Lumber, pulpwood, shingle bolts, and whole logs move at different speeds and were prone to double-up in a V-flume’s low grades and curves. Box flumes were also more capable of handling materials uneven in size and weight simultaneously. They continued to be built when a large volume of water was desired for a secondary use, such as irrigation. These efficient flumes consisted of two boards, 2 feet (0.61 m) wide and 16 feet (4.9 m) feet long, joined perpendicularly, and came in common use in the western United States during the late 19th century. Haines first built the "V"-shaped log flumes that allowed a jammed log to free itself as the rising water level in the flume pushed it up. The greater weight of the water required a sturdier structure, especially heavier trestles. A square box carries much more water compared to a V-shaped flume. These were prone to jams that could cause damage and required constant maintenance. : 395–396 Box flumes Flume box cross section.Įarly logging flumes were square wooden chutes known as box flumes. The steeper the grade the more gradual the curves had to be, or else lumber would jam or go over the sides. Sometimes grades of up to 75 percent were used on short stretches. Three percent was ideal for a straight flume. Some trestles achieved staggering heights to maintain a desirable grade. Other times, round timber trestles of 8 inches (20 cm) to 12 inches (30 cm) diameter were cut and finished from along the route. Square lumber was often provided by a temporary, portable sawmill erected at the head of the flume. But reports suggest that falls resulted in many injuries and deaths. Occupational fatality statistics are unavailable. Working on the flume was a dangerous job. One low man handled and sent up the lumber. On trestles, four worked aloft continuously. Construction crews included six to eight workers. Flume boxes and trestles were built onsite. Unlike railroad construction, this required lumber and supplies to be carried in by hand. : 394įlume sites were mostly in rough, undeveloped wilderness. The main disadvantage of the light construction was they were damaged more easily by fire, floods, wind, and falling timber. They could span gulches using much lighter trestles and they took up less space, fitting inside narrower canyons where there wasn’t room for a railroad. However, flumes had several advantages to logging railroads in steep terrain. įlume routes were surveyed by engineers using the same methods as a railroad survey. Flume construction The high trestle on the Sanger Flume was over 300 feet (91 m) tall. Often, flumes moved water from one drainage basin to another, with rights settled in court. As a result, water rights were often difficult to secure. Logging flumes were only needed in semi-arid regions without rivers or navigable streams. Multiple flume branches leaving the sawmill at Sugar Pine. Feeder troughs resupply water on long routes. Flume boxes are built tight with lumber free of knots to prevent leaks. : 16 The head directs the flow of water into the top of the flume. Often, a log pond or artificial reservoir serves this purpose. Log flumes need a steady supply of water. Soon, log flumes spread across the mountains of the western United States as artificial rivers that brought lumber to market. The 15 miles (24 km) route was between Lake Tahoe and Reno, terminating at the Virginia and Truckee Railroad terminus in Washoe Valley. The v-shaped trough brought a half-million feet of lumber daily from the eastern Sierra Nevada to the Comstock Lode. Haines built the first successful lumber flume in 1859. Today, log flumes remain in the popular imagination as amusement park rides. The logging truck replaced both the logging railroad and the flume after WWII. They could span long distances across chasms with more lightweight trestles.įlumes remained in widespread use through the early 20th century. Flumes were cheaper to build and operate than logging railroads. Logging operations preferred flumes whenever a reliable source of water was available. Flumes replaced horse- or oxen-drawn carriages on dangerous mountain trails in the late 19th century. A sawmill with log flume, Cascade Range, USAĪ log flume is a watertight flume constructed to transport lumber and logs down mountainous terrain using flowing water. For the amusement park ride of the same name, see Log flume (ride).
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