quote:

ORIGINAL: Terminus

I wouldn't bother with the old cruisers. Scrap them and construct additional Akizukis.

quote:

ORIGINAL: PaxMondo

quote:

ORIGINAL: Terminus

I wouldn't bother with the old cruisers. Scrap them and construct additional Akizukis.

Yes, but in war you rarely scrap any ship. I'm trying to think of some examples and nothing comes to mind. I'm sure it was done, but gotta be rare. Something too old and slow to keep up is put into the training fleet. Tennryu aren't too slow, so they would stay in service during a war emergency. I think.

Anyway, for discussions sake, how would you arm them? And I'm only using the Tennryu as the exemplar. In fact, it would apply to all of the IJN CL's if you wanted them converted to CLAA ...

I guess my real question is 100/65 or 80/60? I understand the Aki's using the 100/65 because it really is a DP gun for them. But if I say that this is going to be a CLAA, and surface action firepower is no longer a concern (or very secondary to AA), what armament would you go with? Again the 127/45 is what was used historically, but is that really the best choice?

As I examine the data, the 80/60 looks best. In this era, I cannot see needed higher than 30,000 ft AA for naval forces. Given the weight involved you get 2 80/60 for each 127/45 or 100/65. That a significant increase in batteries. They also have almost double the ROF. BUT, a 127 shell has a lot more boom. So, back to my OP ... appreciate any and all insights into this. THANKS!

quote:

ORIGINAL: Terminus

quote:

ORIGINAL: PaxMondo

quote:

ORIGINAL: Terminus

I wouldn't bother with the old cruisers. Scrap them and construct additional Akizukis.

Yes, but in war you rarely scrap any ship. I'm trying to think of some examples and nothing comes to mind. I'm sure it was done, but gotta be rare. Something too old and slow to keep up is put into the training fleet. Tennryu aren't too slow, so they would stay in service during a war emergency. I think.

Anyway, for discussions sake, how would you arm them? And I'm only using the Tennryu as the exemplar. In fact, it would apply to all of the IJN CL's if you wanted them converted to CLAA ...

I guess my real question is 100/65 or 80/60? I understand the Aki's using the 100/65 because it really is a DP gun for them. But if I say that this is going to be a CLAA, and surface action firepower is no longer a concern (or very secondary to AA), what armament would you go with? Again the 127/45 is what was used historically, but is that really the best choice?

As I examine the data, the 80/60 looks best. In this era, I cannot see needed higher than 30,000 ft AA for naval forces. Given the weight involved you get 2 80/60 for each 127/45 or 100/65. That a significant increase in batteries. They also have almost double the ROF. BUT, a 127 shell has a lot more boom. So, back to my OP ... appreciate any and all insights into this. THANKS!

I'd scrap them before the war. However, for the sake of discussion, I'd do what the IJN did in real life, and use the 12.7cm. It saves the 10cm for the Akizukis and it has more explosive power than the 8cm.

quote:

ORIGINAL: Terminus

I'd scrap them before the war. However, for the sake of discussion, I'd do what the IJN did in real life, and use the 12.7cm. It saves the 10cm for the Akizukis and it has more explosive power than the 8cm.

quote:

ORIGINAL: herwin

The Tenryus were top-heavy. I'm not sure you'd want to put guns on it too far above the waterline. Less, larger guns on the main deck might be better.

quote:

ORIGINAL: Terminus

The Tenryus weren't top heavy.

quote:

ORIGINAL: DBS

The 8/60 Type 98 supposedly had a short barrel life of only around 600 rounds, compared to twice/thrice that for the 40 calibre models (and indeed the 127/40). That may have been a factor against it seeing wider service - a piddling number only were made after all. Maybe there were other issues of ease of manufacturing or cost-effectiveness?

EDIT - The real killer I am sure is that, looking at the Army's 8cm and 12cm AA weapons as approximate equivalents, the 12cm shell produced ten times the "volume of rupture" compared to the 8cm. So even allowing for the lower ROF, potentially five to six times more effective.

quote:

ORIGINAL: herwin
Did the 8cm have a timed fuse? That was needed for an effective barrage until the introduction of proximity fusing by the Americans.

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ORIGINAL: herwin
Which was the light cruiser class that had to be reconstructed for this reason in the 1920s?

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ORIGINAL: JWE

quote:

ORIGINAL: herwin
Did the 8cm have a timed fuse? That was needed for an effective barrage until the introduction of proximity fusing by the Americans.

Yes. A settable time fuse is a necessary component of an AA round. Known for ages and everybody had them. One sticky point is that many nations called their ordinary settable time fuses ‘variable time’ fuses. So you will see hundreds of references to ‘VT’ fuses that were not the same thing as the radar proximity VT fuses we all know and love so well. [;)]

quote:

ORIGINAL: herwin
Which was the light cruiser class that had to be reconstructed for this reason in the 1920s?

None actually, Harry. They were all designed in the ‘teens and all laid down by 1922 – long before the insanity of the 1930 design plan. Some were reconstructed, but for other reasons (Kitikami, Oi, etc.).

quote:

ORIGINAL: DBS

The 8/60 Type 98 supposedly had a short barrel life of only around 600 rounds, compared to twice/thrice that for the 40 calibre models (and indeed the 127/40). That may have been a factor against it seeing wider service - a piddling number only were made after all. Maybe there were other issues of ease of manufacturing or cost-effectiveness?

EDIT - The real killer I am sure is that, looking at the Army's 8cm and 12cm AA weapons as approximate equivalents, the 12cm shell produced ten times the "volume of rupture" compared to the 8cm. So even allowing for the lower ROF, potentially five to six times more effective.