ISSUED: 7-76
D.H. Graves

The volume of timber products in the farm woodland is often an unknown quantity, yet it is of great importance for inventory, management plans, investment evaluation and timber sales.

Units of Measure
All products are measured by some unit. Farm woodland products have many common units of measure, described in the following paragraphs. A thorough understanding of the unit used in the sale of any product is extremely important. Such understanding may help bring a greater financial return and should minimize the chances of misunderstanding a sale agreement's terms.

The piece is the simplest unit of measure, yet there are usually certain specifications involved which should be thoroughly understood before any timber cutting is started. Such specifications cover acceptable diameters, lengths, species, defects and other variables which may set up several grades of a product. Poles, piling, fence posts, railroad ties, and in many cases, mine props, are sold by the piece. Sample specifications for Southern Pine Poles are shown in Appendix A. Specifications for other piece products may be more or less detailed; however, in general the same factors are involved.

Tight Cooperage Units
Some variation of methods may be found in measurement of the tree or bolts which are considered for cooperage products. Only trees of the white oak group are suitable for this use. White oak is preferred; however, bur oak, swamp white oak, swamp chestnut oak, overcup oak and chinkapin oak are commonly accepted.
The stave bolt (Fig. 1) is usually the basic rough product. The bolt is split from a section of the tree trunk which has been cut approximately 39 inches in length. Measurement is taken from outer corner of sapwood to the opposite outer corner of sapwood (B to B). Thus a bolt measuring 12 inches across from outer corner to the opposite outer corner of sapwood would contain 1 bolt-foot. Smaller bolts would contain proportionately less and larger ones more. Sample specifications for stave and heading bolts are given in Appendix B. In general, stave bolts measuring 12 inches across the outside are preferred with a range of from 6 inches to 16 inches accepted. Bolts must also have a certain range of radial or heartwood thickness (C to C). Some buyers set this measurement as ranging from 5 to 8 inches.
Regional practice in measuring by the bolt-foot varies as to whether the measurement is made from outer corner to sapwood to opposite corner or sapwood (B to B), or from outer corner of heartwood to the opposite outer corner of heartwood (A to A).
Stave bolts are graded as suitable for bourbon or oil staves. Bourbon-grade bolts must have clear, straight-grained heartwood. No defects such as worm holes, dote or shake are allowed unless the defect location is such that it would be removed in the end-trimming, edging or jointing of the staves. Oil-grade bolts allow a few small defects, such as one or two tight pin knots, a slight waviness of the grain and more sapwood. A minimum heartwood thickness of 4 to 5 inches is usually allowable in this grade.
Heading bolts follow the same pattern in grades and sizes except that the bolt length is 24 inches. Trees larger than 24 inches in diameter should be worked up into such bolts. Many stave companies do not advocate trees less than 12 inches in diameter for either stave or heading bolts.
A variation from using the bolt foot measure as previously described is found in the practice of estimating the board foot contents of the portion of the tree suitable for stave bolts. In this case a thousand board foot log or tree scale is assumed to be the equivalent of 100 bolt-feet, or a quantity of staves that would make 10 barrels.
Another variation sometimes found is the custom of piling stave bolts in a rick 4 ft high and 8 ft long, face measure. A rick of this size (stave bolts) is estimated the equivalent of 500 bd ft, tree scale, or 50 bolt feet, or 5 barrels.
Heading bolts are usually measured by the rick (24" x 4' x 8').

Lineal Foot
Piling, poles and sometimes mine props in tree lengths are sold locally by lineal measure. As in piece products, there are usually specifications as to species, diameter limits and permissible defects.

Some companies buy mine props, pulpwood or pallet logs at so much per ton, green weight. Here again, the unit of measurement is correlated with specifications as to species, diameter limits and permissible defects.

Cord Measure
This unit is useful in determining the measure of a stack or pile of wood, particularly when the value of the individual piece is not large enough to justify measurement of it. By custom, when this form of measurement is used, all sticks in the pile are cut to approximately the same length, and a face measurement of 4 ft high and 8 ft long is a cord.
The standard cord is set as a unit equivalent to a pile of wood 4 ft high, 8 ft long and 4 ft deep, having a displacement of 126 cu ft (Fig. 2).
Fire wood is usually cut in 16 or 18 inch lengths and is sold in pile units of 4 ft high and 8 ft long. This so-called firewood cord is actually only a third of a standard cord.
Pulpwood and acid wood (chestnut) sticks are cut 5 ft and 5 1/2 ft long respectively, and the "cord" has the same face measurement, 4 x 8 ft. Displacement of the pulpwood cord is therefore 4 x 8 x 5 ft or 160 cu ft and the acid wood cord is 4 x 8 x 51/2 ft or 176 cu ft.
The actual solid wood content of any pile of wood is dependent on care in piling and on surface irregularities of the individual sticks. The solid cube contents of a standard cord vary from 60 cu ft for limb wood, tops and small diameter material to 100 cu ft for large, smooth, straight and regular logs and bolts.

