Royal Navy Alternate Cruiser designs post WW1

OTL?

LNT "Cruisers, Surface vessels of war, other than capital ships or aircraft carriers, the standard displacement of which exceeds 1,850 tons (1,880 metric tons), or with a gun above 5.1 inch (130 mm) calibre."

6"/50 (15.2 cm) QF Mark N5 and 6"/47DP (15.2 cm) Mark 16 would strongly disagree.......

Thanks for that. Knew I missed something, but it doesn't affect the upper range, it seems.

Any good 6" AA gun would have to be some manner of autoloading and would have to have an incredibly beefy mount, as the range benefits given by the larger shell don't really pan out unless AA is comparable. The US did try to start work on the 6"/47 DP gun OTL, but it ran into the age old issue of having no dedicated platform and constant halts to the design. If you had steady, consistent and dedicated development during the 30s, I could see a DP gun by the 40s, but its efficacy would be up in the air. The Mk 16 had inferior autoloading compared to the 8"/55 RF, which did have some potential to be redesigned into a new 6" DP gun, but the wars ended before it could see fruition.

I will note that the 5"/54 had a noticeably lower RoF than advertised as the heavy weight of the gun shells tired out the crews quickly. A heavy 6" shell would tire out gun crews even faster.
 
but it doesn't affect the upper range, it seems.
Article 9
The rules as to replacement contained in Annex I to this Part II are applicable to vessels of war not exceeding 10,000 tons (10,160 metric tons) standard displacement, with the exception of aircraft carriers, whose replacement is governed by the provisions of the Washington Treaty.
All WNT/LNT weight is expressed in standard displacement, LNT even has a long section to get it to work for subs.....

If you had steady, consistent and dedicated development during the 30s,
Sure but you are talking about as likely as centurions for the BEF in 1940 or Meteors for RAF........
 
All WNT/LNT weight is expressed in standard displacement, LNT even has a long section to get it to work for subs.....


Sure but you are talking about as likely as centurions for the BEF in 1940 or Meteors for RAF........

I know the 10k upper limit, yes. I was more indicating there wasn't anything more to it (I was trying to find a section citing that it didn't apply to oil and reserve feed water as per OTL). I'm not aware of anything more esoteric than the standard displacement affecting everything at the time.

Also, yeah, pretty much. You'd need to have a platform that desperately needs DP weapons while also needing cruiser scale weaponry while not having the space to put adequate numbers of heavy AA & cruiser weaponry on board. Just pointing out that it was a goal pursued by the USN throughout the 30s but never received the adequate attention or funding that'd allow it to progress, so there is some basis. But the situation that would engender it would have to be pretty specific.
 
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The complexity in the RN 8” twins meant they weighed the same as US triples. The problem with propellant bag guns was they had to be loaded at low angles so the rammed shell didn’t fall out. 6” would have the same problem.
 
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The complexity in the RN 8” twins meant they weighed the same as US triples. The problem with propellant bag guns was they had to be loaded at low angles so the rammed shell didn’t fall out. 6” would have the same problem.
There was also a slight problem in that you couldn't actually unload them either. If there was a misfire it could only be cleared in a dockyard, HMS Berwick once went to Murmansk and back with 2 live rounds jammed in X Turret.
 
There was also a slight problem in that you couldn't actually unload them either. If there was a misfire it could only be cleared in a dockyard, HMS Berwick once went to Murmansk and back with 2 live rounds jammed in X Turret.

Jesus, how did that design pass muster?
 
Either that or someone let their cousin from the American Torpedo department design a gun...
It would explain why someone thought 8" guns could be useful AA guns even in the 1920s and thus gave them 70° of elevation...seriously if that design choice hadn't been made they could have given the turrets useful armor or used the weight elsewhere.
 
It would explain why someone thought 8" guns could be useful AA guns even in the 1920s and thus gave them 70° of elevation...seriously if that design choice hadn't been made they could have given the turrets useful armor or used the weight elsewhere.

I mean, depends on what you're shooting. If a hostile spruce goose flies overhead...
 
I mean, depends on what you're shooting. If a hostile spruce goose flies overhead...
Of course it makes sense, let's design our heavy cruisers main guns to be able to engage an aircraft not to be built for 3 decades and it is a transport aircraft or maybe a Zeppelin/bliml. This sounds like the Air Ministry/RAF being involved and swearing it would be a useful feature and absolutely not be obsolete/useless the second it enters service
 
There are stories about HMAS Australia freaking out the USN engaging Japanese aircraft at long range.


How did the rate of fire of the twins compare to the pre Baltimore triples?
 
6"/50 (15.2 cm) QF Mark N5 and 6"/47DP (15.2 cm) Mark 16 would strongly disagree.......

Too ambitious performance goals. Heck, even Finland could convert old Canet 6" coastal guns for DP use with minimal resources.

