crane turntable bearings

Turntable bearings are important components of cranes that support the weight of the equipment and allow the crane to turn. A failure in one of these components can result in the collapse of a ship crane. This is especially true in a marine environment where a large amount of water can be present. The turntable bearings used in a marine crane are designed to withstand tilt torque as well as axial force.

When the Mi-Jack crane 4087 collapsed in 1989, the cause was determined to be a failed turntable bearing. Investigators discovered signs of wear and pitting in the raceway, as well as corroded balls in the bearing. They also found evidence of inadequate lubrication. CSX hired a subcontractor who did not properly maintain the left rear wheel turntable bearing. However, it was CSX's failure to maintain the bearing that proximately caused the collapse.

CSX had a duty to protect employees, as well as other cargo vessels, by inspecting and maintaining the bearings on its cargo ship rotating cranes. However, CSX did not monitor the condition of the bearings for over 10 months prior to the collapse. In addition, CSX failed to review maintenance records submitted by its subcontractor. These violations proximately caused the injury and death of Warren Kubicek, an operator of the crane.

According to Edward Holmes, an expert in metallurgical science, the failure of the left rear wheel turntable bearing on the crane was caused by a lack of lubrication. As a result, the bearing was not able to withstand the lateral force on the bearing. He also opined that the bearing was prone to wear due to its high load.

However, forensic engineers found spalling and circumferential cracks in the bearing raceways. These cracks could not be accurately determined because the crane was torn to pieces and the equipment was incinerated. There were no other abnormal phenomena on the crane at the time of the collapse.

The vertical deflection tests on the cranes were not performed for over ten months, despite Central Intermodal's warnings to the crane operators to perform the tests regularly. The records of these tests were not documented and subsequently ignored by CSX.

After the collapse, CSX was forced to pay the costs of litigation against Pacific Rail in a state court. Pacific Rail disputed the CSX's claims that the failure of the left rear wheel turntable was the cause of the crane's collapse. It argued that the breach was not proximately responsible for the collapse. Ultimately, the judge ruled against CSX, but the company was able to obtain a declaratory judgment.

According to the investigation, the left rear wheel turntable bearing on the Kodiak crane had not shown any signs of damage when it was first installed. Nevertheless, the bearing was damaged as the years went on. Although the crack was not visible initially, it appeared to be a circular crack. Workers noticed the noise and top-down inspections, and in the weeks following the storm, they observed vibrations.