constructing and mounting a porpax

[PMBardunias]

Snodgrass says that a majority of finds are of aspises without bronze faces- but his book is old.

And just to clarify (inviting critique) I think that the early aspis was made like a boat--with strakes that were locked together the way ancient ships were planked, and then the rim, face, bronze decoration and/or some internal ropes all helped support the "hull" of the shield.
Then there was some kind of technological change, and shields were (possibly) turned from laid-up blocks of wood--and they became larger and deeper, the internal fittings became decorative because the stresses on the outer edge were totally different. The tech change may even have been driven by societal change--the need for more aspides...
Hey, I'm just rattling on, here, and I accept that these contentions are "edgy." But I have to say that the aspis is a remarkable, fairly high-tech and labor intensive device

I am very glad to hear someone else say this. The parallels between ship and shield construction interest me greatly. It is from ship construction that I hypothesized that the antilabe was origially a truss. Ships of the day had an internal or external rope truss to hold them together. The most common, the tormentum or Upazomata, kept the hull from "hogging", which is exactly analogous to a shield face collapsing.

I'd be curious to know more about parallels in the actual wood working. I know too little about this to comment.

To me , l didn't think this idea feasible ( consider the thick iron of a wagon wheel tyre) and in any event, the bronze is on the face, not the edge as such....imagine how a tyre iron would work fitted to the side of the wheel?

Have you ever worked with metal packing straps? They can be exceptionally strong. I am here talking just of the rim, by the way, not the face. The face can have a different supportive function, but the rim specifically keeps the wooden rim beneath from failing. The wagon wheel is not a good analogy, a barrel hoop would be better since the pressure is from the insided out. To some extent the thickness and the width of metal are interchangable. Imagine a quarter inch cable and a 3 inch wide strap. I don't know what the conversion is off the top of my head, but you can imagine they approach similar strength.

If a strengthening piece was needed, it is more likely to be the iron circular re-inforcement fitted to the inside of later, probably thinner, aspides.

This piece supports in a different way, and is designed to keep the shoulder section of the shield, not the rim, from failing. All of this, with diagrams is on my blog. The aspis is what is called a "shallow dome". They fail in one of two ways: They "pop" inside out like the top of a jar (the inner band of metal and truss help this) or they break at the rim (the bronze rim helps this).