500–2000 kN Hydraulic Waterfall Towing Winch | Double-Drum Tug Towing System

Product Specification

500–2000 kN Hydraulic Waterfall Towing Winch | Double-Drum Tug Towing System

Product Overview

The 500–2000 kN hydraulic waterfall towing winch is a project-engineered double-drum towing system for tug and towing-vessel deck arrangements requiring high line pull, long wire-rope storage and controlled haul-in / pay-out. The two drums are arranged in a waterfall configuration on a common structural base, helping accommodate large rope capacities within a compact deck footprint while keeping the towing line, brake, drive and control functions integrated as one system.

Selection cannot be based on pulling force alone. Rated line pull, brake holding load, rope diameter and length, reference rope layer, vessel bollard pull, towline MBL, fairlead position, fleet angle, deck foundation, hydraulic power and emergency-release philosophy all need to be confirmed together. Where the winch is intended for escort service, additional render / recovery or load-reducing control, continuous towline-tension monitoring and class-specific escort requirements must be defined; a conventional hydraulic towing winch is not automatically an escort winch.

System Configuration

Double waterfall towing drums | Hydraulic motor drive | Reduction gearbox | Drum brake system | Clutch / drum isolation arrangement as specified | Local control station | Remote / wheelhouse control as specified | Hydraulic power unit or vessel hydraulic interface | Rope spooling / level-wind device when required | Towline load, length and speed monitoring when specified

Quick Specifications

• Rated Line Pull: 500–2000 kN from the supplied series → final quotation should define the reference rope layer; class documentation commonly defines rated pull at the first inner layer.

• Supplied Holding Capacity: 1000–3200 kN → should be confirmed as Brake Holding Load (BHL), including the rope layer and brake test basis.

• Rated Haul-in Speed: 5–10 m/min → supplied table values are working haul-in speeds; escort render / recovery speed is a separate design parameter and is not yet supplied.

• Wire Rope Range: Ø36–68 mm with 1000–1600 m capacity → drum core diameter, flange diameter, grooving and fleet angle must match the selected rope.

• Drum Arrangement: Double-drum waterfall → supports two long-rope drums in a compact arrangement; independent or coupled operation depends on the final gearbox, clutch and hydraulic circuit.

• Drive Type: Hydraulic → available pull and speed depend on system pressure, flow, motor displacement, gearbox ratio and HPU power.

• Control: Local and remote control can be arranged → control station, emergency release, alarms and monitoring scope should be confirmed with vessel class and operating philosophy.

• Escort Configuration: Available only when specifically engineered → active pay-out / haul-in or load-reducing logic, continuous tension monitoring and project class approval are not assumed as standard.

Main Technical Parameters

Customer-supplied reference series. Values below are not presented as a class-standard table and should be confirmed against the final GA, hydraulic calculation, rope specification and approved technical agreement.

Performance Definition & Design Basis

• Rated Pull: the maximum hauling-in line force must be stated together with the rope layer and speed. For class review, first-inner-layer rated pull is a common reference; line pull changes as the effective drum radius increases.

• Brake Holding Load: BHL is not the same as rated pull. It represents the maximum towline force the brake arrangement is designed to hold without unintended drum rotation or brake slip under the specified condition.

• Towline & Vessel Basis: winch selection should be checked against vessel bollard pull / escort design force, towline MBL, towing arrangement, fairlead and supporting structure rather than using a fixed pull-to-holding ratio alone.

• Escort Duty: exposed-water escort service can impose rapid dynamic line-load variations. The required rendering force, recovery force, response speed and set-point logic should therefore be defined separately from ordinary haul-in speed.

• Foundation & Load Direction: the winch base, deck seating and under-deck reinforcement should be checked for the most unfavorable anticipated towline direction and project design load, including the brake holding case where required by class.

Hydraulic Drive & Control System

• Hydraulic motor and reduction gearbox provide high torque at low drum speed; final motor displacement, pressure and gear ratio are selected from the rated pull / speed duty point.

• The hydraulic power source may be a dedicated HPU or a vessel hydraulic system. Required pressure, flow, installed power, tank capacity, filtration, cooling and redundancy must be confirmed for continuous towing duty.

• Local control should provide normal haul-in, pay-out and brake / clutch functions according to the final design. Remote or wheelhouse control can be integrated when required by vessel operation or class.

• Load-cell or pressure-based towline tension indication, rope-length measurement, drum-speed indication, alarm history and data logging can be added according to project scope.

• For escort service, control logic should prioritize controlled rendering / recovery and emergency functions rather than relying only on the static drum brake.

Brake, Render & Emergency Release Functions

• The brake type and actuation method are project-specific. Brake holding load, power-failure behavior and manual / emergency operation should be defined in the approved winch specification.

• Emergency release / controlled payout should be engineered for the applicable tug class rules, control stations, expected towline load and blackout philosophy. It should not be described as a standard feature unless included in the ordered scope.

• For escort operation in dynamically exposed conditions, class guidance commonly requires an active load-reducing or pay-out / haul-in function so the operation is not based only on the winch brake.

• Continuous towline-tension monitoring is an important escort function and may be required by the selected class notation; the display location and alarm set points should be agreed during design review.

Rope Management & Waterfall Arrangement

• The waterfall layout provides two drums at different longitudinal / vertical positions, supporting large rope storage while reducing the deck-length demand compared with some side-by-side arrangements.

• Waterfall arrangement alone does not guarantee correct spooling. Fleet angle, distance to the first fairlead, drum width, rope diameter, grooving and any level-wind / spooling device must be checked together.

