Dynamic Lift Analysis

Dynamic Lift Analysis

The lift dynamic model will assess the dynamic behavior of the lift system during the various stages of the lift and will determine limiting wave conditions for the operation based on a set of operational limits. Furthermore the model will produce workability numbers based on the wave scatter diagram for the season and location of the operation.

The dynamic lift model includes various pre-defined cases covering most offshore heavy lift or other operations, e.g.:

1. Free-Floating No connection between cargo barge and HLV
2. Pre-Tension Barge and HLV are connected with taut rigging with a pre-set hookload
3. Free-Hanging Lift is suspending in the crane above the free moving cargo barge
4. Pre-setdown Lift is suspending in the crane above the setdown points
5. Set-Down Lift is set on the jacket or on the bottom slings are still taut with a pre-set hookload

The Analysis procedures have been programmed in MOSES by Orca Offshore. The Dynamic Lift Analysis programs have been used for many projects and have proven to be reliable and accurate.

The dynamic lift analysis results are suitable to be used offshore for Go/No-go decision-making using the Allowable Seastate plots, or through the OMF system, which provides enhanced accuracy by delivering forecasted utilization per analyzed case, incorporating both wind-driven seastate and swell components independently.

Below you can see a video on an actual lift in a swell seastate and the simulation performed, showing the need for a dynamic lift analysis.