The Evolution of Engineering in the 20th Century

By Robert L. Norton

This book describes the technological and educational advances that occurred from 1950 to 2000 and how they have improved the practice and teaching of engineering.  The author began his career as an apprentice machinist out of high school in 1956.  He retired from Wo

• Language: English
• Publisher: Norton Associates LLC
• Release date: Aug 20, 2020
• ISBN: 9781649995919

Robert L. Norton

Robert L. Norton, P.E. has 50 years experience in the practice and teaching of mechanical engineering. He holds undergraduate degrees in mechanical engineering and industrial technology from Northeastern University, and a M.S. in engineering design from Tufts University. Having designed cams for camera mechanisms at Polaroid Corporation, he subsequently spent many years doing design work at Gillette and many other companies. He taught kinematics, dynamics, stress analysis, and machine design to mechanical engineering students for more than 40 years at Northeastern, Tufts, and Worcester Polytechnic Institute, where he is the Milton Prince Higgins II Distinguished Professor Emeritus of Mechanical Engineering. Additionally, he has published many technical papers and holds 13 U.S. patents. He is a member of the Society of Automotive Engineers (SAE) and a Fellow of the American Society of Mechanical Engineers.

Book preview

Chapter 1 Introduction

The main theme of this book is the history of the evolution/revolution in mechanical engineering design that occurred over the last half of the 20th century. The main driver for this was the invention of the computer, and later the graphics microcomputer, solid-modeling Computer-Aided-Design (CAD) software, Finite Element Analysis (FEA) methods, and Continuous Numerical Control (CNC) of machines to manufacture parts.

At the beginning of this era, (1950) mechanical engineering companies were still using the same methods and techniques for mechanical design as they had used for the previous fifty years or more. These consisted largely of the drawing board and slide rule. Most engineering was done by the build it and break it method. That is, engineers and design draftsmen (as most designers were) would make their best guesses as to the required sizes and shapes of parts, largely using the seat of their pants and very little calculation. They would then build a prototype machine and test it. When things broke (and they always did), they would redesign that part and repeat the process. This typically would require at least three complete iterations (and often more) to get to a machine that would actually work. This was very expensive of time and materials.

The modern paradigm in the 21st century is much different. Now, companies that have weaned themselves of the bad old methods (and not all have) generally have engineers that were trained late in this era where they learned about proper modeling techniques that use CAD to create the part geometry in 3-D solids (rather than as multiple 2-D projections of a 3-D object drawn on a 2-D sheet of paper) and also use computerized algorithms to analyze the forces and stresses on these parts before they are ever cut in metal. Properly done, this can and does result in a prototype being built only once and working correctly right out of the box. This saves a tremendous amount of time and expense, and is a significant factor in the improvement in productivity and quality over the past decades.

I was lucky to have witnessed this evolution first hand in my career that began as an apprentice machinist right out of high school in the 1950s, and evolved with the technology to find me in the latter half of that career as a university professor teaching these modern techniques to the new cadre of mechanical engineers that were sent forth to transform engineering and manufacturing. These men and women know how to use the latest CAD, modeling, and FEA tools to design a machine right the first time. They can do so because of a parallel revolution that occurred in engineering education during the second half of the 20th century as well.

In 1957, the USSR launched Sputnik, the first man-made satellite to orbit a planet. This caused a great deal of consternation among those in the U.S. concerned with National Defense, technology, and engineering education. Congressional hearings resulted, and one outcome was a cry for a revolution in engineering education—for more science and math in the curriculum. CAD was still to be developed at that time but figured naturally into the new paradigm when it appeared.

Engineering schools could revamp their curricula fairly rapidly because information has low inertia. But large vessels change course only slowly, so it took some time for industry to adopt the new approaches to design and manufacturing. There is, of course, up to a four-year lag between changing what a student is taught and that student having an opportunity to apply it in practice. There is an additional lag due to the fact that the newly hired engineer has no political power to impose his ideas on his older, more experienced managers, who believed that they knew how to do the job. Thus it took decades for the new approaches to really begin to influence the engineering practices of many companies. It would require some of those new engineers to rise to positions of responsibility in the company.

I have been a practicing mechanical engineer for over a half-century. During that time I worked for a number of companies, large and small, designing consumer products and the automated machinery to manufacture these products in large quantities. I also spent more than half my career teaching mechanical engineering at various universities. While teaching, I continued to actively practice as a consultant to many companies. My experience spans the 56-year period 1956 to 2012 when I retired.

I entered the profession in