Photo: Entrance to the Houston Area Safety Council in Pasadena. HASC and ITI have partnered to offer hands-on crane, rigging, and load handing training to both HASC member and non-member companies.
Dear Friend,
Rigging Workshop - Determine Center of Gravity
A crew must load out a short bridge column which will be used in a creek bed to support one end of a light bridge deck. The crew rigged the precast column at two locations about 24' apart. Using two cranes, they have decided to determine the location of the column's center-of-gravity so they can load the column onto an over-the-road trailer. By properly placing the column onto the trailer, the resulting axle loading allows the tractor trailer to not exceed any travel limits.
Use section two of the Journeyman Rigger's Reference Card to help solve the question about the column's CG. Instead of using Run1 and Run2, consider replacing them with Weight1 and Weight2, to arrive at the percent distribution, times the total space of 24'. To double check your work remember, "Short Stout, Long Light," which translated means, the CG is a shorter distance from the stout (heavier) end, and a longer distance from the light end.
Your Task: Estimate the location of the column's center-of-gravity from the "head end." Check your answer below!
