Load Chart
Improvement

Utilizing a Cranemaster shock absorber enables rig cranes to maintain high lifting capacity despite increasing wave heights. The dynamic load is reduced up to 95%.

Up to 95% of the dynamic forces will be absorbed by the shock absorber, protecting both crane and load and giving a smooth operator experience. We can recalculate your load chart taking the dynamic load reduction into account. The new and improved load chart is normally verified by 3rd party.

Operational Challenges

During offshore lifts, weather conditions can provide several operational challenges, like:

Reduced lifting capacity at increasing wave heights.
Potential damage to crane, rigging and load due to dynamic loads at high sea.

Cranemaster Benefits

When using a Cranemaster unit during the offshore lift operation, benefits will include:

Increased weather window for your lifting operations.
Lifting capacity maintained despite increasing wave heights.
Increased crane utilization through improved operability.
Protection of crane, rigging and load at lift-off.
Easy mounting and handling.
The unit is self-contained. Hook-up and use, no extra connection of cables or hoses.
Smooth and efficient crane operator experience.

Significant Dynamic Load Reduction in Lift-off Situations with Cranemaster

The dynamic amplification factor (DAF) resulting from wave induced movements may be very high even for small wave heights. A Cranemaster® shock absorber mounted between the hook and the load will reduce the dynamic load at lift-off, and thus the DAF. The DAF is typically reduced to 1.3 or below for sea states up to Hs = 2.0-2.5 m.

Load Chart Improvement - Illustration of crane wire tension with and without a Cranemaster — The graph shows the reduction in dynamic load at lift-off with and without the use of Cranemaster. The reduction in maximum dynamic load (and DAF) enables the improvement in load chart capacity.

We can recalculate your load chart taking the dynamic load reduction into account, and will thus increase the acceptable load as function of sea states. The new and improved load chart can further be verified by 3rd party. In order to do the recalculation, we need to have specific information about your crane.

The simulation shows a Cranemaster shock absorber in operation during a lift-off from a supply vessel. Mounted between the hook and the load, the unit will reduce the dynamic load in the crane, and thus the DAF.

Increased Crane Capability at High Sea States

Utilizing Cranemaster, an offshore crane may typically be able to maintain close to full onboard capacity up to a wave height (Hs) of around 2.0 – 2.5 meters.

Load Chart Improvement - Illustration of SWL chart with and without a Cranemaster — Example for a specific radius as function of the significant wave height.
Beige = Original crane capacity | Blue = With Cranemaster

Cranemaster has controlled dampening and spring functionality, providing a fine tuned spring-damper system. This system will efficiently absorb energy created due to the relative motion between crane and load in a lifting operation. Since the energy is absorbed by the Cranemaster unit, crane, rigging and load will be protected. This improves the load chart and makes it possible to conduct the operation in challenging sea states while limiting dynamic load acting on crane and load.