T. Vincent Learson, who went by Vin, was the first CEO of IBM without the last name of Watson. Officially he was an interim chief executive, holding the post from June 1971 until his mandatory retirement at age 60 in 1973 — but he was far more than a placeholder. He oversaw the company’s significant technological progress during the 1950s and 1960s and guided the company through one of its most radical transformations.

Learson is credited with being the institutional force behind the development of System/360. The radical, bet-the-company gamble led to the creation of one of the first commercial business computers and to a full-scale industrial overhaul that made IBM one of the world’s largest and most influential companies.

Fortune called System/360 “the most crucial and portentous — as well as perhaps the riskiest — business judgment of recent times.” Its success helped ensure IBM’s prosperity for the next 20 years.

Learson was born in Boston, the son of a sea captain. He graduated from Boston Latin School in 1931 and from Harvard University in 1935 with a degree in mathematics. He immediately joined IBM after graduation. He steadily rose through sales, marketing and management positions over the next 38 years.

During the early 1960s, Learson ensconced his reputation as, according to IBM historian James Cortada, “a gifted problem solver.” As vice president and then senior vice president, Learson became a trusted aide to Thomas J. Watson Jr., who appointed him chairman. In that role, Learson pushed for the buildout of System/360. Watson would later credit Learson with being the effort’s leading advocate. In his autobiography, Watson went so far as to describe Learson as “the father of our new line.”

The stakes were enormous. The company spent approximately USD 5 billion over four years. Fortune dubbed it the most expensive privately financed commercial project to that date.

Learson stood 6 feet, 6 inches tall, giving him what Watson described as an imposing persona. “His mere presence in a room was enough to get people’s attention,” Watson said. Learson also exhibited a technological acumen matched by few in the C-suite.

In 1957, Watson convened top management to his Vermont ski lodge for a series of lectures on the state of the industry. This was at the inception of the digital age, and the CEO’s goal was to align his team to accelerate the shift from punched-card data processing to electronic computing.

Frederick P. Brooks Jr., a computer scientist who went on to become a professor at the University of North Carolina, was among the speakers. He recalled the sessions in an obituary of Learson for The New York Times: “We took them through the programming line by line, and Learson understood everything immediately. He was incredibly sharp.”

Learson’s grasp of technology enabled him to discern the latent possibilities of the emergent System/360. The project relied on untested integrated circuitry, but Learson recognized its potential for far-reaching effects. IBM was able to harness the resultant models to simplify its product lineup, improve system efficiencies, juice profit margins, and broaden the market to include a variety of corporate and governmental clients.

Watson suffered a mild heart attack in November 1970. After he recovered, he relinquished the reins and tapped Learson as IBM’s new leader.

Learson was an intensively competitive sailor, but also — due to his heritage — had a lifelong regard for marine environments and issues. He followed his passion into politics and advocacy.

From 1975 to 1977, he served as ambassador-at-large and special representative of the president for the Law of the Sea Conference in pursuit of rules to govern international waters, touching on issues from fishing rights to pollution. He also sat on the boards of other corporations, including Chemical Bank, Caterpillar and PepsiCo.

He died in 1996 at the age of 84, survived by his wife and four daughters.