August 10, 2011

It's not an Ironclad Guarantee



What is that object hiding under the Model Railroader back issues? Why it is the beginning of the hull form for the USN Passaic. I had mentioned that this ironclad was in the upper Potomac in the winter 1862. It was towed to Washington, DC Navy Yard for repairs. Presumably it sailed back south under its own power. Did it stop at Aquia for a brief visit? Unlikely, but possible.

After much prodding from Gerry and Rob, I decided to at least try the USN Passiac at the wharf scene.  I mocked it up with a piece of cardboard painted dark brown. It looked tight, but it could work. Brian K. suggested making it sub-scale, but with it being in the foreground, I decided against that.







This first attempt got
thrown away.
I started building the model using a standard ship modeling technique of plank on bulkhead following plans I found on line.  I used a straight pine 1x2 as the center keel for stiffness. I was laser cutting the bulkhead parts. Thus I had to make the longitudinal bulkheads in three lengths as my laser bed is 18 inches long, but the ship is 50 inches long. As I built the frame I realized that it was riding too high. I was building the armored hull to scale height (see plans). But when I re-examined the plans I noticed that the freeboard (the part sticking out of the water) was only about 12 inches, or a quarter inch in scale.  There wasn't any practical way to cut down the bulkhead frame. A much simpler approach for the hull would suffice.


Note how little of the hull is exposed above the waterline

So I trashed the bulkhead frame and used the laser cut a layer cake style model using 4 layers of 1/16th inch thick task board. The top layer was engraved with the armor plate and rivet detail and had the appropriate holes cut for portholes, turret, stacks, etc. I glued the layers together and by the next morning, I had the makings of an iron clad. I attempted to depict the hull camber using spacers under the top layer of task board. I probably should have put the spacers under the bottom layer to get the profile more accurate. There is also some sheer to the hull. Most photos show the ship riding lower at the stern than at the bow. I am thinking about how to show this, even though the effect is subtle.

I had earlier done a test of the task board to see how it would appear when painted to resemble iron armor. I was very pleased with the texture. As an alternate, I may try cutting some sheets of resin impregnated back board as the armor surface.

I may do a new version using a single piece of 1/4 inch plywood as the base and then add small pieces of laser cut profile boards to simulate the camber. It depends on how the task board hull holds up to detailing and painting. I am a little concerned that it might warp. One solution would be to secure it to the table surface with screws to hold it steady and prevent warping. I prefer not to glue it in place in case I need to move it if I change my mind.
The photo below shows a mock up of a possible configuration of the scene with the USN Passaic. By angling the wharf  on the peninsula and moving the paddlewheel steamer into the resulting wider section of  water closer to shore, I have ample room for both big ships. Smaller ships can fill in the other odd water areas. I want to leave space at the end of the wharf for the car floats.  I think the scene looks better on an angle too. This is looking good, but is not a sure thing.


It is amazing how close the roll of duct tape is to the size of the 1/48th scale Passaic turret.

3 comments:

  1. Bernie,

    I was about to "call" you on using the designation USN for the Passaic, however, I decided to do a little checking first. I'm glad I did!

    It wasn't until 1907 that President Theodore Roosevelt issued an executive order which directed that all U.S. commissioned naval ships would be prefixed by either U.S.S. or United States Ship.

    While this doesn't preclude the use of U.S.S. or as you have done U.S.N with the names of Naval vessels such as the Passaic, prior to 1907, those designations were not official.

    More likely than not ships of that ear were simply referred to by the vessels name.

    In case you are wondering, yes, I'm retired Navy! ;)

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  2. I did not know about the USN designation either, but did see it used in several other sources so I went with it.

    Thanks for the comment and welcome aboard!

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  3. Aw, man, what a wonderful touch that will be! Having an ironclad monitor on the layout.

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