Crane Hydraulic Jacking System

When Pacific Kiewit needed help identifying a 20-year-old hydraulic crane jacking system made in France, they called Western Dynamics, Inc . A search of manufactures records showed no information at all, even Western Dynamics records dating back some 30-years was of no help. That left one option, fly down to the job site and look at exactly what we had.

The maintenance personnel had already drained the oil tank and found a plugged inlet screen to the double pumps, which had caused the initial problem of no flow to the pumps. This jacking system operated (14) hydraulic cylinders used to support the crane and load during operation.

That left the problem of how exactly did this unit work and the of condition system. With the top of the tank off revealed a maze of hydraulic lines and components. Two of the manual valves on the operators panel were frozen, with two hydraulic gauges, one 0-60 bar and one 0-400 bar located on the operators panel. With three relief valves, one unloading valve and (11) selector valves to the system, it would take some time to figure this one out.

While we studied the circuit, the maintenance people worked to loosen the frozen valves. We had a fair idea how the circuit was suppose to work, and suggested that we partially fill the oil tank and operate the circuit. Because all plumbing was under oil level, we needed to see if there were any leakage and which relief valves were working.

The circuit worked pretty much as we figured and pretty well for the age of the components. We did replace the gauges, and designed new locking valves for each cylinder, simply to upgrade these valves to a known pressure rating and condition. The locking valves were the most critical components in the system, as they were used to lock the cylinders in position during operation.

Western Dynamics, Inc provided a current circuit drawing, replacement parts list of USA made components and operational procedure for Pacific Kiewit. Some day this system will be replaced with an updated hydraulic circuit, but until then the customer now has the confidence of knowing what they have will provide an operation they can depend on.