I in the second part was referring to the stationary "setups" as you see. One was invented by Bruce Fullem at the NY SHPO which uses flat steel, angle steel, brass hinges, bolts a welder and a screen box. The 2" flat steel is driven in (pointed) in four corners, the short sides of an angle iron attached at the back by bolts, joined by hinges into a larger rectangle of angle iron, is very efficient, and was once for sale at a company in NYC (out of business) that provided archaeological materials. The diagram for one was provided from the NY SHPO office and a second was fabricated at Grossman & Associates, Inc. 

J. G. Grossman, Ph.D., et al, at Rutgers University, NJ (RASO) when excavating at Raritan Landing, NJ, used a system that may have been invented by Kardas and Larabee, Larabee one of the founders of SHA. It used tracks from garage doors and wheels on bases for larger screens that used the available technology for easing the screens.

Edward Johanneman, MA at Stony Brook University had a son in general contracting and had some different systems made and tried. One, say a 1x2 ripped at an angle, with formica glued on both angles resulting, one attached to a small screen box and the other to a base of four threaded pipes and bases attached to a platform, was fairly smooth out on Long Island, primarily glacial outwashes and moraines. Another had small pipe rails on the base and > (less than) 1/2 section of cut pipe and ground of the same diameter attached to the sides of the screen box, which worked well as one is usually lifting the screen box and very short section of the 1/2 pipe gliding along the pipe rails. There was another which made of oak, had a number of PVC pipes over large dowels, creating a wide ladder like deal, about 5 feet long, and the screen box slid over the dowels pretty well, and took the dumping of materials into the screen pretty well. (Suffolk County Archaeological Association, NY, volunteer sites). All used readily 

The best stationary was the first because of the conservation of effort. Six buckets of material could be loaded and operated by less than "Governator" stature, and on one site, about 31 cubic meters of Hudson River prehistoric terrace and 30,000 artifacts or so went quite quickly through it (Wickers Creek, Dobbs Ferry, NY Greenhouse Consultants. Inc.) It was also used in the excavation "Workers Housing" at the West Point Foundry site in Cold Spring, NY (EPA Region 2, Marathon Battery Superfund Site, Grossman & Associates, Inc.)

George Myers