Editing Log flume (section)

===V-flumes===
In 1867, James W. 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. These efficient flumes consisted of two boards, {{convert|2|ft|m}} wide and {{convert|16|ft|m}} feet long, joined perpendicularly, and came in common use in the western United States during the late 19th century.<ref>{{cite book |last=Fregulia |first=Carolyn |date=2008 |title=Logging in the Central Sierra |location= |publisher=Arcadia Publishing |page=50 |isbn=978-0-7385-5816-5}}</ref>

Box flumes were not made obsolete. They continued to be built when a large volume of water was desired for a secondary use, such as irrigation. Box flumes were also more capable of handling materials uneven in size and weight simultaneously. 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. Finally, box flumes could move an unprecedented amount of material, up to a maximum capacity of {{convert|300000|board feet|m3}}, or three times as great as the maximum for a V-flume.<ref name="Logging Principles" />{{rp|400}}

<gallery mode=packed heights=120px>
Log Flume Cross Section V-Box.jpg|V-Box flume cross-section for large logs.
Log-Flume-Cross-Section-V-Box-for-Lumber.jpg|V-Box flume cross-section for lumber.
Madera Sugar Pine Flume.jpg|Water flowing down a V-flume near [[Madera Sugar Pine Company|Sugar Pine, California]].
Madera Sugar Pine Company China Store Flume Trestle.jpg|A tall V-flume trestle around 1900.
</gallery>