STEERING GEAR – REGULATIONS, TYPES, STABILISERs

Requirements for testing steering gear prior to departure.

Requirements for instructions.

Officers competence in steering gear operation / maintenance.

Requirements for testing emergency steering gear drills.

Reduced requirements for ships on short voyages.

Recording of tests and drills

Within 12 hours before departure, the ship's steering gear shall be checked and tested by the ship's crew. The test procedure shall include, where applicable, the operation of the following: the main steering gear; the auxiliary steering gear; the remote steering gear control systems; the steering positions located on the navigation bridge; the emergency power supply; the rudder angle indicators in relation to the actual position of the rudder; the remote steering gear control system power failure alarms; the steering gear power unit failure alarms; and automatic isolating arrangements and other automatic equipment The checks and tests shall include: the full movement of the rudder according to the required capabilities of the steering gear; a visual inspection for the steering gear and its connecting linkage; and the operation of the means of communication between the navigation bridge and steering gear compartment. Simple operating instructions with a block diagram showing the change-over procedures for remote steering gear control systems and steering gear power units shall be permanently displayed on the navigation bridge and in the steering compartment. All ships' officers concerned with the operation and/or maintenance of steering gear shall be familiar with the operation of the steering systems fitted on the ship and with the procedures for changing from one system to anotherIn addition to the routine checks and tests prescribed in paragraphs 1 and 2, emergency steering drills shall take place at least once every three months in order to practise emergency steering procedures. These drills shall include direct control within the steering gear compartment, the communications procedure with the navigation bridge and, where applicable, the operation of alternative power suppliesThe Administration may waive the requirements to carry out the checks and tests prescribed in paragraphs 1 and 2 for ships which regularly engage on voyages of short duration. Such ships shall carry out these checks and tests at least once every week.

The date upon which the checks and tests prescribed in paragraphs 1 and 2 are carried out and the date and details of emergency steering drills carried out under paragraph 4, shall be recordedIn addition to the routine checks and tests prescribed in paragraphs 1 and 2, emergency steering drills shall take place at least once every three months in order to practise emergency steering procedures. These drills shall include direct control within the steering gear compartment, the communications procedure with the navigation bridge and, where applicable, the operation of alternative power supplies. The Administration may waive the requirements to carry out the checks and tests prescribed in paragraphs 1 and 2 for ships which regularly engage on voyages of short duration. Such ships shall carry out these checks and tests at least once every weekThe date upon which the checks and tests prescribed in paragraphs 1 and 2 are carried out and the date and details of emergency steering drills carried out under paragraph 4, shall be recorded.Reg. 26 applies to all ships which proceed to sea except for UK-flagged pleasure vessels of less than 150 gt. Replaces and revises SOLAS V/74 Regulation 19-2. Regulations 24, 25 and 26 supersede the Merchant Shipping (Automatic Pilot and Testing of Gear) Regulations 1981 (SI 1981 no. 571) and together with the Guidance Notes supersede MGN 54 - "Use of Automatic pilots (Heading Control Systems).

 Circumstances when more than one steering power unit required.

In areas where navigation demands special caution, ships shall have more than one steering gear power unit in operation when such units are capable of simultaneous operation.Reg. 25 applies to all ships which proceed to sea except for UK-flagged pleasure vessels of less than 150 gt.Replaces and revises SOLAS V/74 Regulation 19-1.Regulations 24, 25 and 26 supersede the Merchant Shipping (Automatic Pilot and Testing of Gear) Regulations 1981 (SI 1981 no. 571) and together with the Guidance Notes supersede MGN 54 - "Use of Automatic pilots (Heading Control Systems)

Tankers and Chemical and Gas Carriers

Every tanker, chemical carrier or gas carrier of 10,000 tons or more shall be fitted with

(a) an indicator that shows the exact angular position of the rudder independently of the remote steering gear control system;

(b) alarms that sound in the event of the failure of any steering power unit;

(c) steering gear power units that can be brought into operation automatically or manually from the navigating bridge; and

(d) a means of communication between the navigating bridge and the steering gear compartment that is suitable for use in the normal ambient noise conditions and capable of being operated independently of the ship's main power supply.

