The Ship Model Forum

The Ship Modelers Source
It is currently Wed Oct 16, 2019 10:02 am

All times are UTC - 6 hours [ DST ]




Post a reply
Post icon:
None
Username:
Subject:
Message body:
Enter your message here, it may contain no more than 60000 characters. 

Font size:
Font colour
Options:
BBCode is ON
[img] is ON
[flash] is OFF
[url] is ON
Smilies are OFF
Disable BBCode
Do not automatically parse URLs
Question
What is the name in the logo in the top left? (hint it's something dot com):
This question is a means of preventing automated form submissions by spambots.
   

Topic review - Calling all USS Iowa class (BB-61) fans
Author Message
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
chuck wrote:
The process of cementation causes small and difficult to control dimensional changes to the armor plates. This might be the reason why the turret dimensions aren't specified more exactly.


They give theoretical dimensions. However, in the days before CAD programs with 12 decimal digits of precision, the draftsmen used 1/32 as their limit of precision.

The plan will say the [theoretical] maximum roof width is 18' 4-17/32". But that is a rounded figure. If you use that rounded [theoretical] measurement as a starting point in your CAD program, the farther you move way from that point, the more the rounded dimensions deviate from those on the plans.

If you start at the turret face, whose width is a round figure, and follow the angles you get a a figure for the widest point that isn't exactly 18' 4-17/32" but is that when rounded to the nearest 1/32". When you follow the specified angle to the rear corner you get a value that isn't exactly the specified value but is within 1/32 of it.

In fact, there is no rear corner (on the NJ at least). The corners are rounded as the result of shrinkage. The theoretical values on the plans are only theoretical.
Post Posted: Thu Oct 10, 2019 9:03 pm
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
The process of cementation causes small and difficult to control dimensional changes to the armor plates. This might be the reason why the turret dimensions aren't specified more exactly.
Post Posted: Thu Oct 10, 2019 8:15 pm
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
Because it has been dull here for a while, I thought I'd throw out an observation about plans because I got some questions about the turrets.

The drafters used much greater precision with angles than linear dimensions. Angles are frequently specified down to the nearest second while dimensions go down no more than 1/32" in most cases. If you try to model the turret, you have to go by the angles to get to get things to work out right.

The front face of a turret is 31' 10" wide. That is a round figure. If you start with that and follow the angles the published dimensions work out when rounded to 1/32". If you use use the linear dimensions, things do not work out.

These are the major round measurements:

The turrets go 32' aft of the CL. The upper surface goes 12' 2" forward. Front face is 6' 5-1/2" forward of that.
The total length of the armor is then 50' 7-1/2"

The outer radius of the circular gas seal over the barbette is 20’ 9-7/16”.
The overall length of the turret (minus barrels) is 52' 9-7/16"

The barrels are 10' 2" apart.

The turret height is 10' at the bustle. It is 9' where the gas seal projects.
The vertical front face is 12".

The angle outwards going back is 12d 34' 43" from the front edge.
The angle of the side corner from the CL is 3d 17' 31"
The angle from the corner is 5d 30' 6".
The angle from the rounded back the flat side is 9' 58 52".
The angle at the back underside is 13d 8' 2"

Those are all the dimensions needed to model the basic turret shape.
Post Posted: Wed Oct 09, 2019 11:10 pm
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
ModelMonkey wrote:
Regarding New Jersey's original fire control directors, here's New Jersey in June, 1945. At the time of this photo, she still has her original 6-sided Mk.38 directors and angle-back Mk.37 directors.



I am looking for measured drawings of the Mk. 38 directors. I have found some partially measured BuOrd drawings but am looking for something complete. If anyone has such an animal, I'd appreciate getting the info.
Post Posted: Wed Sep 25, 2019 11:02 am
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
Regarding the IOWA Class Battleship Main Battery Rangefinders:

The Mk. 38 Optical Rangefinder has NOT been replaced on these ships. What has been changed is the RADAR that is mounted on top of the rangefinder. Originally, each ship had (2) Mk. 8, Mod. 3 RADAR units which was replaced late in the war with the Mk. 13, Mod. 0 which is still in place today on all 4 ships.

NORTH CAROLINA, ALABAMA, and MASSECHEUSETTS retain one each of the two different RADAR units.