Board Foot
The board foot is the most commonly used unit of measure for standing trees, logs and lumber. It is a unit 1 inch thick, 12 inches wide and 1 ft long. To determine the number of board feet in any rectangular piece of wood the formula is:
Board feet = The quantity thickness in inches times width in inches, divided by 12, times the length in feet.
1" x 8" x 16' would therefore be computed:
Bd ft =
(1 x 8)
x 16 =
x 16 = 10 2/3

In general, rough lumber less than 1 inch thick is computed as an inch. Rough lumber more than 1 inch thick is computed to the nearest full quarter inch. Thus a board 1 3/8 inches thick would be computed at 6/4 inch. Widths are usually taken to the nearest full inch. Some slight variations in thickness and widths by size classes are allowed in grading but are beyond the scope of this discussion. Likewise, the finished sizes in thickness and width are not covered. The board foot content in various common sizes of lumber is given in Table 1. For sizes not listed, use combinations of given sizes. Thus a 4 x 6 inch piece is the same as two 2 x 6's.
The volume of a log in terms of board feet is determined by a log rule. A log rule is merely a tabulation of the board foot volume in logs of various diameters and lengths (Table 2). The log rule seeks to give the volume of sawed lumber that could be cut from a log after allowing for milling losses in sawdust and slabs and edgings.
Log rules have been based on a mathematical formula, diagrams and actual mill tallies. Since different people have different ideas on how the slab and edging and sawdust deduction should be handled, many different log rules have been constructed and used in various sections of the country. The International log rule, based on a 1/4 inch saw kerf, is considered to give values consistently closest to the actual sawed content of sound, straight logs of all sizes. The values given in Table 2 are based on one-inch lumber.
For a "rule of thumb," the formula (D-1)(D-1) x (L/20) will give fairly close results with D equaling the small-end diameter of the log in inches and L equaling the length of the log in feet. Thus the board foot volume of a log with a small-end diameter of 14 inches and a length of 12 ft would be:
(14 - 1)(14 - 1) x
= (13)(13) x .6 = 169 x .6 = 101.4 bd ft

When measuring the small-end diameter of a log, take the average diameter inside bark to the nearest full inch. Length is measured in feet and is to the nearest full foot plus about 4 inches for trimming allowance. Thus a 12-ft log length must measure at least 12 ft, 4 inches.

Table 1 .--Board Foot Contents of Lumber
and width
Board length in feet 
8 10 12 14 16 18 20
Board foot content
1 x 2 1 1/3 1 2/3 2 2 1/3 2 2/3 3 3 1/3
1 x 3 2 2 1/2 3 3 1/2 4 4 1/2 5
1 x 4 2 2/3 3 1/2 4 4 2/3 5 1/3 6 6 2/3
1 x 5 3 1/3 4 1/6 5 5 5/6 5 2/3 7 1/2 8 1/3
1 x 6 4 5 6 7 8 9 10
1 x 7 4 2/3 5 5/6 7 8 1/6 9 1/3 10 1/2 11 2/3
1 x 8 5 1/3 6 2/3 8 9 1/3 10 2/3 12 13 1/3
1 x 10 6 2/3 8 1/3 10 11 2/3 13 1/3 15 16 2/3
1 x 12 8 10 12 14 16 18 20
1 1/4 x 4 3 1/3 4 1/6 5 5 5/6 6 2/3 7 1/2 8 1/3
1 1/4 x 6 5 6 1/4 71/2 8 3/4 10 11 1/4 12 1/2
1 1/4 x 8 6 2/3 8 1/3 10 11 2/3 13 1/3 15 16 2/3
1 1/2 x 4 4 5 6 7 8 9 10
1 1/2 x 6 6 7 1/2 9 10 1/2 12 13 1/2 15
1 1/2 x 8 8 10 12 14 16 18 20
2 x 4 5 1/3 6 2/3 8 9 1/3 10 2/3 12 13 1/3
2 x 6 8 10 12 14 16 18 20
2 x 8 10 2/3 11 1/3 16 18 2/3 21 1/3 24 26 2/3
2 x 10 13 1/3 16 2/3 20 23 1/3 26 2/3 30 33 1/3
2 x 12 16 20 24 28 32 36 40
2 1/2 x 12 20 25 30 35 40 45 50
3 x 6 12 15 18 21 24 27 30
3 x 8 16 20 24 28 32 36 40
3 x 10 20 25 30 35 40 45 50
3 x 12 24 30 36 42 48 54 60
4 x 4 10 2/3 13 1/3 16 18 2/3 21 1/3 24 26 2/3
6 x 6 24 30 36 42 48 54 60