Instructions

A ship fitted with a remote steering control mechanism or a steering gear power unit shall have permanently displayed on the navigating bridge and in the steering gear compartment of the ship simple operating instructions and a block diagram showing the change-over procedures for that mechanism or unit.

Use of the Automatic Pilot

7. Where the automatic pilot of a ship is used, in an area of high traffic density, under conditions of restricted visibility or in any other hazardous navigational situation, means shall be provided to enable the immediate change-over from automatic to manual steering.

8. In any situation described in section 7, the person in charge of the deck watch shall ensure that the services of a qualified helmsman are available at all times to take over steering control.

9. The change-over from automatic to manual steering of a ship and vice versa shall be made by or under the supervision of a person qualified to be in charge of a deck watch.

10. The manual steering of a ship shall be tested

(a) at least once a day after continuous use of the automatic pilot; and

(b) before the ship enters any area where navigation demands special caution.

Operation of Steering Gear

Where a ship is equipped with two or more steering gear power units that are capable of simultaneous operation, the ship shall have at least two of those units in operation in areas where navigation demands special caution.

Steering Gear--Testing and Drills

Subject to section 13, within 12 hours before the departure of a ship, the steering gear of that ship shall be checked and tested and such checks and tests shall include

(a) the operation of

(i) the main steering gear,

(ii) the auxiliary steering gear, except where such gear includes tackle,

(iii) the remote steering gear control systems,

(iv) the steering controls located at different positions on the navigating bridge,

(v) the emergency power supply,

(vi) the rudder angle indicators in relation to the actual position of the rudder,

(vii) the remote steering gear control system power failure alarms,

(viii) the steering gear power unit failure alarms, and

(ix) automatic isolating arrangements and other automatic equipment required for the steering gears,

(b) the full movement of the rudder according to the required capabilities of the steering gear;

(c) a visual inspection of the steering gear and its connecting linkage; and

(d) the operation of the means of communication between the navigating bridge and steering gear compartment.

For a ship that regularly plies on voyages of less than one week, the checks and tests referred to in section 12 shall be carried out at least once every week.

All ship's officers concerned with the operation and maintenance of the steering gear shall be familiar with the operation of the steering systems fitted on the ship and with the procedures for changing from one system to another.

In addition to the checks and tests referred to in section 12, emergency steering drills that do not include the use of tackle shall be carried out at least once every three months in order to practise emergency steering procedures and shall include direct control from within the steering gear compartment, the communications procedure with the navigating bridge and, where applicable, the operation of alternative power supplies.

The date on which the checks and tests referred to in section 12 are carried out and the date and details of emergency steering drills carried out pursuant to section 15 shall be recorded in the log book.

STEERING GEARa) On ships with a gross tonnage of 10,000 GT and over, it must be possible tooperate the steering gear from the emergency source of electrical power for atleast 30 minutes without interruption.b) On ships with a rudder stock diameter of more than 230 mm (at the height ofthe tiller, without ice strengthening) and with a gross tonnage of less than10,000 GT, it must be possible to operate the steering gear from theemergency source of electrical power for at least 10 minutes withoutinterruption.c) The supply to the steering gear from the emergency source of electrical powermust ensure that the conditions for auxiliary steering gears under SOLAS1974/88, chapter II-1, regulation 29, No. 4.2 are complied with (chapter II-1,regulation 29, No. 14). The steering gear includes the control systems and therudder angle indicators.The supply of power by the emergency power supply can be dispensed with ifthe steering gear compartment is equipped with an independent power sourcefor the steering gear which switches on automatically within 45 seconds.

TYPES OF STEERING GEAR

ACTUATOR TYPE

The Actuator type of steering gear provides the reliability and redundancy required for many naval applications, and uses two actuator systems to provide single rudder operation. With one actuator bypassed, 50 per cent of the torque is still available.

The actuator design means fewer interface surfaces with the ship as the anchor brackets can be welded directly onto the hull cartridge, which also makes installation less tolerance critical. The steering gear is available with pressure-compensated or proportional systems

Features and benefits

Maximum redundancy for continued safe operation

Can be configured to meet specific requirements

Available with pressure compensated or proportional hydraulics

HYDRAULICCYLINDERS

Application:Hydraulic cylinders are destined for operation in the hydraulic systems as executing elements. They are used in appliances working ashore and on board of the vessel.

