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PostPosted: Mon Jan 12, 2015 1:21 pm 
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Channell: my understanding is that that is a coupler - the shaft is two piece.

Chuck: I hear you. When constructing this part of the hull I am operating under a set of constraints, defined by (and in order of importance/relevance)
- Floating Drydock plans showing, from a rear view, single-point locations of each shaft. It is a bit ambiguous in the drawing, but it appears the inboards are shown at station 36 while the outboards are shown at station 32 (I can't post this drawing because I don't own the copyright to it).

- Floating Drydock plans showing the side view of the ship. This drawing shows both inboard/outboard shafts for the stbd side. I used it for scaling diameters of various hardware, shaft angle to the horizontal plane, general hull-exit locations, and general spacing of shafts, couplers, and struts.

- various photos.

The most important thing missing here are:

- dimensioned drawings of ANY of this detail, including the struts and the hull exit points.

There are likely more-accurate drawings/data out there, but I don't have them. I use the "measure the photograph" technique as an absolute last resort, and even then only when the perspective view is very close to perpendicular to the object of interest. I DO use photos to gain a relative position of various major objects - in this case the location of the outboard strut with respect to the forward-most point of the inboard flange. Doing this adds another constraint - it positions the strut on the outboard shaft. The position I arrived at also correlates reasonably well (less than a 0.10" difference) with the location of the strut as shown in the FDD side view. Of course, I have ZERO idea as to the accuracy of the FDD drawings.

All of which is a long drawn-out way of saying "Until someone comes up with dimensioned drawings of this area of the hull, I have exhausted my ability to guess."

:)

Tom: interesting that the Haynes model incorporates the flange at the strut-arm-to-hull interface on the outboard shaft, but not the very pronounced one at the shaft interface on the inboard shaft. In fact, looking at the photo at the top of this page, the strut flange appears an entirely different shape: I wonder if these were revised over the lifetime of the ship?


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PostPosted: Mon Jan 12, 2015 1:53 pm 
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It is possible that the strut area was modified during the life of the ship. Since the struts are now curved it may be that it was due to an effort to reduce the vibrations that plagued all the USN fast battleships to some degree. That may be also the purpose of the slanted strake shown in later photos, outboard but parallel to the outboard shaft. This would act as a vortex generator so as to keep the boundary layer energized and reduce flow separation ahead of the propellers. The reduced photo I attached of the Haynes model does not show it but there is a very subtle flang around the inboard shaft, quite subtle! A main reason for bending the strut may be for a reduction on drag at the junction with the hull, a right angle offers less interference, though the flow direction at this point may not be obvious. I would expect this was studied at the David Taylor model basin. Whether all the ships were rigged like this thought their careers is an interesting sidelight.

T


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PostPosted: Mon Jan 12, 2015 2:04 pm 
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Good points. I am sure that the naval engineer of today models the fluid dynamics of the hull everywhere on its surface before ever ordering the first rivet. But the guys back then... they lived in a vastly different world technologically and it still amazes me the quality of what they were able to achieve with sliderules.


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PostPosted: Mon Jan 12, 2015 7:16 pm 
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The strut arms have always had the slight bend in them. You just have to catch the right angle to see it.
It looks straight in almost every photo unless you stand directly forward of the strut arm.
It would take an incredible amount of work to change the strut arm in any way.
I've been looking for the photo of the strut arm foundation but can't find it.
The foundations are massive structures built into the hull framework.
The strut arms extend into the hull about 4 feet and inserted into the foundations and riveted in place.

Randy, if you want to get the shafts absolutely correct you will need the shaft arrangement drawing or the docking plan.
The shafts are all different lengths and are all at different angles starting from the reduction gear.
The end of them where the propellers are are symmetrical.
Let me know if you want to go that far.


The bulb on the shaft is a cover for the coupler.
The shaft are in sections and the sections are connected to each other by plates that are removeable so the shafts can be pulled out of the ship from outside. The bulb covers these plates.

James


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PostPosted: Tue Jan 13, 2015 11:44 am 
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A factor in the rapid sinking of King George V was a torpedo hit in an outboard shaft alley area, the whipping of which broke a coupling and caused severe damage to the shaft alley, allowing water ingress over a long distance. Indeed the guys of the thirties did a bang up job considering the analogue tools available to them. We had no idea how limited we were! I did my thesis before the first hand held calculator and did linear regressions with log tables and an adding machine...

