 The engines, designed by Erasmus W. Smith, were supplied by the Etna Iron Works, which had only recently installed a lathe capable of boring such huge cylinders.The lathe itself was one of the two largest machine tools in the United States, the other being a planer installed by the same company.Work on both "Bristol" and "Providence" was delayed by a long strike, but "Bristol" was eventually launched in April 1866, and "Providence" on July 28 of the same year.