3306 Chapter 27 



The next step is to determine how much lumber (No. 1 Common in this case) 

 is required to produce the necessary ripped pieces for the longest cutting length. 

 The 36 percent estimated yield is the same as 360 feet surface measure of 

 cuttings from 1 ,000 feet surface measure of lumber. The required surface mea- 

 sure of 60-inch cuttings is 145.8 (column 3, table 27-121). When this figure is 

 divided by 360 and multiplied by 1 ,000, 405 feet surface measure of lumber are 

 found to be required to yield the 60-inch cuttings. 



Yields for the other cutting lengths that will be developed in cutting 405 feet 

 surface measure No. 1 Common lumber are next determined. Applying the 

 percent values shown in column 8 to 1,000 feet surface measure indicates 

 recoveries of 103, 156, and 74 feet surface measure for 48, 26, and 12-inch 

 cutting lengths. Since only 405 feet surface measure are being cut, the predicted 

 yields are found by dividing 405 by 1 ,000 and multiplying by the expected yield 

 for 1,000 feet surface measure. Thus, the yield for 48 inches is 0.405 x 103 or 

 41.7 feet surface measure. The yields for all subsequent lengths are calculated 

 and entered in column 10 of table 27-121 . A summary of the cuttings still to be 

 obtained is shown in column 1 1 . All pieces required for the 60-inch length have 

 been obtained so the balance is "0". The balance for the other lengths is obtained 

 by subtracting column 10 from column 3. 



At this point the requirement for 60-inch cuttings has been met, and the 

 requirements for the other subsequent cuttings have been met partially. A second 

 calculation for the unfilled cutting requirements is initiated. It is nearly identical 

 to the first calculation chart with respect to the determination of the values to be 

 entered. Now the 48-inch cutting becomes the longest cutting and is used as the 

 primary cutting length on the nomogram (fig. 27- 16 A). A new determination of 

 the best rip width for the 48-inch length is made from table 27-120, and again, 

 1 .5 inches is the best. No entries are needed in column 2. The figures in column 

 3 are the same as in column 1 1 in the first calculation chart. Figures in column 4 

 are determined by dividing the surface measure required from column 3 by the 

 surface measure in one ripped piece. For example, with the 48 -inch length the 

 surface measure in one piece is 48 x 1.5 inches divided by 144, or 0.5. The 

 required 758.3 feet surface measure divided by 0.5 equals 1 ,517 pieces, 48 x 1 .5 

 inches, required. The values in column 5 are found from the nomogram (fig. 27- 

 16A), using 48 inches as the primary cutting length in exactly the same manner 

 as 60 inches was used in the first calculation. 



Column 8 indicates an expected yield of 48-inch cuttings of 42.9 percent or 

 429 feet surface measure per 1,000 feet lumber surface measure. Since 758.3 

 feet surface measure are required, it is necessary to rip 1,768 feet surface 

 measure 758 3 



429 



x 1,000 = 1,768 



Using 1 ,768 feet surface measure as the new base, yields of 316.5 and 145.0 feet 

 surface measure for 26-inch and 12-inch cuttings are available. Comparing these 

 expected yields with the requirements in column 3 indicates they are more than 

 met. In actual practice the crosscut saw operator would begin to develop cuttings 

 for another cutting bill when he had 167 26-inch and 160 12-inch cuttings. 



