Definition

1. Noun:
   • A railway locomotive powered by a diesel engine that uses a hydraulic transmission system to transfer power to the wheels: This type of locomotive converts the mechanical energy from its diesel engine into fluid power within a hydraulic torque converter or fluid coupling, which then drives the axles, as opposed to using an electrical generator and motors.

Usage Examples

• Noun:
  • The railway company phased out its fleet of diesel-hydraulic locomotives in favor of more modern diesel-electric models.
  • This particular diesel-hydraulic locomotive is renowned for its smooth acceleration and high starting tractive effort.

Advanced Usage

• Technical Context: The term is used to specify the drivetrain technology in rail transport engineering and historical discussions.
  • The debate among enthusiasts often centers on the relative efficiency of the diesel-hydraulic locomotive versus its diesel-electric counterpart.

Variants and Related Words

• Diesel-hydraulic (adj): Describing the type of transmission system.
  • The diesel-hydraulic transmission was particularly popular in certain German and British designs.
• Diesel-electric locomotive (n): A related but distinct type where the diesel engine drives an electrical generator to power traction motors.
• Hydraulic transmission (n): The key component system that defines this locomotive type.

Synonyms

• Hydraulic diesel locomotive: A less common but technically accurate synonym.

Notes on Meaning

• This is a compound technical term. The core concept is a locomotive defined by its specific power transmission method (diesel-hydraulic). It is not simply a "diesel locomotive," which is a broader category, but a specific subtype within it.

Noun

1. a locomotive driven by a hydraulic transmission system powered by a diesel engine