Prater’s Mill Varnell, Georgia Historic Structures Report (Mill Structure) Nicholas M. Patrick The University of Georgia Extention Service; Archways Partnership For the Prater’s Mill Foundation, Inc. June 2012 Table of Contents Introduction Purpose Author Methodology Acknowledgements Scope and Organization Historic Data Section: Narrative Summary Bibliography Architectural Data Section Narrative Structural: Lumber and Masonry Exterior Envelope and Finishes Interior Finishes Mechanical Summary and Recommendations Conclusion Pictures and Figures Introduction Purpose: The purpose of the Historic Structures Report (HSR) is to express the history of Prater’s Mill from its original construction to current use and describe the architectural and structural components of the mill in a succinct yet complete technical report. Author: This HSR was written by Nicholas Michael Patrick, a Historic Preservation graduate student at The University of Georgia. Nicholas has over a decade of construction experience ranging from new construction to award-winning historic rehabilitations. Nicholas’ graduate thesis is on the socio-economic development of Northwest Georgia and how it is reflected in the evolution and current condition of Prater’s Mill. Despite his education and experience, it is recommended that the Prater’s Mill building be analyzed by a qualified structural engineer. Methodology: The methodology used in this report includes archival research, interviews and site visits. The research included written sources provided by the Prater’s Mill Foundation. Members of the Prater’s Mill Foundation, Whitfield County representatives and employees, and descendants of the Prater family were all interviewed. Site visits involved documenting the mill building through measured drawings and photographs. Acknowledgements: Nicholas would like to thank Judy Alderman and the Prater’s Mill Foundation for all the support, Whitfield County Parks and Recreation for the assistance, and finally The University of Georgia Extension Service/Archways Partnership especially Matt Bishop and Mellissa Lu for the opportunity. Scope and Organization: The scope of the report is limited to the mill building. The Prater’s Mill site includes many more historic resources, all of which should be formally documented. The HSR is organized into two distinct sections; Historic Data and Architectural Data. The historic section will narrate the evolution of the mill and establish historical significance. The architectural section will describe the architectural and structural components of the mill building, assess its current condition and provide basic recommendations for maintenance and improvement. Historic Data Section Narrative: Prater’s Mill was built as a grist or custom mill, a mill used to grind grain of customers for a toll. It was constructed on the east bank of the Coahulla Creek, just north of the road that is now GA HWY 2. According to members of the Prater family, local lore, and a sign hanging from the entrance façade, Prater’s Mill was built on its current site in 1855 (Pic 1). The property was originally owned by John Pitner. John drew the property, Lot #231, on June 30, 1832 during the Georgia Land Lottery and arrived in 1837. John and his wife Sarah McGaughty Pitner set up residence three miles north of Prater’s Mill in Blount County Tennessee. Benjamin Franklin (Ben) Prater (1826-1893) married the daughter of John Pitner, Harriet Amanda Pitner (1833-1909) of Sevier County, Tennessee on July 20, 1852. Ben and Amanda moved to the property in 1852 and established the Prater Farm and mill. John Pitner died in December 1855, leaving the farm and nine servants to Ben and Amanda Prater. According to the family history, Ben established Prater Milling Company in 1855 and owned and operated the entire Prater estate until his death (Duncan). The mill was only one component of a larger farm. On his property Ben Prater built the mill, several homes, a gin, a general store, warehouse, a saw mill, a blacksmith shop, two barns and several accessory structures. The farm also included large fields where cotton, grain and vegetables were cultivated. The farm property was split by a local road (now GA HWY 2) and was divided also by the Coahulla Creek, the power source for the grist mill. Once established, farmers from all around Whitfield County and surrounding counties in both Georgia and Tennessee came to have their corn and wheat milled for a fee. From the beginning, Ben’s farm provided not only grist milling but also lumber sawing, dry goods, cotton ginning, and blacksmith services. By 1850, a branch line (East Tennessee Railroad) of the State of Georgia owned Western & Atlantic Rail Road ran within two miles of the mill providing heavy transportation for milled grain (Duncan). In most wheel-driven mills, such as Prater’s Mill, a large gear-wheel called the pit wheel is mounted on the same axles as the turbines, driving a smaller gear-wheel, the wallower (Pic. 2), on a main driveshaft