Longitudinal stringers or Transverse ribs for flat bottom

[dick stave]

I have almost a completed set of drawings for a 16 ft.Garvey style hull.Flat
panels have been developed in Rhino 3D and a 1/8 scale model is being built.
My aim is to design a "quick build" welded boat.The basic layout is a 48" flat
bottom with a modest vee bow entry,[pram] bow transom,70" beam, and 21" sides.A large casting platform will be forward with an open sole [pedastol seat] aft.Power will come from a 30 hp Yamaha tiller longshaft.All sheet material will be .125 5052, and I would like to use common extrusions for the structure.I am confident the casting platform will stiffen the bow sufficiently, but Im unsure on which way to go in the aft flat section.Four 3/16"x2"x4" channel stringers could be evenly spaced and stitched in for stiffness and to support the plywood deck. The problem is every "production" welded flat bottom Ive seen have transverse ribs that carry up the sides spaced at about 12" centers.To my knowledge, on vee hulls anyway, welding is only performed in the direction of the keel to avoid introducing stress across the bottom.Is this configuration specific to flats?I guess an argument for
T-ribs is they provide more stiffness than long stringers as the stringers could be compared to a section of corrogated roofing material, stiff lengthwise ,but not across[the oppossite of what you want].Keeping in mind that simplicity,
low hours,and low cost are the focus of this design which is the best configuration?

[Dutch Peter]

Dick,

There are essentially three systems of building a boat with frames, longitudinally framed, transverse framed and a mix of the both in part of the boat or the complete boat.
Please, don't get fooled by the name of the system of framing. You always have an amount of transverse structure in a longitudinal framed ship and vice versa.
in smaller boats a transverse system is generally used, as the boat is stiff/strong enough lenghtwise because of the hull plating. In larger vessels the longitudinal frame system is used to provide addequate strenght in that direction, as the hull plating is no longer enough.
Now having said this, I'm not really sure as to what your question was? Got lost!!