Ship design, especially battleship is a somewhat iterative ( big word for trial and error) and the US had a unique advantage as being the only nation to build an improving series of fast battleships, each better than the previous. Many of Bismarck's real shortcomings given her tonnage were a result of Germanys last real battleship design being WWI.

Today I imagine metal elasticity under explosive loading can be simulated, in the good old days it was by guess and by gosh with the benefit of some empirical testing. Hydrodynamics could be tested at the David Taylor Model Basin, a unique and valuable facility. Flow could be observed by the old string method, which was even used in aircraft test. However what they could not do was evaluate exactly what the props did to the flow. I can imagine the dirty looks when someone said for several classes, let's try some different props...

A full war economy had a number of bottlenecks, two which affected design of ships in general were cutting of reduction gears and availability of draftsmen to affect changes or improvements under a time restrained environment. An example of the first is the use of the triple expansion reciprocating plants in many CVE's and turbo electric drive in DE's. The second was gee this could be better but no time to change.

T


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PostPosted: Thu Jan 15, 2015 11:40 am 
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Looking at James excellent photo, the flange around the exit of the inboard shaft housing from the hull only extends a short distance aft.

T


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PostPosted: Fri Jan 16, 2015 12:01 am 
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Yes, but a short distance aft of what? The shaft exits the hull in this area at an extremely shallow angle, and is faired-in to the hull in an undefined (ie., no detailed drawings) manner, so without dimensioned construction drawings it is pretty much impossible to determine where exactly the forward-most point of the flange is with respect to an actual datum - say the aft perpendicular. At least, this is one of the problems I encountered when trying to come up with a reasonable facsimile. The flange is not shown at all on the FDD plans, so the only thing I have to go by are photos, and as mentioned previously, IMO trying to measure an oblique photo is not very productive.

The photo below shows the fourth iteration of the strut supports, and this is as close as I can come - while taking into account everyone's appreciated comments - without dimensioned drawings.

Sorry for the poor-quality photo.. you should have seen how the hull was propped up just to take the shot :)

Image


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PostPosted: Fri Jan 16, 2015 12:02 am 
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Tom - re-reading your post, I may have misinterpreted. When you say "only extends a short distance aft" do you really mean - as I assumed - "a short distance forward?" Because in the aft direction is the end of the skeg, which IS fairly-well defined.


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PostPosted: Fri Jan 16, 2015 11:18 am 
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Randy:

Apologies for any confusion. Best to reference James photo above which shows the flange plate fwd where the shaft housing begins to exit the hull. This does apparently not continue aft, the whole thing somewhat resembling a squid. The original kit part carries this aft all the way, which I believe is incorrect.

These are not really important details since I am not aware of any of us doing a full hull plate job. I suppose we might grab some of the low hanging fruit such as the butt plates, perhaps the shaft and prop lifting padeyes etc.

As the hull plate transitions to various thickness and types of plate there are also some strange tuck unders etc as well. It would be interesting to see how fully and accurately John Haynes plated his hull, the best job I have seen so far. Somewhat easier to do on the larger model, at least to get it to scale.

Regards. Tom


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PostPosted: Fri Jan 16, 2015 4:42 pm 
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My fault for any misinterpretation: I usually don't know what I mean, let alone what others are trying to say. I had interpreted that flange as having a step forward, and then flaring and becoming conformal to the hull plating at about where the shaft midpoint is on the exit. Whether the hull plating steps out or the flange steps down... who knows? But you're right, these are second-order issues.


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PostPosted: Sat Jan 17, 2015 11:43 am 
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Randy:

Looks quite convincing! Your whole stern modification has come to fruition!

Regards: Tom


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PostPosted: Tue Jan 20, 2015 12:22 am 
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I decided to open up all the vents on superstructure of trumpeter's 200 missouri, and cover the opening with very fine wire mesh from a reusable metal coffee filter.

On either side of the aft stack of trumpeter's Missouri, there is a raised line tracing a square with semicircular top. It is smooth inside the square. I am guessing this is meant to represent a ventilator opening, but it lacks scribed grill used by trumpeter to represent other bulkhead vent openings. Can anyone verify there is a large square vent with semicircular top near the base on either side of the aft funnel on the missouri?

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Last edited by chuck on Tue Jan 20, 2015 12:34 am, edited 1 time in total.

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PostPosted: Tue Jan 20, 2015 12:32 am 
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Not sure if it's what you're referencing, but does this photo help? http://navsource.org/archives/01/063/016310o.jpg

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PostPosted: Tue Jan 20, 2015 12:59 am 
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Timmy C wrote:
Not sure if it's what you're referencing, but does this photo help? http://navsource.org/archives/01/063/016310o.jpg


I think the thing in question is partially hidden behind the 5" mount, with just the semicircular top showing above the top of the 5" turret.

