rudder types Flashcards
is a primary steering device used on ships, located at the stern, submerged in water.
It functions by deflecting the flow of water, creating a turning force (yaw) that changes the ship’s direction.
The effectiveness of the rudder is dependent on its size, shape, and the ship’s speed.
Rudder
Is basically a rudder plate that is fixed to the rudder stock only at the top of the rudder.
oCharacteristic: The rudder area is partially forward and partially aft of the rudder stock (the axis about which the rudder rotates).
oPurpose: Provides easier steering as the forces on the rudder are more balanced, requiring less effort to turn.
oShip Type: Commonly used on medium to large vessels, such as tankers, container ships, and bulk carriers.
Balanced Rudder
means that the rudder is partly balanced and partly unbalanced
oCharacteristic: Similar to the balanced rudder, but with a smaller area forward of the rudder stock.
oPurpose: Offers a compromise between the ease of operation of a balanced rudder and the simple construction of an unbalanced rudder.
oShip Type: Often found on older or simpler designs of cargo ships and smaller vessels.
Semi balance rudder
Have their stocks attached at the forward most point of their span
oCharacteristic: The entire rudder area is aft of the rudder stock.
oPurpose: Simpler and cheaper to construct but requires more force to operate since the entire area resists movement.
oShip Type: Typically used on smaller vessels like tugs, fishing boats, and older ships.
Unbalance Rudder
A spade rudder is basically a rudder plate that is fixed to the rudder stock only at the top of the rudder.
oCharacteristic: A rudder that is entirely unsupported at its lower end, giving it a ‘spade’ appearance. It is connected to the ship only at the top via the rudder stock.
oPurpose: Provides high maneuverability and is commonly used on modern ships where precise steering is essential.
oShip Type: Frequently found on high-speed vessels, including naval ships, cruise liners, and container ships.
Spade Rudder
is a specific type of multi-section rudder used on boats and ships.
oCharacteristic: A rudder with a hinged aft section (flap) that increases the effective turning angle and thus the lift generated.
oPurpose: Enhances steering at low speeds and in tight spaces, offering greater control and maneuverability.
oShip Type: Commonly used on vessels requiring high maneuverability, such as ferries, tugs, and offshore vessels.
Flap Rudder
is a specific type of profiled rudder used on certain boats and ships
oCharacteristic: A high-lift rudder with a unique, curved shape designed to maximize the flow of water over the rudder surface.
oPurpose: Provides enhanced steering capability, especially at low speeds or in reverse.
oShip Type: Often used on vessels where maneuverability is critical, such as harbor tugs and offshore support vessels.
schilling rudder
A fixed, annular forward extending duct around the propeller.
oCharacteristic: A rudder placed within a Kort nozzle, which is a ducted propeller system that increases thrust and steering efficiency.
oPurpose: Improves propulsion and maneuverability, particularly in vessels that operate at lower speeds.
oShip Type: Common on tugs, trawlers, and other vessels that require strong, controlled propulsion
Kort Nozzle with Rudder
is often found on vessels with twin propellers and is designed to provide improved maneuverability and steering control.
oCharacteristic: Two rudders positioned on either side of the ship’s propeller(s).
oPurpose: Provides better maneuverability, especially in twin-screw ships, by allowing differential steering.
oShip Type: Common on large ships with twin propellers, such as naval vessels, ferries, and cruise ships.
Twin rudders
