The Ship Model Forum

Just for something different to do, I decided to design & then print a generic (no scale at this point) USN Mk. 28 Mod 2 5"/38 Gun Mount - as my 1:200 scale model of USS NEW JERSERY is already completed with Model Monkey mounts, this isn't to replace them - simply a fill in design/print project to see how mine will compare to others currently offering the same item.

Using the cut sheet (pg. 252) for that particular mount as the guide for sizing, etc. and few reference books and photos (Tom Falley has sent me some excellent photos of MISSOURI's 5" mounts), I've done a few hours' worth of design the last couple nights and have come thus far:

The bottom of the mount with the base ring/barbette will be a separate part, as will the gun barrel unit. I've got the bottom part fairly well completed:

The Gun Captain's Blast Shield is also a separate part and I've completed that, as well:

I didn't want this integral with the mount as this is not an item that is present on all the gun mounts. Tom Falley has already created 3D gun mounts as replacements for his MISSOURI & ALASKA models and has sent me his DSM files, but I will attempt to design this myself while making use of his barrel assembly design and adjust it accordingly.

Once completed, I can scale this for various sizes and also add/modify details as needed depending on the Mk./Mod. of what is required.

Edit - The cut sheet (pg. 252) is from the Gun Mount and Turret Catalog, Ordnance Pamphlet 1112, 1945 which can be accessed from HNSA website (https://www.hnsa.org/manuals-documents/ ... e-control/).

_________________
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

Hank:

Dollars to doughnuts you will replace the commercial items on NJ, I did on my Alaska, when you see how good they are. Yes the photos are quite helpful for the mounts as seen on Iowa's though a few items had been scavenged such as the training buffers and the hold open cylinder device for the mount Captain's hatch.

One reason I dd Whitehurst was I already had 3", 40 and 20 mm's that I could use.

A day or two work you should have a really decent mount to grace your parts box!

Cheers: Tom

I'll be watching this. I have the basic 3D design for the mount on the Oklahoma City but I haven't completed the internal workings of the guns for elevation. I think it was a Mk 32 mount with a Mk 31 shield.

I think I found the OP 805 "5-inch Twin Mounts Mark 28,32 and 38 All Mods Description and Inspection" on the Historic Naval Ships Association web site. It is 622 pages and tells just about everything about these mounts.

The actual size of the shield varied a bit, depending upon the type of vessel it was on. The internal dimensions were the same, but the thickness of the shield plating varied from 1/4" on the Mk 41 Mod 0 shield on destroyers and other smaller vessels to 2.5" on the Mk 30 Mod 0 shield on battleships. So the overall width varied up to 4 1/2". At small scales that won't matter, but at 1:100 that is .045", still not something to worry about unless you are a dedicated rivet counter. But it would be 1/8" at 1:35.

I have searched for the blueprints for the 5"/38 guns for years with no luck. I would like to make an accurate CAD model of the gun. I have the OPs for the gun, and they contain a lot of good photos and diagrams of the parts, but they don't include dimensions. I measured some of the dimensions of the guns on the USS Little Rock CG-5 museum ship, so I can make a pretty accurate model.

Phil

PS: Be careful about using the gun outlines on the outline drawings of the mounts. They show the gun barrels changing diameters abruptly about where the barrels exit the shield. This is incorrect! The photos of the guns do not show this feature. They appear to taper more or less evenly from the muzzle all the way up to where the barrels screw (bayonet) into the gun housing. This is one reason I would like to find the actual blueprints.

https://www.okieboat.com/Gun%20mount.html

PPS: Some dual mounts had external training buffers bolted to the outside front, and some had the buffers on the bottom at the rear. You need to check photos for the ship you want to model to see which it had.

_________________
A collision at sea will ruin your entire day. Aristotle

DavidP - Yes, those holes can be for drainage of resin, but more for leaving openings in the barbette base as a way to save on resin usage. Since the part is printed upside down the drainage factor is nil.

Tom - Oh No!!! - I'm not opening the display case for anything else!!! The only consideration at this point regarding replacement of parts would be replacing the scratchbuilt items that, as you've noted, would be much more detailed if done in 3D design, etc. I have considered building a 1:200 scale partial superstructure model of NEW JERSEY as of 1955 which would include the 01/02/03 Levels from the end of the deckhouse up to & incl. the after stack and Mk. 8 RADAR. I have most of the necessary parts to do this but may never get to it - just an idea. It could be mounted in a separate display case with the full model next to it. This would include the 40mm gun mounts and a few other items that were removed during her 1960s commissioning. But, at this point, it's only an idea with the parts box tightly sealed

Phil - Well, glad you're aboard on this design ditty!! I agree - finding dimensioned drawings for the basic mount & associated equipment is almost impossible. I have only one comment - NARA II does have all the original IOWA class "as built" drawings in microfilm and I would "guess" that the 5"-38 mounts may be part of those drawings. But it would take days to sift thru the many reels of M.F. to find those particular drawings. And you know as well as I do that their Microfiche reader/printer isn't worth 2 cents at this point. And most of those working there haven't a clue about how to operate the equipment.

