Cranemaster® High Performance Features
For demanding operations, we have developed Cranemaster® units with improved performance and additional functionality. All our control systems are designed with maximum focus on safety, and depending on system, they offer sensor redundancy, manual override, and fail-safe modes. The computer based systems are DNV GL technology certified.
Our adaptive control systems provide additional performance and control during the lifting operation. It is particularly useful for deep water operations, splash zone crossing of demanding payloads, stroke correction for payloads with high uncertainty in dry or wet weight, reduction of rigging height through piston locking, and payloads with high buoyancy compared to weight.
Adaptive change of Cranemaster® settings during lifting
Subsea lifting operations typically have several phases, including lift-off, splash zone crossing, lowering and subsea landing. For optimal performance, each phase requires a different setup of the PHC unit. With our adaptive control system, used for the first time in the Gorgon project in 2013, we developed a system that was able to automatically change the settings of the Cranemaster® unit for each phase. The settings may be changed automatically based on depth, pressure or forces, or through manual control via radio (in air) or ROV (subsea). Today we have several versions of the CMAC system available, from pure mechanical control to advanced computer controlled systems.
Weight & Temperature Correction
Correction in air and water for temperature variations and variations in load weight and buoyancy. Deviations from calculated loads weigh does not influence performance.
Quick Lift – Avoid re-contact after lift off
For cranes with a slow lifting speed, there may be a risk of re-contact between the structure and the barge. Using on-board Nitrogen pressure, the Quick Lift functionality will lift the payload by pulling in the Cranemaster® piston and thereby avoiding the re-contact.
Lock & Release
The radio-controlled locking system will reduce rigging height by locking the piston in zero-stroke during over-boarding, avoiding the static stroke in air. The system may also be used to lock the piston subsea if required based on depth or ROV control.
A common challenge when using passive heave compensators in deep water, is the deep water pressure pushing the piston back in, resulting in reduced efficiency of the system. Our depth compensation functionality remove this problem as the stroke will remain constant independent of depth.
Cranemaster offers two solutions for depth compensation, electronic and mechanical. The mechanical system excels in its simplicity and ability to compensate for ultra deep water, while the electronic system additionally compensates for temperature variations and changes in buoyancy. A combination of the two principles may also be used.
The mechanical depth compensation system is covered by US patent 7934561 “Depth Compensated Subsea Passive Heave Compensator”. Cranemaster has been granted an exclusive worldwide right for the use of this patent.
Monitoring & Logging
ROV monitoring and control (e.g. piston lock subsea). Logging of forces, velocities, accelerations, pressures, stroke and temperatures for post-lift download and analysis.
Our revolutionary CAST system gives extremely good performance during the splash zone crossing. The probability of slack slings or high DAF is significantly reduced even for the most challenging objects. The CAST system (Patent pending) changes the spring characteristics continuously during the stroke cycle, providing an optimized stiffness at each stroke position.
This will give an enlarged operational weather window, particularly useful for
• Objects with a large horizontal surface (e.g. manifolds, templates, suction anchors)
• Objects with high buoyancy compared to weight (e.g. protection covers, mud mats)