Sided/Molded dimensions

[imported_Snatchblock]

I have been looking at an old set of plans that had a piece's " sided and molded " dimensions- what does it mean?

[htom]

Sided is the direction fore&aft, along the planking, molded is the direction towards the center of the boat. If you walk up to a small boat and grasp the gunwale, with your thumb stretched along it, your thumb points in the direction of siding, the tendons point towards molding.

[Nicholas Carey]

molded is, I believe (I allus have to look it up[1] :D ), the radial dimension, and sided is the lateral dimension.

So, for, say, a frame, the sided dimension is that of the surface that lays against the hull and is parallel with the centerline of the boat, while the molded dimension is that of the surface of the frame lying perpindicular to the skin of the hull.

For a deckbeams and carlins, the moulded dimension is the vertical dimension and the sided dimension is the horizontal dimension.

[1]And I'm sure I'll be corrected if I'm wrong :D

[ 09-10-2003, 01:12 PM: Message edited by: Nicholas Carey ]

[mmd]

The little mnemonic that I learned was that the timber moulded to the curve of the hull and was just sided to thickness.

[imported_Snatchblock]

Originally posted by htom:
Sided is the direction fore&aft, along the planking, molded is the direction towards the center of the boat. If you walk up to a small boat and grasp the gunwale, with your thumb stretched along it, your thumb points in the direction of siding, the tendons point towards molding.what about the stem? which would be sided and moulded? Is molded always the bigger dimension? Why not just say thickness and width?

[ 09-10-2003, 02:11 PM: Message edited by: Snatchblock ]

[dmede]

Originally posted by Snatchblock:
</font><blockquote>quote:</font><hr />Originally posted by htom:
Sided is the direction fore&aft, along the planking, molded is the direction towards the center of the boat. If you walk up to a small boat and grasp the gunwale, with your thumb stretched along it, your thumb points in the direction of siding, the tendons point towards molding.what about the stem? which would be sided and moulded? Is molded always the bigger dimension? Why not just say thickness and width?</font>[/QUOTE]i beleive for a stem the molded dimension is the fore and aft dimension as viewed from the side. the sided dimension is just it's thickness.

[Dave Fleming]

what about the stem? which would be sided and moulded? Is molded always the bigger dimension? Why not just say thickness and width?

The same for stem and sternpost.
And those plans are from the day folks spoke a langauge specific to wooden boats and ships.
Such dimensions were picked up off the lofting as templates to use when cruising the wood lot for appropriate timbers. As most craft of size had sawn frames etc...
Lofting 101, eh?

Look here: Scantlings (http://srmwww.gov.bc.ca/arch/pubs/ship/scantfas.htm)

[ 09-10-2003, 02:36 PM: Message edited by: Dave Fleming ]

[George Roberts]

Dave's link has a link to the table of contents where there is a link a glossary, where one will find definitions of "Moulded dimension" and "Sided dimension."

I will agree with others that the "moulded dimension" is in the radial direction.

The "sided dimension" is the other width dimension.

The length dimension is the normal length.

[Nicholas Carey]

It's got nothing to do with thickness, or with fore-and-aft, or athwartships. It has to do with the orientation of the piece with respect to the center of the boat.

Let us, for the purposes of discussion, model the boat as a sphere (not a very good boat design :D but a useful model for this discussion). We're going to install a piece of framing that will lie in the inside of the sphere.

The sided dimension specifies the measurement of the timber face that will lie against the surface of the sphere; the molded dimension specifies the dimension of the face that is perpindicular to the siding face (and thus extending toward the center of the boat).

The glossary in Dave's reference spins it a bit differently: the molded dimension is that of the face on which you lay the mold (meaning curved template):

Moulded dimension: The measure across a timber face to which a mould, or curvature guide, would be laid. In general, moulded faces of single timbers are parallel to each other. Eg. for a floor timber in place, the vertical dimension is the moulded dimension.

Sided dimension: The measure of a timber face which takes a curve. ie. for a floor in place, the fore and aft dimension of the face upon which the keelson rests is the floor timber's sided dimension. So stems are molded fore-and-aft (towards the center of the boat) and sided athwartships.

[Venchka]

Originally posted by Nicholas Carey:
...So stems are molded fore-and-aft (towards the center of the boat) and sided athwartships.Looking at my Caledonia yawl plans which I keep here in the office for emergencies, I say, "YES!"

[Thad]

I believe that these descriptions are functional working descriptions based on the way the piece is planed in the mill shop to be presented to the mechanic for fitting in the boat. "Siding" is done to the timber to give the flat parallel sides as defined in the plans out of which the builder cuts and shapes (molding) the pieces as called for on the loft floor.

[htom]

If you put your hand on the stem, with your thumb pointing along the sheerstrake (siding), your hand's tendons will point to the center of the boat (molding).

The words are used because they describe dimensions in a "boat world", where things are not always reasonably measured in perpendicular straight lines. In some ways, "molded" is mathematicly normal to the hull's skin, but not always.