TEXT: The Engineering Profession

Engineering is one of the oldest occupations in history. Without the skills included in the broad field of engineering, our present-day civilization never could have evolved.

Some common machines.

The first toolmakers who chipped arrows and spears from rock were the forerunners of modern mechanical engineers. The craftsmen who discovered metals in the earth and found ways to refine and use them were the ancestors of mining and metallurgical engineers. And the skilled technicians who devised irrigation systems and erected the marvelous buildings of the ancient world were the civil engineers of their time. One of the earliest great names in history is that of Imhotep, designer of I laid stepped pyramid at Saqqara in Egypt, built in the twenty-seventh century B.C.

Engineering is often defined as making practical application of theoretical sciences such as physics and mathematics. Many of the early branches of engineering were based not on science but on empirical information that depended on observation and experience rather than on theoretical knowledge. Those who devised methods for splitting the massive blocks that were needed to build Stonehenge in England or the unique pyramids of Egypt discovered the principle of the wedge by trial and error rather than by mathematical calculations. The huge blocks of stone for the pyr­amids were probably raised into place by means of ramps of earth that surrounded the structures as they rose; it was a practical ap­plication of the inclined plane, even though the concept was not understood in terms that could be quantified or expressed mathematically.

Quantification has been one of the principal reasons for the ex­plosion of scientific knowledge since the beginning of the modern age in the sixteenth and seventeenth centuries. Another important factor has been the development of the experimental method to verify theories. Quantification involves putting the data or pieces of information resulting from experimentation into exact mathematical terms.

The great engineering works of ancient times were constructed and operated largely by means of slave labor. After the fall of the Roman Empire there were fewer slaves available in Europe. Dur­ing the Middle Ages people began to seek devices and methods of work that were more efficient and humane. Wind, water, and animals were used to provide energy for some of these new devices. This kind of experimentation eventually led to what is known as the Industrial Revolution which began in the eighteenth century. First steam engines and then other kinds of machines took over more and more of the work that had previously been done by human beings or by animals. James Watt, one of the key figures in the early development of steam engines, devised the concept of horsepower to make it easier for his customers to understand the amount of work his machines could perform.

Since the nineteenth century both scientific research and prac­tical application of its results have escalated. The mechanical engineer now has the mathematical ability to calculate the mechanical advantage that results from the complex interaction of many different mechanisms. He or she also has new and stronger materials to work with and enormous new sources of power. The Industrial Revolution began by putting water and steam to work; since then machines using electricity, gasoline, and other energy sources have become so widespread that they now do a very large proportion of the work of the world.

One result of the rapid expansion of scientific knowledge was an increase in the number of engineering specialties. By the end of the nineteenth century not only were mechanical, civil, and mining and metallurgical engineering established but the newer specialties of chemical and electrical engineering emerged. This growth in the number of specialties is continuing with the establishment of such disciplines as aerospace, nuclear, petroleum, and electronic engi­neering. Many of these are subdivisions of earlier specialties—for example, electronic from electrical engineering or petroleum from chemical. Within the field of mechanical engineering the major subdivision is industrial engineering which is concerned with com­plete mechanical systems for industry rather than individual machines.

Because of the large number of engineering fields today there are often many different kinds of engineers working on large pro­jects such as the development of nuclear power or new aircraft. In the design of a new aircraft mechanical engineers work not only on the plane's engines but on other mechanical aspects such as the braking system. When the aircraft goes into production mechanical and industrial engineers are involved in designing the machines necessary to fabricate the different parts as well as the entire system for assembling them. In both phases of such a project mechanical engineers work with specialists in fields such as aerospace and electronic engineering. Each engineer is a member of a team often headed by a systems engineer able to combine the contributions made by all the different disciplines.

Another result of the increase of scientific knowledge is that engineering has become a profession. A profession is an occupation like law or medicine that requires specialized advanced education; such occupations are often called the "learned professions." Until the nineteenth century engineers were for the most part craftsmen or project organizers who learned their skills through apprenticeship, on the job training, or simply by trial and error. Today it requires at least four or five years of university study leading to a Bachelor of Science degree. More and more often engineers, espe­cially those engaged in research; get an advanced master's or doc­tor's degree. Even those engineers who do not study for advanced degrees must keep up with changes in their profession and those related to it. A mechanical engineer who does not know about new materials cannot successfully compete with one who does. All of this means that an engineer's education is never really finished so he or she must be willing to continue the learning process.

The word engineer is used in two senses in English. One, as just indicated, refers to the professional engineer who has a univer­sity degree and an education in mathematics, science, and one of the engineering specialties. Engineer, however, is also used to de­scribe a person who operates or maintains an engine or machine. An excellent example of this is the locomotive engineer who oper­ates a train on a railroad. Engineers in this sense are essentially highly-trained technicians rather than professional engineers as the term is used in this book.

The systems that engineers produce must be workable not only from a technical but also from an economic point of view. This means that engineers work with management and government of­ficials who are cost-conscious so the engineer must accommodate his or her ideas to the financial realities of the particular project.

The public has become much more aware, especially in the last decade, of the social and environmental consequences of engi­neering projects. For much of the nineteenth and twentieth cen­turies, the public attitude could be summed up in the phrase "Science is good," and the part of science that was most visible was the engineering work that made scientific knowledge useful. Countless cars and other mechanical devices are part of our engineered environment.

Today, however, people are more conscious of the hidden or delayed hazards in products and processes. The automobile is a typical example. No one disputes its convenience but many are also aware of the air pollution it causes and the amount of energy it con­sumes. Engineers are working to solve these problems by designing devices that reduce pollution and improve fuel efficiency. The engineer, then, does not work in a scientific vacuum but must take into account the social consequences of his or her work. Engineering is described as a profession that finds prac­tical application of theoretical science. A successful engineer must enlarge the definition of practical to include the idea that the work is safe and desirable for society.