Table 2.--International Log Rules. 1/4" Saw Kerf.
Log diameter
at small end
Log lengths in feet
8 10 12 14 16
Volume in board feet
8 15 20 25 35 40
9 20 30 35 45 50
10 30 35 45 55 65
11 35 45 55 70 80
12 45 55 70 85 95
13 55 70 85 100 115
14 65 80 100 115 135
15 75 95 115 135 160
16 85 110 130 155 180
17 95 125 150 180 205
18 110 140 170 200 230
19 125 155 190 225 260
20 135 175 210 250 290
21 155 195 235 280 320
22 170 215 260 305 355
23 185 235 285 335 390
24 205 255 310 370 425
25 220 280 340 400 460
26 240 305 370 435 500
27 260 330 400 470 540
28 280 355 430 510 585
29 305 385 465 545 630
30 325 410 495 585 675
32 375 470 570 670 770
34 425 535 645 760 875
36 475 600 725 855 980
38 535 670 810 955 1095
40 595 750 900 1060 1220

Any condition that will cause a reduction in the quantity of lumber that might otherwise be cut out of a log is considered a defect. Thus rot, cracks or splits, crook or sweep, and similar conditions which cause an actual reduction in the scaled contents of a tree or log, are defects. Conditions that cause a lowering of grade only, such as stain, are not considered defects in log-scaling practice.
To warrant a deduction, the defect must penetrate into the central cylinder as determined by the small-end diameter (inside bark) less one inch, extended the length of the log. Thus a surface defect at the butt or large end of the log must be deep enough to penetrate into the central cylinder, and only the depth of penetration into the cylinder is considered as the depth of the defect. Defects can be classified as
end and surface
crook and sweep
uniform surface
cracks and splits

The method most commonly used, and described in textbooks treating with timber measurements, boxes in the defective area and determines its volume in board feet by use of the formula:

Deduction = (D x W x L)/15

In this formula, D equals the depth or thickness in inches, W equals the width in inches, and L equals the length in feet of the defect.
An alternate method of computing deduction for defects has been outlined by L.R. Grosenbaugh of the U.S. Forest Service (Southern Forest Experiment Station Occasional Paper #126, pp. 14-15) in which a percent deduction from the gross scale is computed. In general, the deductions by this method are less than those in similar cases computed by the formula D x W x L divided by 15. Since this formula admittedly imposes a heavy penalty for defective portions, the alternate method should have merit in localities where a high standard of utilization of the log contents is possible.
Procedure for calculating deduction for end or surface defects is given as follows:

1. Enclose the defect cross-section in an ellipse.
2. Measure the short and long dimension of the ellipse. Add 1 inch to each.
3.Determine the ratio of each increased dimension to the log diameter less 1 inch. Round off to the nearest tenth (Table 3).
4.Estimate the length of the defect and determine the ratio of defect length to the log length. Round off to the nearest tenth (Table 3).
5.Multiply the three ratios together. The result is the proportion to be deducted from the gross scale for the defect.

Table 3.--Ratio of Defect Dimension to Log Dimension
Defect Dimension
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
8 .1 .25 .4 .5
9 .1 .2 .3 .4 .6
10 1 .2 .3 .4 .5
11 .1 .2 .3 .4 .5 .5
12 .1 .2 .25 .3 .4 .5
13 .1 .2 .2 .3 .4 .5
14 .1 .1 .2 .3 .4 .4 .5 .6
15 .1 .1 .2 .3 .3 .4 .5 .6
16 .1 .1 .2 .25 .3 .4 .4 .5 .6
17 .1 .1 .2 .3 .3 .4 .4 .5 .5
18 .1 .1 .2 .2 .3 .3 .4 .4 .5 .6
19 .1 .2 .2 .3 .3 .4 .4 .5 .5 .6
20 .1 .15 .2 .25 .3 .35 .4 .45 .5 .55
21 .1 .1 .2 .2 .3 .3 .4 .4 .5 .5 .6
22 .1 .1 .2 .2 .3 .3 .4 .4 .5 .5 .5
23 .1 .1 .2 .2 .3 .3 .3 .4 .4 .5 .5 .6
24 .1 .1 .2 .2 .25 .3 .3 .4 .4 .5 .5 .5
25 .1 .1 .2 .2 .2 .3 .3 .4 .4 .4 .5 .5 .6
26 .1 .1 .2 .2 .2 .3 .3 .3 .4 .4 .5 .5 .5
27 .1 .1 .1 .2 .2 .3 .3 .3 .4 .4 .4 .5 .5 .6
28 .1 .1 .1 .2 .2 .25 .3 .3 .4 .4 .4 .5 .5 .5
29 .1 .1 .1 .2 .2 .2 .3 .3 .3 .4 .4 .4 .5 .5 .6
30 .1 .1 .1 .2 .2 .2 .3 .3 .3 .4 .4 .4 .5 .5 .5

Examples of the various kinds of defects together with sample calculations are shown in the following cases.

Case l.--Butt rot in a log 18 inches in diameter and 16 ft long.
Formula Method
The dimension of the defect as shown are 5 inches thick by 9 inches wide by 4 ft long. In all cases involving a rotten area, 1 inch is added to the thickness and width measurement to make sure the defective area is enclosed. Use of the formula would then give:

Deduction =

((5+ l) x (9+ l) x 4)/15 = (6 x 10 x 4)/15 = 16 bd ft

With a gross scale of 230 bd ft as found in Table 2, the net scale of the log is 230 - 16 or 214 bd ft.

