Bob's Favorite Sport; Moving Rocks, Part Two

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. 

Subsequent steps were taken which rescued this rock from its "comfortable" place in front of the rockery, to its proper place on top. No record of these "after thoughts" and actions were made. But here the rock is, nicely capping a continuation of this beautiful rockery.