My whole point is that i understand multiplied forces etc. And rating of straps is not what the breaking strength or "work load is". That said i have an 1800lb yanmar which is strapped down till tires buldge and wont move by two 10,000lb BREAKING strenght straps, each have a safe working load limit of 3,333lbs, a third or the strenght as per osha standards i think is how thats determined. So i have 20,000lbs of holding strength on my 1800 lb machine i think that is plenty and i have been thinking about adding a third onto it making it 30,000lbs i have full faith in my straps as holding the load down. I am not using 4500 lb total strenght 1.5" straps like some but full size straps next size below the trucker 3" wide straps that are ratted at like 30,000lbs, **** they are only required by law here to throw 2 straps over the 50,000lbs of wood they haul, that makes me better off than they are hauling 50,000lbs with 60,000lbs of strapping ability.