Grosenbaugh Method
As Step 1, the cross-section of the defect can be enclosed in an ellipse. Following through with Step 2, the short and long dimensions are 5 inches and 9 inches respectively; adding 1 inch to each, and dividing by the log diameter - 1 (Step 3) we get:

(5 + 1)/(18 - 1) = 6/17 = .3
(9 + 1)/18 - 1) = 10/17 = .6

In Step 4, we note that the length of the defect is 4 ft. This expressed as a ratio of the length is 4/16 or .25. Step 5 consists of multiplying the three ratios together (. 3 x .6 x .25), giving .045, which to the nearest unit percent is 5. This is the proportionate deduction for the defect from the gross scale of the log, or .05 x 230 = 11.5 or 12 bd ft. The net scale thus is 230 - 12 or 218 bd ft.

Case 2.--Surface defect in a log 18 inches in diameter at the small end, 24 inches in diameter at the large end and 16 ft long.
Formula Method
Again, the defect thickness, width and length can be determined. In this case, the defect is in the butt end of the log and only that portion of the defect which is in a central cylinder of the log's small-end diameter less 1 inch is subject to deduction. The total depth of the defect as given in the sketch is 8 inches, of which 5 inches lie in the central cylinder. The width is given as 7 inches. Length is estimated at 3 ft.
Use of the formula would give:

Deduction =
((4+ l) x (7+ l) x 3)/15 = (5 x 8 x 3)/15 = 8 bd ft

With a gross scale of 230 bd ft, the net scale is 230 - 8 or 222 bd ft.

Case 2a.--Surface defect in a log 18 inches in diameter at the small end, 23 inches in diameter at the large end and 16 ft long.
Grosenbaugh Method
Again the defect cross-section and length can be estimated. In this case the defect is at the butt of the log and all of the defective area is deductible except that occurring in the peripheral half-inch which is the slab collar. Depth of the defect as illustrated in Fig. 5 is 8 inches, width is 7 inches and the length is 3 ft.

Computations would then be:
(7 1/2 + 1)/17 = .5; (7 + 1)/17 = .5; and 3/16 = .2

Proportionate deduction for the defect would then be .5 x .5 x .2 or .05. Five percent of 230 is 11.5 or 12 ft. The net scale of the log would then be 230 - 12 or 218 bd ft.

Case 3.--Center or heart rot in a log 18 inches in diameter and 16 ft long.
Formula Method
With a defect of this type the procedure involves averaging the defect dimensions of small and large ends of the log to get an average defect cross-section. Since the defective area showing at both ends is roughly circular, thickness and width in this case are the same. Adapted to the basic formula, the computation is given as follows:

((5 + 1) + (8 + 1))/2 = 15/2 = 7.5" average diameter of defect
Deduction = (7.5 x 7.5 x 16)/15 = 60 bd ft 15

The net scale of this log would be 230 - 60 or 170 bd ft.

Grosenbaugh Method
Procedure in this case is slightly different, but involves the same principles as in cases 1 and 2a. The rot in this case is almost circular in cross-section. Long and short dimensions are thus the same. The deduction percentage is computed for each half length of the log to compensate for change in dimension of the defect. For the butt half of the log, the cross-section dimensions of the defect are 8 inches and 8 inches. These, in terms of a percentage of the small-end diameter less one inch, are 9/17 and 9/17 or .5 and .5. The length of 8 ft is 50% of the log length, or .5.
Deduction for defect in the butt half of the log is thus .5 x .5 x .5 or 13%. Procedure for the other half of the log is the same except that the defect cross-section is 5 inches. Computations for this half of the log (.4 x .4 x .5) give 8% as the deduction. Adding the two deductions gives 21% as the total deduction from the gross scale; .21 x 230 = 48.3 bd ft. The gross scale would then be 230 - 48, or 182 bd ft.

A short cut in the computations involved would be:
1. square and defect cross-section percentages for large and small ends of the log;
2. add results; and
3.divide by 2.

1..5 x .5 = .25 and .4 x .4 =.16;
2..25 and .16, added together, equals .41;
3..41/2 = .21 or 21%.
This short cut follows the same procedure as does the more detailed computation.

Case 4.--Shake.
Shake is a condition where one or more growth rings are loose from adjacent wood. It may extend entirely around the ring or only for a few inches. Areas having only a limited amount of shake can be considered as having a center defect and standard procedure followed. In some cases, however, where the shake extends completely around the ring, and where a sizeable core of wood 6 inches or more in diameter remains in the center as illustrated in sketch, the procedure is modified to allow salvage of the sound center.
Figure 7 shows an 18 inch diameter log, 16 ft long with a shake zone extending completely around the annual rings and about 1 inch thick. The outside dimensions of the shake zone average 9 inches at the small end of the log, and 12 inches at the butt end. There is a sound core of 7 inches in diameter (small end).