Execution:

Piston hydraulic cylinders of double-action, Plunger hydraulic cylinders of single-action, Telescopic hydraulic cylinders of single-action, Telescopic hydraulic cylinders of double-action, Special executions – independently of fixed,

ROTARY VANE

Compact ,Low weight ,Easy installation ,Easy maintenance High positioning accuracy ,Simple and robust components

FLAP RUDDERS

Features and benefits

Superior steering abilities,Minimum installation time High reliability Custom built to fit hull ,Suits all types of steering gear

Conventional Rudders are the result of years of experience in ship design and hydrodynamics. Key characteristics are reliability, excellent manoeuvring and low life cycle cost. Rudders are produced as full spade rudders with three standard profiles to ensure optimal

manoeuvring for various types of vessel.

Features and benefits

Easy installation ,Easy maintenance ,Custom built to fit hull

Optimal performance ,Suits all steering gear

Rudder type CB is designed for lower speeds. A bulbous profile and large vane end plates improve low speed manoeuvrability. Type CM is designed for medium speeds. The profile is optimized to provide good manoeuvrability with propulsive efficiency, with a tapered or rectangular blade. The Type CS is designed for higher speeds. The slim profile increases overall propulsive efficiency and reduces cavitation risk. The blade is tapered with rounded corners.

A newly developed system in which a hubcap is fitted to the propeller hub, and a bulb is incorporated in a rudder, which has a twisted leading edge. The improved flow of water from the propeller over the rudder gives improved steering and control, and also reduces fuel consumption.

Features and benefits

Higher propulsive efficiency ,Better manoeuvrability ,Reduced fuel consumption ,Conventional ship hull forms can reap benefits ,No additional moving parts ,Less noise and vibration

Non-retractable stabilisers

Retractable stabilisers

Stabilisation-at-rest

Steering.gears.of.piston.type

Piston type steering gears of rated torque Mnom = 6,3 ÷ 2500 kNm, designed for all type of seagoing ships including passenger ships, tankers, chemical tankers and gas carriers. There are 2 or 4 cylinder steering gears. The 2 cylinder steering gears are equivalent to 4 ram steering gears. They meet SOLAS 1974 Convention with all later amendments and are built according to the rules and under the supervision of the following Classification Societies: ABS, BV, DNV, GL, LR, PRS, RMRS. Rules and an approval of other Classification Societies. The steering gears have a double hydraulic system automatically divided into subsystems in case of a single failure.When the oil leakage occurs as a result of pipeline or other hydraulic element failure, the damaged part of the system is automatically isolated and the steering gear remains efficient and ensures continuous ship’s control.

Considering types of applied pumps and the range of rated torques steering gears are divided into two groups:

steering gear maximal with constant gear pumps of rated torque Mnom = 6,3 ÷ 320kNm

steering gear maximal with variable multi-piston pumps of rated torque Mnom = 500 ÷ 2500kNm.

 

Steering gear maximal torque Mmax = 1,25 Mnom.

Steering gear consists of the following main units:

rudder actuator:

split tiller joined with 4 bolts or conically holed tiller for hydraulic fit,

2 or 4 piston type cylinders,

elements connecting tiller with cylinders: bolts, eyes, connecting links, etc.

two identical pump units with indispensable valve blocks, valves and hydraulic fittings:

free-standing with constant delivery gear pumps for steering gears from size MS320,

directly placed on the steering gear cylinders for steering gears from size MS500,

oil spare tank with hand pump,

electrical equipment of electric motors drive and signalling system. All required alarms are in accordance with the Class Rules.

Steering gears from size MS200 are fitted with fan air/oil coolers preventing against oil temperature excessive increase especially in tropical climates. The steering gears are designed to mate with electrical remote control system.

The steering gears elements mating directly with remote control system are as follows:

4 way/ 3 position “ON-OFF” solenoid directional control valve for each pump for steering gears with constant delivery gear pumps up to size MS320,

4 way/ 3 position “ON-OFF” solenoid directional control valve or 3 position proportional solenoid directional control valve for each pump of steering gears with multipiston variable delivery pumps A4VG... (REXROTH) from size MS500.

