Relationship between wing transom, tuck-rail and bottom planks

[alexmd]

Hi everyone

 

Thinking about a POF model and studying the stern framing I have a doubt that I think that is better explained by the drawing below.

 

Question: my understanding of the bottom planking at the wing transom is correct ? (course, if my representation of the wing transom, tuck-rail and its rabbet is correct)

[druxey]

If you are referring to 18th century British ships, it's not quite as simple as that. The lower aft edge of the wing transom has a changing bevel for the bottom planking to land on. The upper 3" or so is left vertical and the junction with the bevel is called the margin line. The tuck rail is attached to the wing transom along the margin line as well as overlapping the bottom plank ends by a few inches. This rail is very tricky to make, as the rabbet on its fore face changes angle continuously along its length.

 

The photos should explain this better than words.

[src]

Druxy, that is some beautifully clean work!

 

 Maybe this should be a separate topic, I dont want to steal this thread, if so I will happily delete this and repost, cause now I am curious.

 

In your picture this tuck rail appears to be an applied molding, is it simply to hide the transition from the transom to the planking or is there more going on on a real ship?

Sam

[druxey]

The rail has more than an ornamental purpose, Sam. It protects the end grain of the lower hull planks from water penetration and premature rotting. Exposed end-grain was to be avoided anywhere on a ship if at all possible.

[alexmd]

Hi Druxey

 

Yes, I was referring to the 18th century British ships, frigates specifically.  Thanks you for your explanation. 

 

In my opinion, the stern is a very detailed structure, with several minor parts difficult to model.

 

 

[src]

Thanks Druxy

sam

[allanyed]

Also watch to see if the tuck rail crosses the ports.  The following sketch and photo of the Leda, a contemporary model in the Rogers collection show this.

 

Allan

[druxey]

With all due respect, Allan, I think the actual construction was as in the modified diagram below. Do you have information to the contrary? A section of the tuck molding was attached to the lower edge of the port lid, of course.

Edited October 20, 2013 by druxey

[alexmd]

Hi Druxey

 

This scheme in your last post can be applied to the 18th century british ships (including frigates) too ?

 

I like it because this "side vision" is perfect to ilustrate the answer to my original question - the relationship between wing transom, tuck-rail and bottom planks (and, also, the margin line)

[druxey]

I believe from my study of the subject that this is correct for 18th century British construction. The width of the margin on the wing transom varies depending on the size of ship, of course. It is as much as 6" for 110 gun ships and down to 3"  on small ships. For frigates it could be, as Allan shows, 4 1/2" or 5".

Edited October 21, 2013 by druxey

[alexmd]

Hi Druxey

Thanks again !

By the by, you (or someone else) could me clarify why, in some plans, the tuck rail has a narrow (almost erased) line ?  It seems a "duplicate line". See the image below.

[mtaylor]

Alex,

 

I think that line shows the amount of roundup of the tuck rail.  In the case of your drawing, it not only shows the roundup but the "round out" as it also curves outward.

[druxey]

The narrow 'second line' is the the upper edge of the tuck rail. The heavier lines are the 'shadows'. If you look at the aft edge you will see the profile. From top to bottom: a rounded bullnose, A small vertical, a concave and, at the bottom, another rounded bullnose.

[alexmd]

Hi Mark and Druxey

 

Thank you for clarify me.

 

I think that this discussion, even about a simple rail, was useful... at least for me, a begginer and curious about details.

[allanyed]

Druxey,

You may very well be right in that your drawing has a rail that truly "tucks" in between the counter planking and hull planking.   I can not quite tell from the contemporary model photos that I dug through, but they truly look to lay over the seam of the planking.   I did dig through my NMM drawings and they do not show enough detail to indicate a tuck nor a laid over tuck rail.  Would love to find a contemporary drawing showing this.  I found the attached at the NMM Collections site when doing a search for "Stern Rail"   The rail does not look to be laid over the planking as I had surmised but much closer to what you show.  Sure looks like a "fun project" making the rail as shown on the photo.

 

Allan