Thomas Davidson (28 August 1828 Nottingham, England – 18 February 1874 Philadelphia) was a naval constructor for the United States Navy.
He came to the United States, at the age of four years, with his parents, who settled in Philadelphia. He early developed a talent for mechanical invention and construction, in consequence of which he was apprenticed to the trade of ship building with Matthew Van Dusen, at the same time studying mathematics with his brother George. His capabilities soon attracted the attention of John Lenthall, then chief constructor of the U. S. Navy.
In 1850, at 22 years of age, he built his first vessel “from the stumps” on the banks of the James River, and soon afterward entered into business in Philadelphia. In 1861, he was appointed quartermaster over the ship carpenters in the Philadelphia Navy Yard, and in 1863 was promoted to assistant naval constructor. He attained the full grade in 1866, with the relative rank of commander, which office he held until his death. At one time during the Civil War, he was conducting the repairs, at the Philadelphia Navy Yard, of 42 vessels, large and small, and also building several new ones. The “Tuscarora,” sister ship of the “Kearsarge,” was built under his direction in 58 working days, and the “Miami” in 27 days. But his greatest feat was the building, in 70 days, of the “Juniata” (1,240 tons, 7 guns) from the frame of a Florida live-oak frigate that had been seasoned for 23 years.
Davidson displayed his engineering abilities in the floating of the “Monongahela,” which had been driven inland on Santa Cruz Island during the earthquake of 18 November 1867, and left stranded 40 feet (12 m) high. With a body of skilled men selected from the different navy yards, in a little over three months he succeeded in moving the ship sidewise to the water's edge, and thence for 2,500 feet (760 m) over a bed of coral to deep water.
Subsequently, he was ordered on duty at the bureau of construction in Washington, and was busy with plans for developing a navy of armored vessels, torpedo boats, and fast cruisers. The models and drawings for the first large torpedo boats built in New York were executed by him. He was about to be sent to Europe for an exhaustive study of foreign navies and navy yards, when his health failed.