One other note - NEW JERSEY retains the original Mk. 37 Secondary Battery Director Enclosure with modifications eliminating the open cupola on the front (as built). MISSOURI retains her original Mk. 37 Directors including the open cupola (as built). IOWA and WISCONSIN received the newer Mk. 37 Director enclosure with the straight walled upper part including the open cupola. This is the version that these two ships retain today.

Hope this clarified things a bit.

Hank
Post Posted: Tue Sep 24, 2019 4:34 pm
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
At least the Iowa still has the 6 sided Mk 38 directors today. The Mk 37 directors have been modified so the shape of the housing is substantially different now.
Post Posted: Tue Sep 24, 2019 1:02 pm
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
Regarding New Jersey's original fire control directors, here's New Jersey in June, 1945. At the time of this photo, she still has her original 6-sided Mk.38 directors and angle-back Mk.37 directors.

Iowa originally had the 6-sided Mk.38s and "angle-back" Mk.37s, too, as did the preceding North Carolina and South Dakota classes. Missouri and Wisconsin were built with the enlarged 7-sided Mk.38 directors and "square-back" Mk.37 directors. So, too, were the Alaskas.

Interestingly, after a deadly friendly-fire incident involving a 5" round destroying USS North Carolina's port-side, angle-back Mk.37 director, the destroyed director was removed and replaced with an enlarged "square-back". To this day, she retains three "angle-back" Mk.37 directors and one "square-back".


Attachments:
Mk.37 angle-back and Mk.38 director (6-sided shield) BB-62 1945.06.24 016201b small.jpg
Mk.37 angle-back and Mk.38 director (6-sided shield) BB-62 1945.06.24 016201b small.jpg [ 329.24 KiB | Viewed 180 times ]
Mk.37 Director BB-55 Mk.37 directors at present..jpg
Mk.37 Director BB-55 Mk.37 directors at present..jpg [ 197.37 KiB | Viewed 180 times ]
Post Posted: Tue Sep 24, 2019 9:29 am
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
In some of the original drawings of the Iowa class, the fire control tower is not connected to the forefunnel. Instead stands alone and separate from the forefunnel more like what is usually shown on drawings of the Montana class.

If I read the chronology right, the initial plan was to have the forward fire control tower lean forward, and the funnel integrated with the fire control tower, with a funnel cap that has squared off front, in a manner similar to the South Dakota class. A conceptual model of the Iowa class shows this configuration. This model almost certainly represent an early design stage, because it lacked much of the light AA positions, still had a bevy of boats midship and two big cranes for handling them, plus a clipper bow that lacked a characteristic bullnose of the Iowa class.

Sometime later, the fore funnel become stand alone with round funnel cap, while the fire control tower stood separated from the funnel like an obelisk, similar to what's on the North Carolina class or planned for the Montana class. I've seen pictures of at least one model in this configuration. In all other respects, including the arrangement of AA batteries midship, this model closely matched the real ship, so I assume this means the separated funnel and fire control tower configuration lasted late into the design stage.

Then still later, the tower and funnel reverted back integrated configuration and the gap between the funnel and stack filled in with additional staterooms. I don't know when this change occurred, but it suspect it is near very end of design phase, it may even have been done at the ship yard. We know the lead ship yard for the Iowa class recommended and made some major changes to the design that was handed to it for construction, including revising the entire layout of the engineering spaces to further subdivide the hull.

So I wonder if the fact that the tower leans in at level 7 is a carry over from the intermediate separated fire control tower and forefunnel design. The revision to the design didn't chose to change the lean of the tower sides when the gap between the funnel and fire control tower was filled in.
Post Posted: Mon Sep 23, 2019 5:21 pm
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
Well geez, I think all of us are gong to have to tear apart and re do our fire control towers! Rather interesting bit of micro geometry, wonder why they did it that way? All of my Box launchers are the same on my model, but I had only the four midships ones to look at on Missouri.

