I'm curious as to the best way to split Unilock - Pisa II double unit wall blocks. For those of you that are unfamiliar, they're a retaining wall piece that you must physically break in half in the center to produce a unique face for each piece. I had 150 of these DU's to do, and i did some experimenting with a sledge and chisel, each took 12-40 blows to split in half. with that each block would take 1-2 minutes+ fatigue, hardly fun work at all. I found a very efficient way to do it (IMO) but i'm curious as to how others do it. I'll chime in with my answer after a reply or two.