Aux 1 Unit 10 Q10

A transverse thruster is a propulsion device mounted on a vessel, typically at the bow (front) or stern (rear), that provides lateral thrust, allowing the vessel to move sideways or rotate in place without relying on its main propellers. They are essential for enhancing maneuverability, especially in confined spaces like harbors or during docking procedures.  

1. Wärtsilä Transverse Thrusters

Key features and operation:

• Tunnel Thruster: Most transverse thrusters are tunnel thrusters, housed within a tunnel that runs athwartships (sideways) through the hull.   1. Thrusters – Wärtsilä www.wartsila.com
• Propeller: A propeller inside the tunnel, driven by an electric motor or hydraulic motor, generates thrust perpendicular to the vessel’s longitudinal axis.   1. Transverse thruster – KSB www.ksb.com
• Directional Control: The thrust direction can be reversed, allowing the vessel to move to port (left) or starboard (right).   1. Transverse thruster – KSB www.ksb.com
• Control System: The thruster is controlled from the bridge, often with a joystick or dedicated control panel.

Applications:

• Docking and Maneuvering: Transverse thrusters greatly improve maneuverability in tight spaces, allowing for precise control during docking and undocking operations.   1. Bow thruster gearbox replacement – ptw Shipyard ptwshipyard.com
• Station Keeping: They can be used to maintain the vessel’s position against wind or current, especially in dynamic positioning systems used in offshore operations.   1. Wärtsilä Transverse Thrusters www.wartsila.com
• Course Correction: They can assist in correcting the vessel’s heading, particularly at low speeds or in strong winds or currents.

Advantages:

• Enhanced Maneuverability: Allows for precise control and lateral movement, independent of the main propulsion system.
• Improved Safety: Reduces the risk of accidents during docking and maneuvering, especially in challenging conditions.
• Increased Operational Efficiency: Enables faster and more efficient docking and maneuvering, saving time and fuel.

Disadvantages:

• Increased Complexity: Adds complexity and cost to the vessel’s design and construction.
• Maintenance Requirements: The thruster and associated systems require regular maintenance to ensure proper operation.
• Potential for Noise and Vibration: Thrusters can generate noise and vibration, which can be a consideration in passenger vessels.   1. Addressing thruster noise and vibration issues – Riviera Maritime Media www.rivieramm.com

Types of Transverse Thrusters:

• Bow Thruster: Located at the bow (front) of the vessel.   1. Bow thruster – Wärtsilä www.wartsila.com
• Stern Thruster: Located at the stern (rear) of the vessel.   1. Maneuvering thruster – Wikipedia en.wikipedia.org
• Retractable Thruster: Can be retracted into the hull when not in use, reducing drag.   1. Special Report: Bow Thruster Choices – SWIZZLE MEDIA swizzlesportsmedia.com
• Azimuthing Thruster: The propeller can rotate 360 degrees, providing thrust in any direction.   1. Standard Rotatable Propeller Drives – Welcome to PT. Marine Propulsion Solutions marinepropulsionsolutions.com

In summary, transverse thrusters are valuable assets on many vessels, providing enhanced maneuverability and control, especially in confined spaces and challenging conditions. They contribute to safer and more efficient operations, making them a common feature on superyachts and other vessels where precision maneuvering is crucial.

A transverse thruster can be hydraulically driven by incorporating a hydraulic motor into its design. This motor converts the pressurized hydraulic fluid’s energy into rotational motion, which then drives the thruster’s propeller.  

1. Transverse thruster: catálogo con amplia gama – Nuñez Vigo

2. Hydraulic motor – Wikipedia

Key Components and Operation:

1. Hydraulic Motor:

• Type: The hydraulic motor used is typically a low-speed, high-torque motor, such as a gerotor motor or a radial piston motor.
• Mounting: It’s directly coupled to the thruster’s propeller shaft or connected via a gearbox for additional speed reduction.

2. Hydraulic Power Unit (HPU):

• Pump: Supplies pressurized hydraulic fluid to the motor.
• Reservoir: Stores the hydraulic fluid.
• Valves: Control the flow and direction of hydraulic fluid to the motor, allowing for forward and reverse thrust.
• Other Components: May include filters, coolers, and accumulators to ensure proper fluid conditioning and system performance.

3. Control System:

• Joystick or Control Panel: The operator controls the thruster from the bridge using a joystick or a dedicated control panel.
• Directional Control Valve: The control system sends signals to a directional control valve in the HPU, which directs fluid flow to the appropriate side of the hydraulic motor, determining the propeller’s rotation direction and thrust direction.
• Flow Control Valve: A flow control valve might be used to regulate the flow rate to the motor, thereby controlling the thruster’s thrust and speed.

Operational Sequence:

1. Command: The operator moves the joystick or activates the control panel to initiate thruster operation.
2. Control Signal: The control system sends signals to the directional control valve in the HPU.
3. Hydraulic Fluid Flow: The directional control valve opens, allowing pressurized fluid to flow to the appropriate side of the hydraulic motor.
4. Motor Rotation: The pressurized fluid acts on the motor’s internal mechanism (gears, vanes, or pistons), causing it to rotate.
5. Propeller Rotation: The motor’s rotation is transmitted to the propeller shaft, causing the propeller to spin and generate thrust.
6. Thrust: The thruster generates thrust perpendicular to the vessel’s longitudinal axis, moving the vessel sideways or assisting in turning.