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PostPosted: Tue Jan 20, 2015 5:55 am 
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Chuck,

Yes, that is a ventilator screen; same as the square vent. screen just aft on either side. If I'm not mistaken, the Pontos detail sets have PE for those vents. I washed mine in flat black and then used the PE covers (Haze Gray) over them. Achieves a nice effect - Gives it a depth, of sorts.
Attachment:
Mk. 56 FC Director Platforms - Rear (Large).JPG
Mk. 56 FC Director Platforms - Rear (Large).JPG [ 70.31 KiB | Viewed 1106 times ]

Hope this helps.

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USS STODDARD (DD-566) 66-68 1:144, Various Lg Scale FC Directors
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USS NEW JERSEY (BB-62) 67-69 1:200
USN Sloop/Ship PEACOCK (1813) 1:48
ROYAL CAROLINE (1748) 1:47
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PostPosted: Tue Jan 20, 2015 6:20 pm 
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BB62Vet:

Thanks. That's helpful.

I chose to open up the ventilators on the superstructures because I notice on the Iowa, the ventilators on the funnels are mostly see through, you can look into ventilators on one side of the funnel and see out the other. I thought that would be a nice detail to capture on a larger scale model.


But the ventilator in question is either not present on the Iowa, or was removed or covered up during modernization.

Another question. On the Iowa, the communication tube underneath the two beam mk-37 directors that leads down to the plotting room are canted forward. But trumpeter depicts these tubes as going straight down. Does anyone know if Iowa and missouri had different communication tube layout, or did trumpeter screw up?

Canted comm tube under starboard mk37 director:Image

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Last edited by chuck on Wed Jan 21, 2015 9:36 am, edited 1 time in total.

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PostPosted: Wed Jan 21, 2015 12:44 am 
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BTW, vent related detail trumpeter completely overlooked are the set of big trapezoid vents on either side of fore funnel, directly under the beam mk-37 directors. It fits between the uptakes for no. 1 and no. 2 boiler rooms, which both trunk into the fore funnel

This vent if normally hidden behind the support for the mk-37 director, but visible if you look straight though the supports, you can not only see the vent, but you can see straight through the funnel out the other side by the way of these vents.

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PostPosted: Wed Jan 21, 2015 5:57 am 
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Chuck wrote:

Quote:
Another question. On the Iowa, the communication tube underneath the two beam mk-37 directors that leads down to the plotting room are canted forward. But trumpeter depicts these tubes as going straight down. Does anyone know if Iowa and missouri had different communication tube layout, or did trumpeter screw up?


This question was, I'm pretty sure, answered (with pictures) earlier in this thread. You'll have to look it up.

Your follow-up statement re. the trapezoid vents - I'm not sure what you're talking about.

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HMS III
Mocksville, NC
BB62 vet 68-69

Builder's yard:
USS STODDARD (DD-566) 66-68 1:144, Various Lg Scale FC Directors
Finished:
USS NEW JERSEY (BB-62) 67-69 1:200
USN Sloop/Ship PEACOCK (1813) 1:48
ROYAL CAROLINE (1748) 1:47
AVS (1768) 1:48


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PostPosted: Wed Jan 21, 2015 6:36 am 
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Here is a picture of the trapezoid vent on the side of the fore funnel on the Iowa, directly below beam mk37 directors, on the level of the flag bridge:Image

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PostPosted: Wed Jan 21, 2015 12:17 pm 
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Chuck,

Nice pictures - thanks for posting! But, still can't recall these vents. However, I'll look at the kit parts tonight and see what's been omitted. You've got to realize that a detail such as this will probably be omitted by the kit mfg'r due to it's "hidden" location and saving cost on molding parts. My speculation is that only Detail Freaks such as the modelers on this forum are going to notice something like this.

To be honest, if you hadn't brought this up, I would have passed it over in all likelyhood. And, similarly, the comm. tube to the directors is also one of those "hidden" items that probably wouldn't be addressed except by the modeler.

Hank

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HMS III
Mocksville, NC
BB62 vet 68-69

Builder's yard:
USS STODDARD (DD-566) 66-68 1:144, Various Lg Scale FC Directors
Finished:
USS NEW JERSEY (BB-62) 67-69 1:200
USN Sloop/Ship PEACOCK (1813) 1:48
ROYAL CAROLINE (1748) 1:47
AVS (1768) 1:48


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