Charles T. Main was born on February 16, 1856, in Marblehead, Massachusetts. He was the only child of Thomas and Cordelia Green (Reed) Main.
Both parents came of colonial New England stock; his father was a native of Marblehead, his mother of Plymouth. Shortly after Charles's birth, his mother died, and he was reared by his paternal grandparents.
Main received a conventional education in the Marblehead schools, but early acquired an interest in mechanical matters at a local machine shop and at the rope factory where his father, a machinist, was master mechanic and his grandfather superintendent.
In 1872, Main entered the Massachusetts Institute of Technology, from which he graduated in 1876 with an S. B. degree in mechanical engineering.
Main stayed on at M. I. T. for a time as an assistant instructor while doing advanced work. In 1879, he took a job as a draftsman at the textile mills in Manchester, New Hampshire, but left at the beginning of 1881 to become an engineer with the Lower Pacific Mills in Lawrence, Massachusetts.
In this capacity, he helped rebuild the company's main factory, rearranging its machinery, installing a new steam plant, and reconstructing a waterpower plant. Though promoted in 1887 to the superintendent of the worsted department, which then employed 2, 500 people, he left Lower Pacific Mills at the end of 1891 to become an independent engineering consultant.
After a year in Providence, Rhode Island, Main formed a partnership in Boston with Francis Winthrop Dean, a well-known power engineer. The partnership lasted until 1907, when Main organized his own firm, incorporated in 1926 as Charles T. Main, Inc.
At first, Main specialized in textile mills, supervising their design and construction and handling reorganizations, valuations, tax problems, and other related matters. He planned and built numerous mills throughout New England and the Southeast, and even as far afield as Montreal and Henderson, Kentucky.
For twenty-five years, beginning in 1899, he supervised the construction of new plants for the American Woolen Company, including the Wood Worsted Mills in Lawrence, Massachusetts, then one of the largest single manufacturing buildings in the country. His Notes on Mill Construction (1886) was for some years used as a textbook at the Massachusetts Institute of Technology.
Before electricity came into widespread use, separate power plants had to be designed for each mill, and Main, who had long been interested in power problems, soon acquired a reputation as an expert on both water and steam power.
In 1891, he published the first of several papers in which he outlined methods for evaluating waterpower plants, and three years later he designed and supervised the construction of a municipal lighting plant in Marblehead and a steam-electric plant for the Lynn Gas & Electric Company.
Over the years, he helped complete a number of steam and waterpower projects, including the Conowingo Dam across the Susquehanna River in Maryland and the Keokuk Dam across the Mississippi. All told, he and his firm designed nearly eighty hydroelectric plants.
Within his community, he served for three years as alderman in Lawrence, Massachusetts, and for several years as chairman of the water and sewer board in Winchester, Massachusetts, to which he moved in 1891.
Main died at his home in Winchester at the age of eighty-seven of a coronary occlusion and was buried in Wildwood Cemetery, Winchester.
Main is known as founder of Charles T. Main, Inc. , and as president of the Boston Society of Civil Engineers (1912), of the Engineers Club of Boston (1914 - 25), of the American Institute of Consulting Engineers (1929), and of the American Society of Mechanical Engineers (1918). In 1919, he established the Charles T. Main Award, given annually to a student member of the A. S. M. E. A man of high standards, Main, while president of the Boston Society of Civil Engineers, drafted the first code of ethics adopted by any engineering society in the United States. His honors included the gold medal of the American Society of Mechanical Engineers (1935) and an honorary degree from Northeastern University (1935).
Main was an active member of the Congregational Church.
On November 14, 1883, Main married Elizabeth Freeto Appleton of Somerville, Massachusets. They had three children: Charles Reed, Alice Appleton, and Theodore.
