FPT has developed a technical solution to manufacture hydraulic jacks with a safety lock ring, even for double-acting models in the CRI-GS Series. This design is extremely useful because it allows the cylinder to retract hydraulically without the return stroke being under load, as is the case with single-acting models.

The threaded ring allows for the mechanical locking and holding of the load even for very long periods and with the power unit disconnected. The operator can therefore work safely under the lifted load.
For this specific application, we designed, to the customer’s specifications, four high-tonnage double-acting hydraulic jacks with mechanical locking rings, rated at 600 tons with a 250 mm stroke and 700 bar pressure.

The four jacks are powered by two electric power units and are used to lift and support a section of the ship during onboard ship maintenance operations.