Double-acting reciprocating steam engine operation: Steam is admitted alternately on both sides of the piston. Does this arrangement produce two working strokes during each revolution of the crankshaft?

Introduction / Context:Steam engines may be single-acting (steam acts on one side of the piston only) or double-acting (steam acts alternately on both sides). The turning-moment uniformity and power output differ between these arrangements. This item checks the basic kinematics and work delivery per revolution for a double-acting engine.

Given Data / Assumptions:

• Single-cylinder, double-acting steam engine.
• Crank makes one full revolution as the piston completes one double stroke (out and back).
• Valving alternates admission and exhaust to opposing sides of the piston.

Concept / Approach:In a double-acting engine every stroke is a power (working) stroke because steam pressure pushes the piston during both the outstroke and the instroke. Therefore, for each revolution of the crankshaft—corresponding to one back-and-forth piston motion—there are two working strokes, one in each direction.

Step-by-Step Solution:Relate kinematics: one crank revolution ↔ one full piston cycle (to-and-fro).Recognize valve timing: steam admitted to one side while the other side exhausts, then roles reverse.Note work delivery: both strokes produce positive work on the crank.Conclude: two working strokes per revolution in a double-acting engine.

Verification / Alternative check:Indicator diagrams for both ends of the cylinder show positive loop areas for each stroke, confirming two power events per revolution.

Why Other Options Are Wrong:“No” and variations assume idle strokes like many I.C. engines; steam engine valving makes both strokes productive.

“Only with two cylinders” is incorrect; it holds with a single double-acting cylinder.

Common Pitfalls:Projecting four-stroke internal combustion logic onto steam engines; forgetting that external steam supply enables power on both strokes.

Final Answer:Yes