Directional valves are fitted with hand local control levers.

STEERING GEAR

CYLINDERSThe steering cylinders have chrome-plated cylinder bores and chrome-plated stainless steel piston rods. The piston is fitted with "U" cup type piston seals. Piston rods and cylinder anchors are fitted with spherical bearings. The steering gear is capable of moving, stopping and holding both rudders at any angle,while moving ahead or astern in free route at full propeller revolutions per minute and is capable of moving rudders from 45 degrees on either side to 40 degrees on the other side in 28 seconds.HYDRAULIC POWER UNITThe hydraulic power unit is based on a single tank with two (2) separate compartments. Each motor/pump draws oil from the compartment beneath it and discharges into a common return header that returns oil to both compartments through (25) micron filters. This provides maximum cooling by circulating oil through both compartments. The center bulkhead between compartments has overflow ports at top so oil entering compartment for which motor is not running overflows back into running motor compartment. The compartment for running motor will show an oil level several inches lower than the other. The return header has a ball valve in center that is normally open. By closing this valve, all oil returns to the same sump it was pumped from while the other is being serviced, including draining the compartment. The hydraulic oil reservoirs have a capacity of 110 percent of the hydraulic system. Each tank compartment is fitted with an oil level switch, which is set to operate about (5) inches below tank top or when oil reaches bottom of sight glass.DIRECTIONAL VALVE ASSEMBLYOil from pump flows to the manifold directional valve assembly. Oil flows through an in-line (65) PSI check valve that provides the back pressure (pilot pressure) required to operate the directional valve spool. Oil from pump flows to a port in manifold block then

into relief valve contained in the module, sandwiched between manifold and directional valve. The system relief valve is set at 1,100 PSI. From relief valve oil flows into the directional valve and back through relief and manifold where it exits and on to the back pressure check valve.PILOT DIRECTIONAL VALVEThe small electric solenoid pilot directional valve directs oil to shift the main directional spool just below it. The system may be operated during emergency or during testing by shifting the direction valve spool manually. To do this, use a tool such as a Phillips Screwdriver to push in on the small plunger located in the end of the small piloting electric solenoid valve. This causes the directional valve to respond exactly as though it has been energized by an electrical current.

COUNTERBALANCE VALVESOn the backside of each manifold are two (2) modified counterbalance valves. These valves act to hold the steering cylinders in position and prevent cylinders from moving ahead of oil flow from pump.CROSSPORT RELIEF VALVESThe hydraulic system is equipped with two crossport relief valves, which have a setpoint of 1300 PSIG. The purpose of the valves is to prevent over pressurization of the system and cylinders in the event there is no demand for rudder movement {pump discharge ported directly to the sump via the 4-way valve) and an external force is applied to the, rudders causing system pressure to reach 1300 PSIG. The valves allow pressure to be relieved to the sump.common return header that returns oil to both compartments through (25) micron filters. This provides maximum cooling by circulating oil through both compartments. The center bulkhead between compartments has overflow ports at top so oil entering

compartment for which motor is not running overflows back into running motor compartment. The compartment for running motor will show an oil level several inches lower than the other. The return header has a ball valve in center that is normally open. By closing this valve, all oil returns to the same sump it was pumped from while the other is being serviced, including draining the compartment. The hydraulic oil reservoirs have a capacity of 110 percent of the hydraulic system. Each tank compartment is fitted with an oil level switch, which is set to operate about (5) inches below tank top or when oil reaches bottom of sight glass.DIRECTIONAL VALVE ASSEMBLYOil from pump flows to the manifold directional valve assembly. Oil flows through an in-line (65) PSI check valve that provides the back pressure (pilot pressure) required to operate the directional valve spool. Oil from pump flows to a port in manifold block then into relief valve contained in the module, sandwiched between manifold and directional valve. The system relief valve is set at 1,100 PSI. From relief valve oil flows into the directional valve and back through relief and manifold where it exits and on to the back pressure check valve.PILOT DIRECTIONAL VALVEThe small electric solenoid pilot directional valve directs oil to shift the main directional spool just below it. The system may be operated during emergency or during testing by shifting the direction valve spool manually. To do this, use a tool such as a Phillips Screwdriver to push in on the small plunger located in the end of the small piloting electric solenoid valve. This causes the directional valve to respond exactly as though it has been energized by an electrical current.COUNTERBALANCE VALVESOn the backside of each manifold are two (2) modified ounterbalance valves. These valves act to hold the steering cylinders in position and prevent cylinders from moving ahead of oil flow from pump.CROSSPORT RELIEF VALVES

