During World War II, American submarines were poles apart from the nuclear subs of today. They were diesel-powered when traveling on top of the water, and when submerged, were powered by electric motors requiring short-term storage batteries. Diesel engines enabled these submarines to travel at high surface speeds and for long distances. But due to the storage battery limitations, the subs were forced to operate more like ships. They remained primarily visible on the surface of the water -- even on combat missions. And although the diesel component of these submarines worked well, a different solution was needed to improve the operation of the submarines beneath the water.

Since that time, diesel engines have operated trains, trucks, buses, boats and automobiles. The efficiency, power and lower volatility of diesel -- as compared with gasoline -- has continued to keep transportation engineers intrigued with discovering new ways to utilize this multifaceted technology. The added durability of diesel engines has kept them at the forefront of strides in transportation.

As diesel technology continues to evolve and become more computer-based, there are increased opportunities for those who desire a career in this field. Many junior colleges and vocational schools offer programs of study that are typically a year or two in length. Students focus on up-to-date diesel technology, basic physics, and how to read technical manuals. They learn how to repair vehicles and equipment with the sophisticated and basic tools of the trade. After completing a course of study, preferably with a hands-on component, experience is usually acquired on the job. The National Institute for Automotive Service Excellence (ASE) offers industry certification to diesel service technicians and mechanics who attain excellence and pass exams in specific areas of specialization.

Those who complete a formal diesel engine training program are likely to advance more quickly. Unskilled workers are generally given basic tasks until they have acquired enough experience or schooling to be promoted. In preparation for a career as a diesel service technician, high school courses in automotive repair, math, English, electronics and physics are helpful.

Diesel mechanics are employed in the trucking industry, in automotive and commercial maintenance facilities, in local government repair garages, in manufacturing, by bus lines, by railroad companies and a number of other venues.