Name: Trailing Suction Dredger Heave Compensation Cylinder - Korea Trailing Suction Dredger Heave Compensation Cylinder Manufacturers, Suppliers - hydraulic cylinders price
SKU: ace8b9c53bb7

Trailing Suction Dredger

Trailing Suction Dredger Heave Compensation Cylinder

The sea moves. The draghead must not. When a trailing suction dredger rides 2-metre swells, the hull rises and falls — but the draghead must stay pressed against the seabed at constant force. The heave compensation cylinder absorbs the wave motion, extending and retracting with every wave to keep the suction pipe stable.

≤400mmBore

≤4,000mmStroke

1,600 KNThrust

32 MPaPressure

Technical Specifications

Parameter	Specification
Product Name	Trailing Suction Dredger Heave Compensation Cylinder
Features	Compensate relative displacement of draghead and hull during wave heave
Bore Diameter	Up to 400 mm
Rod Diameter	Up to 360 mm
Stroke	Up to 4,000 mm
Thrust Force	Maximum 1,600 KN
Working Pressure	Up to 32 MPa
Temperature Range	-40 °C to +100 °C
Application	Trailing Suction Dredger

How Heave Compensation Keeps the Draghead on the Seabed

Trailing Suction Dredger Heave Compensation Cylinder offshore application

A trailing suction dredger (TSHD) sails over the dredging area at 1–3 knots while a draghead on the seabed sucks up sediment through a trailing suction pipe. The pipe hangs from the hull into the water, and the draghead drags along the bottom. In calm water, this works smoothly — but in waves, the hull heaves up and down by 1–4 metres with every swell cycle (5–10 seconds per wave).

Without heave compensation, this vertical hull motion would lift the draghead off the seabed on every wave crest (losing suction) and slam it into the bottom on every trough (risking structural damage). The heave compensation cylinder solves this by acting as a spring-damper between the hull and the suction pipe: when the hull rises, the cylinder extends to pay out slack; when the hull falls, the cylinder retracts to take up the excess. The draghead pressure on the seabed stays nearly constant throughout the wave cycle.

The system uses a nitrogen gas accumulator connected to the cylinder — the gas provides a pneumatic spring force that can be tuned to match the draghead weight and desired seabed contact pressure. Korea Ever-Power supplies the heave compensation cylinder with matched accumulator sizing within the offshore hydraulic cylinder range.

Passive vs Active Heave Compensation

Trailing Suction Dredger Heave Compensation Cylinder

Heave compensation systems for trailing suction dredgers fall into two categories. The choice affects cylinder design, system complexity, and performance in heavy seas:

Passive System (Standard)

The cylinder is connected to a nitrogen accumulator that acts as a gas spring. The gas compresses and expands with wave motion, allowing the cylinder to extend and retract passively — no active control, no electronics, no sensors.

✓ Simple, reliable, low maintenance
✓ No power consumption during operation
✗ Compensation accuracy degrades in irregular seas
✗ Pre-charge pressure must be manually adjusted for load changes

Active System (Advanced)

A motion reference unit (MRU) measures hull heave in real time. A controller drives the cylinder through a servo valve to compensate — actively adjusting position to cancel out wave motion. Much higher accuracy than passive, but more complex.

✓ Maintains draghead contact in sea state 5+
✓ Adapts automatically to load and wave changes
✗ Higher cost, more maintenance, requires electronics
✗ Servo valve failure = loss of compensation

Korea Ever-Power supplies heave compensation cylinders for both passive (standard) and active (with position sensor and servo-valve mounting provisions) systems. Contact the Korea Ever-Power hydraulic cylinder engineering team for system selection guidance.

Key Design Parameters for Heave Compensation Cylinders

Selecting and sizing a heave compensation cylinder requires matching the cylinder's dynamic response to the vessel's wave-motion characteristics. The critical parameters are:

Heave amplitude — the maximum vertical hull displacement in the design sea state. A 6,000 m³ TSHD operating in the North Sea may experience 2–4 metres of heave in sea state 4–5. The cylinder stroke must exceed this amplitude with safety margin.
⏱️ Heave period — the wave period determines the piston velocity requirement. A 7-second wave period with 3-metre amplitude produces peak piston velocities of approximately 1.3 m/s — the seals, guides, and oil flow path must handle this speed without cavitation or pressure spikes.
⚖️ Draghead contact force — the desired seabed contact pressure of the draghead determines the nitrogen pre-charge pressure. Too much contact force damages the draghead and consumes excess towing power; too little allows the draghead to lift off the seabed during wave crests.
Accumulator volume — the gas accumulator volume determines the spring stiffness of the compensation system. A larger accumulator produces a softer spring (better compensation) but takes more space. Korea Ever-Power calculates the optimal accumulator volume for each TSHD model and operating sea state.