The hydraulic system is equipped with two crossport relief valves, which have a setpoint of 1300 PSIG. The purpose of the valves is to prevent over pressurization of the system and cylinders in the event there is no demand for rudder movement {pump discharge ported directly to the sump via the 4-way valve) and an external force is applied to the, rudders causing system pressure to reach 1300 PSIG. The valves allow pressure to be relieved to the sumpSTEERING SELECTOR SWITCHBOXThe Steering Selector Switchbox, located on the forward bulkhead of the Steering Gear Room, determines whether control of the steering systems (port and stbd) is in the Steering Gear Room or the Pilot House. It has a three (3) position selector switch (PORT AFT, STBD AFT AND FWD); it also incorporates local NFU ontrol for the port and stbd. Steering systems.During normal operation, the selector switch will be in the FWD position, llowing port and stbd. Steering gear start/stop control by the system selector switch module of the gyropilot helm unit located in the Pilot House console; it also transfers operational control to the Pilot House. In local control (PORT AFT, STBD AFT) the steering gear is started at the local controller. Control of the steering gearis accomplished by the local NFU control for the selected system.

AMENDMENTS(RECENT)

Regulation 29, Art. 1:. . . The main steering gear and the auxiliary steering gear shall be so arranged that the failure of one of them will not render the other one inoperative.

Regulation 29, Art. 6.1.3:

. . . the main steering gear is so arranged that after a single failure in its piping system or in one of the power units the defect can be isolated so that steering capability can be maintained or speedily regained.

Regulation 29, Art. 12.2:. . . a low-level alarm for each hydraulic fluid reservoir to give the earliest practicable indication of hydraulic fluid leakage. Audible and visual alarms shall

be given on the navigating bridge and in the machinery space where they can be readily observed; and Regulation 29, Art. 12.3:. . . A fixed storage tank having sufficient capacity to recharge at least one power actuating system including the reservoir, where the main steering gear is required to be power-operated. The storage tank shall be permanently connected by piping in such a manner that the hydraulic systems can be readily recharged from a position within the steering gear compartment and shall be provided with a contents gauge.

The modular concept of configuration for the Sperry Marine steering systems uses standard components configured in almost any required arrangement

INTEGRATED STEERING SYSTEM

SAFEMATIC

Automatic isolation system for 4-cylinder / 2-ram type steering gears.Designed acc. to latest rules of class. societies and IMO for automatic isolation of one cylinder group in case of leakage, failure or emergency. A must for tankers

Connectible to all HATLAPA 4-cylinder steering gears allow automatic emergency operation with two independent mechanical and hydraulical systems In case of pipe burst or other defects involving oil leaking, the leakage can be isolated and steering capability is maintained with two cylinders and one pump unit The ship's manoeuvrability is restored immediately and loss of hydraulic fluid is kept to a minimum, due to the very short time required for automatically detecting, isolating The HATLAPA SAFEMATIC detects, isolates and switches off the defective system automatically within a few seconds. Steering gear remains operational with the remaining system and switching over All HATLAPA 4-cylinder steering gears have still their hand operated stop valves for the same purposes

7.2. Steering Gear Principles7.8.1 state that the gear is vital to the safety of a ship; it must function correctly

and be properly serviced and maintained7.8.2 state that there must be two independent means of steering7.8.3 state that alternative control of the steering gear must be provided in the

steering gear compartment7.8.4 draw a line and block diagram to represent the major component of a

steering system showing;7.8.4.1 the steering-wheel transmitter –located in the bridge space

7.8.4.2 the rudder-control receiver unit-located aft in the steering compartment

7.8.4.3 the systems conveying the transmitter signal to the receiver7.8.4.4 the power system which moves the rudder7.8.4.5 the rudder-control feedback to the system

