I found the dimensions of the Oseberg frame (an archelogical find from a sunken Viking ship) in small print in the end notes of Hoffmann's The Warp-weighted Loom: height 119 cm and width 75 cm at the base (about 47 x 29.5 inches).
I plugged that into the calculator: 119 divided by 75 = 1.5866. That's so close to the golden ratio, Φ, phi, 1:1.618, the proportions the Parthenon were based on. Ooooh, aaaah.
I am using artist canvas stretchers for a frame when making språng fabric. I have 50 inch pieces for uprights with 16 inch cross pieces, and I have 31 inch pieces I can use for cross pieces instead. That would get me very close to the size of the Oseberg frame. I hear from someone who has made a full-size one that a reproduction Oseberg frame has quite a lot of mass especially at the base. Thin stretcher bars won't get me the same stability, unfortunately, and that's a problem. You need to have your hands free to plait the threads.
I saw the same picture of the Oseberg frame in a different context with the label "sprangvævstol."
Hoffmann doesn't call the Oseburg find a språng frame at all, she calls it a loom. Reading the passage, she must have found rather galling that its attributes and those of the frame in the Hrabanus Maurus MS De universo didn't make sense to her. She was trying to make them fit the mould of a warp-weighted loom. All her objections (such as the thin line in the MS that runs across the warp like a cord, not a heddle rod) get resolved when you think of working språng. But she writes, "We do not know for what purposes the looms were used," (p. 330). Earlier in the book (p. 167-170) in the context of selvedges and tablet-woven starting borders, Hoffman discusses the språng stocking or sleeve from the Tegle find. She speculates that it was done on a two-beam tapestry frame. This indicates that she did understand språng. Perhaps this section was written later than the one about the frames. Anyway, neither she nor her editor caught the connection.