This Clock Made Power Grids Possible

On 23 October 1916, an engineer named Henry E. Warren quietly revolutionized energy transmission by putting in an electrical clock within the L Street producing station of Boston’s Edison Electric Illuminating Co. This grasp station clock saved a really specific sort of time: It used a synchronous self-starting motor along side a pendulum to assist keep the station’s AC electrical energy at a gradual 60-cycle-per-second frequency.

As extra energy stations adopted the clocks, the frequency regulation allowed them to share electrical energy and create an interconnected energy grid. Until the late Nineteen Forties, station clocks from the Warren Telechron Co. regulated over 95 % of all U.S. electrical energy traces. The Telechron Model Type E grasp station clock proven at high was used on the Tennessee Valley Authority starting within the Thirties.

The 60-hertz commonplace (or 50 hertz in many of the remainder of the world) is taken with no consideration immediately, however within the early days of electrification—earlier than the invention of the grasp station clock—the usual was seldom commonplace. And Warren, who ultimately solved the grid-frequency drawback, was really engaged on a distinct puzzle when he got here throughout the reply.

How Warren’s clocks regulated grid frequency

Henry E. Warren poses with one in every of his grasp station clocks. Until the late Nineteen Forties, his firm’s clocks regulated over 95 % of U.S. electrical energy traces.Electric Time Co.

Henry Ellis Warren was born in Boston on 21 May 1872, a decade earlier than Edison’s Pearl Street Station went on-line, in New York City, ushering within the daybreak of the electrical age. He graduated from MIT in 1894 with a level in electrical engineering, and throughout the yr he (alongside along with his pal George C. Whipple, who went on to turn into an professional in water sanitation and to cofound the Harvard School of Public Health) had filed for his or her first patent: an electrical thermometer supposed for use to measure temperature at a distance or in inaccessible locations.

Warren went on to work in Michigan as an engineer for the Saginaw Valley Traction Co., returning to Boston in 1902 as superintendent of the Lombard Governor Co. He dabbled in actual property, arrange a machine store, continued patenting innovations, and arranged the Warren Gear Works to make and promote his units.

In 1912, Warren established the Warren Clock Co., which produced battery-operated clocks. His preliminary designs, as described in a sequence of patents, had been for a pendulum clock with a everlasting magnet as its bob (that’s the burden on the backside of the pendulum). The battery would supply an electrical impulse to maintain the pendulum swinging, by opening and shutting a circuit relying on the amplitude of the pendulum swing. Unfortunately, these early clocks had been awful timekeepers, their potential to maintain time deteriorating together with the battery. Warren sought a greater strategy and suspected electrical motors could be the reply.

In Warren’s personal telling of the story, his first try at an electrical chronometer was a crude motor that related the gears of a clock to the Boston Edison electrical system. When he discovered that the clock was nonetheless shedding 10 to fifteen minutes a day, he known as up the Edison energy station—as one apparently did in 1915—and politely informed them that their frequency was roughly a half cycle off. They countered that their devices had been appropriate, and Warren urged the laboratory requirements they used to verify their meters have to be in error.

The dialog might have stopped there, however Robert Hale, a analysis engineer, took the priority significantly and helped Warren arrange an experimental demonstration on the L Street station. There, Warren designed, constructed, and put in the instrument he dubbed the Warren Master Station Clock. On 23 October 1916, it went into service, enabling the ability transmission revolution.

These frequency measurements from Commonwealth Edison had been taken earlier than [top] and after [bottom] the set up of a Telechron grasp station clock.Electric Time Co.

This condensed model of occasions belies the truth that Warren had already been working for greater than a decade on methods to control clocks, in addition to constructing a dependable self-starting synchronous motor. Clocks and synchronous motors go hand in hand. In a synchronous motor, the shaft rotates on the identical alternating-current frequency as the electrical present; assuming the present is regular, it might be superb for a clock. But so as to make his electrical clock correct, Warren wanted an correct and regular present, therefore the grasp station clock.

