Trenching and Shoring

I'm at work right now [ha HA!] and I'm taking some on-line saftey tests. I'm done with the ones I was supposed to have mastered, and I came across one about "Trenching and Shoring." I realized that I want to master this knowledge, too.

Here are some critical quotes from the slide show regarding "trenching and shoring":

"When you dig a trench, you're not just digging a big hole—you're entering a different world. And it can be a dangerous world down there."

and

"When you set foot in a trench it's like entering another world. Whether you come back out alive or not depends on how well you know the natural laws of dirt."

I will tell you more once I have become a MASTER.