Why Dredging Fleets Choose Korea Ever-Power

⏱ Fast turnaround — 8–12 weeks standard, 5–6 weeks emergency. Every day of TSHD downtime costs USD 50,000–120,000 in lost production.
Factory-direct pricing — 20–40% below European OEM equivalents. No distributor chain. The engineer who designs your cylinder is in the same building as the machine that makes it.
Retrofit and reverse-engineering — existing vessel? Send the old cylinder or its drawing. Korea Ever-Power will match dimensions and upgrade the seals, surface treatment, and valve integration.
Classification society documentation — BV, DNV, LR, ABS, CCS. Material certificates, welding procedures, witnessed testing — aligned with your vessel's flag state and class requirements.

Heave Compensation Cylinder OEM & ODM

What You Provide

Vessel model, mechanism drawing, required force (push/pull), bore/rod/stroke, system pressure, operating environment, classification society requirement, and surface treatment preference.

What the Factory Delivers

Complete cylinder set with engineering drawing, anti-corrosion treatment, saltwater seals, integrated valves, test certificates. Classification documentation on request. Seal kits included. Browse the full offshore hydraulic cylinder range.

Korea Ever-Power hydraulic cylinder factory

Hydraulic cylinder manufacturing and types

Frequently Asked Questions

Common questions about the trailing suction dredger heave compensation cylinder answered by Korea Ever-Power engineers:

Can this cylinder be retrofitted on an existing vessel?

Yes. Korea Ever-Power manufactures replacement cylinders for existing dredging vessels, including reverse-engineering from worn-out originals or from the vessel's original equipment drawings.

What classification society approvals are available?

Bureau Veritas (BV), DNV, Lloyd's Register (LR), ABS, and CCS documentation and witnessed testing can be provided on request.

What surface treatment options are available for saltwater service?

Ceramic spraying (HVOF), laser cladding (Inconel/Stellite/nickel-chrome), and standard hard chrome plating. Selection depends on the operating environment, maintenance schedule, and target service life.

What is the typical lead time?

Standard lead time is 8–12 weeks from drawing approval. Emergency/rush orders for operating vessels can be accommodated in 5–6 weeks. Contact the engineering team for current availability.

Can integrated valves be included?

Yes — load-holding valves, counterbalance valves, sequence valves, relief valves, check valves, and pressure measuring joints can be machined directly into the cylinder body. This reduces external piping, potential leak points, and installation time. Browse mobile machinery hydraulic cylinders and industrial engineering hydraulic cylinders for related heavy-duty applications.

What Our Customers Say

★★★★★May 2026

"The heave compensation on our 8,000 m³ TSHD used to lose draghead contact in anything above sea state 3. We replaced the original cylinders with Korea Ever-Power units and retuned the accumulator pre-charge — now we maintain contact up to sea state 4.5. The longer stroke (3,600 mm vs 2,800 mm original) gives us more travel for bigger swells."

Capt. J. Pedersen — Dredge Master, Denmark

★★★★★Feb 2026

"The high rod-to-bore ratio (360/400 mm) of the heave comp cylinder makes the annular area very small — which is exactly what you want for a heave compensation system. The cylinder moves fast with minimal oil volume change, responding instantly to wave motion. Good engineering understanding from the Korea Ever-Power team."

Dr. K. Weston — Hydrodynamics Lead, UK consultancy

★★★★☆Oct 2025

"Reliable heave compensation cylinders for our 4,500 m³ TSHD. We operate mainly in the North Sea, so the -40 °C seal rating gives us comfortable margin for winter dredging. One minor point: the paint on the barrel exterior started showing rust spots after 18 months — recommend specifying marine-grade epoxy over the standard primer for exposed installations."

F. Nielsen — Fleet Maintenance, Norway

★★★★★Jul 2025

"We ordered 4 heave compensation cylinders as part of a suction pipe overhaul. The cylinders were delivered pre-filled with the specified hydraulic oil and nitrogen-charged to the correct pre-charge pressure — ready to install without any field setup. Saved us a full day of commissioning time."

I. Pereira — Ship Engineer, Brazil

★★★★★Mar 2025

"Third TSHD we've fitted with Korea Ever-Power heave compensation. Consistent quality across all three orders (2023, 2024, 2025). The integrated gas charging valve and pressure gauge on each cylinder makes routine pre-charge checks a 5-minute job instead of the hour-long procedure our old design required."

W. Zhang — Technical Superintendent, Chinese dredging fleet