Pipes are laid above ground beside the trench, or within the trench on top of supportive sandbags in steep terrain. “Stringing” is the method by which pipeline construction workers assemble the pieces prior to completing the “puzzle,” making sure everything is accounted for. Every length of pipe is marked to indicate where it belongs along the line, as the thickness of the pipeline and the coating used on it has been applied based on the location and soil conditions in the area.