USN decision 1937

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Re: USN decision 1937

by Werner » Mon Mar 10, 2008 5:56 pm

Quite so, but the General Board had prepared general characteristics for a range of ships from large independent cruisers to fleet support units in the early Thirties. One limitation of Friedman's design books is they are based to some degree on the correspondence and private memos of Captain Chantry, who was between the General Board and detail design at C&R. That's why Chantry's "Ironsides" design gets any mention and why it is linked (however implausibly) to the BB-57 design, which is, after all, a straightforward development of BB-55 with higher power and more armor to bring the design back into line with the initial specification for any USN battleship.

Higher power made available via capitalism, and not some unique sacrifice of internal arrangements like the Japanese.

Re: USN decision 1937

by SumGui » Mon Mar 10, 2008 5:48 pm

Preliminary design was not finished for Atlanta (CLAA) until June 1938, and the first ships were ordered 25 Apr 1939.

(Source: US Cruisers, and Illustrated Design History, Norman Friedman, Chp 8 pgs 233-240)

So, CLAA's were not yet availible in 1937.

I'd have built the bejesus out of Essex, Cleveland (with Atlanta dedicated to CV group escort), Gato and the almighty Fletcher abover all other classes, given the choice.

Re: USN decision 1937

by Tracy White » Mon Mar 10, 2008 12:50 am

Werner wrote:(Note: even Essex was designed for 3-4 Mk.37 directors.
3 max for the class, only on the long hulls, and only two were ever mounted, even on the long hulls.

Re: USN decision 1937

by Werner » Sun Mar 09, 2008 9:23 pm

The USN rule of thumb is 4 40mm quads for any 180 degree opposed arc for self-defense. The count of 20mm is really dependent on the deck space and size of the crew, so in a larger ship these will prosper. Neither of these weapons are of much use beyond a mile or so. For that you need an AAA director. The argument swayed between 2-4 directors for some time, with Des Moines bearing the weight of the debate. When the Kamikaze threat materialized. the issue was settled in favor of a minimum of 4 directors on cruisers and larger ships (Note: even Essex was designed for 3-4 Mk.37 directors.

The Mk.37 system and it's computers, stable elements and predictors was so far superior to any device 1939-1945 that it was specified for HMS Vanguard. The corresponding British system was much heavier and not able to deal with targets flying as fast as could the Mk.37

Re: USN decision 1937

by phil gollin » Sun Mar 09, 2008 6:01 pm

So many factors not mentioned.

In general (very, very general) the larger the ship the more stable a gun platform and the better the performance from the "same" systems.

Electronic and passive jamming of radars could cause a severe drop in performance.

WW2 era VT fuzes had much better performance against directly approaching targets than crossing targets.

Separate directors for bofors/pom-poms were excellent.

.

Re: USN decision 1937

by chuck » Sun Mar 09, 2008 5:14 pm

Werner wrote:After much experimentation, the USN found a combination of 4 major directors and multiple blind-fire radar (Gunar) would defeat any threat from any directon, even straight-on or from astern.
It could direct fire towards threat from any direction. There is no guaranty of defeating threats from any direction

Re: USN decision 1937

by Werner » Sun Mar 09, 2008 5:05 pm

After much experimentation, the USN found a combination of 4 major directors and multiple blind-fire radar (Gunar) would defeat any threat from any directon, even straight-on or from astern.

In this sense, the USN CLAAs were exactly 1/2 a battleship in AAA.

Remember, in reality a 40mm can, at best, support the next ship in the column. The 20mm is a self-defense weapon. For task group wide AAA defense, only the 5-inch gun and it's associated director counted.

Re: USN decision 1937

by Filipe Ramires » Sun Mar 09, 2008 3:44 pm

chuck wrote:There may also be additional advantages to being able to place a larger number barrels under a single director when necessary.
So could CLAA's like the Dido's or the Atlanta's.

Re: USN decision 1937

by chuck » Sun Mar 09, 2008 3:36 pm

Battleship is a much more steady platform and would be able to retain effectiveness in rougher seas. There may also be additional advantages to being able to place a larger number barrels under a single director when necessary.

Re: USN decision 1937

by Werner » Sat Mar 08, 2008 8:17 pm

The advantage in USN AAA is entirely ship-independent. It is based on the procurement of Orlikon and Bofors designs and getting them into production (with major help from the British), and on the VT fuse for the 5-inch gun (which, ironically, first went to sea on Helena).

Two cruisers have the same number of 5-inch and directors and about as many guns as a battleship.

Re: USN decision 1937

by Filipe Ramires » Sat Mar 08, 2008 6:10 pm

SumGui wrote:My point was that even if we did build more cruisers, they would have been less effective AA platforms due to the pre-war designs. The BBs built were well beyond their CA and CL conterporaries in AA ability - only with Baltimore and Cleveland did the cruisers catch up.
Point taken, but how many "decent" CA's or CL's can you build for the price of 1 BB? Perhaps 2 or 3. Though the cruisers crew adding will pass the BB crew number for sure.

Re: USN decision 1937

by SumGui » Sat Mar 08, 2008 6:05 pm

Doubtless the most effective design to build (setting treaties aside) would have been more Yorktowns - but don't forget to add the cost of the air group into the cost to the Navy.

My point was that even if we did build more cruisers, they would have been less effective AA platforms due to the pre-war designs. The BBs built were well beyond their CA and CL conterporaries in AA ability - only with Baltimore and Cleveland did the cruisers catch up.

