Need Help With Tables of Offsets

[proflooney]

I find pics of the thayer but not the drawings I wouldnt mind doing that one also as always wanted an r/dc sailing ship and the hulls should be similar

[proflooney]

ok found the thayer drawings and put them away til later first i need to get the Wapama figured out

[proflooney]

Ok I seem top have the Half-Siding Dimension however cant seem to get the Deck Sheer or Plank Sheer Numbers to work

[proflooney]

Ok so I got things all adjusted in my excel file and any changes and repacked it all up so now it is current as to what I have it as now


http://www.proflooney.net/Steamer-Schooner-Wapama.zip

[proflooney]

Ok got a test loft going. looking good but for the transom. will add some buttock lines to my loft to help the shapes more.

[proflooney]

Ok So now I decided to try working with the Buttocks. it makes it tricky as not all hit every station thus i need to do it in sections. once I get it though I can create more stations and wont need the Buttock Lines. this should give me a better hull shape when finished

[proflooney]

Well I got all the image planes made and mated into the proper locations. I took the planes and did intersect curve to them from my loft and the front 90% of the ship turned out beautiful. I still need to figure out the transom area but will take a break for now while I make all my 3D stations. it is always nice to take a break when something is driving you nuts. who knows maybe someone else with tons more experience, while playing with cad will have it figured out while I work on the other stuff

[proflooney]

well I got the basic middle station shape my problem is going to be finding an easy way yo get the rest of them and have a smooth transition between each without having the starved horse look. too bad the inner and outer portions werent the same shape but nooooo that would be too easy hehehe

[DrPR]

Looks pretty good.

I used the buttock lines as test curves to check the accuracy of the hull surface stretched over the station lines. I used a light cyan like you used for the hull surface because it shades nicely and ripples show up pretty good. The buttock lines from the Table of Offsets were a bright color like red. When the hull was shaded, if the surface was perfect all of the buttock lines were visible. If any part dipped below the surface I knew the surface was a high at that point. Looking at the shaded hull surface from the inside I could see places where the surface was too low (high/low = transverse offset from the center line).

Also, I created vertical longitudinal contour lines (slices or intersection of a vertical plane and the hull surface) at the buttock line positions. Then I looked just at these contours and the buttock lines. If the hull surface is perfect the contours and buttock lines will be identical. Good luck getting that to happen!

Another useful trick is to create horizontal contour lines at different vertical heights. These are like the waterlines, and can be compared to the waterlines from the Table of Offsets. Also, if you just look at the contour lines along the length of the line (bow to stern, etc.) you can clearly see of there are any ripples in the surface - the lines won't be smooth curves but will be "wiggly."

Finally, by changing the light angle on the surface any ripples will show up as shadows.

Phil

[proflooney]

yea this is much tougher than the fletcher as the insides of the stations are narrowed and not parallel so will see how it turns out

[DrPR]

Joe,

The stations were not something that was actually constructed. They were just drafting aids for calculating the Table of Offsets. So they really don't have an "inside." In this plan the station lines are on the outside surface of the planking.

The hull was built up of frames, as shown in drawings 00012a.tiff, 00013a.tiff, 00014a.tiff, 00025a.tiff, and 00029a.tiff. The frames were built up of two layers with 13 futtocks - individual boards curved to the hull shape - as shown in 0014a.tiff.

Unless you plan to model the individual frames don't worry about the inside curvature of the frames.

Looks like there were 84 frames. Frame spacing was 30" (2' 6") center to center. The frames were made up of two layers of 10.5" thick futtocks, or 21" thick. So the gap between frames was 9". See 00025a.tiff.

These really are great drawings!

****

It's too bad the ship wasn't saved. It was the last of it's kind. The National Park Service just let it rot away. That is the fate of many museum ships. The USS Olympia C-6, Dewey's flagship at Manila in the Spanish American War, one of our nation's most historic ships, is in danger of sinking for lack of maintenance and repairs.

For the cost of a single F-22 fighter ($412,000,000 each) all historic ships in the US could be repaired and saved!

Phil

[proflooney]

yea i read them and thats what I am drawing them up by. but i want to get the insides correct as close as possible as I am wanting to do it completely as framed as I can in cad virtually. I will do some mods when I make an R/C Model but I am trying to do it proper right now so that I understand how they were framed up