Blasting Ledge - Not DIY No Way No How
Blasting ledge was done years ago with hand drills and sledge hammers. You'd drill down about 18 inches, pack the hole with black powder and light a fuse. Now we have modern safer explosives like TNT and dynamite.
The first step in blasting ledge is drilling holes into the rock. Modern machinery can do this in just minutes. The spacing of the holes depends on the hardness of the rock that's being removed.
Once the TNT or dynamite is packed into the holes, giant mats that have rubber tires and steel mesh are placed over the rock. These absorb the impact of the exploding rocks so they don't go flying through the neighborhood.