🔍 Key Concepts

• Crankshaft axial alignment – what keeps the crankshaft from moving ahead/astern along its length • Function of an engine thrust bearing in taking propeller shaft thrust • Difference between radial support (up‑down/sideways) and axial/thrust support (fore‑and‑aft) in bearings

💭 Think About

• Which engine component is specifically designed to handle fore‑and‑aft forces coming from the propeller and shaft? • Which of these choices mainly keeps parts lined up side‑to‑side or up‑and‑down, rather than fore‑and‑aft? • Think about where propeller thrust ends up: which part of the engine must safely absorb and transmit that push to the hull?

✅ Before You Answer

• Identify which option is designed to carry axial (thrust) load, not just radial load • Eliminate components that mainly guide reciprocating motion (back‑and‑forth of pistons/crossheads) rather than shaft alignment • Confirm which part is located where the propeller thrust is transmitted into the engine and hull structure