Early November 2012; On Site at the Tennis Club --
In the continuing saga of the movement of rocks, we ultimately encounter disaster -- of a humorous sort! The victory of Physics over Engineering. Keep your toes and fingers out of the way!!
In this second installment of the "rocky" adventures of the inveterate and never-discouraged Z-Brothers, we find them moving the third biggest rock from the pile on the lower side lawn into an elevated position in this meter-high rockery. Please note the use of advanced technology here -- a five-sheave block and tackle! [What is this world coming to that these two would resort to such modern equipment when faced with the trivial task of raising a 6-700 pound rock a mere meter and half above the surrounding terrain?]
After using "normal" brute force and cleverness to move this rock from its long-time place on the lower side lawn, to a judicious position below its intended place atop some previously-placed large and intermediate rocks, the brothers decided to employ a recently re-strung set of block and tackle. This set, using five sheaves (pulleys), would provide a force on the rock end of roughly five times the pull on the rope at the other end of this gadget. A carefully-placed and Mechanically-engineered ramp of two-centimeter thick lumber would provide a bridge along which this rock would be moved uphill on rollers to be positioned by the Physics-ian brother. BSME brother, the ever-inventive Engineer of the ramp-bridge, would provide the grunt-power on the working end of the block and tackle rope.
| Victory of Physics (gravity) over Engineering (design errors). |
All went well as the rock moved smoothly up the ramp, past the judiciously-placed bridge abutment that had been previously placed by the thoughtful Engineer. Disaster, in the form of the victory of Physics over Engineering, struck -- exactly as subsequently calculated by said thoughtful Engineer -- as the rock came to the mid-span point between the bridge abutment and the final end of the ramp-bridge. Previously-thoughtful Engineer had neglected to continue his thoughtfulness and provide a support at this critical mid-span point.
