Great replys. As a 12 year Operating Engineer before my Fire career I was a crane operator. Definetly stop by and talk to an operator. Better if their in the IUOE. You will get more accurate info. The general rule of thumb is the tonage rating of your crane or ladder truck in this case, is divided by the number of outriggers that you have. That then gives you the square footage of the pads to throw down. Example: 100 ton crane with 4 outriggers. 100 divided into 4 = 25. You then need 25 square feet under each pad. you should have a 5'x5' pad under each one. Example: a ladder truck rated @ 80,000 lbs totally loaded in service = 40 ton divided by 4 outriggers is 10 square feet per pad. As in other replys the situation will dictate if that is enough , not, or too much. Better safe than sorry. Also someone asked why the pins in the riggers and not the hydro. rams on the ladder. The outriggers once deployed are done being used unless you start to sink and need to extend them more, which you should be able to do without removing the pins. Just a safety feature. The rams on the ladder are constantely being raised and lowered so that feature is not available. I hope that was helpfull.