Passive · Adaptive · Active
Heave Compensation Systems
Norwegian Dynamics designs and delivers passive, adaptive and active heave compensators — heave compensation systems for offshore lifting, from a 12.5 t compensator cylinder to 10,000 t heavy-lift units. Every system is sized to DNV-RP-N202 and screened deck-to-seabed in CONSTELLATION, our time-domain lift simulator, before you commit to a weather window.
Send your lift caseCONSTELLATION lift screening
SWL, water depth and expected Hs/Tp are enough — a first-pass sizing and operating-window view come back. Designed & classed · DNV-ST-0378 · ISO 9001:2015.
Compare heave compensators: capacity, stroke and control
On this page: Selection guide · Passive · Adaptive · Active · Sizing & DNV · Support
| System | Type | Capacity (SWL) | Stroke | Control | Certification | Best for |
|---|---|---|---|---|---|---|
 View RIGEL → | Passive · basic | 55–1,000 t | 1.0–6.0 m | Manual damping & stiffness · set on deck | Designed & classed · DNV-ST-0378 | Predictable splash-zone crossings and standard subsea lifts |
 View CYGNUS → | Passive · wide range | 12.5–10,000 t | 1.0–6.0 m | Manual damping · self-centering spring | Designed & classed · DNV-ST-0378 | Full-range passive lifts — 12.5 t heave compensation cylinders to 10,000 t heavy-lift units |
 View ANTARES → | Adaptive passive | 30–4,000 t | 2.5–8.0 m | Automatic damping · self-centering spring · quick lift | Designed & classed · DNV-ST-0378 | Complicated, multi-step subsea lifts |
 View VEGA → | Active · in development | 75–2,500 t | 2.5–6.0 m | Automatic damping · active cylinder control · self-centering spring | In development · designed to DNV-ST-0378 | Topside and subsea lifts needing the tightest motion control |
Swipe sideways to compare stroke, control, certification and best-for →
DNV Type Approval for RIGEL is in progress — once granted, repeat units enter service without a per-project certification loop.
Crane shock absorption (POLARIS) and riser tensioning (SIRIUS) are covered on their own pages: POLARIS crane shock absorber · SIRIUS riser tensioner.
Selection
Which type of heave compensator do you need?
The three families solve the same problem — decoupling the load from vessel heave — with different trade-offs in power, complexity and control. Most lifts are well served by a passive unit; the question is how much control the operation sequence demands.
Passive 70–90% efficiency
- Power: no external power — sealed gas spring and hydraulic damping; CYGNUS carries a small battery, no umbilical
- Complexity: lowest — no operator during the lift
- Wave sensitivity: tuned to the target period at set-up; efficiency falls off in long swell away from the tuning point — the sensitivity ANTARES automates away
- Typical use: splash-zone crossing, subsea lift & landing, retrieval
- Products: RIGEL (55–1,000 t), CYGNUS (12.5–10,000 t)
Adaptive passive top of the 70–90% band, all sea states
- Power: battery (medium) for the control system, no umbilical — the compensation itself is unpowered
- Complexity: moderate — remotely adjustable
- Wave sensitivity: automatic damping control re-tunes through the lift
- Typical use: multi-step lifts — locked, splash-zone, subsea and soft-landing modes in one deployment
- Products: ANTARES (30–4,000 t)
Active 90–98% efficiency
- Power: battery operated (large battery), no umbilical
- Complexity: highest — MRU-driven closed-loop feedback
- Wave sensitivity: compensates in real time across the spectrum
- Typical use: precision landings, topside motion control, long-duration operations
- Products: VEGA-T topside / VEGA-S subsea (75–2,500 t, in development)
Five questions that decide it
Can you answer these five? That is a complete lift case — send it and the sizing comes back. Want the long-form comparison first? Read active vs passive heave compensation — the full comparison.
The range
Four heave compensation systems, one engineering basis
Every Norwegian Dynamics compensator — passive, adaptive or active — is sized from the same first principles and screened against the same acceptance gates before steel is cut.
Passive heave compensators
no external power, no umbilical — the workhorsesA single-cylinder passive compensator with manually adjustable damping and stiffness, set on deck to the lift. No electronics offshore. DNV Type Approval is in progress — once granted, no per-project certification loop.
- SWL
- 55–1,000 t
- Stroke
- 1.0–6.0 m
- Depth rating
- subsea, 3,000 m
- Control
- manual damping & stiffness · set on deck
- Power
- none · no electronics offshore
A gas-over-oil heave compensation cylinder with external accumulators, manually set damping and a self-centering spring — the full-range passive line, from 12.5 t up to 10,000 t for monopile, jacket and salvage work. First deliveries 2026, configurations from USD 15,000.
- SWL
- 12.5–10,000 t
- Stroke
- 1.0–6.0 m
- Control
- manual damping · self-centering spring
- Power
- battery (small) · no umbilical
Adaptive passive
passive physics, electronic brainsAn adaptive compensator with automatic damping control and quick-lift ability, switching operation mode through the lift — locked for the deck lift, stiff through the splash zone, soft for the subsea run, soft-landing for set-down. One unit covers the whole operation sequence without re-rigging, holding the top of the passive efficiency band across sea states.
