Stern Tube Seal
critical
IMO Required
Sealing system preventing seawater ingress at stern tube
8000h
Service Interval
5 yr
Class Survey
10 yr
Typical Lifetime
Typical Manufacturers
Wartsila
Blohm+Voss
Kemel
Duramax
Known Models (4)
Blohm+Voss Simplex Compact
Per propulsion shaft design
· Seawater / Lube Oil barrier
Common Failures:
- • Chromium liner scoring
- • Seal ring wear
- • Oil leakage
- • Spring failure
Service: Lip seal type; replace seals at drydock; check chrome liner condition.
Spares: Blohm+Voss: Dichtungs-Elemente und Verschleißmesswerkzeuge an Bord vorhalten. Lead time: 4-8 Wochen.
Duramax DM Seal 300
Per propulsion shaft design
· Seawater / Lube Oil barrier
Common Failures:
- • Seal lip degradation
- • Shaft liner groove wear
- • Aft seal seawater ingress
Service: Duramax lip seal; inspect aft seal at every drydock.
Spares: Duramax: Dichtungs-Elemente und Verschleißmesswerkzeuge an Bord vorhalten. Lead time: 4-8 Wochen.
Kemel KS-3 Marine
Per propulsion shaft design
· Seawater / Lube Oil barrier
Common Failures:
- • Seal face wear
- • Stuffing box leak
- • Spring corrosion
Service: Face-type seal; monitor stern tube oil consumption for early leak detection.
Spares: Kemel: Dichtungs-Elemente und Verschleißmesswerkzeuge an Bord vorhalten. Lead time: 4-8 Wochen.
Wärtsilä Airguard 200
Per propulsion shaft design
· Seawater / Lube Oil barrier
Common Failures:
- • Seal lip wear
- • Air pressure loss
- • Oil leakage to sea (environmental!)
- • Spring deterioration
Service: Air-type seal; maintain air pressure at 0.2 bar above draught pressure.
Spares: Wärtsilä: Dichtungs-Elemente und Verschleißmesswerkzeuge an Bord vorhalten. Lead time: 4-8 Wochen.