running vertically from the turbine to the top of the turbine building. This system of gearing ensures that the main shaft turns faster than the associated turbine, which typically rotated at around 10 rpm (http://www.engr.psu.edu/mtah/articles/grist_milling_process.htm). The wallower ran a belt wheel that spun belts connected to the main driveshaft wheels of the mill stones (Pic. 3). The heart of the operation, the millstones, turn at around 120 rpm, one laying on top of the other. The bottom stone, called the bed, is fixed to the floor, while the top stone, the runner, is mounted on a separate spindle, driven by the main shaft. A wheel called the stone nut connects the runner's spindle to the main shaft, and this can be moved out of the way to disconnect the stone and stop it turning, leaving the main shaft turning to drive other machinery, including a mechanical sieve to refine the flour. The distance between the stones varied to produce the grade of flour or meal required; moving the stones closer together produces a finer product. Prater’s Mill evolved just as many other grist mills of the same era, ever improving speed, efficiency and output by adopting new and better technology. Historically, rope drive was used, and later leather belts were used in grist mills (Pic. 3). White leather was first used for elevator belts to hold elevator cups, later to be replaced by canvas belting (Pic. 4). Elevator cups were either made of wood, or fashioned out of tin by the tin smith. The miller learned to lace leather belts with leather lacing. In the beginning of the 20th century metal belt lacing came into use. Wooden pulleys became made of metal, and more and more machinery became belt driven within the mill, even the millstones themselves. The miller was also responsible for dressing the millstones, regrooving the millstones once every few years. Prater’s Mill was constructed around the crucial power source using a floor plan and design common to many grist mills throughout the Southeast. The power source for the mill machines was originally single ‘Leffel-like’ turbine. Designed and manufactured by the Virginia born James Leffel in Springfield, Ohio, the turbine was the pinnacle of milling technology during the 1850s. During the late 1860s, the single turbine was replaced by the famous Leffel American Double Turbine (Pic.5) . Gristmills installed with Leffel's turbine doubled flour production (http://www.leffelcompany.com/). His turbine proved to be faster (RPMs), smaller, more adaptable, and cheaper than rival turbines and waterwheels (http://www.greenenergyohio.org/page.cfm?pageID=338). When demand for Ben’s milling increased, two more Leffel turbines were installed bringing the number to three. The two additional turbines were housed in a new turbine house. The Prater’s Mill turbines were completely submersed in the water of the flume, only the central shaft of the turbine is visible reaching up to the mill. The operator would turn a wheel on the main floor to adjust the gates to produce the proper power requirements (Pic. 6). As the gates open, water flowed to the blades of the turbine. The weight of the water propelled the blades, causing them to spin. A vertical shaft was connected by gears to the line shafts in the basement of Prater’s Mill. The line shafts distributed the power to the milling equipment. Components of the Leffel American Double Turbine are still extant (Pic.7). There were three turbines running the various milling machinery in Prater’s Mill including grain elevators, sifters and cleaners. The process of milling was labor intensive at Prater’s Mill. When grain arrived in a cart or wagon or in a sack slung over a horse, it was weighed then dumped into collection hoppers to be conveyed to the third floor using belt-driven elevator cups. These cups bring the corn to the top floor (head house), then gravity feeds the raw corn into the separator which removes unwanted material from the corn such as dirt, sticks and stones. From the separator, the corn The ‘cleaned corn’ then is moved via auger to storage bins where the corn is stored until milling. The corn is then transferred to a hopper which regulates the total amount of corn to be milled. The corn falls from this hopper into the mill stones where it is ground (http://www.arps.org/amhersthistory/grist_mill/How_It_Works/how_a_grist_mill_works.htm). The miller and assitants were constantly busy. They had to keep the hopper full, watch the grind, and change the gap between the stones, sometimes no more than the thickness of paper, as needed. Even when there was no hand sifting to do, the meal had to be measured, tolled, and bagged in the presence of the customer. A man wanted his own grain ground, not just an equivalent amount of some other man's grain. So the miller had to tag each man's sacks and grind them separately when that customer’s turn came. The strict first-come-first-served process was always observed (Duncan). With the clouds of war on the horizon, Ben Prater