Calling all Iowa-class (BB-61) fans

[BB62vet]

Dave,

First, thanks for your service! I would like to assure you that you know quite a bit about RADAR and various GFCS being deployed currently. More than I do, I assure you.

I will point out one other fact - the optical rangefinders on IOWA Class BB's work quite well and DON'T need replacement, or they would have already disappeared from the conning towers in the 1980's refits. As RADAR goes, I'm sure a more up to date replacement for the Mk. 13 main battery would have been sought had it been deemed necessary by the Navy at the time (again - 1980's). Since we are talking about a "what-if", possibly something newer would be in consideration along the timeframe you've given (2012). One thing that can't be overlooked - when the electronics goes out, THEN what do you do??? You rely on a proven, albeit limited fire control system - based on optical rangefinding; simple as that.

The 16"/50 gun is the IOWA class' primary weapon system - and today that use is just about 100% confined to shore bombardment, not taking out ships (although....with the presence of more Chinese carriers, cruisers, destroyers over the horizon...who's to say, right?) Thinking "what if" I could see a RADAR replacement to augment the existing Mk. 13 optics. As for the replacement of 5"/38 mounts with 5"/54 mounts, that's your call. I don't personally think the ship is designed to handle the 5"/54 gun system without major changes internally which would be ineffective cost-wise for the resulting firepower.

I'll leave it at that - but, please do create a build log for your project - it's always interesting to see other's ideas about how they would "resurrect" the IOWA class!

[Fliger747]

Indeed I don't think the Mk38 system could effectively be replaced for the main battery, though it has been augmented by such things as choreographing the fired rounds, improved radar, drone spotting and whatnot. If one replaced the dual 5"38 mounts, certainly the MK37, as excellent as it was for WWII would be anachronistic.

The power plants, as advanced as they were for the time are 80 year old technology. As much time as elapsed between the Civil War and WWII.

[bigjimslade]

I had always read that the primers for the 16-inch guns were similar to 30 caliber blanks. Last week I got to play with the lock and some primers.

It turns out that a primer may look like a blank bullet cartridge they are not at all like one.

To begin with they are MUCH heaver than a rifle cartridge because the walls are much thicker.

There is no percussion cap at the end of the primer as there is on a bullet.

The internal workings of a primer are much different than on a bullet. There is insulation so that a complete electrical circuit can be created from the outside case to the center of the end. That circuit passes through a filament wrapped with guncotten that sets off the an initiator charge that then sets off the primer's main charge.

[Fliger747]

Thanks! Interesting!

[bigjimslade]

[Fliger747]

The above tool is used for a different type of "primer"? Red Lead?

[bigjimslade]

The above tool is used for a different type of "primer"? Red Lead?

It is a plan for one of these

https://www.homedepot.com/p/Warner-1-ga ... /205052771

There are also plans for coat hangars, sword holders, ....

[BB62vet]

I'll go out on a limb and a-s-s-u-m-e that these drawings have all now been de-classified for public consumption.

I would hate to think that the Spublovians might have access to some of our most top secret tools and formulas

[bigjimslade]

Here is a picture I took of a primer and a 7.62 case. They look similar to "assault weapons" types but are quite different in shape. A major technical difference is visible here. Note the dark ring at the base of the primer. That is insulation so that a circuit can form from the case to the center of the base. The center is not a percussion cap like on the 7.62 case and is smaller. The center is a plunger that can mechanically trigger the primer.

[Fliger747]

It looks quite tapered. How are they extracted?

[bigjimslade]

It looks quite tapered. How are they extracted?

It is very tapered. The primer automatically ejects when the breach opens.

[Fliger747]

I know maybe 20 years ago Remington made an electrically fired sporting rifle with the idea of reducing lock time. Not sure what primers were used.

[bigjimslade]

I've received some requests on information on plating. I am trying to put together a reference on this. Assembly the data requires piecing information from many different sources together. It is not practicable for me to do a giant document jump and provide anything meaningful.

I have come to the conclusion that the hull was largely riveted in a misguided belief that the greater flexibility of a riveted hull than a welded hull was necessary for a ship of this size. I have not come across any references to that effect but that is the only conclusion I can come to. Some of the strake plates are welded. The structural members are welded. So inexperience in welding does not explain why the navy went to the cost and time of riveting the hull.

Here is a photo of the bow. I have labeled the strakes. There are several Q and R strakes at the bow. The current top of the boot topping is slightly below the designed waterline. So the K1 strake would not have been visible at all. The M strake is at the waterline for most of the hull length.

In this zone between about Frame 40 to Frame 2 the strakes are arranged in an inverted clapboard manner where the lower strake overlaps the strake above. Just forward of frame 40, the N strake overlaps the O strakes but aft this reverses with the O strake overlapping the N strake. Farther aft they switch to a butt alignment. The lower side strake switch to a butt alignment in this region as well.

A feature that is not visible is that the thickness of the strake plates vary. They are all 1/4" at the bow. They tend to get thinner immediately aft then get thicker aft. The visible plates range from 7/16" to 1-1/4". There are chamfers at the thickness transitions so the thickness variations are not apparent.

