Share 'Trench Rescue Techniques'

In regards to setting up "Ladder Bridge" systems for trench rescue scenarios... 1) What does your ladder bridge system consist of? 2) Do you use ground pads AND ladder bridge, or use one or the other? 3) When using the spoils pile to support one side, do you dig into the pile and/or crib a base, or just shoot the ladder into the pile? I am trying to find some detailed information online... anyo…