continued to operate his mill and farm. Just as before, local farmers brought raw grain to be milled for consumption or sale. Ben Prater was also the local grain broker, providing opportunities for regional sales. In January of 1861, the State of Georgia seceded from the Union and joined the Confederate states of America. During this time when communication and transportation networks were still primitive, grist mills in the rural agrarian South were the source of local and regional news and culture. News regarding the war and politics was another significant topic for discussion at the mill. In October of 1862, the Confederacy began amassing troops around the mill and surrounding areas to prepare for the battles for Chickamauga, Chattanooga, Dalton/Varnell, Ringgold, and Tunnel Hill. The mill’s status as a focal point for material and news was bolstered by the needs of the Confederate Army (Duncan). In 1863, Ben Prater, then 37 years old, enlisted in the local regiment of the Georgia State Guards of the Confederate Army, leaving his mill and farm to be tended by his wife, children and servants. During the remaining two years of the Civil War, Ben was stationed as a sentry at Villanow, Snake Creek Gap, Calhoun and Atlanta. By late 1863, Northwest Georgia was crowded with retreating Confederate troops pushed south from the Battle of Chattanooga and Ringgold Gap. Both Confederate and Union troops camped along Coahulla Creek relying on confiscated meal from the mill and creek water. With Union successes at Chattanooga and Sherman’s push towards Atlanta, Union armies passed Prater’s Mill en route to the industrial hub of Dalton. The Armies of the North occupied Prater’s Mill and its vicinity, also confiscating milled grain and food stuffs, while drinking and washing with Coahull Creek water (Duncan). Prater’s Mill is unique and significant because it survived this tumultuous time when most grist mills were destroyed by order of Union commanders. Postbellum Prater’s Mill returned to peace-time operation, expanded services and increasing success and profits for Ben. Ben Prater and his brother-in-law, Tilman, H. Pitner held the first Whitfield County Fair in 1868, highlighting the successful milling industries in Northwest Georgia, including his own. Ben’s lucrative operation of Prater’s Mill allowed him to purchase land in nearby Dalton for his formal residence and expanding ginning operations. The double gin, able to gin two bales of cotton at once, was located at the corner of Gordon and Glenwood Streets in downtown Dalton and operated into the 1930s. Ben built his new in-town residence at 35 North Thornton Ave (later 314 N. Thornton Ave.). However, the residence was sold to the local Baptist Church (Duncan). Despite Ben’s profitable milling company, Prater’s Milling Company was not the only milling company in Whitfield County. By 1879, there were at least 32 other grist mills in Whitfield County providing similar services. However, the competition did not detract from the ever increasing customer base and by the year of Ben’s death, 1893, the Prater’s farm provided not only grist milling but ginning, sawing and blacksmithing services (Duncan). The second generation of owner/operator of Prater’s Mill was Ben’s son, William Howard (Bill) Prater (1866-1941). William married Ruby Freeman (1876-1900) of Gordon County, Georgia. Just as his father, William was the owner of Prater’s Milling Company and proprietor of the Prater’s estate until his death in 1941. It was during Bill’s reign that the Prater’s farm, as many other Southern farmsteads, transitioned to the tenant farming model. Plots were subdivided and at least five small tenant farmer residences were constructed. A general store was constructed on the south side of the road, across from the mill in 1898 by Bill and provided the tenant farmers and local citizens with dry goods and equipment (Duncan). This store remains and is listed on the national register. The blacksmith shop and warehouse stood just east of the store but do not remain. The extant homestead was originally constructed in 1907. It burned and was rebuilt in 1910 identical to the original residence (Pic. 8). It was at this time that the mill was converted to electrical power to operate the main drive shaft. After Bill Prater’s death in 1941, his son-in-law William Gordon Kettles (1908-1962) of Whitfield County, Georgia, took over the operation of the Prater’s Milling Company and became administrator of the Prater estate. Gordon married Harriet Jean Prater (1907-1982) in 1928. Gordon and Harriet also built and operated a feed store located on the property of the former double gin at the corner of Gordon and Glenwood Streets in Dalton. In 1954, Gordon and Harriet retired from the milling and feed business and sold the 410 acre Prater’s Mill and Farm complex to C.T. Pratt, a representative of the next owner; The Church of God of the Union Assembly, Inc. (Duncan). The Church of God continued to operate the mill under the name of