I've been talking with a colleague about barbed wire and have learned some surprising things, such as how many patented types there are. How many of those barbed wire types are in use today, I have no idea.
Below is an example of one type.
Image from Barbs, Prongs, Points, Prickers, and Stickers - a book cataloging the various barbed wire types.
3D Model of Gunderson's Closed-spanner Barb
Turntable animation/video of Gunderson's Closed-spanner Barb
