four-coupled

A four-coupled locomotive pulls a long train of freight cars.

Definition

• Adjective: "four-coupled" describes a type of locomotive or vehicle that has four wheels arranged in two pairs, with the wheels in each pair being coupled together (i.e., linked to move in unison). This term is primarily used in railway engineering to specify the wheel arrangement of steam locomotives.

Usage Examples

• (A locomotive with four wheels in two coupled pairs.)
• (Engines with this wheel arrangement.)

Advanced Usage

• "Four-coupled tank locomotive": a type of steam locomotive with a water tank and no separate tender, having four coupled wheels.
  • The four-coupled tank locomotive was ideal for short-distance shunting duties. (A compact engine for moving trains in yards.)
• "Four-coupled bogie": a bogie (a wheeled undercarriage) with four wheels arranged in two coupled pairs.
  • The four-coupled bogie provided stability for the passenger car. (A wheeled frame with coupled wheels.)

Variants and Related Words

• Coupled (adj): joined or linked together, especially in mechanical contexts.
  • The coupled wheels of the train rotate together. (The wheels are connected.)
• Six-coupled (adj): a similar term for a locomotive with six wheels in three coupled pairs.
  • The six-coupled locomotive offered even more pulling power. (A larger wheel arrangement.)

Synonyms

• Double-coupled: a less common synonym, meaning with two pairs of coupled wheels.
• Four-wheeled: a broader term for any vehicle with four wheels, not necessarily coupled in pairs.

Related Idioms

• No common idioms are associated with "four-coupled," as it is a technical term.