WWII Battlecruiser matchup

[shep854]

BTT; re, Alaska thread.

 

 

Oops! Sorry, Colin, I see it's already done.

Edited July 22, 2007 by shep854

[irregularmedic]

Alaska and Guam would have stomped all over the Scharnhorst and Gneisenau. (If you're going to take sides, you might as well go all the way, right? )

 

Scharnhorst-class had 12.6" belt armor tapering to 6.7" at the bottom, and 1.9" and 5.9" decks. The Alaskas carried less armor with a 9.5" 10-deg sloped belt, 1.4" STS bomb deck, 3.25" and 2.8" armor decks on 1" STS.

 

Gunpower: Alaska's 12"/50 could penetrate 15" of side armor at 16,000yds and 5.5" of deck at 30,000yds (per Friedman--approx. 15.5" & 5.1" per NavWeaps). So the German armor scheme should be vulnerable to the 12"/50. By contrast, NavWeaps lists the German gun as penetrating 13.2" of belt armor at 16,000yd, but only 3" of deck armor at 30,000yd, so both ships will have to achieve belt hits to do damage, although the American ships probably have a better chance of doing nasty damage to the upperworks at long range, poking holes in the Scharnhorst's upper deck at all ranges longer than ~14,000yards, while the Scharnhorst won't penetrate the Alaska's upper deck at less than 28,000-30,000yds. The German ship's batteries are somewhat better protected with 14.1" face and 7.5" side armor (12.8" face, 6" forward side, 5.25" after side, 5" roof for the Alaska), but I don't think that it makes too much difference in a confrontation--the two ships will achieve penetration at approximately the same ranges (slight advantage to the Alaska--a couple thousand yards). The German guns fire slightly faster at 3.4rpm vs. 2.4-3.0rpm for the US gun. I don't know who has the advantage as far as main battery directors--the Alaska's director is 80' above the waterline, but I don't have a similar number for the Scharnhorst. With US/British radar developments, the Americans should be able to detect and achieve hits at longer range than the Germans.

 

Airpower per ship: 3 x Ar196 (193mph, 665mi range, 2x20mm + 1x7.92 fixed + 1 x 7.92 flexible, 2 x 110lb bombs) vs. 3-4 SC-1 (310mph, 625mi range, 2 x .50cal, 650lb bombload). Alaska wins the dogfight and has the advantage of aerial spotting. Also, the CBs have a better AAA battery of 12x5"/38 with 2 Mk37 directors, 56 x 40mm (14 quads) and 34x20mm, so there is little chance the Ar196 will be able to do much to the CBs. On the other hand, the German ships have 14 x 4.1-inch, 16 x 37mm, and 10 x 20mm giving the SC-1s better survivability.

 

Speed: The CBs have about a 1 kt speed advantage, but may be able to make better use of their speed as they are probably drier ships than the German vessels. I'd give the seakeeping award to the American vessels. I believe the US propulsion systems were probably better/more reliable than the German systems, so would probably be able to deliver closer to their rated performance while in service.

 

Douglas

 

I think it is a little unfair to compare the SC-1 to the Arado 196, given that the SC-1 didn't see action until June 1945

Edited July 22, 2007 by irregularmedic

[Ol Paint]

I think it is a little unfair to compare the SC-1 to the Arado 196, given that the SC-1 didn't see action until June 1945

Perhaps. Unfortunately, I am not aware of a more modern replacement for the Ar196. Admittedly, the Ar196 has better performance & armament than the OS2U (with the exception of range & bombload, which doesn't win a dogfight in most cases). On the other hand, the Alaskas didn't see service until late 1944-1945, either. ;-)

 

Douglas

[irregularmedic]

So did the Alaska's ever have an earlier type of seaplane onboard, or were they equipped with SC-1's from the entry into service?

 

I don't think I was aware that the Alaska's had entered service so late, and assumed that they must have operated Kingfishers or something prior to be equipped with SC-1's...

[KingSargent]

So did the Alaska's ever have an earlier type of seaplane onboard, or were they equipped with SC-1's from the entry into service?

 

I don't think I was aware that the Alaska's had entered service so late, and assumed that they must have operated Kingfishers or something prior to be equipped with SC-1's...