7.8.5 state that the function of the receiver is to act on the signal from the transmitter and through a control element to operate the rudder power system

7.8.6 state that the rudder power system can be hydraulic or electrical7.8.7 identify the particular requirements of oil tankers

7.3. Steering Gear Hydraulic Control Systems 7.9.1 describe the transmitter, receiver and associated pipes and valves, etc. as a

telemotor system7.9.2 state that for reasons of safety, two independent pipe systems are used

between the transmitter and the receiver7.9.3 describe a telemotor system using single line diagrams, showing how:

7.9.3.1 fluid is displaced by movement of the steering wheel7.9.3.2 fluid displacement at the receiver affects the control element of the

rudder power system7.9.4 describe the properties required of telemotor fluid7.9.5 explain how, in telemotor system:

7.9.5.1 deficiency of fluid is made up automatically and manually7.9.5.2 excess pressure is relieved7.9.5.3 an imbalance of pressure can be corrected7.9.5.4 tests are made for leaks7.9.5.5 air and other gases are bled from the system

7.9.6 explain the importance of maintaining the system free of air and other gases

7.9.7 explain the importance of maintaining the system leak-free

7.4. Steering Gear Electrical Control 7.10.1 describe the principles of operation of an electrical control system

7.5. Hydraulic Power-Operated Rudder Systems 7.11.1 explain that the systems can be principally cylinders and rams or a radial-

vane motor7.11.2 sketch, using lines and block diagrams, the system of cylinders and rams,

showing how, with a pair of rams in line and two rams in parallel hydraulic pressure actuates the rudder through a crosshead or trunnion and tiller-arm assembly

7.11.3 state that, in a radial-vane-type system, hydraulic pressure acts on radial vanes attached to the rudder stock, this producing movement of the rudder

7.11.4 describe normal operation of rudder drive pumps and system indicating which valves are open and which are closed

7.11.5 state the materials normally used in the main components in the above objectives

7.6. Hydraulic Power Rotary Pumps 7.12.1 state that rotary positive-displacement pump is used to obtain

displacement of fluid and produce movement of the rudder7.12.2 state that the pump in the above objective is driven by an electric motor7.12.3 describe the principle of operation of a radial cylinder pump7.12.4 describe the principle of operation of a swash-plate pump7.12.5 describe how the pumping action is controlled:

7.12.5.1 by linkage to the telemotor receiver and7.12.5.2 by linkage to the rudder, for feedback control

7.5.13 describe with the aid of single line sketch, how the pump is controlled to move the rudder from one position to another

7.5.14 state that the fluid in the system must be the correct mineral-base oil which is clean and free of moisture

7.5.15 explain how the reserve of fluid in the system is checked and how make-up is achieved

7.5.16 explain how shocks to the system from wave action on the rudder are absorbed

7.5.17 explain the conditions which may require the use of one or two pumps in normal operation

7.5.18 describe how a steering system is tested prior to leaving port with reference to IMO recommendations

7.7. Electric Steering Systems 7.13.1 describe how the control system incorporating transmitter and

receiver can be based on a Wheatstone bridge7.13.2 explain how movement of the steering wheel or rudder will produce

an out-of balance current in the bridging circuit7.13.3 state that the out-of-balance current can be used directly or

indirectly to produce power in the motor driving rudder7.13.4 explain the principle of the Ward-Leonard system7.13.5 explain the principle of the single-motor system

7.8. Emergency Steering 7.14.1 describe how the systems can be controlled from:

7.14.1.1 a local position in the steering compartment at the rudder head7.14.1.2 an emergency steering position on deck

7.14.2 describe alternative systems of steering that can be used in an emergency

9. REFERENCES:

9.1 Hind, J. Anthony. “Ship Gears”.9.2 Althouse. “Refrigeration and Air conditioning”. 9.3 Morton, T.D. “Motor Engineering knowledge for Mar. Engineers”.

9.4 Jackson, L. and Morton, T. “General Engineering knowledge for Marine Engineers”.

9.5. Millan, Mario D. “Auxiliary Machinery 2”.