- SWL
- 30–4,000 t
- Stroke
- 2.5–8.0 m
- Control
- automatic damping · self-centering spring · quick lift
- Power
- battery (medium) · no umbilical
- Modes
- locked · splash-zone · subsea · soft-landing
Active heave compensation
closed-loop control, MRU-drivenAn inline, self-contained active heave compensation system: active cylinder control driven by real-time motion reference unit feedback, layered on automatic damping control and a self-centering spring. Battery operated, no umbilical. VEGA-T executes motion control topside; VEGA-S holds and lands loads at depth when passive compensation cannot keep the set-down inside the window. In development — engineering data available on request.
- SWL
- 75–2,500 t
- Stroke
- 2.5–6.0 m
- Control
- automatic damping · active cylinder control · self-centering spring
- Power
- battery (large) · no umbilical
- Variants
- VEGA-T topside · VEGA-S subsea
Sizing & engineering
Sized to DNV-RP-N202, screened in CONSTELLATION
A compensator is only as good as its sizing. Norwegian Dynamics sizes gas volume, damping and stroke from first principles to DNV-RP-N202, the recommended practice written specifically for heave compensating systems. Hydrodynamic load inputs — slamming, added mass, snap criteria — are modelled per DNV-RP-N103, and operational acceptance follows DNV-ST-N001.
Then the whole lift is screened, not just the unit: CONSTELLATION runs the operation deck-to-seabed in the time domain, across the full Hs×Tp sea-state range, checking every acceptance gate — splash DAF, slack-sling, landing DAF, touch-down velocity, stroke utilisation. You see the operating window before you mobilise, and the compensator is sized to the window you need.
Green = workable · hatched = outside the operational limit · ◎ = modelled design cell (Hs 2.0 m / Tp 8 s). Workable sea states, screened gate-by-gate to DNV-RP-N103 and the Norwegian Dynamics design standard ND-DS-10 — a representative deck-to-seabed installation on an ANTARES 250 t adaptive compensator, modelled in CONSTELLATION. Project screenings use your metocean and vessel.
The physics input
Vessel motions: what a heave compensator absorbs
A floating vessel moves in six degrees of freedom at once — surge, sway and heave (translations), roll, pitch and yaw (rotations). Only heave runs straight down the crane wire, but roll and pitch feed it: with the crane away from the vessel’s centre of flotation, the lever arm turns rotations into extra vertical motion at the tip, so effective crane-tip heave can be significantly larger than the vessel’s pure heave.
| DOF | Motion | Lifting relevance |
|---|---|---|
| Surge | Fore–aft translation | Positioning, minor for hook load |
| Sway | Side-to-side translation | Positioning, pendulation input |
| Heave | Vertical translation | Direct crane-tip motion — the compensator’s target |
| Roll | Rotation, longitudinal axis | Adds crane-tip heave via the lever arm |
| Pitch | Rotation, transverse axis | Adds crane-tip heave via the lever arm |
| Yaw | Rotation, vertical axis | Heading — minor for vertical motion |
How much a given hull moves in a given sea is set by its Response Amplitude Operators (RAOs) — the vessel’s motion per unit wave amplitude, by frequency and heading, unique to each hull form and loading condition. RAOs combined with the wave spectrum give the crane-tip motion that sizes the compensator: stroke must exceed the peak-to-peak crane-tip heave with margin, maximum piston velocity follows from amplitude and wave period, and the natural period is tuned clear of the dominant wave periods.
| Vessel type | Motion character | Where it fits |
|---|---|---|
| Semi-submersible | Lowest heave RAOs — small waterplane area | Heavy lifts, demanding operations |
| Monohull CSV | Moderate heave, roll and pitch | The workhorse of subsea installation |
| Jack-up | Zero heave jacked up; motion in transit | Shallow water, repeat operations |
| Barge | Highest amplitudes, roll especially | Heavy-lift cranes in calm windows |
Semi-submersibles carry the demanding heavy lifts for a reason — small waterplane area, lowest heave. The wave side of the story is on the waves page.
The physics
How heave compensation works
Heave compensation is the decoupling of a suspended load from the vertical motion of the vessel carrying it. Heave — the vertical translation of a vessel in waves, one of its six degrees of freedom — is the critical motion for lifting, because it moves the crane tip straight up and down. A North Sea construction vessel can see peak-to-peak heave of several metres at periods of 5–15 seconds, and without compensation every metre of it reaches the load.
A heave compensator puts a compliant element — a spring — between the moving crane tip and the load. In practice the spring is compressed nitrogen acting on a hydraulic cylinder, with gas volume and pre-charge pressure selected so the spring force barely changes over the stroke for the given payload weight: near-zero effective stiffness. The softer the effective spring, the less crane-tip motion reaches the load — it stays nearly stationary while the crane tip follows the waves.
