.sg regulation
.steering gear regulation .sgr
SG regulation
Regulation
SOLAS Chapter II-1 in Part C states steering gear regulation on board a ship.
Regulation 29:
- every ship shall be provided with a main steering gear and an auxiliary steering gear. 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.
- Where main steering gear provided with two or more identical power units, an auxiliary steering gear shall not be fitted
- Main steering and rudder stock shall be of
- adequate strength and capable to steer the ship at max speed
- Capable to turn rudder from 35° to 35° either side, from 35° to 30° in not more than 28 sec at deepest draught at max speed
- Aux steering able to put from 15° to 15° on either side not more than 60 sec at deepest draught and at ½ speed
- Steering gear compartment shall be readily accessible, separate from machinery space, provided with rails and non-slip surface in case of leakage
- Rudder stroke diameter minimum 230mm
- All components to be of reliable construction
- Design pressure for piping and construction at least 1.25x max working pressure
- Setting of relief valve not more than design pressure
- Steering gear control is provided on both bridge and steering compartment.
- Have means provided in steering gear compartment to disconnect control system of bridge
- Rudder angle indication independent of control system, indicated on bridge and steering gear
- Means of communication provided between bridge and steering gear compartment
- Means of indicating power unit if running is installed at ECR and bridge
- Low level alarm at each fluid reservoir to ECR, bridge
- A fixed storage tank with level indicator having sufficient capacity to recharge at least one power actuating system including the reservoir. The storage tank shall be permanently connected by piping so that the hydraulic systems can be readily recharged.
- one of the 2 steering gears should be supplied by the emergency supply. Not only the steering power but also provide power to its associated control system and the rudder angle indicator.
- alternate power supply provided in 45sec, supply at least of 30 minute continuous for 10,000 GT, else 10 minute below 10,000 GT
- Main and aux steering gear arrange to
- a. restart automatically after power failure
b. capable of being brought into operation from a position from navigation bridge
c. in the event of power failure an audible and visual alarm shall be given.
d. In cargo and passenger ship capable of operating rudder with either of the power unit
e. Single failure in piping system or any of the power units can be automatically detected, isolated and steering capability automatically regained.
- a. restart automatically after power failure
- Short circuit protection for steering gear control supply circuit
- The electrical power circuits and the steering gear control systems, cables and pipes shall be separated as far as is practicable throughout their length.
- Rudder stock 0.23m diameter,
- Every tanker, 10,000 GT above and other ships of 70,000 GT, main steering should have 2 identical unit, single failure, steering regained in 45sec.
- Interconnection of hydraulic power system provided, loss of hydraulic fluid capable of detection and defective system isolated
- Within 12 hours before departure, checking of steering gear system, and communication
- Emergency steering test at least in 3 months
Source:
“https://imorules.com/GUID-CF547534-23B3-4162-8415-6C806370E406.html”
Steering Gear Regulation Study Tips:
Main and Auxiliary Steering Gear
- Every ship must have both main and auxiliary steering gear.
- They must be independent to prevent total failure.
- Exception: If main steering has two or more identical power units, auxiliary steering is not required.
Performance Requirements
Main Steering Gear:
- Must turn rudder 35° to 35° in ≤28 seconds at max speed and deepest draught.
Auxiliary Steering Gear:
- Must turn rudder 15° to 15° in ≤60 seconds at half speed and deepest draught.
Design and Construction
- Steering gear compartment: Accessible, separate from machinery space, with safety features.
- Minimum rudder stock diameter: 230mm.
- Components must be reliable.
- Piping design pressure: ≥1.25x max working pressure.
- Relief valve setting: ≤design pressure.
Control and Communication
- Control on bridge and in steering compartment.
- Bridge control can be disconnected in steering compartment.
- Independent rudder angle indicators on bridge and in steering compartment.
- Communication between bridge and steering compartment required.
- Power unit status indicators in ECR and on bridge.
Safety and Emergency Features
- Low fluid level alarms to ECR and bridge.
- Fixed storage tank for hydraulic system recharge.
- Emergency power supply for one steering gear.
- Alternate power supply within 45 seconds.
- Automatic restart after power failure.
- Audible and visual alarms for power failures.
- Automatic fault detection and isolation.
- Short circuit protection for control circuits.
Special Requirements for Large Ships
- Tankers ≥10,000 GT and other ships ≥70,000 GT: Main steering with two identical units, 45-second recovery.
Maintenance and Testing
- Pre-departure checks within 12 hours.
- Emergency steering tests every 3 months.
Remember the key numbers: 35°-30° in 28 seconds for main, 15°-15° in 60 seconds for auxiliary, 230mm minimum rudder stock diameter, and 45-second recovery time for large ships.