🔍 Key Concepts

• Location of label Y in relation to the crankshaft, connecting rod, and crosshead • How lubricating oil or cooling water is supplied to a moving crosshead in a large low-speed diesel • Difference between fixed piping and telescopic/hidden internal passages shown by dashed lines in machinery drawings

💭 Think About

• Look at where the dashed line labeled Y starts and ends: what components is it connecting, and what fluid would need to flow along that exact path? • Ask yourself which of the options would reasonably need to move up and down with the piston/connecting rod, rather than remain fixed to the engine structure. • Consider why the line is drawn dashed inside the connecting rod instead of as an external solid pipe—what does that usually mean in sectional machinery drawings?

✅ Before You Answer

• Confirm whether Y is drawn inside the crankcase/connecting rod or outside along the engine frame. • Check if the line associated with Y must accommodate relative motion between crankshaft and crosshead (up‑and‑down stroke). • Verify which of the four choices would typically be arranged as a telescoping or internal line in a crosshead-type slow‑speed diesel engine.