Willimantic Linen Company Mill Number 2, Windham Connecticut
willimantic Linen Company began operations in 1854 using cotton mills built in 1825, and soon shifted from linen to thread production when the Crimean War interrupted European flax supplies. By 1895, the firm built three new mills, a bleachery and dye house, a storehouse, an office, and other auxiliary structures. American Thread Company purchased Willimantic Linen in 1898 and continued to expand the Willimantic complex until c1915, adding or completing two mill buildings, a second dye house, and a warehouse. Thread manufacture persisted here until 1984.
Information on 19th-century Willimantic Linen hydropower facilities is limited, but the overall sequence of development can be inferred from several sources. Between 1854 and 1864, the company purchased or developed four consecutive water privileges on the Willimantic River, which falls about ninety feet through the Borough of Willimantic over a ledge-dominated two-mile distance. Of the four privileges, totalling some 63 feet of fall, the lowermost had 16.5 feet of fall at a framed timber dam built c1825 in conjunction with a frame cotton mill on the north side of the river. Willimantic Linen bought this site in 1854, along with an 1825 stone cotton mill on the north bank between the two uppermost privileges (the "Spool Shop," at or just above the site of the cl915 warehouse). The firm began operations in the older mills, and immediately began construction of Mill No. 1 and related hydropcwer facilities. Willimantic Linen built two dams cl854, above and below the Spool Shop, perhaps replacing or improving an earlier dam in the process. The uppermost dam (the "Spool Dam") was a mortared granite block structure about 500 feet upriver from Mill No. 1, and developed a water privilege with 13.6 feet of fall. The second 1854 dam, a framed timber structure (later encased in granite block) built at the downstream end of Mill No- l, provided 11 feet of head. Willimantic Linen developed its last water privilege C1862-64, building a mortared granite-block dam with 22 feet of fall for Mill No. 2.
The surviving configuration of narrow intake arches in Mill No. 2's wheelhouse, in an ell over the river, suggests that this installation originally had three turbines. Material evidence described below indicates that by the late 19th century, three 36-inch single-runner horizontal-shaft turbines were installed here by the Swain Turbine and Manufacturing Company of lowell, MA. A late-19th-century Swain catalog asserted that a 36-inch wheel (runner) with 22 feet of head would generate 167.23 hp (Swain Turbine and Manufacturing Co. 1897; 10). The three wheels in Mill No. 2 would thus have been expected to generate about 500 hp, a figure exactly matching the reported situation here cl880. It is therefore possible that the three horizontal-shaft Swain turbines were in place by this date. Installation of the Swain turbines required raising the arches over the turbine bays, as indicated by evidence of arch alteration and the re-use in place of the Swain pressure cases and draft tubes, which survived in 1988 (VIEW SOUTHWEST OF TURBINE BAYS AND DRAFT TUBES; see Photos). There was, then, apparently an undocumented, earlier set of turbines here C1864-80, probably set far closer to the tailwater elevation than the Swain installation. In this wheelhouse, built just above granitic ledge, the Swain horizontal-shaft arrangement was only possible with high draft tubes. It is thus likely that the original installation of C1864-80 involved vertical-shaft turbines.
Lowell mechanic Asa M. Swain (1830-1908) began commercial turbine production cl860, making important modifications of an earlier generation of inward-flow Francis-type turbines used at the great textile-making city. Swain was perhaps the earliest developer of the mixed-flow turbine which as a type dominated American industrial hydropower installations C1870-1915. With fewer, axially- deeper, more curved runner blades, and decreased runner diameters, mixed-flow turbines had greater efficiency than American turbines of C1848-60, and functioned better in low-flow situations. Many firms emerged with stock-size turbines of this durable and relatively inexpensive type. Swain's firm was one of a few in this era to make some horizontal-shaft installations, which were unusual prior to the growth of small-scale hydroelectric generation, beginning C1890, despite the decrease or absence of expensive bevel gearing made possible by such arrangements. The survival of one of these machines here appears to represent a relatively rare and early example of horizontal-shaft installation in New England.
Although the transmission of power from the Swain turbines in Mill No. 2 is not documented, Willimantic Linen Company made very early use of electric lighting in some of its production areas beginning in 1878, and it is possible that the Swain turbines in Mill No. 2 drove electric generators prior to the replacement of these units. Water power alone was insufficient for Mill No. 2 production demands by c1880, however, when steam power was constantly required for auxiliary use. By the early 20th century, steam provided most of the power at the American Thread complex, with a boiler house just upstream from Mill No. 2 powering engines in another part of the mill (Associated Mutual Insurance Company 1908). The wheelhouse provided at least some of the electricity used for lighting well into the 20th century. American Thread replaced the headgates cl902, and two of the three Swain turbines C1915-17 with somewhat more efficient, probably stock-order turbines of the same size made by the S. Morgan Smith Company of York, PA, and deactivated the remaining Swain unit. Each Smith turbine, installed in the Swain pressure cases and draft tubes, developed about 289 hp at 185 rpm. The original generator equipment used with the Smith turbines is not documented, and was replaced cl940, probably after damage suffered in the 1938 hurricane. There were no later known modifications to wheelhouse installations, which were typical of early 20th-century hydroelectric facilities prior to the development of vertically-arrayed turbine-generators after C1915.