confederate - RevuAIR

Why Three Views are Necessary

By fStop Fitzgerald | 2 July 2017 | Comments 0 Comment

We live in a three-dimensional (physicists may say four, fantasists say more) world. To visually represent that, one needs to meld length, width, and depth. Absent any one and the result is a bizarre view of the world.

http://telegraphharp.com/album-category/digital/ Hence, we can start with something as seemingly complex as this flat, 2-dimensional—up and down, left and right—drawing . . .

Dover

And get something that looks a bit more real-worldly with not only left-right, up-down, but also front-back.

What if one dimension is missing?

Archaeologists, historians, and other scholars have for years been wondering what the Confederate submersible H. L. Hunley really looked like. The historic vessel was discovered a number of years ago, has been raised, and is currently under minute excavation and discovery in Charleston, South Carolina. Many questions have been answered, especially what she looked like. (https://hunley.org/) Here is a link to the most recent detailed (extremely!) analysis of the vessel by the Underwater Archaeology Branch of the Naval History and Heritage Command. (https://www.history.navy.mil/research/underwater-archaeology/sites-and-projects/ship-wrecksites/hl-hunley/recovery-report.html)

But before this, to envision the boat, historians had to rely on a written record, no known photographs exist. There were a few sketches and one watercolor wash painting by R. G. Skerrett, which gave a fair idea of her form, but they—as is all art—were reliant on the artist’s eye and especially, hand. What is real? (Naval History and Heritage Command)

One of the early references was this two-view tracing of a predecessor boat, the “Rebel Submarine Ram” Pioneer. It was from a contemporary 1864 Civil War report from U.S. Navy Fleet Engineer William H. Shock to the Assistant Secretary of the Navy. (National Archives and Records Administration)

The upper drawing shows a side view of the ram, with some interior details. The bottom drawing shows a top view looking down of the vessel.

There is nothing, however, to show us the third dimension, a front view. The illustrations below will demonstrate the impact of that missing third dimension.

All the views you will see were made with this set of lines that I pulled from the original drawing. The only thing that is different between the pairs of renders is that in one, I let the original drawings determine the final shapes, and in the other one I assumed the third dimension to be curved.

These are the top views of the two versions, the lower has many more lines because those are necessary to draw the curves in the 3D rendering of these lines. Note however that the external lines of each part are identical. This reflects the lines’ origins from the lines pulled from the original.

This shows the resultant 3D render.

Similarly, here are the side views, again with the lower drawing and render showing the addition of curved lines.

And this drawing shows the resultant third dimension, the front views, based on the base (left) and curved lines.

Here are the resultant images in full 3D.

Note that, both 3D renderings match the original 2D drawing. Which is correct?

While that is certainly obvious, this is just an illustration of issues that can occur in the absence of information.

This rendering further illustrates the need for three views. Notice the two highlighted areas.

Many times with all three views provided, even that information is not enough. Sometimes it is a confusion on the part of the original craftsman with regard to how a particular line should be depicted in each of the three views. More often, however, lines are hidden. These require either additional drawings, or better yet, a perspective drawing of their intersections. No examples come immediately to mind, but I am certain at least one will crop up on an upcoming drawing. I will address that when it happens.

This final rendering shows the curved 3D version over the original lines. The other version would similarly line up.

CSS Tennessee Brooke Rifles

By fStop Fitzgerald | 25 June 2017 | Comments 0 Comment

The Confederate ironclad Tennessee was effectively armed with a concentrated and powerful armament of two 7-inch Brooke double-banded rifles fore and aft on pivot mounts and four 6.4-inch Brooke double-banded rifles, two per broadside.

The 7-inch rifles, weighing 15,300 pounds each, were manufactured in Selma, Alabama. This, the bow gun, tube no. S-10, is property of the Naval History and Heritage Command (NHHC) and located at the Washington Navy Yard in Washington, DC. Its companion tube, no. S-5 at the stern pivot, is also the property of NHHC, is on loan and on display outside the Selma City Hall. In the background, the three visible guns are from Tennessee’s four-gun broadside battery.

This gun is one of the four 9,000 pound 6.4-inch broadside rifles, three of which are also at NHHC in Washington. It was forged at the Tredegar Ironworks in Richmond, Virginia.

This illustration shows the guns mounts. The pivot guns were mounted on large sliding carriages and the broadside guns on two-wheel Marsilly carriages.

CSS Tennessee

By fStop Fitzgerald | 25 June 2017 | Comments 0 Comment

Making Sausage: You Really Don’t Want to Know

This is an incomplete project. Although portions of it were published in the December 2009 issue of Naval History magazine, they were carefully cropped to eliminate errors that exist because of lack of documentation and skill on my part. My goal is to do the definitive model with accurate interior detail.

I am posting this to ping the greater world for more information so that I can properly detail the interior and fix the exterior, and perhaps rework the whole drawing. These renders are eight years old, so my skills have improved, but until I get more information this will sit on a back burner.

For the hull and casemate, I was only able to find these two drawings.

I do not have my sources readily at hand, but the profile and plan are obviously from a book. They are small and while apparently detailed, it is all lost in the small reproduction on poor absorbent paper. I believe the sections are from a different source. They are larger and cleaner, a big help.

The only way to approach a subject is to envision it in the simplest parts possible to keep your drawing time to a minimum. One fortunate aspect of ships (along with aircraft) is that you generally only have to do 50 percent of the project because of symmetry along the centerline. You simply copy, paste, reflect, and merge your work. With Tennessee, I created three basic pieces; the hull, hull armor, and casemate. Everything else is detail.

Using Illustrator, I created the lines for each. This is not a difficult process, but is somewhat challenging in trying to visualize your 2-dimensional work in 3-dimensions. Once those are complete, I import them into my 3-D software, Strata 3D, and proceed to extrude, lathe, hull, and whatever else needs to be done to get something that resembles Tennessee.

The hull sections, as noted, were clean and easy to reconstruct.

Once drawn, they were laid out in position along the length of the hull for “erecting” in the 3D program.

The failings of the hull—primarily because of my inexperience—is the plating. The interior, however, is another matter. Despite their size, the interior plan was really quite good for its level of detail. It allowed for proper positioning of the guns and their interaction. The funnel drops down through the gun deck to the engine room below. The capstan has an interesting position, but again, its linkages, unless below deck, are non-existent.

But details of the interior are sorely lacking. The gun handling fixtures are pretty much standard, so those details were easily added. But the real issue is the wheel stand and its workings. The drawings show that it was elevated above the gun deck and hung from the overhead, but how? How was the wheel linked to the rudder? What navigational equipment was associated with it? How did they use a compass surrounded by all that iron? Many questions, no answers. So the wheel is just suspended over the deck.

I added a drawing to illustrate the composite laminated construction of the casemate armor. It’s interesting to see how the laminations go together and how thick the armor was in relation to its backing.

I don’t normally share rejects. The faults in this are obvious, but it is here because it shows relationships and details, especially in the overhead grating, not visible in the others.The overhead view shows the layout of the fore (right) and aft 7-inch Brooke double-banded rifles on swivel mounts. These align with the three fore- and aft-most gunports. The four 6.4-inch Brooke double-banded rifles occupy the four broadside ports.

These are some other interior views as well as the overall fore and aft views.

Again, if you can help by pointing me toward drawings that will get this closer to what it should be, please let me know.