There are three classes of levers, depending on the relative positions of the effort is applied, load, and fulcrum. 1  First-class levers have the fulcrum located between the load and the effort (LFE). If the two arms of the lever are of equal length, the effort must be equal to the load.
1 Ebro: From the 120 Foot level of the new cell tower, This is Ebro.
You see, this is what I was taught as well. But our Air Force training books say Architectual E size is 30x42 and has said that for the last 10 years. Soooo, either they have been wrong all along, they use a different Architectual Standards system (which contradicts its name), or thats some other kind of alternate E size.