THE SPRAG INDUSTRY OF EASTERN 



PENNSYLVANIA 



By John L. Strobeck 

 Pennsylvania Department of Forestry 



IN this day of proper realization of 

 the limit to which Natvire bestows 

 her bounty, and of the consequent 

 conservation movement, any action 

 which tends toward the closer utilization 

 of Nature's products is a boon to the 

 conservationist. The fact that the 

 fruits of the soil were exposed to the 

 exploits of man in an unduly high- 

 handed manner, and with the dis- 

 cussion and agitation attend put thereto, 

 left the impression that anytning below 

 a par excellence quality comprised the 

 waste in our industries. Espe dally is 

 this true in the timber industry. 



Business is a matter of dollars and 

 cents, and sometimes, a few accessories 

 thrown in. Where those dollars do not 

 come to the surface, the business 

 becomes defunct. In the matter of 

 Forestry, no progress has been made 

 with the practical man unless he is 

 shown its resiilts in figures. It is true 

 that Forestry is applied in cases where 

 other motives besides the desire to gain 

 money value is concerned. Also, there 

 are cases where it is practiced with no 

 particular end in view, but a man who 

 looks for his living comforts to come from 

 his lumber industry will not install the 

 practice of Forestry to his business if 

 it does not pay any more readily than he 

 will an unprofitable office device. 



But the fact that timber is being 

 utilized as closely, in the judgment of 

 the operator, as is permitted from a 

 financial standpoint must be admitted. 

 However, in many cases, he lacks some- 

 what in judgment. In this particiilar it 

 is the intention to discuss in this article 

 an industry, though small in extent, yet 

 serves the purpose to show the extent to 

 which timber in certain localitits is 

 utilized and how it may be extended to 

 serve the purpose of closer utilization in 

 other localities. 



142 



A sprag is a cylindrical piece of hard- 

 wood, twenty-one inches long and is 

 pointed at both ends. Generally, speci- 

 fications call for a thickness of from 

 two and one-fourth to three and one- 

 fourth inches. In certain mines, how- 

 ever, they require a somewhat more 

 uniform size, namely three to three and 

 one-quarter inch diameter. 



Sprags are used in coal mines for the 

 purpose of checking the speed of the 

 small cars used therein. When it is 

 necessary to check the speed of a car or 

 train of cars, a sprag is thrown between 

 two spokes of a wheel. When the wheel 

 has rotated so that the sprag strikes the 

 beam of the car, rotation of that wheel 

 ceases entirely and the sprag has served 

 its purpose in that the momentum of the 

 car or train of cars is reduced. 



Upon a sprag depends the safety of a 

 car or train of cars when running down 

 a grade in a mine. The cars are not 

 equipped with "brakes" as ordinarily 

 are found on cars above the surface. 

 However, if a sprag breaks, it ordinarily, 

 precipates no undue excitement, for the 

 train crew become, by experience, some- 

 what expert in placing a sprag even when 

 the cars are moving rapidly. However, 

 consuming companies generally, but not 

 always, require sprags of certain speci- 

 fications so that no undue risk is 

 entailed by their use. A case where 

 unusually small sprags were used came 

 to the notice of the writer recently when 

 in conversation with a mine "boss" 

 who remarked with some bitterness, 

 bom of long usage of small sized sprags, 

 that "this much-talked of conversation 

 has a grand basis on which to make a 

 claim by eliminating the small sprags 

 from usage and thus prevent the undue 

 waste, the breaking of the small-sized 

 sprags entails." 



Also, the species to which the making 