In 1916, the Warren Clock Co. started producing the Type A grasp station clock, which is definitely two clocks superimposed on a single clock face. The dial is split into 5 1-minute sectors and has two palms, one black and one gold. The black hand is related to a typical mechanical pendulum clock; the gold hand is pushed by a synchronous motor. Both palms circle the clock face at 60 seconds per minute. To learn the clock, the operator merely needed to verify that the 2 palms had been in sync; that will imply the mills had been operating at exactly 60 hertz.

The heyday of Warren’s electrical clocks

The grasp station clock solved Warren’s drawback of making dependable electrical clocks to be used in houses and home equipment. But grid operators wouldn’t have embraced it however for his or her coalescing need to type an interconnected electrical energy grid.

That need was properly captured by electrical engineer Benjamin Lamme in a 1918 presentation to the Washington, D.C., part of the American Institute of Electrical Engineers (one of many founding organizations of the IEEE). In his discuss, “The Technical Story of the Frequencies,” he gave the historical past of the previous couple of many years, as producers and energy firms debated and tailored to totally different frequency requirements.

At the start, when the fledgling energy business served only some clients, there was no use for a nationwide commonplace. But as electrical energy demand rose for each business and residences, the necessity turned important. Warren’s grasp station clock arrived at exactly the appropriate time. (Warren was later awarded the AIEE’s Lamme Medal for his “outstanding contributions to the development of electrical clocks and means of controlling central station frequencies.”)

In 1935, Henry Warren [right] acquired a medal from the Franklin Institute, in Philadelphia, for his invention of the Telechron synchronous motor. Also honored was Albert Einstein [middle], for his contributions to theoretical physics. Bettmann/Getty Images

A second purpose energy stations adopted the grasp station clock was revenue. Recall that Warren was initially engaged on an electrical clock for the house, and he had a grand imaginative and prescient that each family would ultimately personal one. More electrical clocks meant extra electrical energy utilization, which meant extra income for the ability firms. In a 1937 paper that Warren learn earlier than the Clock Club in Boston, he estimated {that a} energy firm might earn US $75,000 (about $1.6 million immediately) if 100,000 clients every ran an electrical clock 24 hours a day. Warren was pondering large for his personal firm and needed to get the utilities on board.

There had been a number of variations of the station clock. In 1920, the cheaper (and fewer correct) Model B grasp station clock was launched for stand-alone installations not related to a wider electrical grid. The following yr, the corporate unveiled the Type C clock to be used within the few remaining DC energy stations. According to the extremely informative web site maintained by clock fanatic Mark Frank, the Type D existed as an inner testing system and by no means went into manufacturing. The last mannequin, the Type E, got here out in 1929. It functioned as a reference monitor for a number of interconnected grids.

A 1929 advert for Telechron’s electrical clocks touts their use of “accurately timed impulses from the power station.” Telechron/Telechron.web

Beginning within the Nineteen Fifties, improved electronics displaced electromechanical grasp station clocks. These days, energy stations use atomic clocks to control grid frequency.

Back in 1917, General Electric had purchased a 49 % curiosity within the Warren Clock Co. Warren continued to function president till he retired in 1943. GE integrated Warren’s self-starting synchronous motors into its personal clocks and different devices and licensed the motors to different firms. In 1926, the corporate was renamed the Warren Telechron Co. After Warren’s retirement, GE absolutely absorbed Telechron into its operations, ultimately forming the Clock and Timer Division.

In its heyday, Telechron held an enormous share of the house electrical clock market—by 1926 the corporate had bought 20 million clocks. But by the Nineteen Fifties, clocks with improved batteries and oscillating quartz crystal resonators started to exchange shopper electrical clocks that synchronized with the ability grid. The introduction of digital clocks sealed the deal. GE bought its final Telechron plant in 1979.

Today, the Telechron legacy lives on on the Electric Time Co., in Medfield, Mass., which was spun off from Telechron’s analysis labs in 1928. Today, Electric Time custom-manufactures tower clocks, avenue clocks, and constructing clocks. It additionally hosts the Electric Clock Museum, the place you can also make an appointment to see the Telechron Type E Master Station Clock.

Part of a persevering with sequencetaking a look at historic artifacts that embrace the boundless potential of know-how.

An abridged model of this text seems within the March 2024 print challenge as “The Clock and the Grid.”