I may go ahead and make a 2nd design with the blast shield & gas cylinder mechanism after I've finished the initial design w/o that shield. That way you could see both versions. Anyhow, I've done a bit more inside work for mounting the barrel assembly tonight -

I still have a bit of work to do on this for some further bracing, but basically, I think this should work ok to hold the barrels and allow for elevation. I will add a bottom vertical support to the base plate that will hold the central barrel cylinder in place. Maybe I'll get to the back face details in a day or so; depends on other projects and yard work, etc.

Hank

_________________
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

Hank:

My system is much simpler for the barrels, they simply fit in the gun house opening with an interference fit which both holds them in place and allows elevation retention. There seems to be a lot of variation in the external arrangements of the mounts, detail wise. Interestingly the whole external gun house could be lifted off leaving the internal guns exposed. The Mount Captains blast hood was variously added or removed with a couple of bolts. Alaska had none fitted where as the Iowa's seem to have them fitted only when there was a nearby super firing mount Glad I could furnish you with the Missouri photos, though the exact arrangements of a different ship at a different time is always subject to uncertainty. The basics of hinges, bolts, hatches and whatnot were likely the same.

I found the printing of the barbette in one piece with the mount external was quite satisfactory and allows access to the barrels for adjustment or should I break one. The 1:200 won't show orientation of bolt heads, but 1:100 might.

These are fun and satisfying to produce, always fun to have bunch in the parts box. I have a lot of them.

Cheers: Tom

Tom,

Well, perhaps you'll have a few to send to the UKR for border defense!!!! I find working on this late at night before Taps is quite satisfying - esp. if things work out and the details come together. Sometimes, this doesn't happen and progress comes to a screeching halt.

Like an owl facing a tree trunk.

Hank

_________________
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

For some reason the front vertical of the BB mounts seem to be taller than those on Cruisers and destroyers, more than would be reflected by the thickness of the plating. Hank:

Hank: Feel free to post any of the BB63 photos I sent which are great for the surface detail. The Missouri ones have two rung ladders on the aft sides whereas Cruiser mounts more typically have a single ladder aft as shown on Phil's example. From the photos, easy enough to count the number of external bolts. The six bolt patterns, on the forward sides and aft on the curved section, apparently hold the mount cover structure to the base, as I have seen these lifted off via a crane and stacked on the dockside for major mechanical work. Normally the twin barrels are locked together in elevation though they can be de clutched for maintenance.

The strength of the resin is a determining factor in printing small detail such as the hand grabs and ladder rungs. Though quite fragile these can be printed quite finely, being very short and not much of a span. Whether or not the longer vertical grabs outboard of the doors will come out is more problematic.

The mounts I made for Missouri are held on with magnets, the ones on Alaska friction fit over a round disc turned out of plexiglass. The magnets are a good solution if one has allowed for this earlier in construction.

Cheers: Tom

A couple of the mount photos that I sent Hank. I realized that he probably doesn't have easy capability to reduce size to fit the requirements here. Notice the tall front vertical and the absence of the front training buffer s wells the size of the barbette.

Tom

Tom,

I have noticed that some 5"/38 mounts do have taller front faces, one angled face and a flat top, unlike the mount in my drawings with a small flat top, and angled top, angled front face and short vertical front. The larger ships had an armored barbette around the mount base, whereas smaller vessels had an exposed base.

Hank,

I wouldn't bet on finding the 5"/38 mount drawings in the Iowa blueprints. The gun mounts were BuOrd drawings, and the blueprints I have for the ship are BuShips drawings. Given that the smaller Clevelands have about 9000 blueprints and searching thorough them is tedious, I can imagine that the much larger Iowas have several times that many blueprints. However, the complete 6"/47 turret blueprints are in the Cleveland drawings. They were BuShips designs.

The blueprint collections (and microfilm) are are arranged in order by Ships Material Group Codes. I have tried to attach a PDF with the codes but that failed. Send me a PM and I can email the 365 Kbyte file. These are useful for looking through the blueprint sets. For example, group S1 is design of the vessel (drawings like a Booklet of General Plans), hull structural drawings are in the S11 group and armor plating is S14. Propellers are S44 and turrets are S72. The last group is S85 photography. Knowing what group you are looking for tells you about where the drawings will be in the entire collection of drawings.

Dealing with Archivists at NARA is a hit and miss thing. Some Archivists know little about the naval drawings (not surprising given the enormous amount of things in the Archives) but occasionally you get one who is very knowledgeable. I got a lot of useful information from one of the Archivists who scanned some things and sent them free by email.

Phil

_________________
A collision at sea will ruin your entire day. Aristotle

Tom,

Thanks for posting those photos - I've also been using a couple of the 1945 PSNSY photos that show quite a bit of the smaller details of the mount at that time -



I've also got some from her 1967-69 commission, but those are not quite as sharp as these photos, so small details are vague.

Phil,

Thanks for the additional NARA II info - I quite agree in your overall assessment of current conditions there and what's available for researchers, etc. When I was there in 2016, I did have one archivist who was both knowledgeable and willing to help me out - most of the others at the time were neither. Several seemed to show indifference to our group's requests & questions as I recall. Anyhow, I've emailed you regarding your .pdf offering.

