Calling all Atlanta-class & Oakland-class (CL-51) fans

[Steve]

Ray has posted a number of new CDs - one is for the Atlanta class!

[famman47]

This is my first post to this forum. I'm starting a 1/700 build of USS San Juan, CL-54, which seems to me to be the least well represented (in the builds I see out there) of the first four Atlanta's. I'm building her as she was fitted out, modified, and painted in late '44. I've got the Warship Perspectives book, and I believe I've found most of the resources on line, including Navsource. I'm using the Dragon San Diego kit. I've decided to live with the somewhat incorrect bow knuckle, but I am working on making the super structure correct for San Juan, including the splinter shield configuration above the wheel house, which is a bit different from the other of the first four Atlantas. I'm correcting the "jog" in the lower part of the forward funnel, where it juts out toward the aft as it comes up to the wheel house level. Since the forward funnel is integrated with the forward superstructure, the who thing is having to be reshaped somewhat to get rid of the jog. I may end up having to repostion the five rectangular vents that are on either side, so I've got the Eduard PE set on order, which I believe has some decent replacement vents. If I go this route, I'll also have to replace the vents on the aft funnel as well, for consistency.

With regard to the 40mm AA, there is a post on the first page of this thread, from author Dick J, which includes, "The Oakland's all commissioned with 8 twin 40MM, the two by the bridge, two replaced the boats, 2 replaced the wing 5" mounts, one was between the after director and #4 5" mount, and the last one on the stern. During the war, Oakland and Reno replaced the last 4 mentioned mounts with quads, and deleted the torpedo tubes. Tucson was upgraded to this config post-war."

I'm confused by this information, as other sources of info seem to indicate that the ships of the first batch of four started out with quad 1.1" mounts, which were then eventually upgraded to a total of three twin 40mm mounts (two wing and one aft superstructure) plus one quad 40mm mount near the stern. My understanding is that this is the 40mm armament that San Juan had in Late '44. We're there actually a bunch more 40mm guns that I'm not seeing in any of the pictures?

Thanks in advance to anyone who can give me an answer to this!

[Timmy C]

Welcome!

I'm not Dick, but since his post talks about the Oaklands (CL-95-98), I imagine the info he gave does not necessarily apply to San Juan, which, as you've noted, is one of the original four Atlantas.

[Michael Potter]

Welcome, FamMan -- With research and work, you can build a very good model from the Skywave/Dragon kit. My improved model of USS Flint from the Dragon USS Oakland kit won first place among ships and best of show at the local IPMS last year.

Site sponsor Floating Drydock offers USN blueprints of USS San Juan during 1944-45, and Ray Bean's photo DVDs (he has two) of the Atlanta class. These will help you greatly.

The Ship Camouflage site points out, I believe accurately, that her camo scheme was Ms 32/22D, although the pattern was issued as 33/22D. Her vertical surfaces appear to be black, ocean gray, and light gray.

The kitted forward superstructure is too high by over 2mm. Trim about 1.5mm from the bottom of parts A30-A31, and about .6mm from the bottom of A32-A33. On A1, lower the molded deckhouses for the forward and amidships deckhouses.

The upper forward superstructure needs to extend 2mm further aft. Cut A32-A33 vertically and insert a 2mm spacer aft of the bridge front, A2. While A2 is in hand, fill most of the lower row of portholes. Insert another shim between the catwalks on A10. The "jog" under the kitted forefunnel is reasonably accurate, among the few accuracies in the Skywave/Dragon kit.

The amidships deckhouse should be cut back by 2mm to open an athwartship passage between the boats.

The aft deckhouse needs a trapezoidal piece at the main deck level athwart the aft funnel. The aft deckhouse A34-A35 has no vault for the practice loaders.

All the 20mm gun bulwarks are too low and too thick. Aft, sand off the misplaced circles for the fantail 20mm guns. These guns were mounted much further aft.

San Juan mounted five twin 40mms, and one quad 40mm. Make your own accurate gun tubs for all the twin 40mm guns. If you have the Dragon USS Oakland kit, deck D1 may be usable for San Juan.

What else ... The kitted masts are jokes. Site sponsor Admiralty Model Works offers much better gun turrets and gun directors. For San Juan, you need to clip off the rear hood from each turret. The kitted lower hull was made for a Dremel tool and sandpaper to attack.

With work you can make a beautiful model from this deformed kit.

[famman47]

Thanks for the input! So you're saying there were two more twin 40mm mounts than what I was thinking (wing tubs on either side of the pilot house, and centerline tub aft of of the rear director.) Where were these located? The most obvious location seems to be the area previously occupied by the boat farm, above the single level midship deckhouse. As the kit is molded, there are already two 20mm tubs on either side near the aft end of the boat farm space. Were there 40mm tubs on either side near the forward end of the boat farm area?

[Michael Potter]

Yes, you are right about location of the additional pair of twin Bofors 40 mm gun mounts from 1944. One pair, not two pairs, of single 20 mm guns was aft of the Bofors guns on that level.