Whitfield County Milling Company. After lying dormant for nearly ten years, the church restored components of the mill bringing it back to operational status again producing flour and meal. The extant grainery on the property was also constructed by the church in 1955 to store the milled grain. The church operated the mill until the sale of the property and all machinery to Dalton Asphalt owned by the Boring Family in 1963 (Duncan). The mill stayed idle after Dalton Asphalt purchased it until several individuals formed the Prater’s Mill Foundation. Inc. in 1971 in order to advocate for and maintain the deteriorating mill. It was at this point, Dalton Asphalt began leasing the land and the buildings to the Prater’s Mill Foundation. The foundation was responsible for the creation of the Prater’s Mill Country Fair which was first held in May 1971 (www.pratersmill.org). The fair was a venue for artisans and craftsmen to demonstrate their crafts and brought Prater’s Mill back into the spotlight. The mill was further updated and partially restored to operational condition in order to accommodate visitors and provide small scale grist milling. Corn and wheat meal was produced and sold during the fairs to help supplement funds raised through capital improvement drives (www.pratersmill.org). On May 20th, 1995, the mill was set fire by teenage arsonists. The fire began on the north side of the mill adjacent to the two story addition (www.pratersmill.org). The majority of the damage was to the interior, scorching the structure and damaging the roof of the north addition and areas on the northside of the original roofline. The windows, electrical system, areas of the siding and roof sustained enough damage to be replaced. In most cases, repairs were completed like-for-like in order to maintain historic appearance. The mill still operates on a small scale and still is the sight for semi-annual fairs. The foundation has also been responsible for the collection of several other historic resources located on the former Prater’s Farm property. These resources include several barns, a doctor’s office, a double cotton gin, and a caboose, all of which were moved to the property during the 1980’s. In January of 2010, the property and all resources located on the property were deeded over to Whitfield County by the Boring Family (http://www.whitfieldcountyga.com/Clerk_Court/clerksearch.htm). Whitfield County maintains the lease granted to the Prater’s Mill Foundation but is now responsible for the majority of maintenance of the property and associated structures. Maintenance responsibilities are often accepted by various volunteer groups organized by the Prater’s Mill Foundation. Summary: Prater’s Mill is a unique and significant historic resource. Its remarkable survival is due to the preservation efforts of the owners and operators throughout its history. It is an important component of the history of Whitfield County. Its evolution traces the changes in milling technology and the socioeconomics of Northwest Georgia, from its rural agrarian beginnings through to post World War II industrial expansion. The information compiled in this HSR is critical to maintain the mill’s significance and preserve the mill for future generations. Bibliography: http://www.arps.org/amhersthistory/grist_mill/How_It_Works/how_a_grist_mill_works.htm Duncan, Albert. The Old Prater Mill. Duncan-Everden, Inc. Michigan, 1990. http://www.engr.psu.edu/mtah/articles/grist_milling_process.htm http://www.greenenergyohio.org/page.cfm?pageID=338 http://www.leffelcompany.com/ www.pratersmill.org http://www.whitfieldcountyga.com/Clerk_Court/clerksearch.htm Architectural Data Section: Narrative Structural: Lumber and Masonry Prater’s Mill is a timber framed structure built on a supplemented pier foundation. It is a three story front gabled form. The original structure is 44’ x 50’ with three historic additions: a single story shed roof 21’ x 44’ addition spanning the south elevation (room 101), a single story shed roof 9’ x 20’ addition over the turbines and sluice at the west façade (room 102), and a 12’ x 16.5’ two story shed roof addition centered on the north elevation (rooms 103 & 203). Across the front/east facade, a single story open porch spans 38.5’. The entire building is enclosed by clapboard and the roof is standing seam galvanized metal. Originally, the mill was constructed on field stone piers at every corner and spaced approximately every ten feet under every sill and beam (Pic. 9). The sluice, dam and foundation of the turbine house are poured concrete (Pic. 10). Supplemental CMU and concrete piers have been poured adjacent to and between the repointed fieldstone piers (Pic. 11). A formed concrete foundation runs the full length of the south elevation of the mill. The east elevation sits on the repointed piers and on footings on grade. The north elevation sits on grade and the west elevation rests on a formed foundation created by the ‘pool and hunt’ sluice and dam structure. The