Load Chart Improvement

Utilizing a Cranemaster® shock absorber enables rig cranes to maintain high lifting capacity despite increasing wave heights. 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 can further be verified by 3rd party.

Operational Challenges

  • Reduced lifting capacity at increasing wave heights.

  • Potential damage to rig crane and load due to dynamic forces at high sea states.

Cranemaster Benefits

  • Increased weather window for your lifting operations.

  • Lifting capacity maintained despite increasing wave heights.

  • Increased rig utilization through improved operability.

  • Protection of crane, rigging and load at lift-off.

  • Easy mounting and handling.

  • Smooth and efficient crane operator experience.

Cranemaster will help you reduce the dynamic load at lift-off, and thus improve your weather window

Ready for lift-off.

The Cranemaster® unit with shackles in both ends can be hung in the existing crane hook.

Impacts from load absorbed before transferred to the crane.

Protection of both crane and load.

Significant improvements 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.

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.

crane tension lift-off supply vessel rig shock absorber cranemaster DAF

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.

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.

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, both crane and load will be protected. This makes it possible to conduct the operation in challenging sea states while limiting dynamic load acting on crane and load.

Load chart improvement using cranemaster

Example for a specific radius as function of the significant wave height.
= Original crane capacity = With Cranemaster.

Cranemaster® shock absorber in action during lift-off from supply vessel.

Featured References – Load Chart Improvement

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