Steering Gear
critical
Known Models (8)
Frydenbo / Noreq (Norway) Frydenbo Steering Gear
Torque 50-1,500 kNm
· Hydraulic Oil
type: Rotary Vane Steering Gear
size_range: ['FRY-50', 'FRY-200', 'FRY-500', 'FRY-1000', 'FRY-1500']
power_range_kw: [5, 75]
variant_count_approx: 5
period_start_year: 1960
period_end_year: None
drive_type: Electric-Hydraulic
construction: Rotary vane, compact design
Common Failures:
- • Vane seal leakage
- • HPU pump wear
- • Feedback sensor drift
Service: Standard steering gear maintenance.
Spares: Noreq (Bergen, Norway, ehem. Frydenbo). Lead time: 3-5 weeks.
Hydac / Van der Velden (Netherlands) High-Lift Rudder + Steering Gear System
Torque 50-3,000 kNm
· Hydraulic Oil
type: Rotary Vane Steering Gear + Schilling/Becker Rudder
size_range: ['VdV Standard', 'VdV High-Lift', 'VdV Flap Rudder']
power_range_kw: [10, 150]
variant_count_approx: 3
period_start_year: 1975
period_end_year: None
drive_type: Electric-Hydraulic
construction: Rotary vane gear + high-lift rudder blade (Becker/Schilling type)
Common Failures:
- • Vane seal leakage
- • Flap rudder mechanism wear on flap models
- • Rudder bearing wear
- • HPU motor failure
Service: Rudder bearing clearance check at drydock. Flap mechanism (if applicable) inspection annually. Standard steering gear maintenance.
Spares: Van der Velden Marine Systems (Hardinxveld, Netherlands). Lead time: 3-6 weeks.
Jastram (Germany) Rotary Vane Steering Gear
Torque 50-2,000 kNm
· Hydraulic Oil
type: Rotary Vane Type Steering Gear
size_range: ['Jastram RV-50', 'RV-200', 'RV-500', 'RV-1000', 'RV-2000']
power_range_kw: [5, 100]
variant_count_approx: 5
period_start_year: 1960
period_end_year: None
drive_type: Electric-Hydraulic
construction: Cast steel housing, rotary vane, dual HPU
Common Failures:
- • Vane seal leakage
- • HPU pump wear
- • Solenoid valve sticking
- • Feedback unit drift
Service: Standard steering gear maintenance. SOLAS hard-over test.
Spares: Jastram (Hamburg, Germany). Lead time: 3-6 weeks.
Kawasaki Heavy Industries (Japan) KHI Steering Gear
Torque 100-10,000 kNm
· Hydraulic Oil
type: Rotary Vane / Ram Type Steering Gear
size_range: ['KHI RV', 'KHI Ram']
power_range_kw: [15, 200]
variant_count_approx: 2
period_start_year: 1975
period_end_year: None
drive_type: Electric-Hydraulic
construction: Rotary vane or ram type, dual HPU
Common Failures:
- • Vane/ram seal leakage
- • HPU motor/pump failure
- • Control valve issues
Service: Standard steering gear maintenance per KHI manual.
Spares: KHI Japan. Lead time: 3-5 weeks Asia.
MacGregor / Porsgrunn / Cargotec (Finland/Norway) Ram Type Steering Gear
Torque 200-20,000 kNm
· Hydraulic Oil
type: Ram (Rapson Slide) Type Steering Gear
size_range: ['RS 200', 'RS 500', 'RS 1000', 'RS 2000', 'RS 5000']
power_range_kw: [30, 300]
variant_count_approx: 5
period_start_year: 1960
period_end_year: None
drive_type: Electric-Hydraulic
construction: Hydraulic rams, tiller arm, Rapson slide mechanism, dual HPU
Common Failures:
- • Ram cylinder seal leakage causing rudder drift
- • Tiller arm bushing wear from dynamic loading
- • Rapson slide block wear after 20,000+ hrs
- • HPU relief valve malfunction
- • Emergency steering changeover valve sticking
Service: Hydraulic oil analysis every 6 months. Ram cylinder seal inspection at drydock. Tiller arm bushing clearance measurement at drydock. Rapson slide block inspection annually. SOLAS hard-over test. Emergency steering drill monthly.
Spares: MacGregor/Porsgrunn/Cargotec. Lead time: 4-8 weeks. Ram seals: keep onboard. Rapson slide blocks: 6-10 weeks.
Mitsubishi Heavy Industries (Japan) MHI Steering Gear
Torque 200-15,000 kNm
· Hydraulic Oil
type: Ram Type Steering Gear (Heavy Duty)
size_range: ['MHI Ram-200', 'MHI Ram-500', 'MHI Ram-2000', 'MHI Ram-5000']
power_range_kw: [30, 250]
variant_count_approx: 4
period_start_year: 1970
period_end_year: None
drive_type: Electric-Hydraulic
construction: Ram type with Rapson slide, dual HPU
Common Failures:
- • Ram seal leakage
- • Tiller arm bushing wear
- • Rapson slide block deterioration
- • HPU relief valve malfunction
Service: Standard ram-type steering gear maintenance.
Spares: MHI Japan. Lead time: 3-6 weeks Asia.
Rolls-Royce / Kongsberg Maritime (UK/Norway) Rotary Vane Steering Gear
Torque 100-15,000 kNm
· Hydraulic Oil
type: Rotary Vane Type Steering Gear
size_range: ['RV 100', 'RV 300', 'RV 600', 'RV 1000', 'RV 1500']
power_range_kw: [15, 200]
variant_count_approx: 5
period_start_year: 1970
period_end_year: None
drive_type: Electric-Hydraulic
construction: Cast steel housing, 2 or 4 vanes, dual HPU
Common Failures:
- • Vane seal leakage causing internal bypass (most common failure)
- • HPU motor bearing failure after 30,000+ hrs
- • Solenoid valve sticking from oil contamination
- • Helm pump relief valve malfunction
- • Rudder feedback unit calibration drift
Service: Hydraulic oil analysis every 6 months. Vane seal inspection at drydock. HPU relief valve setting check annually. Rudder movement test (hard-over to hard-over in 28 sec per SOLAS). Emergency steering drill monthly. Complete overhaul every 10-15 years.
Spares: Kongsberg Maritime (ehem. Rolls-Royce). Lead time: 3-8 weeks. Vane seals: keep onboard. Solenoid valves: 1 set onboard.
Wärtsilä Rotary Vane / Ram Steering Gear
Torque 100-10,000 kNm
· Hydraulic Oil
type: Rotary Vane / Ram Type Steering Gear
size_range: ['Wärtsilä RV', 'Wärtsilä Ram']
power_range_kw: [15, 200]
variant_count_approx: 2
period_start_year: 1980
period_end_year: None
drive_type: Electric-Hydraulic
construction: Rotary vane or ram type, dual HPU
Common Failures:
- • Vane/ram seal leakage
- • HPU motor failure
- • Control valve issues
- • Feedback unit drift
Service: Standard steering gear maintenance per Wärtsilä manual. SOLAS compliance testing.
Spares: Wärtsilä global network. Lead time: 3-6 weeks.