In-house lift simulation

The weather window your lift can actually work in.

CONSTELLATION — our in-house time-domain lift simulator — models your whole operation deck to seabed, then screens it across every sea state to DNV-RP-H103. You get your operating window (Hs×Tp), the governing limit, and what the compensator buys — before anyone mobilises.

Send your lift case See how we screen your lift

Where CONSTELLATION fits

CONSTELLATION solves the whole operation from first principles — the payload equation of motion with real-gas gas-spring thermodynamics, Morison hydrodynamics, and the splash-zone and landing dynamic-amplification basis per DNV-RP-H103, on our ND-DS modelling basis. It builds the complete load path — crane, vessel, rigging, compensator and payload — as one coupled time-domain model and screens it across the full sea-state range.

First-principles, coupled

The complete load path — crane, vessel, rigging, compensator, payload — solved as one time-domain model, not a static factor.

Screened across every sea state

Hs×Tp swept gate by gate, so you get the operating window — not a single number.

The governing limit, named

We tell you which gate binds — splash DAF, landing, touch-down speed or stroke — and by how much margin.

Modelled, not certified

A fast pre-engineering operating-window view to DNV-RP-H103 / ND-DS — confirmed against your project basis before issue.

The operating window, screened

Every sea state, gate by gate. The example below is a representative deck-to-seabed install of a ~190 t subsea structure on the ANTARES 250 t adaptive compensator at head sea.

Operability — sea state Hs × Tpworkable region vs cut-off
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Workable No-go Cut-off Design cell

The cut-off line is the workable Hs boundary — it passes Hs 2.5 m at the design period (Tp 8 s). The ringed design cell is the modelled sea state (Hs 2.0 m).

Operate up to
Hs 2.5 m
at the design period, head sea — the compensator keeps the rigging in tension through the splash and softens the seabed set-down.
~85%
of the season workable on this representative climatology
0.53×
splash snap load vs the DNV gate — rigging stays in tension
Workable Hs cut-off vs Tp
Long-period governed: the window is widest in short, steep seas and narrows toward the swell.
Modelling basis · governing limit
StandardDNV-RP-H103 · ND-DS-10
Payload~190 t subsea structure
CompensatorANTARES 250 t adaptive
HeadingHead sea
ClimatologyRepresentative winter
Governing limitSplash-zone gates in steep seas; stroke toward the swell
Acceptance gates splash DAF ≤ 2.0 · slack-sling = 0 · landing DAF ≤ 2.5 · touch-down ≤ 0.5 m/s · stroke ≤ 90%

What we simulate

One continuous run from deck to seabed — not a static check. The compensator switches gas mode per phase as the load goes overboard and submerges.

Crane vessel with the payload rigged on deck and the compensator locked out.
1 · On deck
Rigged and lifted off; the compensator is locked out.
The payload entering the water through the splash zone off the crane vessel.
2 · Splash zone
Overboard through the wave zone — slam and snap load checked.
The payload lowered on the heave compensator through the open water column.
3 · Lowering
Mid-water descent through the heave-resonance band; drag and added mass build.
The payload set down softly on the seabed beneath the crane vessel.
4 · Seabed landing
Soft set-down onto the soil reaction.

The gates we check

Each screened sea state must clear every acceptance gate to count as workable.

Acceptance gateLimitBasis
Splash-zone crossing DAF≤ 2.0DNV-RP-H103
Slack-sling events= 0DNV-RP-H103
Landing DAF≤ 2.5ND-DS-10
Touch-down speed≤ 0.5 m/sND-DS-10
Stroke utilisation≤ 90 %ND-DS-10

Acceptance limits shown are CONSTELLATION screening defaults aligned to DNV-RP-H103 practice and our ND-DS basis — not a project-specific certified limit. For execution we screen against the project’s own DNV basis.

What the compensator buys

2.5 m
Workable Hs at the design period — the window the screen clears.
0.11 m/s
Modelled seabed touch-down speed, well inside the 0.5 m/s gate.
In tension
Sling stays loaded through the splash — the compensator absorbs the wave force into stroke.

Screen your operation

Send us the structure, the vessel and the site, and we’ll model the lift and return the operating window, the governing limit and the recommended compensator setup.

CONSTELLATION results are engineering predictions screened to DNV-RP-H103 and our ND-DS basis on the supplied metocean — not a certified analysis. The operating window is confirmed against project metocean and the contracted vessel before issue.

Send your lift caseFind the right compensator