the escapes we had with concertina were with double thick blankets (old wool Navy style) thrown over the top. Were favored the inward (Towards Mexico) curved fence and none of our staff or inmates could get over it.
https://duckduckgo.com/?q=curved+prison+fences&t=osx&iar=images&iax=images&ia=images
“the inward (Towards Mexico) curved fence”
Much tougher for free climbers, but actually easier for a ladder (unavailable to inmates).