Advantages of Hydraulically Driven Thrusters:

• High Power Density: Hydraulic motors can deliver high torque and power in a compact package, making them suitable for powerful thrusters.   1. Hydraulic and Electric Thrusters for ROVs – SEAMOR Marine Ltd. seamor.com
• Precise Control: The flow rate and pressure of hydraulic fluid can be easily controlled, allowing for precise control of the thruster’s thrust and speed.   1. Hydraulic and Electric Thrusters for ROVs – SEAMOR Marine Ltd. seamor.com
• Reliability: Hydraulic systems are generally robust and reliable, especially in demanding marine environments.   1. The key benefits of hydraulic systems | Primary Fluid Power www.primaryfp.co.uk
• Variable Speed: Hydraulic motors offer variable speed capabilities, enabling adjustments to the thruster’s output for different maneuvering situations.

Disadvantages:

• Complexity: Hydraulic systems are more complex than electric thrusters, requiring additional components and maintenance.
• Potential for Leaks: Hydraulic systems can develop leaks, requiring regular inspection and maintenance.   1. Importance of Inspecting Hydraulic Systems for Equipment Performance – Boom & Bucket www.boomandbucket.com
• Noise and Vibration: Hydraulic pumps and motors can generate some noise and vibration.   1. Hydraulic Noise Control www.airlinehyd.com

In Summary

Hydraulically driven transverse thrusters utilize a hydraulic motor to convert hydraulic pressure into rotational motion, driving the propeller and generating the necessary thrust for lateral movement. These thrusters offer high power density, precise control, and reliability, making them valuable assets for enhancing maneuverability on various types of vessels, including superyachts.

Key Components & Their Functions

• Hydraulic Motor:
  • The heart of the thruster. Converts pressurized hydraulic fluid into rotary motion.
  • Typically a low-speed, high-torque motor like a gerotor or radial piston type.
  • Directly coupled to the propeller shaft or connected via a gearbox.
• Propeller:
  • Enclosed within a tunnel through the hull, positioned athwartships (sideways).
  • Its rotation generates thrust perpendicular to the vessel’s longitudinal axis.
• Hydraulic Power Unit (HPU):
  • The source of pressurized hydraulic fluid.   1. Hydraulic Power Unit (HPU) for Oil & Gas Industry | IMI Critical www.imi-critical.com
  • Consists of a pump (often variable displacement for flow control), reservoir, valves, and filters.   1. The Main Components of a Typical Hydraulic Power Unit stthappyfamily.ac.id
  • Can be located remotely, connected to the thruster by hydraulic lines.
• Directional Control Valve:
  • Controls the direction of fluid flow to the motor, determining propeller rotation (clockwise/counterclockwise) and thus thrust direction (port/starboard).
• Flow Control Valve (Optional):
  • Regulates the flow rate of hydraulic fluid to the motor, allowing for control of the thruster’s speed and thrust output.   1. How Does a Hydraulic Flow-Control Valve Work? sapphirehydraulics.com
• Control System:
  • Typically a joystick or control panel on the bridge.
  • Sends signals to the directional control valve to command thruster operation.

Operational Sequence:

1. Command from Bridge:
   • The operator activates the thruster using the joystick or control panel.
2. Control Signal to HPU:
   • The control system sends a signal to the directional control valve in the HPU.
3. Hydraulic Fluid Flow:
   • The directional control valve opens, allowing pressurized fluid to flow to the appropriate side of the hydraulic motor within the thruster.
   • If a flow control valve is present, it regulates the flow rate to control thruster speed.
4. Motor Rotation:
   • The pressurized fluid acts on the motor’s internal mechanism (gears, vanes, or pistons), causing it to rotate.
5. Propeller Rotation & Thrust:
   • The motor’s rotation is transmitted to the propeller shaft, causing the propeller to spin.
   • The propeller generates thrust, pushing the vessel sideways (port or starboard) depending on the direction of rotation.
6. Stopping the Thruster:
   • The operator releases the control, and the directional control valve returns to its neutral position, stopping fluid flow to the motor.
   • The thruster’s propeller stops rotating, and the vessel’s lateral movement ceases.

Advantages of Hydraulically Driven Thrusters:

• High Power Density: Hydraulic motors can deliver significant power and torque in a compact package, essential for effective thrust generation.   1. Hydraulic direct drives tackle rugged marine applications – Fluid Power World www.fluidpowerworld.com
• Precise Control: The hydraulic system allows for precise control of the thruster’s speed and thrust output through flow control valves and variable displacement pumps.
• Reliability: Hydraulic systems are robust and well-suited for the harsh marine environment.   1. The key benefits of hydraulic systems | Primary Fluid Power www.primaryfp.co.uk
• Quick Response: Hydraulic systems can provide rapid response to control commands, important for maneuvering in tight spaces.

Disadvantages:

• Complexity: Hydraulic systems are more complex than electric thrusters, requiring additional components and maintenance.
• Potential for Leaks: Hydraulic systems can develop leaks, necessitating regular inspections and maintenance.   1. Know About Hydraulic Leaks: Causes, Detection, and Solutions – Harvard Filtration www.harvardfiltration.com

Overall:

Hydraulically driven transverse thrusters provide a powerful and reliable means of enhancing a vessel’s maneuverability, particularly during docking, undocking, and close-quarters operations. Their ability to deliver high thrust, precise control, and quick response makes them valuable assets on various types of vessels, including superyachts.Sources and related content