Use of Air Knife

How many of you use the "Air Knife" for rescue ops. Does it work well with the vacuum attachment?

We use both the air knife and the vacuum. The air knife works great but we have a tough time with the vac. We seem to have the correct air pressure but it never seems to work well at all. I am very happy with the knife, never had a problem with it. Good luck and let me know if you find any answers.

What about industrial vac trucks? We have an agreement with local public works which allows us access to this machine. They can be a valuable asset if used properly. The tradeoff is the noise and vibration they cause, but this should be considered on a situational basis. If you have sand or sandy loam type soil...they are perfect. Our only problem is the amount of shale we have in our soil. They can basically take in anything that fits in the hose, liquid or soild.
At a recent major trench collapse my department handled, we discussed such option and determined that the truck was available in that town. The two things which worked against us in that particular case were the blocked driveway (with a rescue vehicle) and the inaccessability of the "hot zone" due to it being surrounded on 3 sides by trees and cut into an embankment. The soil was a very sandy loam type which continued to collapse at the far ends of the trench (which was in excess of 18 feet deep in spots)and made digging around the body difficult due to the running nature of such soil. Had a vac truck been available we could have moved alot of soil and removed the body faster than shovel and bucket style digging.