Slate has a fascinating
column discussing why in the twenty-first century we use bags of sand to attempt to stop flood waters from breeching levees. The answer comes down to the fact that they are low-tech, cheap, easy to use, and surprisingly effective in battling
floods.
Comments
The article bears out what I have long suspected from my days in the military when I filled plenty of sandbags in Vietnam. On TV the volunteers throw the bags down every which way, leaving gaps and not packing the bags tightly, rather loosely in fact.
To build a good wall of sandbags you have to fill the bag no more than half full, flatten it by swinging the bag and banging it flat on both side, then laying them like bricks, interlocking them in say a Flemish bond or something similar. That will hold back a blast. For water you need the wall wider at the bottom for stability not only against water pressure but also the force of the current.
I also shudder at what passes for sandbagging in Hollywood movies. I once survived a hit by an RPG on the sandbags I laid around my foxhole, so I know whereof I speak.
thanks that really helped me