For modelers at 1:200 - 1:350 scale the thickness of the overlaps are around 1/1000" (hardly visible). The butting seams midship are hardly noticeable on the ship until you get really close.

For most of the length, the M and N strakes have a scarf joint.

The same kind of arrangement is at the stern as well.

[chuck]

On 1/200 scale I used paint masking technique to produce what I consider realistic and scale accurate plating patterns on the Missouri. It takes maybe 5-6 coats of Tamiya spray can lacquer applied Fairey lightly to achieve it for midship underwater plating overlap, and 3 coats for bow and stern.

Regarding welding, there was not enough experience with welding in 1938. Welding was considered suspect with higher strength steel. Welds were considered intrinsically less suitable for containing battle damage in high value structures because tears in steel can rip right across welded seams, where as riveted seams form nature rip stops that prevents propagation of tears across seams.

The US also wasn�t the world leader in warship ship welding, the Germans and the Japanese were. It was well known the German and Japanese experienced major structure failures in welded members, and failed ships were rebuilt with riveted seams. The Germans had by far the most experience with welding in naval construction, and were comfortable using welding to a far higher extent in major warships than anyone else. But even they were not confident enough to use welding on very high strength steel

[Thomas E. Johnson]

On 1/200 scale I used paint masking technique to produce what I consider realistic and scale accurate plating patterns on the Missouri. It takes maybe 5-6 coats of Tamiya spray can lacquer applied Fairey lightly to achieve it for midship underwater plating overlap, and 3 coats for bow and stern.

Regarding welding, there was not enough experience with welding in 1938. Welding was considered suspect with higher strength steel. Welds were considered intrinsically less suitable for containing battle damage in high value structures because tears in steel can rip right across welded seams, where as riveted seams form nature rip stops that prevents propagation of tears across seams.

The US also wasn�t the world leader in warship ship welding, the Germans and the Japanese were. It was well known the German and Japanese experienced major structure failures in welded members, and failed ships were rebuilt with riveted seams. The Germans had by far the most experience with welding in naval construction, and were comfortable using welding to a far higher extent in major warships than anyone else. But even they were not confident enough to use welding on very high strength steel

I used the same method on my 1/200 hull.

[BB62vet]

Referring to the above 2 posts re. hull painting techniques - I used that same technique with my 1:200 NEW JERSEY only I had a scaled plating pattern that was developed by another modeler for his 1:200 MISSOURI (Same Trumpeter kit) by drawing this up in CAD (3D Solidworks, I think). I used a wide fan brush with bottle paint and I believe I detailed this in my build over on Completed Models, etc. Using the brushed, flat, lacquer paint it only took a couple coats to achieve the weld lines that I had laid out with masking tape.

Welding, in regards to the IOWA Class, was minimal on the initial 4 ships actually completed, while KENTUCKY and ILLINOIS were almost completely welded with minimal riveting as things by 1944 onward had progressed a great way in accuracy, quality, and technique. I think this is fairly well documented in U.S. Battleships, an Illustrated Design History (Friedman), but it could be Battleships: U.S. Battleships in World War II (Dulin, Garzke, Sumrall).

[chuck]

One really tricky aspect of using masking tape to paint overlapping hull seams is at several locations on the Missouri, the direction of overlap abruptly reverses. The horizontal seam transitions from bottom strakes overlapping top strake abruptly to top strake overlapping bottom strake. But otherwise the strakes themselves continued without any vertical seams. It is impossible to abruptly transition from masking the top strake to making the bottom strake without leaving a discontinuity in the paint. I though about sanding away the discontinuity when I am done. But I found it was impossible to do without marring the intended horizontal strake overlap.

The way I found around it it to hold a piece of paper about 1/3 inch away from the model at the location where overlap reverses. You mask the overlap one way up to the paper. Spray until you get the depth of overlap right. The paper ensures where the transition is, the paint feathers to nothing rather than abruptly end leaving a discontinuity. Then move the paper to the other side of discontinuity, and make the side with the reverse overlap. This way, at the location where the reverse is, the paint making up the strakes feather into eachother.

[Thomas E. Johnson]

I always thought all ship construction by 1940 or so was predominantly welded.....

This is very enlightening.

[chuck]

Apparently riveting was still used in European ship building as late as the late 1950s.

[bigjimslade]

I have been trying to find sources that address the welding v. riveting question. Dulin has a page on welding but it does not really address the question of why. None of the other standard references address it. If anyone knows of a source(s), let me know. I have asked in other fora to no avail.

We do know that there was some level of distrust of welding. When Liberty Ships and T-2 Tankers were breaking in half, weld quality received the blame initially. It turned out the quality of welds had little to do with it and poor quality steel that became brittle with cold and poor design for welding (e.g., hatches with square corners) were to blame. The latter is similar to the problem the Comets had.

On the Iowas, the bow is welded. All but the upper four strakes are welded end to end. The structural members are welded. The hull is welded where riveting would have been impracticable. And the Superstructure is welded.

So a lack of trust in welded joints does not appear to be the concern.

I have been puzzled that they butt welded the hull strakes but in much of the ship there appears to have been a distrust of butt joints. In the barbette supports, there are butt plates welded over the butt joints; something that is weaker than a simple but joint. Then, oddly, the turret supports are riveted.