Re: USN decision 1937

by bengtsson » Sat Mar 08, 2008 2:37 pm

Tracy White wrote:I'd have built more carriers. :thumbs_up_1:
I couldn't agree more :wave_1:

Bob B.

Re: USN decision 1937

by Filipe Ramires » Sat Mar 08, 2008 1:01 pm

From my point of view I would place my bets on more numbers of cruisers rather then battleships. WWII did show very little use for the battleships rather then a dozen surface actions (Hunt of the Bismarck, 2nd of Savo, Surigao and a few more). Regarding AA capability the battleship is a very expensive platform...perhaps with what you spent with one battleship you can build 3 proper cruisers with less AA obviously then a battleship but operating together will pump out more fireworks, yet, it haves some disavantages as well.
Now to get things more interesting...why stick with battleships, carriers and cruisers? Both destroyers and submarines had proven their worth before the 30's and yet they saw little improvements other then ponctual episodes like the appearance of the Fubukis which led to everyone to build stronger destroyers but yet again very little was offered to develop ASW capabilities for them. Had the main Navies developed proper ASW in the interwars the Battle of Atlantic would have most likely take another development and the submarine war against Japan would have been harder.

Re: USN decision 1937

by Werner » Fri Mar 07, 2008 12:41 pm

The USN was still honoring the treaty until mid-1940. There was much discussion about the design of cruiser CL-55 as to whether it should be an 8,000 ton ship as required by law or something else because the British had given notice that they were suspending obedience to the treaty for the duration of the current "emergency".

Even if the USN threw the treaty out the window in 1940, this was not 2008. There was no Autocad. There was a severe limitation in the availability of qualified draftsmen, and existing designs had to be reused until there were enough free personnel to engage in preparing the changes to the designs. That's why Hornet existed.

Re: USN decision 1937

by SumGui » Fri Mar 07, 2008 12:22 pm

phil gollin wrote:
SumGui wrote:
Keep in mind this descision was while we were under limitation treaties, which I believe didn't end until 1939. .............
No, this was the year that theBritish, Americans and French lost patience with the Japanese and increased the capital ship limit to 45,000 tons.

The prime movers for this were the US who wanted to counter perceived Japanese "cheating". I can't be dogmatic about their real thoughts, but what they told the British confidentially (both diplomatically and on the naval side) was that they wanted to the 45,000 tons because they wanted to build 12 x 16-inch ships. The British told them they would prefer a limit nearer 40,000 tons (where they thought they could build a well-balanced 9 x 16-inch) but the US were adament about the extra tonnage.

The British "thought" that the reports abouts Japanese monsters were extremely unlikely and it was likely that the actual ships would be in the 42 - 43,000 ton mark.

The British eventually gave up trying to persuade the US not to increase to 45,000 tons but then tried to convince the French (already cheating on the tonnage limit), Germans (already cheating on the tonnage limit) Italians (already cheating on the tonnage limits and Russians (???) to keep the "European" increase down to 40,000 tons, but they all said no - the French even regretting the fact.

.

The tonnage increse of capital ships was in 1938:

Article 25 however gave the right to depart limitations if any other country authorised, constructed or acquired a capital ship, an aircraft carrier or a submarine exceeding treaty limits, if such a departure would be necessary for the national security. For this reason, in 1938 the treaty parties agreed on a new displacement limit of 45,000 tons.

http://en.wikipedia.org/wiki/Second_London_Naval_Treaty
(I have this info in many books in my library, but chose to link to Wikipedia because we can't all read my books right now....)

The tonnage limits I was talking about were limits on Cruiser and CV tonnage - they were not abrogated until 1939.

Re: USN decision 1937

by phil gollin » Fri Mar 07, 2008 9:52 am

chuck wrote:
Actually, the French were the Japanese in refusing to accept the original second London treaty. ................
No, you are thinking of earlier - by 1937 the French had signed up (but were still cheating)

Re: USN decision 1937

by Werner » Fri Mar 07, 2008 9:16 am

The mind is a powerful battlefield.

Re: USN decision 1937

by JWintjes » Fri Mar 07, 2008 4:10 am

Werner wrote:
JWintjes wrote: Again, things are slightly different in times of peace. Here, the regime was bent on keeping up the general spirit of economic success, while at the same time investing vast sums in rearmament and huge infrastructural projects. You can do this for a while by simply printing money, which the Reichsbank effectively did. But this will carry you only so far - one day, you'll have to pay the price, and then you are better prepared. The Reich sure as hell wasn't.

Jorit
Did the spectre of Communism (like the WW.I mutiny) leave a lasting impression which caused hesitancy?
While I must admit I don't know what the current consensus on this particular part of the question is, I'd personally think that to be one of the main reasons - after all, the regime had hammered into the people that WW1 was lost because the home front collapsed into a morass of communist attempts at revolution (Dolchsto�). Of course this is factually wrong, but by all accounts the regime was actually believing its own propaganda to some extent.

Interestingly, if you look at it from their point of view, they were quite successful in keeping up the home front right up to the end of the war.

Jorit

Re: USN decision 1937

by JWintjes » Fri Mar 07, 2008 4:06 am

chuck wrote:
I would think half-measure war economy Germany adopted from 1939-1943 would promote the need to grow potatoes in the Ruhr soccer fields by encouraging people to ignore the war and eat more.
Certainly not. Growing potatoes on soccer fields would have conjured up pictures of the 1917/1918 winter, and the regime wanted to avoid that at all costs. Better have the Winterhilfswerk distribute food and other stuff.

Jorit

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