[James Hood]

Non-modeling, class history query, please.

'Have heard San Juan was the most successful ship in the W II USN against aircraft, had the highest shoot-down score. Anything to that?

[Michael Potter]

In his very first article in Naval Institute Proceedings, Norman Friedman explained that shoot-down scores are unknowable:
"One aspect of battle history the American and British anti-aircraft cruisers share is a kind of anonymity. Often when enemy planes were downed keeping score was a luxury for which there was no time. The primary objectives were to fight off the attack, brace for more attackers, and move on. It was almost impossible to assign credit to anti-aircraft cruisers for planes shot down."
Norman Friedman, Anti-Aircraft Cruisers: The Life of a Class, U.S. Naval Institute Proceedings, January 1965

[famman47]

Work on the 1944 USS San Juan, CLAA54, is proceding. I'm using bits from the Eduard San Diego kit, as well as Evergreen styrene. Builder's plans from Floating Drydock show light AA director locations, some of which are designated as "MK 51 Director," while others are designated as "40 mm Director." I'm wondering if perhaps the ones tagged 40 mm ended up getting the MK 52 directors, which were a bit larger machine than the MK 51, and had a small radar dish on the front. I can't find any conclussive evidence on the internet as to which type of director occupied these positions. Do any of you have insight as to what specific directors were in which positions following the 1944 refit?

[MartinJQuinn]

Famman,

NIce work!

I've edited out the discussion of the 350 kit and merged it with the discussion over on the main forum.

[Rick E Davis]

As to your question about the difference between "40-mm Director" and "Mk 51 Director". Depending on when the drawings were made/updated ... "40-mm Director" could be a Mk 51 Director or a Mk 49 Director early in the war. And one of the newer Gunfire Control Systems (GFCS), like the Mk 63 GFCS (radar installed on the mount not the director), late in the war. In 1944, the directors used would likely be Mk 51 directors.

At the beginning of the war for the USN, the Mk 49 director was "suppose" to be "the" director for the quad 1.1-in mounts and the 40-mm mounts with a radar for ranging and some auto-tracking. But, development was delayed (especially on the radar) and problems arose with the Mk 49 and it was cancelled in late 1943. The Mk 51 director was a "stopgap" development using the Mk 14 lead angle sight intended to be installed on the 20-mm guns. The Mk 52 director was used on DE's and such vessels and had a radar installed on the director.

[Cliffy B]

Rick, could it also be referring to the Mk-57 director? Those seemed to supplant some Mk-51s later in the war and had a radar on the director.

[famman47]

Thanks for the help! I found a picture of a Mark 57 director, http://www.navsource.org/archives/01/015947.jpg , and its size and form appear to be a reasonable fit for the tiny Skywave Mark 52 part. However, I also found information, http://www.ibiblio.org/hyperwar/USN/Adm ... Ord6R.html (page 147), suggesting that it was not until early '45 that the Mark 57 entered use. Since I'm modeling the October '44 refit of San Juan, and since there seems to be no conclussive evidence of when in '45 one or more of the Mark 51 directors would have been upgraded to a Mark 57, I think I just stick with all Mark 51 directors for this build. An additional incentive to stick with Mark 51 directors is the fact that they are available in finely molded white metal from Paper Lab, which Pacific Front seems to have in stock. I think I'll also get the 5" practice loaders as well. The Paper Lab 5" twin mounts would also be tempting, but I've already put a bunch of work into adding details to eight Skywave 5" mounts. Below are some pictures of the guns I've assembled for this build. All are PE-plastic hybrids. The PE used on the 20's and 40's is from Flyhawk, while I used mostly bits from the Eduard San Juan PE kit for the 5" mounts.

[famman47]

Correction: it's the Eduard San Diego PE kit I'm using, not the one they make for San Juan, which I believe is a less extensive kit.

[famman47]

Non-modeling, class history query, please.

'Have heard San Juan was the most successful ship in the W II USN against aircraft, had the highest shoot-down score. Anything to that?

That would be interesting to know, even if it's anecdotal.

[Rick E Davis]

Cliff,

Yes in the Spring of 1945 the Mk 57 GFCS could be a possibility, but since Famman47 said he was modeling SAN JUAN as she appeared after her October 1944 refit, the Mk 51 is about the only game at that point. They may have PLANNED on fitting the Mk 57 GFCS later, but it just wasn't available by then. The only images I have of SAN JUAN show these directors covered with canvas. Given the size of the "covered" object, it looks too small to be a Mk 57 GFCS. The first Mk 57 GFCS were delivered in October 1944, but were installed on the new construction MISSOURI, ALASKA, and GUAM.

Even the Mk 63 GFCS wasn't installed on USN warships until November 1944.

[Steve]

Any news on the development of the Dragon 350 scale Oakland kit?

[Timmy C]

Nope, unfortunately.

[Steve]

Again I seek any news or just rumors about this "planned" kit by Dragon.

[Timmy C]

Nope. If there is anything we're allowed to say, we'll be sure to post it.