I did get some further work done last night on the back face, correcting my access door hinges and starting to add the various openings and details -

Note: The lines on the stbd access door are due to the surface of the item, not actual lines that will appear on the part once printed.
I'll probably continue with these items later this evening.

Thanks to both of you for the input!

Hank

_________________
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

Hank:

Nice work! I wonder what the progression was on NJ post war in the configuration of the external details of these mounts. WWII photos such as the PSNS ones show bucklers for the bloomers on the twin mounts, Missouri has certainly shed these at some point with no ridge around the openings in the face plate. The six bolt patterns such at the lower edge do not appear at the top near the mount Captain's position. The Missouri photos show latchings for the doors and access panels though these are a bit small for printing at a very small scale.





Note the flat top of the mount without projections. A previous mount I did for Alaska has a grab rail on the curved back. The hatch seems fairly thin, not the 2 1/2 " thickness of the plating and dished. For trolls and rivet counters the non inclusion of the plethora of bolts on the bottom of the mount would be fatal omission of detail.

In the PSNS photos the small racks on the tops of the mounts were I believe associated with small sighting units (.50 BMG?) and not operationally retained.

Cheers: Tom

Taken in a downpour! Not the the latches for the entry and access doors, they are at the top of the door swings and simply dropped over the top of the doors to hold them completely open. On Missouri not all mounts had the ladder rungs on both sides!

Cheers: Tom

Tom,

Thanks for the kind remarks and for the additional info/pix, etc.!! Yes, the latch I will take under consideration

The mounts on NEW JERSEY in 1967 still had a small lip around the opening for the barrels on the two exterior faces of the mount shell. I've added these. I still need to revise the bottom mount ring & barbette to show the outer circular lip as shown in your last photo.

All those cages, racks, etc. in the 1945 photos were removed prior/during the 1950s so were long gone by the time our crew was aboard in 1968-69. I have corrected the access door shape to a complete round on top/btm as this was a noticeable mistake on my part. I probably will make this first edition a generic version as I can always add/remove details or make other versions if needed. I've also noted that there are lifeline rings welded on the faces of some mounts depending on where the mount would be positioned relative to nearby lifelines.

Hank

_________________
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

The variation, even on one ship is boggling. Some mounts had only one side ladder, the vertical grabs for the doors was sometimes on the back, sometimes on the side and on and on.

Your hinges look good as do the side hand grabs. These had the drop so as to keep feet from sliding off sideways. Mine are currently straight but I will give it a thrash. in Theory they may not print as they are not attached at the bottom. I'll give it a thrash though.

Cheers: Tom

Hanks effort here urged to have me examine my mounts suitability for Missouri, as I had med them For Alaska.

A few revisions, though in actuality it seems every mount on Missouri is a little different.

Tom,

Nice mounts!! I'm glad you posted those photos - it made me realize that the gun captain's hatch needs the actuator cylinder in the back. I need to "turn on" my actuator, right now it isn't visible and wouldn't print as such. Thanks for reminding me!!!

Hank

_________________
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

Well Hank:

Those were removed from the mounts on Missouri, possibly in storage or canabalized for other ships. On mine I need to convert the ladders to drop rungs, if they will print. The advantage of doing the base your way is you will be able to replicate the exact number and pattern of the bolts on the underside. Leaving the barbette open has an advantage in being able to access the barrels though the whole arrangement depends on how you fasten the mount to the deck. Looking forward to seeing if the drop rungs print!

Cheers Tom

Tom,

Luckily, I have several photos/illustrations of the hatch mechanism to use for guidence and have now got that in place. Of course, in the midst of all this I managed to get the access doors incorrectly sized and located and removing them was/is impossible. So, I recreated the mount shell 100mm above the 1st edition and then spent several hours adding back the details that had been added to the original design. So, I'm now almost back to where I was Friday night before things went south in a hurry

Here are a couple shots of the 2nd Edition Mount before I get started on the back face details:


The 2nd Edition Shell is actually a bit more accurate than the 1st Edition, so that is a plus when considering the time spent having to do all this!
In order to get the doors located properly this time, I'm going to use a protractor and compass to measure the exact angles from C.L. on the plan view of my cut sheet. Hopefully, the 2nd Edition will be correct and I won't get the toe from #2 (ref. - From Russia With Love)

Hank

_________________
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

Hank:

The height of the front vertical looks just right. I suppose that running a tape around the curved back would add more precision, if the ship was available. The drawings in turret/mount catalogue may be slightly generic. One nice thing about 3D is it's easier to go back and revise!

Cheers: Tom

Thanks, Tom! - Yes, it's possible that what's shown in the T/M catalog is not quite correct, but without further info, I've used that sketch as the basis for the design. I've finally gotten the 2nd edition shell completed and have a print running now. Here's the final version of the mount shell -


So, later today (6+ hours print time) we shall see what happens!! Also reprinting one of STODDARD's stacks along with the mount, so a resin consuming print run this time!

Hank

_________________
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