This document provides an overview of steering gears used in marine engineering, detailing their functions, requirements, and various types including hydraulic and electric systems. It emphasizes the necessity of having independent power units for safety and outlines the operational mechanisms of steering gear systems. Additionally, it highlights compliance with international regulations governing steering gear systems on ships.

1. King Abdul-Aziz University
Faculty of Maritime Studies
Marine Engineering department
Introduction to Marine Engineering (MSE 389)
Lecture 7. Steering gears
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2. Introduction
• A Steering Gear is the equipment provided on
ships to turn the ship to left (Port side) or to right
(Starboard side) while in motion during sailing.
The Steering Gear works only when the ship is in
motion and, does not work when the ship is
stationary.
• All the ships are to be provided with, an
efficient main steering gear, an auxiliary steering
gear and, except for very small ships, the main
steering gear should be power operated.
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3. Steering System General Arrangement
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4. Steering System
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5. Steering gear in steering gear
compartment
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6. 6
Steering Gear System
The steering gear system has three main parts:
• Control equipment
• Power unit
• Transmission system to the rudder stock.
• In brief, the operation of the steering gear can be
explained as - With the help of the control system, a
signal of desired rudder angle is sent from the
bridge. This signal activates the power unit with
which the rudder is attached. The rudder moves with
the help of the power unit till the right angle is
reached.

7. Steering gear system requirements
• According to an international legislation, all the ships must have two
independent power units, one as the main power unit and the other as
auxiliary. In case , the ship has two identical power units, then there is
no need for an auxiliary unit.
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• Moreover, each power unit should be capable of transmitting a torque
that swings the rudder from 35 degree on one side to 35 degree on the
other side, while the ship is moving at the full speed.
• It is also to be noted that this whole process shouldn't take more than
28 seconds.
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8. 8
Steering gear system arrangements
• The whole steering gear arrangement should be
kept in a separate compartment, known as the
steering gear compartment/room.
• Both the steering gear systems should be
connected to the bridge and operated from the
same.
• The system should be such designed that in case
of failure of one, the changeover to the other
system should be automatic and within 45
seconds. Proper audible and visual alarms should
be provided in case of failure of any part.

9. 9
Steering gear system arrangements
• Most of the steering gears found on ships have
hydraulically operated equipment known as telemotor.
• This telemotor can also be electrically operated. The
system is also provided with pumps to quickly supply
hydraulic fluid to the rudder.
• All the pumps are quick-repose pumps, and as the
signal from the bridge does not allow enough time for
the pump to switch on and off, a continuously running
pump is required.
• Usually Variable displacement pumps are used for this
purpose.

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Steering Gear System
• Steering gears can be arranged with hydraulic
control equipment known as a 'telemeter', or
with electrical control equipment.
• The power unit may in turn be hydraulic or
electrically operated.

11. Types of steering gear systems
• Manually operated,
• Mechanical Steering Gears
• Fully hydraulic type
• Electro-hydraulic type
• Fully electric type
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12. Manually operated steering gear
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13. Electro hydraulic
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14. Electro steering
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Fully hydraulic type
Power units
Two types of hydraulically powered transmission units or
steering gear are in common use, the ram and the rotary vane.
Ram type
Two particular variations, depending upon torque
requirements, are possible the two-ram and the four-ram. A
two-ram steering gear is shown in Figure.

16. Four and two rams
hydraulic steering gear
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17. Two ram steering system
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Assignment # 7
1. What are the main components of ship Steering
Gear System?
2. What are the main requirements for ship Steering
gear system according to the IMO regulations?
3. What are the main types of ship steering gear systems?
4. Explain with drawing the operations of the four and two
rams hydraulic steering gear systems for ships?