Diesel Plant Operating Engineer Third Class

If you’re looking for a career as a Diesel Plant Operating Engineer, ASOPE® is here to facilitate. ASOPE® offers an opportunity to obtain a Diesel Plant Operating Engineer - Third Class license. Outlined below is a list of qualifications that are required to receive your Diesel Plant Operating Engineer - Third Class license. Requirements include being a minimum of 18 years or older (a legal adult), a high school diploma/GED or equivalent, and one year experience in opertations or maintenance for marine or stationionary diesel engine plants.

If all qualifications are met, you will be required to schedule  a written examination (oral or practical if necessary). The exam consists of a wide range of curriculum including, but not limited to, basic thermodynamics, operation fundementals, high speed engines, valve arrangements, and environmental effects. Upon completion of the Diesel Plant Operating Engineer - Third Class license exam, an ASOPE® representative will notify of a "pass" or "fail" status. If failed, you will be offered additional opportunities to retake the exam. Please review our Failed Test Procedures to learn more.

If you have any questions or concerns regarding the Diesel Plant Operating Engineer- Third Class license, please contact the ASOPE® national office.


  • Minimum age - Adult
  • Education - High School Diploma or GED or equivalent.
  • Experience - One year operations or maintenance of marine or stationary diesel engine plants.
  • Examination - Written 50 questions multiple choice (Oral or Practical when necessary)

Curriculum at the Minimum:

  • Basic Thermodynamics
  • Basic Measuring Instruments
  • Fuels
  • Operating Fundamentals
  • Two-Stroke and Four-Stroke Cycles
  • High Speed Engines
  • Low Speed Engines
  • Engine Construction and Layout
  • Diesel Engine Components
  • Valve Arrangements
  • Typical Operating Efficiencies
  • General Industrial Safety
  • Basic Electrical Theory
  • Environmental Effects