Hi Thomas,

thanks for your valuable remarks, they all make very much sense to me.

A general note about my interpretation of "flexibility" : if an internal structure should be able to move somewhere it must be given space to do so. Trying to follow this rule my interpretation for particular details are the following:

upward bend:
the particular scarf joints of the keelson allow controlled upward bending, bringing upper edge of bow and stern closer together, hence the clearance at the front of cockpit coaming and at the stern.

front and rear poles:
I agree with your 5) and noticed the same. My interpretation is that these poles are the major pieces keeping the distance between the gunwales while lashing them together tightly, so that bow and stern plates can move freely without being pressed together. I am very confident that the length of both poles is adjusted to deliver a small clearance (I would give it 1mm or so) to the half pieces. Hence lashing the plates together would be contraproductive.

So we are really getting flexibility in 3 dimensions here, as we can
- bend the mid-ship axis upward (keelson, clearance of deck stringers)
- move the starbord side against the port side (bow and stern halves - this would maybe work best if the ribs are not pressed hardly, but fitted loosely into their mortises which is mentioned in some sources, too)
- rotate (roll) the bow section beneath the bow halves which leads to a somewhat more complicated movement of the parts.

I will keep this in mind when I start cutting into my lumber ;-) and report about the results - gonna be interesting to see ....

I haven't yet noticed or thought about your 7), but will do so in a few days after returning from a business trip.

Kind regards
Mike
(sorry for the somewhat unstructured text - bit in a rush tonight)

: Dear Mike,

: thanks for your remarks on Zimmerly's Article, particularly for point 3 which
: I had not noticed before.

: As far as I know the connections of the single pieces have not been
: understood as a whole.

: So I would like to draw your attention to some more points (which may have
: been discussed elsewhere already): 5) Stern section
: Contrary to Zimmerly's desription (page 80) it seems that the stern blocks of
: the original were not directly lashed together. Instead, the lashing went
: through the stern piece (see photos on page 31). This kind of lashing is
: described in Morris' book, as well. The thin round deck beam near the
: stern blocks would allow for a well-defined small gap and for a lengthwise
: movement of the gunwales. The lashing around the thin deck beam holds the
: gunwales together.

: 6) Bow section
: Near the bow blocks there is a thin round deck beam, as well. The lashing
: around it seems to have been similar to the stern (see top photos on page
: 31). This construction would allow for a small gap between the bow blocks,
: as well. Unfortunately, there is no description in Zimmerly's Article
: about the lashing of the bow blocks. Were the bow blocks of the original
: directly lashed together or was each bow block lashed to the upper bow
: piece? Zimmerly writes on page 80: "Lash the bow piece to both the
: gunwales and the bow block." I think, in accordance with Harvey, that
: the bow blocks were not lashed to the upper bow piece.

: 7) Keelson
: Is it possible that a number of ribs near the bow and the stern were not
: lashed to the keelson? (At least, Zimmerly's photos don't show any
: lashings on the first bow rib or on the last three stern ribs.) The lower
: bow piece would then be able to move sideways and twist the keelson, as
: well. In that case, the smaller radius of the upper bow piece (compared to
: the larger radius of the horizontal bow plate) would even make more sense
: regarding twisting of the keelson.

: I'm sure that the complex bow and stern construction add to the flexibility
: of the frame which I think was a major design goal. Just not easy to
: understand ...

: Best,
: Thomas