Wood deck on steam tug

[Patrick Matthews]

I'm attempting to do a more-correct version of the Dumas Brooklyn tug, and am stuck on the deck.

 

Brooklyn (designed 1910) had a steel hull and steel deck beams, but an all-wood deck. The kit would have us scribe plywood sheet with a straight fore-aft planking pattern. Doesn't seem right.

 

Brooklyn's deck house sides "parallel" the deck edge in plan view, and the one cross section view we have from the original plans show 3x3 pine deck planks between the waterways. (Is the beveled plank adjacent to the deck house also a "waterway"?).  Anyway, this suggests that the planking would follow the deck edge curvature over the fore & after decks, which leads to joggling at a central king plank. But I have found no plan or photographic evidence that this was done on tugs of this era. 

 

Anyone have better info before I go and joggle a whole bunch of planks in vain? 

Edited Wednesday at 11:47 PM by Patrick Matthews

[Patrick Matthews]

Well, I found a video and a still of W.O. Decker that show:

- Planks curving to follow the deck edge;

- Apparently NO joggling at the king plank, just pointy-ended planks. 

 

I wonder if that's the original layout?

[Patrick Matthews]

And here is Decker's foredeck during restoration. 
Hmm, I have to assume this is being done in a prototypical fashion?

And nothing like Brooklyn's 3x3 deck planks!

[Patrick Matthews]

And why no joggling here? 

My guess is that the steep angle of approach means the cut plank ends aren't "too" pointy, therefore joggling isn't needed to allow for secure attachment close to the end. A more slender yacht will have a shallower approach & sharper ends, so joggling is called for.

 

I think I've seen a rule-of-thumb for this... anyone have that handy?

[Patrick Matthews]

OK, did my searching here and found:

Clear! 
Thanks for the help everyone, it's been a blast.

[wefalck]

The purpose of 'joggling' of planks is to facilitate caulking: the point would be difficult to caulk, because it is likely to break off, when you drive in the cotton with the caulking iron.

 

However, no 'real' caulking would be needed on wooden decks laid over steel-decks. I would be sufficient to fill the seams with pitch/marine-glue. The wooden decks are a sort of sacrificial protection of the steel-decks, make them less slippery, provide thermal and acoustic isolation for the spaces underneath.