During the early 19th century, Charlestown’s shipyard bell called several hundred civilian tradesmen and laborers to work each morning. Laboring from sunrise to sunset under the supervision of naval officers and civilian shop masters, these yard employees built, repaired, and supplied United States warships for naval duty around the globe. Fluctuating government budgets, changing seasons, and the uneven demands of war and peace made navy yard work intermittent and unpredictable. [Illustration: A navy yard rigger tightens a warship’s mast shrouds.] The Ropewalk Several factors enticed the U.S. Navy into constructing its only ropemaking facility at the Charlestown Navy Yard in the 1830s: skilled labor, access to raw materials, and technical expertise. The port of Boston already boasted more than a dozen ropewalks employing many skilled artisans. Perhaps most importantly, the Navy was eager to take advantage of newly developed labor-saving machines like those already in use in New England’s textile mills. Because rope had to be twisted in a straight line, the maximum length that could be produced was determined by the length of the ropewalk (so called because workers spinning the hemp fibers by hand walked the length of the building). The Charlestown ropewalk’s quarter-mile length allowed production of rope up to 1200 feet long. Designed by architect Alexander Parris (best known for Boston’s Quincy Market), the ropewalk complex included the rope “laying” area running the length of the building, spinning and preparing machine rooms, the hemp house, and the tar house. The complex was powered by massive steam engines and tended by men and boys. The Navy’s move to mechanized rope production came at a critical time, as machine-spun rope began to replace intricate hand-spinning techniques. The hand spinners’ resistance inspired contests in the 1840s, in which they challenged the quality of machine-made rope. The results of such a challenge to the Charlestown ropewalk were somewhat ironic. Though its machine-made rope proved to be stronger and cheaper to produce, hand-spun rope was superior in the smaller sizes, and the mechanized ropewalk began producing some hand-spun rope, doing so until the end of the 19th century. [Illustration: Ropewalk, building] [Illustration: Ropewalk, machinery] [Illustration: Spinning Combed bundled fibers called “roving” are fed from a can onto the spinning frame. At the spindle they are spun counterclockwise into yarn, which is wound on a bobbin.] [Illustration: Forming the Strand Bobbins are mounted on the twisting frame. The yarns are threaded through the register plate to equalize tension and tied to a rotating hook on the rolling “jack.” The jack pulls yarns from the bobbins and twists them clockwise into a strand.]