IIRC the first deployment of the SC-1 was on Alaska.

[JOE BRENNAN]

So did the Alaska's ever have an earlier type of seaplane onboard, or were they equipped with SC-1's from the entry into service?

 

I don't think I was aware that the Alaska's had entered service so late, and assumed that they must have operated Kingfishers or something prior to be equipped with SC-1's...

Some sources say Guam was first with SC's but Larkins "Battleship and Cruiser A/c of the USN" is specific that BuNo. 35303-35306 were delivered to Alaska in March '44, before commissioning (June 17). That would be the 3rd-6th production a/c and loss lists separately show Alaska lost 35304 in December and 35303 in March, so it seems right. The ship's first combat operation was escorting carrier strikes against Japan in February, Guam joined in March (having been commissioned in Sept). CL's Savannah, Topeka, Dayton, Oklahoma City and Amsterdam and CA Chicago (CA-136) also had SC's assigned before the end of 1944; SC's were roughly half the floatplanes assigned by the end of the war.

 

Joe

[JWilly48519]

Not that it's particularly apropos to the "BC Matchup" thread topic, but in continuation of the naval-shell-effectiveness side discussion a few posts up:

 

In 1939-40 the French Edgar Brandt company developed a series of tungsten-alloy-core shells, with a light alloy sabot/surround, for enhanced armor penetration and velocity maintenance at long ranges.

 

The Germans also were working on reduced-diameter tungsten-alloy shells in this time period, for tanks and anti-tank guns. Brandt, though, in addition to shells for ground weapons up to 75mm, supposedly also developed a 203mm shell for naval use.

 

I have no knowledge of what happened to this naval-shell development work. Several of the Brandt engineers responsible for the smaller-caliber tank/anti-tank projects, however, escaped to England where they were put to work on the then-less-advanced British tungsten shell program, eventually resulting in the highly effective 6 pounder and 17 pounder discarding sabot AP designs.

 

Presumably a higher-velocity, smaller-penetrating-diameter, very hard, integrally-impact-resistant penetrator would have offered enhanced armor penetration of either homogeneous or face-hardened plate. On the other hand, it would have no internal destruction mechanism other than penetration-volume ejection plus spall...certainly highly lethal and incendiary inside a tank, but of unknown efficacy inside a ship.

 

Thoughts?

[KingSargent]

Not that it's particularly apropos to the "BC Matchup" thread topic, but in continuation of the naval-shell-effectiveness side discussion a few posts up:

 

In 1939-40 the French Edgar Brandt company developed a series of tungsten-alloy-core shells, with a light alloy sabot/surround, for enhanced armor penetration and velocity maintenance at long ranges.

 

The Germans also were working on reduced-diameter tungsten-alloy shells in this time period, for tanks and anti-tank guns. Brandt, though, in addition to shells for ground weapons up to 75mm, supposedly also developed a 203mm shell for naval use.

 

I have no knowledge of what happened to this naval-shell development work. Several of the Brandt engineers responsible for the smaller-caliber tank/anti-tank projects, however, escaped to England where they were put to work on the then-less-advanced British tungsten shell program, eventually resulting in the highly effective 6 pounder and 17 pounder discarding sabot AP designs.

 

Presumably a higher-velocity, smaller-penetrating-diameter, very hard, integrally-impact-resistant penetrator would have offered enhanced armor penetration of either homogeneous or face-hardened plate. On the other hand, it would have no internal destruction mechanism other than penetration-volume ejection plus spall...certainly highly lethal and incendiary inside a tank, but of unknown efficacy inside a ship.

 

Thoughts?

Considering that the Germans couldn't afford enough tungsten to put penetrators in 75mm tank and AT guns, I can't imagine anyone using tungsten penetrators in naval shells. It would be a waste - the chance of a hit is slim, the chance of a hit on armor even less, and the chance of a hit and penetration on armor over a vital spot is even more minuscule, especially with no burster.

 

Tungsten was just too valuable in machine tools to waste shooting at ships.

