Different types of Steering Gears found on ships

Summary

In this video, the presenter discusses the different types of steering gear systems found on ships, focusing on their components and functionality. They explain the role of the steering gear system in controlling the ship's rudder, including how the system works in conjunction with the autopilot. The presenter covers the differences between main and auxiliary steering gears, and details two common types: RAM type electro-hydraulic and rotary vane steering gear. The video aims to provide essential knowledge for deck officers, ensuring they understand these systems for exam preparation and practical application on board ships.

Takeaways

• 😀 The steering gear system on ships includes machinery, rudder actuators, power units, and means of applying torque to the rudder to steer the ship.
• 😀 The system is vital for safe operation, and its failure can lead to accidents or close-quarter dangers.
• 😀 A ship's steering system is composed of the steering gear, control equipment, rudder carrier, rudder, and rudder horn.
• 😀 The steering gear responds to signals from the bridge, with the autopilot system linked to the steering gear to move the rudder to the desired angle.
• 😀 The steering gear compartment must be easily accessible and separated from the engine room for safety, particularly in emergencies like fires.
• 😀 The main steering gear is responsible for regular operation, while the auxiliary steering gear is used in case of failure of the main system.
• 😀 The auxiliary steering gear must be capable of steering the ship at a speed of 7 knots or half the maximum service speed, whichever is greater.
• 😀 Steering gear control systems include transmitters, receivers, hydraulic control pumps, and motors for transmitting orders from the bridge to the steering gear power unit.
• 😀 RAM type electro-hydraulic steering gear uses hydraulic rams connected to a mechanism to transfer movement to the tiller for rudder control.
• 😀 Rotary vane steering gear works by increasing pressure in compartments formed between the ship’s structure and a rotor attached to the rudder stock to steer the ship.
• 😀 The RAM type system is more fault-tolerant as it has multiple cylinders; a failure in one doesn’t completely disable steering, whereas rotary vane systems can lose steering if a fault occurs.

Q & A

What are the key components of a steering gear system?

The steering gear system consists of machinery, rudder actuators, steering gear power units, and the means of applying torque to the rudder stock. These components are essential for affecting the movement of the rudder and steering the ship in the desired direction.

What is the purpose of the steering gear system on board a ship?

The purpose of the steering gear system is to control the rudder and steer the ship in the desired direction, based on orders from the bridge. The system works in conjunction with the autopilot to maintain the ship's course.

What is the difference between main steering gear and auxiliary steering gear?

The main steering gear includes all equipment necessary to steer the ship under normal service conditions, including machinery, rudder actuators, and power units. The auxiliary steering gear, on the other hand, is designed to steer the ship in the event of a failure of the main steering gear, without including the main steering components like the tiller and quadrant.

What is the required capability of the auxiliary steering gear?

The auxiliary steering gear must be capable of putting the rudder over from 15 degrees on one side to 15 degrees on the other side in no more than 60 seconds, with the ship at its deepest seagoing draft and running at 7 knots or half of the maximum service speed, whichever is greater.

What are the main types of steering gear systems used on ships?

The two main types of steering gear systems used on ships are the RAM type electro-hydraulic steering gear and the rotary vane steering gear.

How does the RAM type electro-hydraulic steering gear work?

The RAM type electro-hydraulic steering gear uses hydraulic rams (either two or four) connected to a link mechanism that moves the tiller, which turns the rudder. Hydraulic fluid under pressure moves the rams to impart torque to the rudder, with independent pumps provided for redundancy.

What are the advantages of the rotary vane steering gear over the RAM type system?

The rotary vane steering gear has a larger working area, requiring lower hydraulic pressures compared to the RAM type system. It also allows for greater rudder movement (up to 65 degrees) and is more compact in design.

What is one potential disadvantage of the rotary vane steering gear system?

A potential disadvantage of the rotary vane steering gear system is that if there is a fault inside the unit, steering can be completely lost, requiring specialist repairs.

What is the significance of the steering gear compartment on a ship?

The steering gear compartment is a critical space on a ship where steering gear machinery is located. It must be accessible, separated from the engine room, and designed to handle hydraulic fluid leakage and allow for emergency escape. This ensures that the steering system remains functional even in case of incidents in the engine room or steering gear compartment.

Why are two independent pumping units used in the RAM type electro-hydraulic steering gear?

Two independent pumping units are used in the RAM type electro-hydraulic steering gear to ensure redundancy. This setup allows the system to continue functioning even if one pump fails, eliminating the need for an auxiliary steering gear in passenger ships and providing continued operation in case of an emergency.