Products / ANTARES · Adaptive PHC ANTARES

Adaptive Passive Heave Compensator

ANTARES is an adaptive passive heave compensator for subsea lifts where splash-zone crossing, subsea landing/retrieval, changing buoyancy or multiple lift stages need to be managed in one unit. It combines passive reliability with automatic damping control and quick lift ability.

Designed & classed to DNV-ST-0378

Mature flexibility

ANTARES uses fewer components than older adaptive PHC designs, improving reliability and reducing cost. The design also adds practical offshore functions for handling, setup and operation:

  • External pressure tested
  • No pilot accumulator filling
  • No oil/gas mixing
  • Easy maintenance
  • Improved seal configuration
30–4,000 t
Maximum force
2.5–8.0 m
Stroke length
3,000 m
Depth rating
Automatic
Damping control · extension & return
Technical data

The numbers, first

ANTARES adaptive passive heave compensator in-line on the crane wire above a subsea payload SWL 30–4,000 t · stroke 2.5–8.0 m
Fig. 01 — ANTARES Adaptive PHC
Maximum force (SWL)30–4,000 tStandard steps: 30 · 75 · 125 · 150 · 250 · 300 · 400 · 500 · 600 · 700 · 800 · 900 · 1,000 · 1,250 · 1,550 · 1,750 · 2,000 · 2,500 · 3,000 · 3,500 · 4,000 t
Stroke length2.5–8.0 mStandard steps: 2.5 · 3.0 · 3.5 · 4.0 · 4.3 · 4.5 · 5.0 · 5.5 · 6.0 · 6.5 · 7.0 · 7.5 · 8.0 m
Depth rating3,000 m
ArchitectureHydraulic cylinder · gas accumulators · self-centering spring
DampingAutomatic extension & return damping control
Operation modesLocked · Splash zone · Subsea · Landing
Quick liftYes — multiple times per charge
PowerBattery operated — no umbilical · no external HPU
CushioningFull-stroke & zero-stroke hydraulic cushioning
SealingDouble seals · externally pressure tested at the factory
Hydraulic fluidCompatible with biodegradable fluids
CertificationDesigned & classed to DNV-ST-0378 · double seals, pressure-tested · pull-tested in frame at FAT
Budget priceConfigurations from approximately USD 100,000
DocumentationGA drawing · datasheet · calculation sheet · OrcaFlex model — on request via the form below
Modelled in CONSTELLATION · representative example

The weather window ANTARES opens

A representative deck-to-seabed install of a ~190 t subsea structure on ANTARES 250 t, screened across the full sea-state range in CONSTELLATION, our in-house time-domain lift simulator — head sea, representative winter climatology. The adaptive gas spring runs stiff through the splash and soft for a compliant seabed set-down.

Operability — sea state Hs × Tpmodelled workable region
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The workable region reaches Hs 2.5 m at the design period (Tp 8 s). The marked design cell is the modelled sea state (Hs 2.0 m).

Hs 2.5m
Operate up to — 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.

Modelled prediction screened to DNV-RP-N103 and ND-DS-10 on a representative metocean basis — an engineering estimate, not a certified analysis. The operating window is confirmed against project metocean and the contracted vessel for each lift.

See how we screen your lift →
Application videos · modelled in CONSTELLATION

See ANTARES in action

All three films are rendered frame-for-frame from CONSTELLATION simulations — the motion you see is the computed result, and the telemetry is real.

Deck to seabed

A 150 t subsea manifold on ANTARES 250 t / 4.5 m at Hs 3.0 m / Tp 8.0 s, 150 m water depth — 67% of stroke used, wire tension held splash to seabed, touch-down 0.11 m/s, landing DAF 1.00.

Quick lift: clear first time

A 250 t module lifted clear first time from a heaving feeder barge on ANTARES 400 t / 5.0 m at Hs 3.5 m / Tp 7.5 s — 0 re-contacts against 7 for a conventional crane, clear by over 2.5 m.

