Since its founding in 1918 in Japan, NTN Driveshaft has established itself firmly as one of the world’s leading general manufacturers of bearings
Runway trouble
Late in 2011, Nathan Beane, new business development for Konecranes, met with representatives from NTN Driveshaft about performing inspections on their overhead lifting equipment, but he quickly learned that their most pressing concern was not inspections—it was with the alignment of their three 5-ton double girder under-running overhead cranes in relation to their
800-foot runway.
With the runway issues, the bridge wheels on the crane were wearing out nearly every week. Replacement wheels cost a few thousand dollars, not including installation. Plus, having these cranes out of service had cost them a fortune. To keep production running, they had to use two mobile cranes with two crews to move the equipment. These expenses added a cost of $50-
60,000 USD per month.
After asking their crane service vendor for an answer to the true source of the problem, it was unclear whether the runway or the cranes were the problem. Beane presented Konecranes RailQ Runway Survey, which would provide NTN Driveshaft with a 3D, computer-generated report of the condition of their runway.
Straightened up
The RailQ Runway Survey revealed straightness deviation and problems with the elevation and the span of the runway. Because the span of the runway did not match the span of the crane, a Konecranes Crane Reliability Services specialist performed a crane geometric survey and determined that the crane had to be modified to run along the runway correctly.
Konecranes changed out the runway beams and engineered modifications to the end trucks and mounting connections so that the span of the crane matched the span of the runway. The runway was straightened and leveled according to CMAA Spec 74 specifications for under-running cranes.
“Now, the customer is very, very satisfied. We weren’t even doing their inspections at that time. Since the repair, we now perform all of their MAINMAN inspections,” said Beane.