Definition

1. Noun:
   • A type of locomotive: A diesel-hydraulic is a railway locomotive that uses a diesel engine to power a hydraulic transmission system. This system converts the engine's mechanical energy into fluid pressure, which then drives the wheels. It is an alternative to diesel-electric locomotives.

Usage Examples

• Noun:
  • The railway company phased out its fleet of diesel-hydraulic locomotives in favor of more modern electric units.
  • This particular model is a classic diesel-hydraulic known for its distinctive sound.

Advanced Usage

• Technical context: The term is used specifically in rail transport engineering to describe a powertrain configuration.
  • The efficiency of a diesel-hydraulic transmission is often compared to that of a torque converter in automotive applications.

Variants and Related Words

• Diesel-hydraulic locomotive (n): The full, more precise term for this type of engine or vehicle.
  • The museum restored a vintage diesel-hydraulic locomotive.

Synonyms

• Hydraulic diesel locomotive: A less common but synonymous phrase.

Related Phrases

• Diesel-electric (n): A different type of locomotive where a diesel engine drives an electrical generator to power electric traction motors. This is a related but distinct technology often compared with diesel-hydraulic systems.
  • The debate between the merits of diesel-hydraulic versus diesel-electric propulsion was a key topic for mid-20th century engineers.

Noun

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