM, RichTO90 said:

The Washington Naval Treaty defined cruisers and established tonnage allocations of the type by nation. They were limited as ships to 10,000 tons and maximum 8" guns.

The London Treaty defined a difference between light and heavy cruisers and established tonnage allocations of each type by nation. The light cruiser was also limited to 10,000 tons, but a maximum 6" gun.

2nd London Treaty limited Light Cruisers to 8000 tons (probably by British initiative?), but by then the system was already on its last legs.

[Yama]

On 12/5/2023 at 3:24 AM, 17thfabn said:

I would guess that  it wouldn't happen too often that  a light and heavy cruiser would have a one on one shoot out due to most naval actions being a team sport. But there could be actions where a light and heavy cruiser traded shots during an engagement. 

How would a light cruiser fare against a heavy cruiser. The heavy has the advantage of bigger shell with better penetration. The light has the advantage of more guns and higher rate of fire. 

Quite a plenty of cruiser vs cruiser engagements actually, so it's possible to get some sort of impressions.

In general, 10 000 ton limit was too tight to get a 'proper' heavy cruiser: ie. with 8 to 10 main guns, 30+ knot speed and decent armour. It was just impossible, especially after requirements for AAA and fire control increased. So usually interwar heavy cruisers either had just six guns, or then they had very little armour.

Wartime experience was that in 'pool table' engagement, 8 inch cruiser will dominate 6 inch cruiser. 8-incher has something like 5km more effective range, allowing it to dominate the engagement. In nighttime actions, distances were often shorter, evening the odds. Battle of the Barents Sea one of the best known examples.

On the other hand, against smaller ships like destroyers, 6-inchers were often more efficient. Unarmoured ship is equally vulnerable to 6 inch shell as it is to 8-incher, and higher rate of fire easily compensates for smaller calibre.

[RETAC21]

3 hours ago, Yama said:

Wartime experience was that in 'pool table' engagement, 8 inch cruiser will dominate 6 inch cruiser. 8-incher has something like 5km more effective range, allowing it to dominate the engagement. In nighttime actions, distances were often shorter, evening the odds. Battle of the Barents Sea one of the best known examples.

Are you sure about that? I can't think of examples of that happening.

[Yama]

Java Sea and Komandorski Island comes to mind from Pacific,  also several engagements in the Med where heavy cruisers mixed it with light cruisers. At some point Cunningham (IIRC) requested heavy cruisers, as Mediterranean fleet didn't have any; but RN had few heavy cruisers to spare.

I suppose one could throw in Pinguin vs Cornwall, but that would have likely ended same way with a light cruiser.

6-inchers vs 5-inchers  was of course an analogous situation, again in favour of larger gun.

[sunday]

1 hour ago, Yama said:

Java Sea and Komandorski Island comes to mind from Pacific,  also several engagements in the Med where heavy cruisers mixed it with light cruisers. At some point Cunningham (IIRC) requested heavy cruisers, as Mediterranean fleet didn't have any; but RN had few heavy cruisers to spare.

I suppose one could throw in Pinguin vs Cornwall, but that would have likely ended same way with a light cruiser.

6-inchers vs 5-inchers  was of course an analogous situation, again in favour of larger gun.

I thought of Java Sea, but there was disparity on destroyers, torpedoes, and airpower.

[Yama]

Obviously at Java Sea there were many other factors working against the ABDA fleet than just number of 8" guns, and in the end gunfire didn't do the most damage. However in actual gunfire portion of the fight, heavy cruisers dominated the engagement and light cruisers did little.

[17thfabn]

10 hours ago, Yama said:

Obviously at Java Sea there were many other factors working against the ABDA fleet than just number of 8" guns, and in the end gunfire didn't do the most damage. However in actual gunfire portion of the fight, heavy cruisers dominated the engagement and light cruisers did little.

That is the hard thing in many of these naval battles. Rare to have a one on one shoot out between ships. Often one ship was taking hits from multiple ships. And of course in the Pacific torpedoes played a big part. I think how hectic some of the actions around Guadalcanal were.

[Markus Becker]

On 12/7/2023 at 10:02 AM, Yama said:

Obviously at Java Sea there were many other factors working against the ABDA fleet than just number of 8" guns, and in the end gunfire didn't do the most damage. However in actual gunfire portion of the fight, heavy cruisers dominated the engagement and light cruisers did little.

The light cruisers weren't up to treaty spec. One was a pre WW1 design and the two modern ones were rather small at 6,000/7,000 tons. A far cry from a Town or a Brooklyn. 

