Thomas Seavey Hall was born on April 1, 1827, in Upper Bartlett, New Hampshire, United States; he descended from John Hall who was born in Charlestown, Massachusetts, in 1645 and ultimately settled at Dover, New Hampshire, was born at Upper Bartlett, New Hampshire, the son of Rev. Elias and Hannah (Seavey) Hall.
Thomas attended Middlebury College, Middlebury, Vermont.
Engaging in the textile industry, with headquarters at Stamford, Connecticut, Thomas Hall became one of the most prominent woolen manufacturers of New England. In 1866 he retired from business and shortly thereafter, while on a railroad trip, was aboard a train that was wrecked by a misplaced switch. Through good fortune he escaped injury, but in viewing the wreck it occurred to him that such catastrophes should and could be prevented.
Accordingly he immediately turned his attention to perfecting a system of signals that would prevent accidents not only from misplaced switches but also from open drawbridges, collisions of trains, and collisions at highway crossings. He analyzed thoroughly the fundamental requirements of the problem and focused his attention almost immediately upon the practical application to it of electric automatic signals. On February 26, 1867 he received patent for “an alarm or bell to warn those at a distance. ” That same year he organized the Hall Drawbridge & Signal Company at Stamford.
Because sleet, snow, and ice interfered with moving the parts of the signal he had originally patented, Hall devised the electric inclosed disc or “banjo” signal, the initial patent on which was granted to him on April 27, 1869. The signal was controlled by a wire circuit through track treadles - keys or instruments operated by the passage of wheels of passing trains. A very satisfactory electromagnetic device operating a wire-framed disc covered with silk of a suitable color for a day signal, surmounted by a glass or other transparent material of corresponding color for the night signal, was subsequently developed. A kerosene lamp was placed behind the glass to produce the night signal. A number of patents were issued to Hall for the various features of this system. Later, designs were worked out for signals at drawbridges controlled by a circuit controller mechanically operated by the movable draw, thus providing protection in both directions. Lastly, highway-crossing protection was devised, and a patent issued to Hall in 1879 was made effective immediately.
His first signal was installed at Stamford in 1868 and the first installation of his automatic block-signalling system was made on the Eastern Railroad of Massachusetts on sixteen miles of road in 1871.
Hall was married to Sarah C. Phillips.