Formula Method
Computations would be as follows:
((9 + 1 ) + ( 12 + 1 ))/2 = 23/2 = 11.5 average diameter of shake
Deduction = (11.5 x 11.5 x 16)/15 = 2116/15 = 141 bd ft
if the entire center were shakey. In this case, however, a 7 inch sound core is equivalent to a 7 inch log, 16 ft long. The scale of such a log, using the rule of thumb, is

(D - 1)(D - 1) x L/20, is (6)(6) x 16/20, or 29 bd ft.
Thus, the deduction for Case 4 would be 141 - 29 or 112 bd ft. The net scale would then be 230 - 112 or 118 bd ft. Except for the log of a valuable species, such a deduction of approximately 50% would cause the log to be a cull.

Grosenbaugh Method
Computations would be as follows:
10/17 = .6, .6 x .6 = .36
13/17 = .8, .8 x .8 = .64
(.36 + .64)/2 = .50 or 50% initial deduction
If the gross scale of the log is 230 bd ft, the initial deduction would be .50 x 230, or 115 bd ft. This however is less the scale of the sound core. A 7 inch by 16 ft log will scale out approximately 29 bd ft. Thus, 115 bd ft less 29 bd ft is 86 bd ft, which is the deduction for this defect.

Case 5.--Rotten sapwood or any condition which is surface in nature and can be confined to a collar or uniform thickness.
In Figure 8 the log's defective portion is estimated to be 2 inches thick. The log is 18 inches in diameter at the small end. Procedure in this case is to reduce the diameter by twice the average thickness of the defective sheath and scale as a 14-inch diameter log. The net scale would thus be 135 bd ft.

Case 6.--Crack or Splits.
If the log is straight-grained, the defect can be enclosed in an area having thickness, width and length, and the standard procedure followed. If, however, the log has spiral grain, the defect is best enclosed in a sector of the log.
In Figure 9 a crack spirals along the log's length and extends in approximately to the log center. The sector which enclosed the defect is equivalent to 1/4 of the log volume, or a 25% deduction from the gross scale.

Case 7.--Sweep in a log 18 inches in diameter and 16 ft long.
Sweep is a curve in the log. When the sweep occurs in one place, the actual deviation of the log center from a line connecting the center point at each end is considered the measurement of the sweep(s). Deduction percentage for sweep is obtained by use of the formula:

Proportion deducted = S - 2/(Scaling diameter of log)
In case of a sweep of 6 inches in the log diagrammed above, the deduction percentage would be computed as (6 - 2)/18 or 4/18 or 22%. In terms of board feet this would be .22 x 230 or 51, and the net scale 230 - 51 or 179 bd ft.

Case 8.--Crook in a log 18 inches in diameter and 16 ft long.
Crook is a sharp bend in a log while sweep has a rather uniform curvature along the log length. Measurements of the magnitude of the crook are taken as indicated in Figure 11. The deduction is then computed by the rule:

Proportion deducted =

(sideways measurement of crook)/(scaling diameter of log) x (length of log affected)/(log length)
Computation of deduction in Case 8 would be:

Proportion deducted = (9)/18 x (4)/16 = .50 x .25 = 12 1/2%
12.5 % of 230 is 29 bd ft. The net scale for this case is then 230 - 29 or 201 bd ft.

Measurement of Log or Tree Dimensions and Equipment Used
Measurements are taken of the average small-end diameter (inside bark) and of the length. A common yardstick or any scale graduated in inches can be used. When measuring the diameter, be careful to get the average measurement, since many logs are not exactly round. Length is measured in feet to the nearest full foot plus about 4 inches for trimming allowance. With a diameter and a length measurement, the volume of the log in board feet can be obtained by consulting a log rule (Table 2).

Standing Trees--Diameter Measurements
Measurement is customarily made of tree diameter (outside bark) at D.B.H. (Diameter at Breast Height). This point is standardized at 4 1/2 ft above ground level.
Perhaps the simplest and most consistently accurate method of measuring the diameter of a standing tree is to measure the circumference by stretching a tape measure around the tree, and then divide the reading by 3. To be strictly accurate, the reading should be divided by 3.1416; however, the approximate diameter obtained by dividing by 3 is within the standards of accuracy usually required.
Calipers and the Biltmore scale can also be used if available. The principle of the Biltmore scale follows:

(Figure 12)

The lines AB' and AE represent diverging lines of sight when a person looks at the side of a tree. B'C' or D/2 is a radius of the circle (tree diameter). CD is the proportionate measurement that would be included on a stick held horizontally against the tree. AB or a would represent the distance the stick was held from the eye. Angles ABC and AB'C' are right angles and thus triangles ABC and AB'C' are similar. From this relationship, an initial proportion can be set up

CB/AB = C'B'/AB'

Simplifying this proportion in terms of a and D (reach and diameter) we can derive the following formula:

S = a(D)(D)/(a + D)

In the above formula, a equals the reach, which for the average person will be 25 inches, and D represents a particular diameter. S is then the scale measurement (line CD) for the particular diameter used.
For example, the graduation, (S) for a 10 inch diameter and a 25 inch reach (a) would be computed as follows:

S = (25 x (10)(10))/(25 + 10) = 2500/35 = 71.43+(square root) = 8.45+"

Graduations for other diameters can be computed in a similar fashion. In case of a longer or shorter reach than the standard 25 inches, the value of a in the formula can be changed to whatever is considered a normal reach. A table of graduations for a 25 inch reach is given in Table 4.