[Tiornu]

In general, the direct-fire weaponry of land warfare has such different requirements compared to naval gunnery that there is relatively little crossover. I'm not sure why Brandt would waste time tinkering with an 8in shell of that description.

[irregularmedic]

Some sources say Guam was first with SC's but Larkins "Battleship and Cruiser A/c of the USN" is specific that BuNo. 35303-35306 were delivered to Alaska in March '44, before commissioning (June 17). That would be the 3rd-6th production a/c and loss lists separately show Alaska lost 35304 in December and 35303 in March, so it seems right. The ship's first combat operation was escorting carrier strikes against Japan in February, Guam joined in March (having been commissioned in Sept). CL's Savannah, Topeka, Dayton, Oklahoma City and Amsterdam and CA Chicago (CA-136) also had SC's assigned before the end of 1944; SC's were roughly half the floatplanes assigned by the end of the war.

 

Joe

 

 

Thanks that's some detailed info!

 

Any idea how they lost a seaplane before actually seeing action?

 

I'm surprised that SC-1's made up so many of the floatplanes, I thought the floatplanes were doing a fair amount of rescuing of downed aircrew and that the older craft would be better for this.

[JWilly48519]

Considering that the Germans couldn't afford enough tungsten to put penetrators in 75mm tank and AT guns, I can't imagine anyone using tungsten penetrators in naval shells. (...) Tungsten was just too valuable in machine tools to waste shooting at ships.

 

Only the Germans had such a shortage. The French prior to 1940, and the Allied nations in general subsequently, had ready access to considerably more tungsten than could possibly be needed for machine tool purposes. The British eagerly adopted APDS ordnance as quickly as they could design it, having had a later start than the French and of course working in the context of progressively improving hard-steel metallurgy, ordnance and armor. The only limitation on a greater and earlier use by the US in AP ordnance was doctrinal...it was different and Not Invented Here, and was entangled in the tanks-are-not-for-fighting-other-tanks issue.

 

My general understanding of the reason for the Brandt interest, and apparently some interest from the Marine Nationale, was that it would would increase the armor penetration capability of 200mm-class cruisers and shore batteries by 1.5x to 2x, which would give them the ability to penetrate BB/BC-armored ships in low-trajectory engagements in limited-visibility waters, i.e. the Channel. Conceptually, it's a good thing to double the number of barrels you've got that can penetrate the enemy's heavy armor in a likely engagement-range scenario.

 

I don't know if that design was ever built and tested, though.

Edited July 26, 2007 by JWilly48519

[Tiornu]

I'd be very interested if you can direct me to some references on the naval application of this sort of weaponry.

Every once in a while, someone will get excited to learn of shaped-charge naval shells developed by the Germans only to be disappointed to learn that it was meant for coast-defense batteries firing high-trajectory (rocket-mortar type) ammo. Personally, I don't see the point of that either; a 200mm shell dropping onto the deck of an LST does not need a shaped charge, while a near miss would do less damage with a shaped charge.

[JWilly48519]

I'd be very interested if you can direct me to some references on the naval application of this sort of weaponry.

 

My reason for posting here was that AFAIK only Brandt ever pursued that technological direction in that caliber range, and I don't know how far they got. I'd love to know more.

 

APCR/APDS technology has nothing in common with HEAT technology, of course, other than that both are "different" from the traditional approach.

[Tiornu]

Let me know if youfind anything.

What APDS and HEAT have in common is that they are direct-fire anti-armor technologies that excite some folks' fantasies regarding naval applications, thinking there's some wonder-weapon possibilities. Disappointment ensues.

[KingSargent]

Thanks that's some detailed info!

 

Any idea how they lost a seaplane before actually seeing action?

 

I'm surprised that SC-1's made up so many of the floatplanes, I thought the floatplanes were doing a fair amount of rescuing of downed aircrew and that the older craft would be better for this.

Seaplanes tend to break up on hard contact with water, especially in heavy ocean seas. Also pilots of a brand-new type of airplane are not apt to be experienced with it, hence there tend to be OOPS!es.

 

The SC-1 had a special compartment behind the pilot (it was a single-seater) specifically to carry rescued personnel or stretcher cases. True, it did lack a second crewman to get those people into the compartment.