BALTEK® SB - Series, BALTEK® SBC - Series

Common issues

• Hydraulic oil leakage past vane seals reducing rudder torque and response
• Air entrainment in the hydraulic system causing spongy or delayed rudder response
• Rudder angle transmitter misalignment causing a helm/rudder indication mismatch
• Relief valve setting drift allowing overpressure or reduced torque at hard-over
• Variable displacement pump wear reducing rudder speed below the required rate
• Rotary vane housing/stator seal wear leading to internal leakage between chambers
• Changeover/solenoid valve sticking, affecting main/auxiliary steering changeover

Inspection checklist

• Function-test steering gear from full port to full starboard and confirm rudder movement within the required time
• Check hydraulic oil level and condition (water/particulate contamination); sample if due
• Test changeover between main and auxiliary steering systems
• Verify the rudder angle indicator agrees with actual rudder position at several angles
• Check relief valve settings and confirm no seal leakage at rudder hard-over (stall test per class procedure)
• Inspect for external hydraulic leaks at the pump, pipework and rotary vane unit
• Test emergency/local steering position operation and communication to the bridge
• Check alarm functions (low oil level, hydraulic lock, phase failure)

Service intervals

Critical spares

• Rotary vane seal/gasket kit
• Relief valve or repair kit
• Hydraulic pump seal kit
• Rudder angle transmitter
• Changeover/solenoid valve
• Hydraulic oil of the correct maker-specified grade

Safety

• Loss of steering is a critical casualty - never carry out maintenance on the operating steering gear at sea without confirming an available backup steering method
• High-pressure hydraulic system - relieve pressure before opening any joint; pinhole leaks can cause a fluid injection injury
• Rudder movement during testing - clear personnel from the tiller flat/rudder trunk and follow lockout procedure before manual barring or hands-on work
• Confirm communication with the bridge before any function test that moves the rudder

Class survey

Steering gear is statutory equipment under SOLAS. Class requires documented steering gear testing before departure, periodic full-rudder-angle timing tests, and confirmation that both main and auxiliary steering systems - and their independent power supplies, where required - are operative at each periodical survey.