pine timber structure is of braced frame construction combining hand hewn corner posts and drop girts with machine sawn lumber (Pic. 12). The heavy hand hewn horizontal and vertical timbers are fastened using pegs (Pic. 13). The original joists, perlins and braces are machine parallel pit sawn members fastened by machine headed cut nails (Pic. 14). Other structural members were circular sawn (Pic. 15). All building materials and practices found in the original structure support an early to mid-1800s build date. The south and north additions were built using circular sawn modern dimensional lumber and wire nails, supporting build dates in the early 1900s. The true 10” x 10” first floor joists run parallel to the entry façade mortis and tenoned into the original exterior 10” x 10” hand hewn sills and three 10” x 10” beams (fig. 1). These beams run perpendicular to the floor joists and are spaced approximately 10’ on center. These beams and sills carry the tremendous live and dead loads and resist the vibrations typical in grist mills. The first floor joists in the additions are true 2” x 10”s set 20” on center and rest on 10” x 10” reappointed sills (Pic. 16). The corner posts are braced with true 2” x 4” lumber both at the sills and at the second and third floor 10”x 10” top plates. All top plates and diagonal bracing members are mortised into the hand hewn corner posts and fastened by wood pegs. All four corner posts rise full height from first floor sills to the bottom of the third floor roof framing. At the center of each elevation there are additional 10” x 10” diagonally braced posts mortised into the sills bellow and top plates above. These center posts carry 10” x 10” floor joists that provide the additional structure required for the machinery loads from the second and third floors. Perpendicular to the front elevation runs a series of 10” x 10” columns that carry the center load of the second floor (Pic. 17). These columns rest on the center beam of the first floor system and provide mounts for various milling machinery. Between the heavy posts, smaller 4” x 4” studs rise vertically between the sills and top plates on which the exterior clapboard siding is nailed (Pic. 18). At the rear of the mill, the first floor level rises approximately 2.5 feet to clear the drive shafts and drive belts as they enter the mill building from the turbine house. This raised level comprises approximately one quarter of the square footage of the first floor and is accessed by two simple staircases adjacent to the north and south walls. A small door provides access to the drive mechanisms and turbines allowing maintenance and repairs to be performed. Access to the first floor of the north addition is through a cased opening. This room (rm 103) contains the original electric motor (Pic. 19). The second story floor structure and column locations are identical to the first story and access is provided by a dog leg staircase of twenty risers and landing located in the south corner of the mill building. The second story floor joists run parallel to the front façade (just as the first story floor joists). The exterior top plates/sills for the second story floor system are 10” x 10” and are diagonally braced to the corner posts and center posts. The floor joists on the second story are circular saw cut true 2” x 10” with every fifth being 10” x 10” heavy joists mortised into the 10” x 10” sills. Just as in the first story, the heavy members are fastened with pegs and the lighter joists are fastened with cut machine head nails. The span of the second story joists is full width of the front elevation. However, a heavy 10” x 10” beam runs centrally perpendicular to the second story floor joists. This beam’s load is carried by the center posts and columns of the first story. The second story contains a storage room at the north corner (Pic. 20) and grain hopper rooms occupy the east corner of the mill (rm 202). The remaining space is occupied by milling and sifting equipment (rm 201) (Pic. 21). Access to the second floor of the north addition is provided by a cased opening. This room (rm 203) contains the belt wheels originally driven by the electric motor. The third story is accessible by dog leg staircase of seventeen risers and landing in the west corner of the building and the floor joists are identical to the second floor. The roof structure is comprised of circular saw cut true 2” x 10” primary rafters and bracing resting on heavy 2” x 10” top plates. These top plates in turn sit on the third floor joists resting on 10” x 10” plates (fig. 2). The ridge beam is supported by 4” x 4” vertical posts resting on the floor joists. Short circular sawn true 2” x 2” vertical braces carry the rake span of the rafters to the floor joists bellow (Pic. 22). These vertical braces are attached to a circular sawn true 2” x 8” continuous perlin, spanning the full length of the gable roof. The head house milling machinery is located in this story (Pic. 23). Exterior