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Strand Jacks Smart Cylinder Control System Enable Safe and Synchronous Lowering of Shaft Lining for Underground Mine


Oyu Tolgoi




The proper installation of shaft lining is crucial to the safety of mine workers. Conventional methods may involve workers on the shaft floor during the installation process, which poses a safety risk.

Oyu Tolgoi, one of the largest known copper and gold deposits in the world, needed to install steel lining in vertical ore bins up to 3 metres in diameters and 30 – 70 metres deep. They were seeking a safe and reliable solution that offered precision and synchronous control.


Enerpac strand jacks are powered by electrical or diesel driven hydraulic power packs and controlled by proprietary SCC-Smart Cylinder Control System to ensure full control of lifting and lowering operations. They are ideal for customers seeking precise synchronous control with heavy lifting capacity in an economical, compact, and reliable foot print. Four HSL7006 Strand Jacks were used to install the steel lining at Oyu Tolgoi.

Typically used in above ground applications to lift large loads over great distances, this marked the first time Enerpac strand jacks were used underground. With an automated locking-unlocking operation, the system can be controlled by a single operator from a central location for increased safety. Besides providing greater synchronous control during lowering, it also allows fine adjustments to be made while lowering to clear obstacles during installation.

The system provides clear feedback on distance travelled, stroke and load per point, an important feature that enabled precise, synchronous lowering of all strand jacks.

With 2.5 minimum safety factor over strand breaking load and the Enerpac SCC propriety control systems, the jacks operated safely and effortlessly without concern of any sequencing errors as telescopic strand guide pipes prevent bird caging the strand or strand guides.

Satisfied with the performance and safety of the solution, more units of the strand jacks were procured for other applications. The Enerpac strand jacks elevated the overall operation safety for Oyu Tolgoi.

Hydraulic Strand Jacks