Operations
Subsea Retrieval
Break out, lift off the seabed and recover through the water column with the snap load held in check — and a wider weather window to work in.
Subsea retrieval is unforgiving at the moment of break-out: the payload is held by soil suction and adhesion, the wire tensions until it releases, and the stored energy lets go as a snap load — all while the crane vessel keeps heaving. With a rigid winch the wire tension can climb toward its break strength before the soil lets go, and the same heave keeps loading the line through the ascent. Norwegian Dynamics puts a heave compensator in the load path so the cylinder absorbs the release and decouples vessel motion from the lift. The result is a controlled break-out, lower dynamic loads through the column, and a usable weather window for the recovery.
What we control
Soften the break-out snap
When soil suction releases, the stored wire energy lets go as a snap load. RIGEL holds it as a passive gas spring; ANTARES adds presetting so the gas charge and damping are matched to the payload's wet weight before the lift.
Decouple heave through the ascent
Vessel heave keeps cycling the wire all the way up the column. RIGEL and ANTARES extend and retract on stroke to keep wire and sling tension steady, so the payload isn't re-loaded on every wave.
Carry heavy recoveries
For large-SWL retrievals beyond the RIGEL range, CYGNUS uses a cross-accumulator configuration to deliver high capacity at lower weight — useful headroom on the crane for deep, heavy subsea lifts.
Add active control when needed
Where passive and adaptive-passive compensation is not enough, VEGA adds active stroke control with an HPU and battery to drive position directly through break-out and ascent. (In development.)
Choose the right compensator
The engineering behind it
For the full method and worked examples, see the engineering guide — forces are sized to DNV-RP-N103 and checked against the crane’s derated capacity.
Plan a de-risked subsea retrieval — talk to us about the right compensator for your break-out load.
Send SWL, stroke, sea state, payload and operation sequence. We’ll come back with a recommended compensator, an operating-window view and the next engineering step.