Barnhart was hired to remove and replace three vessels at a chemical plant in Georgia. One in particular, a 313,000-pound stripper, posed a challenge as it was encased behind structural steel building elements and piping.
Barnhart engineering had to devise a unique approach to removal and replacement. The first challenge was safely crossing an underground electrical tunnel on the approach to the crane setup area. The crew had to partially assemble the crane and then use a Goldhofer trailer to move the house, car body and tracks over the tunnel using Barnhart’s bridge jumpers.
A second crane, which is normally used to assist the main crane in the handoff operation, could not be used due to site constraints. Barnhart used a Tri-Bar to connect to the stripper, then ran the rigging up to a set of pull-up gantries sitting on top of a 500-ton slide system.
The 41' long and 12' diameter piece was drifted horizontally 5 feet and then rotated 45 degrees and lowered as it was passed to the crane for removal. Using 3D mapping, Barnhart was able to create the path, which only allowed for as little as a quarter-inch of clearance in some areas.
The piece was then lowered until it could be tailed safely down onto a Goldhofer self-propelled trailer. The process was reversed for the new stripper, which required different rigging because it was not identical to the old one. By finishing three shifts early, Barnhart saved the customer $1.5 million.