[shep854]

3 hours ago, Markus Becker said:

The light cruisers weren't up to treaty spec. One was a pre WW1 design and the two modern ones were rather small at 6,000/7,000 tons. A far cry from a Town or a Brooklyn. 

But for her guns, Houston would have been classed a light cruiser, with armor to match.

[Markus Becker]

Light or heavy was only a matter of gun caliber, not armor. 

Huston was handicapped in that regard twice though. A 1st Gen ship and she came out almost a 1,000 tons under the planned displacement. 

[Yama]

14 hours ago, Markus Becker said:

The light cruisers weren't up to treaty spec. One was a pre WW1 design and the two modern ones were rather small at 6,000/7,000 tons. A far cry from a Town or a Brooklyn. 

But if put against a heavy cruiser of equivalent tonnage, the result would probably still be the same. At Battle of Cape Spartivento, four British Town-class cruisers lobbed thousands of shells at Italian heavy cruisers, without gaining a single hit on them. And even if they had, the shells were not so likely to do damage at those ranges.

[RETAC21]

9 hours ago, Yama said:

But if put against a heavy cruiser of equivalent tonnage, the result would probably still be the same. At Battle of Cape Spartivento, four British Town-class cruisers lobbed thousands of shells at Italian heavy cruisers, without gaining a single hit on them. And even if they had, the shells were not so likely to do damage at those ranges.

But this only underlines that long range fire with 8 inch guns was a myth. Hit rates were negligible and the shells weren't big enough to cause damage: "In the first hour of action up to 1720, the Japanese fired 1,271 rounds of 8” shells and scored five hits, only one of which was effective.  The Allies didn’t do so well. Any hits they might have landed were duds and not acknowledged by the Japanese. "

http://www.microworks.net/pacific/battles/java_sea.htm

Light cruisers could get in range and their weight of fire was greater in terms of effects, see River Plate, Cape Esperance, Empress Augusta, etc.

Where the big County class failed, the lighter cruisers of the Leander and Amphion classes succeded, and the RN pretty much gave up on larger caliber cruisers (even though they were projected during the war) in exchange for 6 inch cruisers.

[shep854]

20 hours ago, Markus Becker said:

Light or heavy was only a matter of gun caliber, not armor. 

Huston was handicapped in that regard twice though. A 1st Gen ship and she came out almost a 1,000 tons under the planned displacement. 

Until the treaties specified main battery caliber, the classification was based on displacement, and those early USN 8" cruisers were definitely light.  

[Markus Becker]

Oh, you mean compared to pre and eraly-WW1 'armoured' cruisers. Yes, those were considerably larger.

[shep854]

51 minutes ago, Markus Becker said:

Oh, you mean compared to pre and eraly-WW1 'armoured' cruisers. Yes, those were considerably larger.

No, I was thinking about post-treaty cruisers which really were heavier than their 6" armed contemporaries.  Drachinifel and Alex Clarke have both pointed out that the Pensacolas were originally classified as light cruisers due to their displacement.  When I first heard this, the thought of an 8" light cruiser sounded weird.

 

Edited December 9, 2023 by shep854

[17thfabn]

At least for the U.S. most of the cruisers early war were treaty cruisers, other than the odd ball Omaha class.

I've never understood why the USN built the Omahas with some of the 6 inch guns in casemate mounts. They were a post World War I build.

[Markus Becker]

1 hour ago, shep854 said:

Drachinifel and Alex Clarke have both pointed out that the Pensacolas were originally classified as light cruisers due to their displacement.  When I first heard this, the thought of an 8" light cruiser sounded weird.

That seems to have been an internal US thing done before the light/heavy entered the treaties. Looks like the French did the same with their even less armored early 8" cruisers. 

Eggshells with sledgehammers. 

[Markus Becker]

1 hour ago, 17thfabn said:

I've never understood why the USN built the Omahas with some of the 6 inch guns in casemate mounts. They were a post World War I build.

The design went back some time and the US really missed out on cruisers with turbines as there was not enough money available until late in WW1. So what was went into battleships. 

[shep854]

1 hour ago, Markus Becker said:

That seems to have been an internal US thing done before the light/heavy entered the treaties. Looks like the French did the same with their even less armored early 8" cruisers. 

Eggshells with sledgehammers. 

The USN did wander off on some odd tangents during the rearming pause...

Edited December 9, 2023 by shep854