Exam Question

(a) Sketch an outboard type of oil seal suitable for oil filled stern tube indicating the principal component. (5)

(b) Explain how the seal compensated for wear of the seal face maintains oil tightness. (5)

(c) What is the effect of seawater contamination of stern tube oil and how contamination risk can be reduced? (3)

(d) State the physical properties required for the bearing material in oil filled stern tube. (3)