• Grooved drum, Lebus-type grooving or powered spooling / level-wind systems can be considered for long wire ropes, high fleet angles or applications where stable layer build-up is difficult.

• Towline termination, minimum retained turns, rope bending radius, drum flange margin and inspection access should follow the selected rope manufacturer, class and vessel arrangement requirements.

Selection & Inquiry Guide

Step 1: Define the vessel and duty: harbour towing, ocean towing, terminal tug, escort service or other towing operation; provide vessel type, bollard pull, intended class notation and operating area.

Step 2: Confirm performance: required rated line pull, brake holding load, reference rope layer, haul-in speed, required rendering / recovery force and speed, and maximum towline design load.

Step 3: Confirm towline: steel-wire or approved synthetic rope type, diameter, length, MBL, termination and required drum grooving / spooling method.

Step 4: Confirm hydraulic interface: available system pressure, flow, HPU power source, cooling-water / air conditions, redundancy requirement and vessel electrical supply for controls.

Step 5: Confirm control and safety scope: local / wheelhouse control, emergency release, render-recovery or constant-tension mode, load / length / speed monitoring, alarms and data logging.

Step 6: Provide GA / deck foundation drawing, fairlead position, available footprint and height, quantity, class society, FAT / witness requirements, delivery destination and required delivery date.

Structure & System Components

Structural base frame | Front and rear waterfall drums | Drum shafts and bearings | Hydraulic motor(s) | Reduction gearbox | Drum brake(s) | Clutch / drum isolation as specified | Rope guide / level-wind when required | Hydraulic piping and valve block | Local control station | Remote control and monitoring interface | Protective guards and access provisions

Engineering & Safety Advantages

• Project-based sizing links winch pull, brake holding load, rope selection, hydraulic power and foundation loads instead of treating each rating as an isolated catalogue number.

• Double-drum waterfall configuration can accommodate a main and secondary towline or two project-defined rope duties without requiring the same deck width as a large side-by-side arrangement.

• Hydraulic drive provides controllable low-speed torque and can be integrated with dedicated or vessel hydraulic power, allowing the drive to be matched to towing duty rather than fixed catalogue motor power.

• Brake, clutch, emergency-release and monitoring functions can be engineered around the vessel's towing philosophy and classification notation.

• Optional active render / recovery and continuous load monitoring provide the functions normally associated with high-performance escort towing, subject to class approval and final control-system design.

• Drum grooving, fairlead geometry and powered spooling can be selected to protect long wire ropes and reduce cross-winding or flange climbing where the installation geometry requires it.

Custom Attributes

Rated Line Pull: 500–2000 kN → customer-supplied range; reference rope layer to be confirmed.

Holding Capacity: 1000–3200 kN → to be defined as Brake Holding Load and verified against class / project load cases.

Rated Speed: 5–10 m/min → supplied haul-in speed; render / recovery speed is separate when escort duty is required.

Wire Rope: Ø36–68 mm × 1000–1600 m → rope construction, MBL and minimum bending radius to be confirmed.

Drum Arrangement: Double-drum waterfall → final drum independence, clutch arrangement and simultaneous operation logic depend on the drivetrain.

Drive: Hydraulic → HPU pressure, flow, power, cooling and redundancy are project-specific.

Control: Local + remote available → wheelhouse controls, interlocks and monitoring according to operating philosophy.

Escort Functions: Optional / project-specific → active pay-out / haul-in, load reducing control, line tension monitoring and emergency release require technical confirmation.

Classification: CCS / NK / BV / ABS / DNV / LR / KR / IRS / RS / RINA / CRS according to project requirement → approval, survey and certificate scope to be agreed before order.

How It Works

Hydraulic power is supplied to the selected motor → Gearbox transmits torque to the selected towing drum → Drum hauls in or pays out the towline under operator control → Brake / clutch holds or isolates the drum according to the operating mode → Rope guidance controls the line path → Monitoring provides load, length and speed information when fitted → For an approved escort configuration, active control can render and recover the towline to limit dynamic load peaks and reduce slack-line events.

Applications

Harbour and terminal tug towing | Ocean towing and salvage-support towing | ASD / tractor tug towing stations | Offshore support vessel towing duties | Long-wire towing systems | Escort towing only when the required render / recovery, monitoring, emergency functions and class approval are included

Certifications & Class Approval

Class approval, survey witnessing, material traceability, FAT, brake / load testing and hydraulic function testing can be arranged according to project requirement and the selected classification society. Final certificate scope should be agreed before quotation and is not assumed to be included by default.

Certification: CCS, NK, BV, ABS, DNV, LR, KR, IRS, RS, RINA, CRS, Makers Test Certificate.

Drawing & Photos

FAQ

Q1: What is the difference between rated line pull and brake holding load?

A1: Rated line pull is the winch's hauling force at a defined rope layer and speed. Brake Holding Load is the maximum towline force the brake system is designed to hold under the specified condition. They are different design values and should not be used interchangeably.

Q2: Is every hydraulic waterfall towing winch suitable for escort towing?

A2: No. Escort service, especially in exposed or dynamically loaded conditions, requires additional design review. The winch may need active render / recovery or load-reducing control, continuous towline-tension monitoring, emergency-release functions, suitable towline and fairlead geometry, and approval to the vessel's escort class requirements.

Q3: Can the two waterfall drums operate independently or simultaneously?

A3: Independent drum operation can be engineered, but it depends on the number of motors, gearboxes, clutches, brakes and the hydraulic circuit. Simultaneous or coupled operation should not be stated as standard unless it is shown in the approved drivetrain and control schematic.

• System layout drawing

• Hydraulic diagram

• Product photos