Maintenance Manual Kongsberg Steering Gear type SR and SV

Maintenance Guide for KONGSBERG SR and SV Steering Gears

The maintenance guidelines for the Konigsberg SR and SV steering gears were released in 2020 and have been revised multiple times. The core specifies safe operating procedures, graded maintenance cycles (daily/5/10/15/20/25 years), distinguishes the structure and exclusive maintenance processes of variable frequency pumps and conventional pump systems, specifies the designated models and testing standards for hydraulic oil, clarifies the operation methods for key tests such as leakage and steering time, and provides specific requirements for spare parts reserves, data submission, and official technical support. Maintenance work is divided into four levels: A/B/C/D according to skill levels, corresponding to crew autonomous operation, port assistance, Konigsberg professional support, and exclusive workshop maintenance.

Maintain basic definition and grading

Abbreviations for Maintenance Categories: Clarify the abbreviations for 13 types of maintenance operations to provide a unified standard for maintenance records and execution. The core categories are shown in the table below:

|Abbreviation | Meaning | Core Applications|

|CHK | Inspection | Daily leakage, oil temperature, alarm status inspection|

|TST | Testing | Emergency Steering, Internal Leakage, Steering Time Testing|

|FC | Replace filter element | Replace hydraulic system filter element every 6 months|

|SAM | Sampling | Hydraulic oil sample collection and testing every 6 months|

|OC | Oil Change | Mandatory Oil Change Every 10 Years, Early Abnormal Status|

|REP | Replacement | Mandatory 10-year replacement of pumps, frequency converters, rubber hoses, etc|

Skill level: divided into 4 levels, A level refers to routine maintenance independently completed by crew members on board the ship; B-level is carried out at the port, requiring crew and local port support; Level C is for port development and requires professional support from Kongsberg; D-level is the maintenance/overhaul of the exclusive workshop of Kongsberg.

Facility code: divided into 4 categories, A (shipborne), B (port), C (dry dock), D (Kongsberg/port workshop), matched with skill level for execution and maintenance.

Maintenance cycle and core tasks

Maintenance is divided into crew daily regular maintenance and shipyard/graded professional maintenance. The former is carried out according to a fixed cycle, while the latter is graded according to equipment operation for 5/10/15/20/25 years, based on equipment status and operating years. The core cycle and tasks are as follows:

Daily Regular Maintenance: Covering multiple cycles from 1 day to 1 year, the core high-frequency task is to inspect the actuator for leaks, surface temperature, and abnormal vibrations/noise within 1 day; Check the frequency converter for faults, add hydraulic oil, and start/stop the backup pump within one week; Clean equipment in January, test emergency/routine steering, and check for clogged filter cartridges; Detect internal leaks, collect oil samples, and replace filter elements within 6 months; 1 year inspection of frequency converter alarm logs, motor megohm testing, and visual inspection of electrical components.

Shipyard classification maintenance: It needs to be carried out by Kongsberg engineers at the dry dock/port, and maintenance recommendations should be developed based on equipment status (self inspection/testing/PMS logs submitted through Kongsberg mobile application) for 5 years; 10 years is a mandatory maintenance node, requiring replacement of core components such as bearings/seals, hydraulic oil, pumps, frequency converters, rubber hoses, etc; Develop maintenance recommendations based on previous maintenance records and current equipment status by 2015/20/25, and complete comprehensive status checks and core component evaluations by 2025.

Core system structure of steering gear

The manual distinguishes between two systems: Variable Frequency Pump (FCP) and Conventional Pump (PU), with significant differences in structure and operating characteristics. At the same time, it clarifies the core design of the actuator:

Execution mechanism: Hydraulic mechanical structure, driven by a spherical rotor to rotate the rudder stock. The synthetic bearing pad always has 100% surface contact and is continuously lubricated by hydraulic oil. Disassembling the lower seal/bearing pad requires lifting the rotor and fixing the rudder unit with a third-party professional organization. If the operating space is less than 1.5 meters, the deck needs to be modified/the rudder stock needs to be lowered.

Variable frequency pump system: New equipment after 2019 comes standard with dual reversible frequency pump units, valve blocks, and electrical feedback units. The pump starts and stops with the rudder command, and the single pump operates at a regular speed. The dual pump operates at double the speed, and the valve block integrates a filter. The number of valves is small and the structure is simple.

Conventional pump system: The pump operates continuously and controls the hydraulic oil through a control valve. It is divided into models such as PU30/45/50, where PU30 is a gear pump and the rest are vane pumps. The pump is immersed in oil and connected to the actuator and oil storage tank through three pipes.

System oil capacity: Different models/pump types have different oil capacities. The variable frequency pump system SR562 is about 35L, SV850 is about 230L; the conventional pump system SR562+PU30 is about 60L, SV570+PU50 is about 570L.

Core maintenance process and testing

The manual provides detailed operating procedures for hydraulic oil management, core performance testing, and specialized maintenance. The testing processes for variable frequency pumps and conventional pumps are completely independent, and the core operations are as follows:

Hydraulic oil management

Oil requirements: Must comply with DIN 51524 standard, ISO32 viscosity grade, pour point ＜ -30 ℃, contain anti-wear, water-resistant/anti foaming additives, and prohibit mixing with other oils; Kongsberg has designated AGIP ARNICA 32, SHELL TELLUS S2 VX 32 and other oils, and CASTROL Biobar 32 biodegradable oil can be selected.

Oil change standard: If the oil sample test shows that the neutralization value is too high, the residual amount of extreme pressure additives is low, there are too many insoluble particles, or the cleanliness is lower than ISO 4406 17/14 (NAS 1638 level 8), or if the hydraulic system components are damaged, the oil needs to be changed immediately.

Oil sample collection: After the equipment is running, collect samples from the sampling points of the actuator/valve block/filter. Rinse the hose first, then fill it into a clean sample bottle, label the oil type/date/duration of use, visually detect color/impurities, and immediately send the sample for analysis.

Core performance testing: All tests are carried out by the chief engineer in sheltered waters, and pumps 1 and 2 need to be tested separately. The test results are recorded in the feedback form and sent to the designated email of Kongsberg. The core tests include internal leakage testing and steering time testing. The variable frequency pump test involves bidirectional switching of 30 ° steering angle, while the conventional pump requires bidirectional switching of 30 ° -35 ° steering angle. At the same time, the leakage oil volume, pressure, and oil temperature are recorded.

Special maintenance process

Inverter fault log: Check that the cooling air duct is not blocked, press the alarm log button, view the fault record of timestamp+running hours through the up and down keys, and press the status key to exit.

Emergency steering test: Adjust the motor controller to local control, operate the steering through the emergency button, restore remote control after testing, and communicate wirelessly with the bridge throughout the process.

Filter replacement: Stop the machine and close the expansion tank oil valve, drain the oil in the filter chamber, replace the filter element and reinstall it, open the oil valve and release the air from the distribution valve, and restore remote control.

Cooler cleaning (B10/M10-30 type): Mild pollution can be backwashed with water, severe pollution can be washed with 5% phosphoric acid/oxalic acid solution, M10 type can be disassembled and manually cleaned (board width not exceeding 88.4mm), B10 type cannot be washed and replaced. After cleaning, the gasket needs to be dried 24 hours or replaced directly.