Question 392Steam Plants - 1st Asst/Chief

The correct answer is B) Babbitt. Main steam turbine bearings are typically lined with a soft alloy called Babbitt, which is an anti-friction metal. Babbitt provides a smooth, low-friction surface for the turbine shaft to rotate against, helping to reduce wear and heat buildup. This material is specifically designed for use in high-speed rotating machinery like steam turbines. The other answer choices are incorrect because ferrous oxide is not a bearing material, steel and cast-iron are too rigid and would not provide the necessary lubrication and low-friction properties required for steam turbine bearings.