Through resonance, in control

A 120 t open-top suction pile — about 430 t of entrained water in tow — crosses its resonance band near 1,300 m on ANTARES 150C / 5.0 m at Hs 2.9 m / Tp 10 s: DAF 1.94 on the rigid line becomes 1.02, peak wire tension 234 t down to 144 t, payload acceleration down 98%.

Working principle

Passive reliability, adaptive control

01

Gas accumulators carry the load

ANTARES combines a hydraulic cylinder with a set of gas accumulators. The accumulators provide the spring effect, and a self-centering spring holds the unit at mid-stroke through the lift.

02

Damping controls itself

Oil flow between cylinder and accumulators is precisely controlled — with automatic extension and return damping control. Battery operated, no umbilical and no external HPU.

03

Four modes, one lift

Locked reduces required lifting height during lift-off from the vessel deck. Splash zone sets optimal stiffness and damping for the crossing. Subsea reduces stiffness and damping for high performance in the water column. Landing opens the valves and releases the EQ function for a soft set-down on the seabed.

Compact and rugged package

A considered mechanical layout protects key components while making adjustment, handling, upending and maintenance straightforward.

Committed to safety

We follow and exceed the testing requirements in DNV-RP-N202. ANTARES compensators have double seals to protect against water ingress and are externally pressure tested at the factory. ANTARES is pull tested in a frame as part of FAT, and all lifting points are pull tested.

Sustainability

Compatible with biodegradable hydraulic fluids for environmentally sensitive areas. The efficient passive design requires no external power supply during operation, minimising energy consumption and emissions on deck.

Engineered for precision

Designed on decades of experience with subsea and compensation equipment. Common problems and time-consuming actions are removed.

Piston rod lockingData loggingTemperature compensationDepth compensationBuoyancy compensationFull-stroke cushioningZero-stroke cushioningAuto extension dampingAuto return dampingQuick lift · multiple timesBattery — no umbilical
Frequently asked questions

ANTARES, answered

What applications can ANTARES adaptive PHC be used for?
ANTARES Adaptive PHC is very well suited for lifting through the splash zone, resonance avoidance, subsea landings and subsea retrievals. It can also be used for shock absorption and quick lifting.
How does ANTARES adaptive PHC work?
ANTARES Adaptive PHC combines a hydraulic cylinder with a set of gas accumulators. The gas accumulators provide the spring effect while the oil flow is precisely controlled between the cylinder and accumulators to provide damping. ANTARES has the following operational modes:
  • Locked — reduces required lifting height during lift-off from the vessel deck.
  • Splash zone — optimal stiffness and damping settings for splash-zone crossings.
  • Subsea — reduced stiffness and damping for high performance subsea.
  • Landing — valves open and the EQ function releases for a soft set-down on the seabed.
ANTARES adaptive PHC is usually fitted to the crane hook via slings and connected to the payload via slings. Read more in our guide to how adaptive passive heave compensation works.
What are the technical benefits of ANTARES adaptive PHC versus competing PHC units?
  • Reduced leakage risk
  • Easier and much faster filling of gas and oil
  • Easier air bleeding
  • Lower stiffness and lower weight
  • No pilot accumulator filling/draining required, hence no need for an external HPU
  • No risk of oil/gas mixing due to internal leakage in valves
  • Automatic extension and return damping control
  • Quick lift ability
  • Battery operated — no umbilical
  • Rugged, leak-free, normally closed gas valves
  • Improved upending/shipping frame
  • Better filling kit and an easier-to-use calculation sheet
When should I choose a RIGEL Basic PHC instead of an ANTARES adaptive PHC?
If the main challenge is a predictable splash-zone crossing, RIGEL may be the more economical choice. If the lift has multiple phases, changing buoyancy or a need for high performance, ANTARES is usually the better first choice.
Request further information

Send your lift case.

ANTARES configurations from approximately USD 100,000

Lead time and project pricing depends on capacity, stroke and classification — fill in the form and we’ll send drawings, datasheet and a project-specific quotation.