Table 4.--Biltmore Scale Graduations (25 inch reach.)
Diameter Scale gradation
to the nearest
1/10 of an inch
8 7.0
10 8.5
12 9.8
14 11.2
16 12.5
18 13.7
20 14.9
22 16.1
24 17.1
26 18.2
28 19.2
30 20.2
32 21.2
34 22.1
36 23.0

To make a Biltmore stick, take a piece of lath, lattice or a yard stick and plane or sand one face clean and smooth. Next measure the indicated scale for the smallest diameter reading (for example 8 inches) from the left end of the stick, and mark it on the face of the stick in a suitable manner. This then is the 8 inch graduation of the Biltmore scale. Repeat for other diameters.
To use the stick, hold it horizontally against the tree at D.B.H.; line up the left upper corner of the stick with your line of sight, cutting the left side of the tree trunk. Then without moving your head, swivel your line of sight to the right side of the tree trunk and read tree-diameter on the Biltmore scale. Remember that the scale was graduated on the basis of a specified reach. Accuracy in use of the scale depends on how closely the correct reach (a) is maintained. Also, be sure to take an average of the largest reading and the smallest reading, since many trees are oval in cross-section.

Standing Trees--Heights
Measuring the height of the point on the tree trunk where the last cut will normally be made requires some training; however, the procedure and equipment can be relatively simple. The length of the usable section of the tree trunk is influenced by (1) the taper of the tree trunk, and (2) the breaking up of the central trunk into large branches. In the latter case, the top limit of usable trunk length is just below the fork, and is easy to determine. However, in the first case, a point on the tree trunk must be chosen where the minimum usable diameter (usually 8 inches inside bark) is estimated to occur. If bark is estimated to be about one-half inch thick at the 8-inch diameter point, the outside dimension would thus be 9 inches. Determining the point on the tree trunk at which it would measure 9 inches outside the bark is at best an approximation. If the D.B.H. is known, it can be used as a comparative measure.

Method l.--Formula
Some estimators use the formula:
(Circumference in inches at D.B.H. x .28) - 2" equals diameter inside bark at the top of the first 16 foot log. For each 16 ft additional length, deduct 2 inches to secure the diameter inside bark at the top end of the log in question.

Thus a 20 inch D.B.H. tree would give the following:
(63" x .28) - 2 = 17.6 - 2 = 15.6" diameter inside bark at the top of the first 16 ft log length. At 32 the diameter (i.b.) would be 13.6 inches, and at 48 ft, 11.6 inches.
The above example assumes that the tree tapers gradually and extends up at least 48 ft before any large branches occur. For thick-barked trees, use the factor .27 instead of .28.
Having estimated the point on the tree trunk that is the limit of usable trunk length of logs, one still must determine how high that point is above stump height. Stump height can usually be standardized at about 1 ft above ground for this purpose.
Many methods of measuring height require special and sometimes expensive equipment; however, Method 2 is just as accurate and employs quite simple equipment.

Method 2.--The Merritt Hypsometer (Similar Triangles)
Based on a known distance (for example 66 ft) from a known height unit, and holding a stick in a vertical position a known distance from the eye (25 inches) one can calibrate that stick so that tree heights can be read from it when standing 66 ft from the tree and holding the stick 25 inches from the eye. For example, in Fig. 13, AB is equal to the reach, or 25 inches; AB' is equivalent to the set distance that one must stand away from the tree (66 ft); C'B' is a set height unit (16 ft), and BC is the interval or scale graduation that the lines of sight would cover on the measure stick. The following relationship of sides can now be set down:

BC/AB = C'B'/AB'
Substituting values as used in above explanation:
BC/25" = 16'/66'
BC = (25" / 12" x 16')/66' = 33.33'/66' = .51' or 6.06"

A scale unit of 6.06 inches on the stick will cover 16 ft on the tree with the 25 inch reach and 66 ft distance factor. Multiples of this unit can be marked on the stick. Thus when one is 66 ft from a tree with the stick held 25 inches from the eye, and the lower lines of sight to the stump height cuts the bottom of the stick, the upper line of sight to the point of height-measurement can be read on the scale in terms of 16 ft units. A slight error is involved; however, results are within limits of accuracy of this type of measurement.

Method 3.--Similar Units
In this approach a pole of known length, say 10 ft, is leaned against the tree and used as an ocular yard stick in estimating the number of 10-ft units in the usable part of the tree bole.

