🔍 Key Concepts
• Identify visual features of an electric starter motor (field windings, armature, brushes, solenoid) versus a fluid‑driven motor (air or hydraulic vanes/pistons, ports, and gear train).
• Distinguish between air and hydraulic motors by looking for pressure ports, control valve bodies, and overall construction typical of a starting air motor on diesels.
• Eliminate options that would require components clearly missing from the illustration, such as ignition/fuel systems for gasoline engines.
💭 Think About
• Study the long cylindrical section and rotor in the illustration: does it look like an electrical armature with windings and commutator, or more like a smooth rotor used with compressed fluid?
• Look closely for any fittings or ports on the housing—what kind of working medium (electricity, fuel/air mix, hydraulic oil, or compressed air) would connect there on a real engine?
• Consider what starting systems are commonly used on larger diesel auxiliaries on tugs—would they practically use a small gasoline engine to crank them, or something else?
✅ Before You Answer
• Verify whether there are electrical components (wires, brushes, solenoid, commutator) present anywhere in the drawing.
• Verify whether there are any fuel or carburetor/ignition components that would be needed for a gasoline cranking engine.
• Check for one or more pressure ports and valve/gear assemblies consistent with a fluid (air or oil) driven motor used for diesel starting.