Good info!
Post Posted: Mon Sep 23, 2019 4:29 pm
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
jim,

Thanks for posting your very fine ABL 3D rendition! As you & I have been discussing, the ABLs were not all the same and making a "master" unit that would fit all models is probably not realistic. Esp. from your own findings on NEW JERSEY. In contrast, I have included the photo I took last week on WISCONSIN of her port angled ABLS:
Attachment:
Port 04 Level Angled ABLS_1.jpg
Port 04 Level Angled ABLS_1.jpg [ 175.01 KiB | Viewed 228 times ]

and one of her amidships ABL in raised position:
Attachment:
Resized Port ABL Launcher_1.jpg
Resized Port ABL Launcher_1.jpg [ 185.26 KiB | Viewed 228 times ]
Post Posted: Mon Sep 23, 2019 1:48 pm
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
I think I have finally remedied the lack of references on the ABLs. I climbed over ABLs and filled two notebooks with measurements. There are a few caveats.

1) The feet at the ends vary in length. They are not even the same on each ABLs.
2) There are two variants. The one shown has a ladder on one side. The six aft-most ABLs on the NJ are like this. The two forward-most ABLs have rungs welded to the ABL on both sides.
3) There is 2-1/2" of blast shielding under the back ends. The ABLs are cut upwards over the shielding. Not shown here.


Attachment:
Tomahawk ABL V2 02.jpg
Tomahawk ABL V2 02.jpg [ 68.8 KiB | Viewed 240 times ]
Post Posted: Mon Sep 23, 2019 12:47 pm
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
chuck wrote:
Class A armor used on US battleships were sourced to several specialty steel makers. They each had slightly different processes and quality controls. Those made by Midvale steel had particular problems with heat treatment that resulted in their showing surface cracking and spalling. It is said these did not affect their protective qualities. But they were unsightly. Missouri used mostly Midvale plates.


I'd be interested in seeing a source list of plates for the Missouri and Wisconsin. I have that for the New Jersey and Iowa.

All of the upper belt class A plates on the New Jersey were from Midvale where any pitting would not be seen. The Iowa has a mixture of Midvale and Carnegie plates on the belt. All the readily visible class A plates for both ships (barbettes, turrets) came from Bethlehem. Transverse class A plates came from Carnegie.

So there is no safely accessible places where the hardened face of a midvale plate is visible on those ships.

On another typic, I noticed a new kit error on the 08 (secondary conn) on the Tamiya kit. It is not symmetrical. The shape of the deck as ot goes around the fire control tower is correct for the the right side but not the left. It extends farther aft on the left side than on the right. This is because of the ladder on the right side that is not on the left.

Image

While I am at it, here is illustration of another common defect I have seen in kit (including above). The sides of the director tower start to taper in at the 07 level. The forward part of the 08 level weather deck (where the stack is) cuts in to meet the sloped in tower side. That creates the triangular panel in the side of the structure. This is visible in photographs.

Kits ignore this and start the taper at the 08 level.

Attachment:
Screen Shot 2019-09-16 at 10.49.26 AM.jpg
Screen Shot 2019-09-16 at 10.49.26 AM.jpg [ 198.03 KiB | Viewed 285 times ]
Post Posted: Thu Sep 12, 2019 8:48 pm
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
Thanks for the info. I presume by Foremast you mean the Fire Control Tower? Always interesting to see how ships differ from one to another and during their service lives.

The Seven sided Mk 38 directors, were these adopted because of a requirement for more internal volume?

Cheers: T
Post Posted: Thu Sep 12, 2019 3:19 pm
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
pascalemod wrote:
I have a question on 1944 Missouri to New Jersey conversion. Aside from the bridge detail, is there anything else that needs to be done for 1944 New Jersey? Im going for the black dragon from the Academie kit. :)



Many other things.

1. The shape of the air defence platform on top of the foremast is different.

2. The shape of the mk 38 main battery director on top of t foremast are different. Those on the Missouri had 7 sides with vertical back, those on the New Jersey had 6 sides with slanted back

3. The shape of the mk37 5” director are different. Those on the Missouri has a open copula where as those on the New Jersey didn’t.

4. The conning position on level 8 on the foremast is different. Those on New Jersey is cubical and those on the Missouri is semi-cylindrical.