A pure spring would oscillate, especially near resonance. Hydraulic orifices resist the oil flow, converting kinetic energy to heat — the damping caps the resonant response and settles the system. The spring carries the load, the damping dissipates the wave energy: the sea keeps moving, the load stops.
All three families on this page — passive, adaptive passive and active — build on this same spring-and-damper physics; they differ in how the spring and damping are controlled, compared line by line in the selection guide.
The principle in one picture: compressed nitrogen carries the load, orifice damping dissipates the wave energy, and the load is isolated from the crane tip’s motion.
See it in action
The compensators at work, simulated in CONSTELLATION
Each clip is a CONSTELLATION simulation of a real lift case — the same time-domain model behind the screening above. Watch the compensator hold line tension through the sea state.
Applications
Where heave compensation earns its keep
Subsea lifts
Drag, added mass and snap criteria from surface to seabed — compensation keeps wire tension positive throughout the screened operating window.
Subsea lifting loads →Splash-zone crossing
Slamming and buoyancy transients drive the DAF spike that sets most weather windows. Passive stroke absorbs it.
How passive compensation works →Offshore wind
Monopile, transition-piece and nacelle lifts on compressed installation schedules — heavy capacity meets tight tolerances.
Heave compensation for offshore wind →Decommissioning
Weight uncertainty and corroded lift points eat DAF margin — compensation puts it back.
Decommissioning lifts →Working one of these lifts now? Send your lift case — we screen it in CONSTELLATION against your metocean and vessel.
Proof
Certified & delivered
- Delivered: a 150 t / 4.5 m adaptive passive heave compensator for an international offshore EPC contractor.
- Delivered: a 3 t / 1.25 m unit in the UK — six weeks from order to handover.
- Certified: all units designed and classed to DNV-ST-0378; DNV Type Approval for RIGEL in progress. ISO 9001:2015 quality management.
- Efficiency: passive 70–90% · adaptive holds the top of the band across sea states · active 90–98%.
Operational support
Supported through the campaign, not just the sale
The engineers who size your compensator commission it, support it offshore and keep it certified — one team from lift data to demobilisation.
FAQ
Heave compensator questions, answered
What is a heave compensator?
A hydraulic-pneumatic unit installed between the crane hook and the payload (or integrated in the lifting arrangement) that absorbs the relative vertical motion between vessel and load. It keeps wire tension inside acceptance limits, cuts the dynamic amplification factor and prevents slack-wire and snap-load events inside the screened operating window. For the physics, see how heave compensation works.
Passive, adaptive or active — which do I need?
Passive (RIGEL, CYGNUS) for most splash-zone and subsea work with no external power; adaptive passive (ANTARES) when one deployment must cover locked, splash-zone, subsea and soft-landing phases; active (VEGA, in development) when the operation justifies MRU-driven active cylinder control — battery operated, no umbilical. The decision guide above compares them line by line.
What size heave compensator does my lift need?
Capacity follows the payload SWL; stroke and damping follow the sea state (Hs, Tp), water depth and operation sequence. We size to DNV-RP-N202 and confirm the choice by screening the whole lift in CONSTELLATION. Send your lift case — SWL, depth and expected Hs/Tp are enough to start.
Which DNV standards apply to heave compensators?
DNV-RP-N202 (heave compensating systems) is the governing recommended practice; units are designed to DNV-ST-0378 (offshore lifting appliances); load modelling follows DNV-RP-N103 and operational acceptance DNV-ST-N001. Our DNV standards guide maps them all.
Can a heave compensator extend my weather window?
Yes — by cutting the DAF and keeping rigging tension positive, a correctly sized unit raises the workable significant wave height and recovers capacity lost to DAF derating on the crane load chart. See weather windows for offshore lifting, and quantify it for your lift with a CONSTELLATION screening.
What is the typical delivery time for a heave compensator?
Every unit is engineered to the lift, so schedule follows scope. As a reference point, a 3 t / 1.25 m unit was delivered in the UK in six weeks. Send your lift case and the schedule comes back with the sizing.
How much does a heave compensator cost?
Entry configurations start from approximately USD 15,000 (CYGNUS at low SWL), USD 20,000 (POLARIS) and USD 35,000 (RIGEL); beyond the entry point, pricing follows capacity, stroke and configuration. Send your lift case — SWL, water depth and expected Hs/Tp — and a budget indication comes back with the first-pass sizing.
What is heave compensation?
Heave compensation is the decoupling of a suspended load from the vertical motion of the vessel carrying it. A heave compensation system — passive, adaptive or active — absorbs the vessel’s heave in a hydraulic-pneumatic cylinder so the load’s motion and the wire tension stay controlled through the lift.
Content reviewed by Norwegian Dynamics engineering — July 2026.
Have a lift in mind?
Send us the basics — SWL, water depth and expected Hs/Tp (a sketch is enough to start). We'll screen the lift in CONSTELLATION and come back with a suitable compensator, a first operating-window view and the next engineering step.
post@nodynamics.com · +47 9664 7886 · Product brochure (PDF)