Estimating the Board-Foot Content of a Standing Tree
By Use of a Volume Table
A volume table (Tables 5 and 6) shows the average volume in trees by D.B.H. and height classes. Thus, all that is needed to determine the volume in any tree of normal form is a measurement of the D.B.H. (outside bark) and a measurement of the usable length of the tree. The methods of obtaining these measurements are explained in the previous section. A tree that is determined to be 14 inches at D.B.H., and to have 1 1/2-16 ft units (from 20-27 ft) of usable trunk length, will contain 112 bd ft (International 1/4" Rule). This is found in Table 6 by reading at the intersection of the 14-inch D.B.H. and the 1 1/2 log columns. The volume for any normal tree of a size within the D.B.H. and height range of the volume table can be determined in a similar fashion.
Since volume tables are necessarily based on average volumes of a large number of trees, and the height is treated by half-log or 8-ft units, the volume given for any individual tree may be slightly greater or less than the actual volume in the tree, depending on how closely the tree approximates the average of that particular size class. In general, volume tables are most usable for trees with a central bole or stem that ( 1 ) tapers gradually to the inside bark diameter that is determined to be the limit of merchantability, and (2) does not have any very large limbs or forks within this usable bole length. Tables are based on an 8-inch (inside bark) top diameter. Volume tables are also based on Form Class, which is the relationship of the diameter (inside bark) at the top of the first 16-ft log to the D.B.H. (outside bark). Tables are based on a Form Class of 80, which is about right for trees on average sites in Kentucky.
The volume table is useful because it requires only two measurements (D.B.H. and usable height). When used with large numbers of trees, the individual errors tend to balance out and the end estimate is within the limits of error permissible for this type of work.
Deduction for defect may be handled in the manner previously described for logs and the defect calculated and noted for each tree. An alternate method is to estimate the percentage of the gross scale that may be defective and make deductions on a percentage basis. Either method is at best a guess when dealing with standing timber, and considerable experience is required to become proficient.

Table 5.--TREE SCALE--Doyle Rule
Compiled for Hardwoods
Number of 16-Foot Logs
1 1 1/2 2 2 1/2 3
10 16 20 23    
12 31 39 47    
14 52 67 82 93 104
16 77 101 125 143 161
18 110 140 180 210 230
20 140 190 240 280 320
22 190 250 310 370 420
24 230 310 400 470 540
26 280 390 490 580 660
28 340 470 590 700 810
30 400 550 700 830 960
32 470 650 820 980 1140
34 540 750 950 1140 1320
*Diameter at 4 1/2 feet above ground.

Several forms of tally sheets may be used for tallying the number of trees of different sizes and species. A sample sheet that will fulfill most requirements is shown in Fig. 14. Changes can be made in size ranges and species group to fit conditions at hand. Individual trees are tallied in the appropriate space by making a short line or a dot. If care is taken, a large number of any one-size trees can be tallied in the space provided. Also, if the stand is composed of predominantly smaller-tree sizes, the spaces allocated for these sizes can be tailored to fit the need.
Additional tally sheets can always be used if more space is required. After the field work has been completed, a count of the lines or dots in each space will indicate the number of trees in each D.B.H. and height-class by species group. By consulting the volume table, one can find the volume of an average tree for each D.B.H. and height-class. Multiplying each average-volume by the number of trees tallied in its size-class will give the volume in board feet for the individual size classes. Total volume for all the trees tallied is then a simple matter of adding up all of the volumes determined for the various size classes.

Table 6.--TREE SCALE--International 1/4 inch Rule
Number of 16-Foot Logs
1 1 1/2 2 2 1/2 3
10 39 51 63    
12 59 78 98    
14 83 112 141 164 186
16 112 151 190 223 256
18 140 200 250 290 340
20 180 250 310 370 430
22 220 300 390 460 530
24 270 370 470 560 640
26 310 440 560 660 770
28 370 510 650 780 900
30 420 590 760 900 1050
32 480 680 870 1040 1210
34 550 770 990 1190 1380
*Diameter at 4 1/2 feet above ground.

By Use of a Log Rule
As noted in an earlier section, a log rule is a tabulation of the estimated volume in logs of various small-end diameters and length classes. Thus, if the sizes of the logs that could be cut from a standing tree could be determined or estimated, the volume of each log could be found by the log rule and the sum of the volumes of the logs in a tree would represent the board-foot content of the tree. This method requires more work than the "Volume Table Method" and a little more skill; however, it is more accurate in the case of short, thick-boled trees, and for any one individual tree since the actual log sizes that could be cut from the tree are computed exactly as they would be if the tree were felled and bucked into logs. The difficulty lies in estimating the correct small-end diameters and lengths of the logs as they appear in a standing tree. Any standard of comparison, such as a 10- or 12-ft pole with a yardstick fastened across its top and leaned against the tree, is a great help to the beginner.
A form of tally sheet that can be modified to suit local requirements is shown in Fig. 15. Spaces have been provided for identifying the individual tree by a number and by species, for noting the diameter and length of as many as 4 separate logs, and for the tree volume after it has been computed.