Envelope and Finishes: The entire building is finished with 1” x 6” horizontal clapboard (Pic. 24). The building is trimmed with a simple cornice at the rooflines of the original building and the additions. All windows are double hung six over six sash windows (Pic. 25). The windows in the original building are all 33” x 77” and have been replaced with rebuilt windows since the 1995 fire. The windows in the north addition are all 34” x 27.5” and are also post-fire replacements. The main entrance door to the mill is centered on the original front façade and is 3.5’ x 6.5’. Two smaller doors provide access to the additions; a 4’ x 6.5’ door into the south addition and a 2’8” x 6’8” door into the north addition. Exterior entry to the turbine house is provided by a 4’ x 6’2” door accessible by climbing on the concrete sluice walls. The single story front porch runs nearly the full length of the front façade, approximately 38.5’ (Pic. 26). The porch shed roof is attached through the clapboard to the interior studs and is supported by four 10” diameter solid rough turned columns (Pic. 27). The gable roof and shed roofs of the original building and additions are covered by modern standing seam galvanized metal material attached to 1” x 4” lathe. There are no gutters or down spouts attached to the building. Interior Finishes: The majority of the mill has remained unfinished due to its industrial use. The interior of the north corner is finished with vertical bead board wainscot to the height of approximately 3’ (Pic. 28). In the additions, the original clapboard siding attached with machine head cut nails is visible, acting as an interior finish (Pic. 29). The storage room on the second story (rm 202) is finished with modern gypsum drywall providing some protection against moisture infiltration. Mechanical: The mill in its entirety is wired for electricity using modern materials running from a breaker panel located in Room 103. There are no HVAC or plumbing systems in the building. Other mechanical systems include the milling equipment referenced earlier. Summary and Recommendations: Over all, Prater’s Mill is in excellent condition for its age. The heavy timber frame construction and supplemented pier foundation has maintained the structural integrity of the building. However, there are some areas requiring repairs: 1) rotting and sagging sill at south corner of front porch (Pic. 30), 2) rotted and sistered roof rafters in the south addition (Pic. 31), 3) fire damaged roof rafters in the third floor of the original mill building (Pic. 32), and 4) compromised clapboard where the roof structure of the south addition intersects the original building and attaches to original structure (Pic. 33). Minor clapboard replacement is also needed in various areas of the entire building to improve the function of the exterior envelope. The front porch sill should be removed and the floor should be jacked up to level. Once level, two concrete footings should be poured bellow formed concrete or CMU piers. Modern dimensional pressure treated lumber should be installed above these piers, matching the dimensions of the removed historic lumber. Care should be taken during the jacking process due to the corresponding change in roof height and position. The rotted roof rafters in the south addition should be completely removed and replaced with modern lumber. Simultaneously, the compromised clapboard at the roof intersection with the original building should be removed and blocking should be installed to properly reattach the flashing and siding. The fire damaged roof rafters in the third story of the original building should be analyzed by a structural engineer specializing in timber frame construction. Even though there is no evidence of the structure compromising due to the fire damage, a professional should be contacted regarding the integrity of the timber framing. Conclusion: In conclusion, Prater’s Mill is a significant historic resource worthy of preservation. The difficulty of such preservation arises in the lack of funding. Increase income should be sourced through various sources through the input from The University of Georgia technical resources and Whitfield County. Sources for increased income should be a core component of any future plans for Prater’s Mill. The Prater’s Mill Foundation should keep an active role in determining these funding sources while maintaining the historic integrity of the mill. Minor repairs can improve this integrity. Major repairs to the milling machinery in order to improve the functionality of the Mill would also help draw more visitors, increasing revenue. Prater’s Mills story is unique and significant, justifying its preservation for future generations. Pictures and Figures: Pic. 1 Pic. 3 Pic. 2 Pic. 4 Pic. 5 Pic. 7 Pic. 6 Pic. 8 Pic. 9 Pic. 11 Pic. 10 Pic. 12 Pic. 13 Pic. 14 Pic. 15 Pic. 16 Pic. 17 Pic. 19 Pic. 18 Pic. 20 Pic. 21 Pic. 23 Pic. 22 Pic. 24 Pic. 25 Pic. 27 Pic. 26 Pic. 28 Pic. 29 Pic. 31 Pic. 30 Pic. 32 Pic. 33