Besides, the idea would not be to replace 4"-5" caliber range guns with 6" DP guns, but rather give more engagement range. 6" DP gun cruisers could still have 4"-5" range secondary guns, as they historically did.
 
It would explain why someone thought 8" guns could be useful AA guns even in the 1920s and thus gave them 70° of elevation...seriously if that design choice hadn't been made they could have given the turrets useful armor or used the weight elsewhere.

If you're engaging a target from long range enough, the mount has not to be trained as quickly as the angular velocity is not as high. Longer range AA allows you to engage enemy bomber / torpedo bomber formations from longer range, distrupts their final approach and causes the psychological problems of having shells exploding within their formations. Furthermore, with 8" shell, the kill/damage radius is rather high.

This is especially important, as before radar there's no possibility of directing interceptors towards the approaching enemy.

However, the British tried to accomplish too much with their Mark IX, aiming for too high elevation rate.
 
Standard displacement is for a warship outfitted for war with ammunition, crew, and supplies but without fuel or reserve boiler feed water. Normal displacement includes two-thirds supplies of fuel and ammunition onboard, so it's a reflection of how much a ship would typically weigh.

DP guns of the WWII era were manually loaded but power rammed, so the loaders would place ammunition on a tray and use the ram to push it into the chamber. To keep up a good rate of fire (15+ rpm), you need light ammunition, with no component weighing more than 60 lbs or so, and a spacious mount where loaders can easily pass around ammunition from the hoist.

The British 8-inch twins weighed only about 20 tons more than US Treaty cruiser twins (205 vs 187 tons), though that wouldn't include alterations to the barbette to accommodate high-angle loading. The Treaty cruiser triples weighed 250 tons compared to the Baltimore's three-gun turrets at about 300 tons.
 
DP guns of the WWII era were manually loaded but power rammed, so the loaders would place ammunition on a tray and use the ram to push it into the chamber. To keep up a good rate of fire (15+ rpm), you need light ammunition, with no component weighing more than 60 lbs or so, and a spacious mount where loaders can easily pass around ammunition from the hoist.
And the hard bit requiring directors, fire control, predictor, etc was the fusing for the shell. Heavy AA was to disrupt the attack and put off the aim. Defending fighters were also part of the equation. Actually shooting down planes was secondary. It wasn’t till 1944 that Kamikaze/terminally guided missile meant that the target had to be shredded.
 
Too ambitious performance goals. Heck, even Finland could convert old Canet 6" coastal guns for DP use with minimal resources.

Besides, the idea would not be to replace 4"-5" caliber range guns with 6" DP guns, but rather give more engagement range. 6" DP gun cruisers could still have 4"-5" range secondary guns, as they historically did.
I don't think fitting RN style Auto Barrage Units makes them DP by any reasonable standard.....if you are fitting secondary 4"-5" (or even better 3" ?) then why bother calling them DP?
 
It would explain why someone thought 8" guns could be useful AA guns even in the 1920s and thus gave them 70° of elevation...seriously if that design choice hadn't been made they could have given the turrets useful armor or used the weight elsewhere.

At the time the Counties were designed, the thinking in Europe on AA fire was focused on the barrage defense. The threat was the level bomber, and secondarily, the torpedo plane. Large guns like the 8in were better, larger bursting charge, more weight to create shrapnel, better range and ceiling. The concept was there, but the technology at the time was not up to the execution. It would take a semi-fixed cartridge like the Des Moines class had to make the auto-loading concept work, and of course the proximity fuse for detonation.

The 8in against aircraft is not unheard of; when the convoy in Dan Callaghan's care was attacked on the way to First Guadalcanal, San Francisco fired her 8in turrets to break up the attacks of the Bettie torpedo bombers by throwing up shell splashes in front of them.

Regards,
 
At the time the Counties were designed, the thinking in Europe on AA fire was focused on the barrage defense. The threat was the level bomber, and secondarily, the torpedo plane. Large guns like the 8in were better, larger bursting charge, more weight to create shrapnel, better range and ceiling. The concept was there, but the technology at the time was not up to the execution. It would take a semi-fixed cartridge like the Des Moines class had to make the auto-loading concept work, and of course the proximity fuse for detonation.

The 8in against aircraft is not unheard of; when the convoy in Dan Callaghan's care was attacked on the way to First Guadalcanal, San Francisco fired her 8in turrets to break up the attacks of the Bettie torpedo bombers by throwing up shell splashes in front of them.

Regards,
If they were going for barrage AA fire it would have made more sense to install more 4" guns with a useful rate of fire, say 12 of them instead of the 4 the counties originally got.
 
If they were going for barrage AA fire it would have made more sense to install more 4" guns with a useful rate of fire, say 12 of them instead of the 4 the counties originally got.

Yup, when the realization rate-of-fire counts/was needed for the faster aircraft of the second half of the 30s, it's little wonder the Counties had their single 4in replaced with twin mounts....

Regards,
 
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