Making a domed Late Roman shield

[Medicus matt]

Dug Simon James' Dura report out of the book room to see what he had to say about the oval shields found there.

Average is 1.05m high by 0.9m wide. Board thickness at centre under the boss was 9mm, tapering down to 3-5mm at the edges. Covexity is impossible to judge accurately due to post depositional distortion (some of them show no sign at all and may well have just been flat ovals) but he estimates that the high point at the centre would be 10 cm above the height of the rim (as evidenced by the remains of shield 619, where some planks were still curved)

Looking at the drawings of the surviving boards, most of the concavity must have been achieved by shaping/carving/planing after assembly, as the planks themselves don't seem to show much evidence of the tapering needed at the top and bottom to allow a barrel stave construction. You can get a good curve in one plane by butting parallel edged boards but to get a real lenticular shape you have to shape the boards either before or after assembly.
The boards do show signs of having been shaped with a plane or draw knife.

Holes for the attachment of the leather/hide rims are about 8-10mm in from the edge and 6-9 mm apart.