PLUMES AND FLUMLNG. 29 



upon this should depend largely the decision of what type or size of 

 flume should be constructed. The capacity of a 24-inch V-shaped 

 flume 10 miles in length, operated on a grade that was neither very 

 flat nor exceptionally steep, with plenty of water, has been demon- 

 strated as being capable of handling 25,000,000 feet b. m. of railroad 

 cross ties and lumber per annum, under especially favorable conditions. 



For handling small material, such as railroad crossties, cordwood, 

 mining stulls or props, and loose lumber, a 30-inch V-shaped flume 

 (inside measurement) will usually be found of sufficient capacity for 

 most any requirement, provided the grade is neither too flat nor too 

 steep. Where either of these exceptions obtain, the size of the 

 flume should preferably be increased to 36 to 40 inches. 



For a log flume nothing less than a 36-inch V-shaped flume should 

 be built, and a 40 to 60 inch V would be preferable, even for medium- 

 sized logs, if there is a sufficient volume of water available. To oper- 

 ate a log flume successfully and economically there should be a suffi- 

 cient volume of water available to fill the flume three-fourths full on 

 all moderate grades. It will be apparent that if the grade of a large 

 log flume were very steep, a very large body of water would be 

 required. The larger, longer, and heavier the material to be han- 

 dled, the larger the size of the V should be, the lesser degree of curva- 

 ture is permissible, and the stronger must be the construction work. 



Tables showing the approximate amount of water in cubic feet 

 required to fill a V-shaped flume on steady grades of different per 

 cents will be found in another portion of this bulletin. 



COST OF TRANSPORTING DIFFERENT CLASSES OF MATERIAL. 



The cost of transporting material by flumes varies greatly accord- 

 ing to the conditions under which the flume is being operated, the 

 class of material, time of year, number of men necessary to operate 

 the flume, and all the other factors that go to make up or reduce the 

 expense of operation. Railroad crossties have been flumed a distance 

 of 20 miles at an actual cost for operation alone of one-half cent per tie, 

 or 15 cents per thousand; sawed lumber in cants of from 2 to 6 inches 

 in thickness at approximately the same rate. 



If a flume line is properly constructed on a favorable and steady 

 grade where it can be operated with a plentiful supply of water, the 

 actual cost of transportation alone is very slight after the flume is con- 

 structed. But the important fact should not be lost sight of that a 

 flume works only in one direction and that all supplies intended to be 

 used in lumbering operations have to be hauled to the head of the 

 flume by animal or other power. 



