February 10. 1917 



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^ A Mill Scale Study of 'Maph ^ 



BY DAVID G. WHITE 

 Editor's Note 



The following summary of a mill scale study of maple was written by David G. White, an examiner for the 

 nnlted States Forest Service, connected with the government laboratory at Madison Wis. Its chief value lies m 

 STlact that the fi^rerand charts are based on actual conditions as found in practice at sawmills where maple lumber 

 is sawfd for comme?cial purposes. The study extended over a period sufficiently long to elim nate errors which might 

 resuU from ha^r The^eed of r_eliable d^ta on the subject, has been _keenlj;JeU,^ and ^mm^operato^^^ as^^^^^^^^^ 

 timber owners. 



will doubtless read this report very carefully, with the idea of applying the lesson to their own operations. 



To keep pace with the general industrial development in the United 

 States the lumber industry must as soon as possible base its operations 

 on exact data. The opinions and experience of men are excellent as 

 far as they go, but they do not form the basis needed to meet present- 

 day competition. The mill scale study is designed to secure exact 

 detailed data of this character upon one phase of lumbering opera- 

 tions. The ordinary intensive mill scale study of the Forest Service 

 is designed to secure information on the quantity and quality of 

 lumber that can be obtained from logs of various sizes, the rate of 

 production per hour of logs of different sizes and the relative cost of 

 sawing per M feet net lumber tally, the cost of manufacturing lumber 

 from logs of different sizes, and 

 waste in manufacturing lumber. 

 During August, 1915, the Forest 

 Products Laboratory of Madison, 

 Wisconsin, conducted a coopera- 

 tive mUl scale study on maple at 

 the plant of the Goodman Lum- 

 ber Company at Goodman, Wis- 

 consin. 



In considering the results of 

 the study and their general ap- 

 plication, it should be kept in 

 mind that only 50 logs cut on a 

 single band head saw were in- 

 eluded in the test, hence the data 

 is insufficient to enable conclu- 

 sions to be drawn in finality. 

 Thfe effect of using resaws and 

 gang saws to supplement the 

 head-saw was not studied and 

 this places further limitations 

 upon the application of the ten- 

 tative results. The data on costs 

 of production and manufacture 

 as furnished by the cooperator, 

 include, along with all other 

 charges, an allowance for stump- 

 age at $2.00 per thousand on tim- 

 ber suflBcient to continue the 

 operation of the mill for 11 years, 

 together with taxes and insur- 

 ance; 6 per cent interest on all 

 capital invested and engaged in 

 the business, including that cov- 

 ered by stumpage; 6 per cent 

 profit on aU capital employed, ex- 

 clusive of stumpage; depreciation 

 on all equipment, and the like. 



With the foregoing in mind, the following brief summation of the 

 more interesting indications is presented. It is followed by a 

 detailed description of the methods used in conducting the test and 

 in analyzing the data. 



The net lumber tally from individual logs of the same diameter 

 varied over a vride range, but in only two cases was less than the 

 Boyle scale, the overrun varying from 98 per cent for the probable 

 average for a 9-inch log to 24.5 per cent for a 17-inch log. 



In the entire 50 logs used, no firsts a'nd seconds were secured 

 from logs below 13-inch top diameter, while with 17-inch logs 20 per 

 cent of the net lumber tally were firsts and seconds. The No. 1 

 common varied from about 4 per cent with 9-ineh logs to 32 per cent 



—41a— 



MILL OF THE GOODMAN LUMBER COMPANY, GOODMAN, WIS. 

 A flrst-class operation for the manufacture of hardwood lumber. The 

 government selected this mill for the study of converting maple logs into 

 lumber. 



with 17-inch logs; the No. 2 common varied with aU logs from about 

 14 per cent to 20 per cent; and the No. 3 common varied from 80 per 

 cent for 11-inch logs to approximately 31 per cent with 17-inch logs. 

 •The rate of production per hour increased from 1,953 feet for 9-inch 

 logs to 3,357 feet for 17-inch logs and the cost of sawing decreased 

 from $5.51 per M net lumber tally for 9-inch logs to $3.21 for 17-inch 

 logs. 



Considering realization and the costs of production as previously 



explained, the following are the more striking indications of the work : 



Including all charges in the costs of production, the maximum sized 



log which showed production costs less than the realization per M net 



lumber tally was 15% inches top 

 diameter for the average of the 

 entire 50 logs, and 15% inches 

 top diameter for the average of 

 the 35 logs which yielded 50 per 

 cent Doyle scale. No. 2 common 

 and better. 



Assuming that stumpage, car- 

 rying charges, and a portion of 

 the logging costs were not 

 charged against the smaller logs, 

 then the maximujn sized log 

 which did not show a production 

 cost greater than the realization 

 per M net lumber tally was ap- 

 proximately 13% inches top diam- 

 eter for the average of the entire 

 50 logs, and approximately 12% 

 inch top diameter for the aver- 

 age of tlie 35 logs which yielded 

 50 per cent Doyle scale. No. 2 

 common and better. 



The method of distribution of 

 the cost of production as sug- 

 gested by the cooperator, and 

 presented for consideration in 

 this report, shows that when the 

 35 logs yielding 50 per cent, 

 Doyle scale. No. 2 common and 

 better, were used, the cost of pro- 

 duction for the No. 2 common 

 and better was greater than the 

 realization until a diameter of 

 practically 15 inches was reached. 

 With the No. 3 common, the dis- 

 tributed cost of production for 

 logs of all diameters was greater 

 than the realization. If, however, 

 no stumpage charge be made against the No. 3 common, especially for 

 logs of small diameter, the distributed cost of production fell very 

 close to the realization. 



In manufacturing the logs, the waste in slabs, edgings, and trim- 

 mings amounted to approximately 29.83 per cent of the total volume, 

 and the waste in sawdust to 8.6 per cent. 



Detailed Discussion of the Study 



The logs were sawed on a single band head saw and hence the cost 

 of sawing as shown in this report would not be comparable to the 

 results that would be obtained in using a resaw or a gang saw in con- 

 junction with the band mill. A stop watch was used to catch the 