5. The fog horn platform around the foremast are different.

6. The Missouri has SK-2 and the New Jersey Sk-1 Radar.

7. The array of ECM antenna around the foremast are different.

8. The bulwarks around the 20mm Oerlikon platform on top of the bow is shaped differently.

9. The arrangement of the ammunition locker around the 4 foremost Oerlikon on the bow are different.

10. The antenna leads between the stacks are very different.

12. The number and location of mk51 directors for the 20mm Oerlikon on the superstructure were significantly different.

13. New Jersey carried a unique experimental spherical radar equipped AA director for her 40mm bofor during much of the war. Missouri never had those.

Etc etc

I can probably come up with 50 more. But suffice it to say if you want to accurate capture all visible differences, you will have to do quite a lot of detailed research and kit modification.
Post Posted: Thu Sep 12, 2019 1:20 am
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
bigjimslade wrote:
The most pitted plate armor is the class A armor. The heat treatment process leaves the plates with a very irregular surface. I have been told that the pitting is more pronounced on the Wisconsin and Missouri than on the Iowa and New Jersey. You can see the contrast on the turret where the class B front plate meets the class A side plates.



Class A armor used on US battleships were sourced to several specialty steel makers. They each had slightly different processes and quality controls. Those made by Midvale steel had particular problems with heat treatment that resulted in their showing surface cracking and spalling. It is said these did not affect their protective qualities. But they were unsightly. Missouri used mostly Midvale plates.

During the 1980s commission, the crew of Missouri went around and used epoxy putty to fill in most of the surface cracks and spalls on missouri’s exposed A class armor. So these are mostly no longer visible.
Post Posted: Thu Sep 12, 2019 1:04 am
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
I'm going to suggest Navsouurce as a starting point.
They have a lot of photos of her during that time frame.

http://navsource.org/archives/01/062/016209r.jpg

James
Post Posted: Tue Sep 10, 2019 6:37 pm
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
BB62vet wrote:
PASCALEMOD wrote:
Quote:
I have a question on 1944 Missouri to New Jersey conversion. Aside from the bridge detail, is there anything else that needs to be done for 1944 New Jersey? Im going for the black dragon from the Academie kit.


Don't know anything about the kits, but you may want to research the AA batteries carried by NEW JERSEY in 1944 vs those on MISSOURI during the same time period. I'm talking mostly about those located between the stacks. On NEW JERSEY, that area was modified extensively during her 1945 Puget Sound yard period. I'm not sure how it was configured in 1944, etc. That would also include her 40mm, 20mm, and associated GFCS as well as her main and after stack masts/RADARs, etc.

Hope this helps,

Hank


oh... the nightmare begins.
Post Posted: Tue Sep 10, 2019 8:23 am
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
PASCALEMOD wrote:
Quote:
I have a question on 1944 Missouri to New Jersey conversion. Aside from the bridge detail, is there anything else that needs to be done for 1944 New Jersey? Im going for the black dragon from the Academie kit.


Don't know anything about the kits, but you may want to research the AA batteries carried by NEW JERSEY in 1944 vs those on MISSOURI during the same time period. I'm talking mostly about those located between the stacks. On NEW JERSEY, that area was modified extensively during her 1945 Puget Sound yard period. I'm not sure how it was configured in 1944, etc. That would also include her 40mm, 20mm, and associated GFCS as well as her main and after stack masts/RADARs, etc.

Hope this helps,

Hank
Post Posted: Tue Sep 10, 2019 7:28 am
  Post subject:  Re: Calling all USS Iowa class (BB-61) fans  Reply with quote
I have a question on 1944 Missouri to New Jersey conversion. Aside from the bridge detail, is there anything else that needs to be done for 1944 New Jersey? Im going for the black dragon from the Academie kit. :)
Post Posted: Tue Sep 10, 2019 7:16 am
  Post subject:  Funnel  Reply with quote
Here's another detail where kits usually deviate. This is the top of the funnel. Notice the funnel slopes back, rather than going vertically. The rail apparently is to keep crewmen from accidentally touching the hot pipe. It's hard to get shots here because of the limited space.

Attachment:
P1050142.jpg
P1050142.jpg [ 260.42 KiB | Viewed 519 times ]
Attachment:
P1050141.jpg
P1050141.jpg [ 211.14 KiB | Viewed 519 times ]
Post Posted: Mon Sep 09, 2019 10:27 pm

All times are UTC - 6 hours [ DST ]


Jump to:  
Powered by phpBB® Forum Software © phpBB Group