Figure 14. -- Field Tally Sheet
  Location  Sheet No.
1/2 1 1/2 2 1/2 1/2 1 1/2 2 1/2

Figure 15.--Field Tally Sheet for Individual Tree Measurements
  Location Sheet No. 
Tree No. Species
Log Dimensions
Diam Lgth Diam Lgth Diam Lgth Diam Lgth

Estimating the Board-Foot Volume in a Tract of Timber
The two previous sections have indicated how tree diameters and heights can be determined, and how these measurements can be used to determine the volume in a tree.
In small tracts of timber up to 10 or 15 acres in extent, it is best to measure diameter and height of every tree that is above minimum size for the inventory of sale. When only large, mature trees are being considered, then only the trees in this category are measured and tallied.
In larger tracts, the same procedure can be followed with considerable expenditure of time and effort; however, it is more practical to limit the work to sample areas in the form of parallel strips or lines of plots running across the area. The strips or lines of plots should be aligned so as to obtain a proportionate coverage of variations in size and density of the timber. When there are ridges and valleys involved, the strips or lines of plots should cross the main ridges and valley at approximately right angles so that sparser ridge timber is obtained as well as the larger and denser timber on the lower slopes and in the valleys.
One side of the tract can be used as a baseline and the spacing of the strips or lines of plots laid off along it. A staff or pocket compass can be used to maintain strip alignment. A tape or chain should be used to determine distances.
The strips can be of any set width; however, a narrow strip of one-half chain width (33 ft) is easier to stay within, as are small circular plots of 1/5 acre (52 ft radius) or 1/10-acre plots of 37 ft radius. The distance traveled along the strips must be measured so that the area cruised can be determined. Thus, a strip of 1/2 chain (33 ft) wide and 20 chains ( 1,320 ft) long covers 10 square chains, or 1 acre. Likewise, in lines of 1/5-acre plots spaced at a set distance from center to center, the number of plots taken divided by 5 gives the acreage of the sample. In order to eliminate personal choice of sample areas, the spacing of the strip or line-of-plots-intervals should be mechanical, and carried out according to a predetermined pattern.
The number of strips or lines of plots to be run should be determined by the percentage of estimate that will satisfy the requirements of accuracy. Usually the smaller the tract, the larger the sample should be. Thus, for tracts of 20 to 100 acres, a 20% estimate should give a fair standard of accuracy. If the timber is fairly uniform, a 10% estimate may do. On larger tracts, a 10% estimate is usually satisfactory, or even a 5% may do in some timber.
With the percentage of estimate determined that will be satisfactory, the spacing between strips or lines of plots can be computed. If 1/2-chain-width strips are used, a spacing of 5 chains between strip centers will give an approximate 10% coverage of the tract. In the case of 1/5-acre plots, a spacing of plots in the line at 4-chain center distance and 5 chains between lines of plots will also give an approximately 10% estimate. Strips or lines of plots should be one half of the strip or line of plots spacing interval inside of the timber edge. Figure 16 and Figure 17 illustrate most of the details explained in this section.
When using the strip method, use one tally sheet for each 5 or 10 chains of strip covered. Individual tally sheets may be numbered or otherwise identified by strip number and distance interval such as "Strip #1, Distance 0-10 chains." Likewise, separate tally sheets for each circular plot help to keep the records straight and each should be identified as to line and plot number.
When the field work is completed, the volume of the trees on the strips or lines of plots can be computed as given in the section dealing with "Estimating the Board Foot Content in a Standing Tree." The area of the strips or plots can also be determined. The relationship of the measured sample area and its volume to the tract area and tract volume can be expressed by the proportion:

V/v = A/a or V = (vA)/a

In the above proportion, V equals the volume of timber on the tract, v equals the volume of timber in the sample area; A equals the area of the tract in acres, and a equals the area in acres of the sample area.

Evaluating Timber Volume on a Tract by Species Groups and Sizes
Knowing the total volume of timber on a tract is extremely valuable for inventory or sale. An average value per 1,000 bd ft can be set and total value thus easily computed. It is better business, however, to be able to compute volume and value by species groups and sizes when such variation in the timber occurs. This can be done easily if species groups are separated in making the tally during the estimating procedure as advocated in Section III. The sample tally sheets proposed in this section are likewise designed to allow such separation. Thus, the estimated value of the species groups, such as White Oak, Red Oak, Beech, and Hickory or Yellow Poplar, are their diameter ranges (for example: 8"-12", 13"-16"', 17'-20', etc.) can be determined and computed separately. This separation is more satisfactory than attempting to set an average for all species and all sizes.

Appendix A: Specifications for Southern Pine Poles
(From American Standard Specifications and Dimensions for Southern Pine Poles. American Standards Association, (05.1-1979)
This standard consists of specifications and dimensions for southern pine poles that are to be given preservative treatment as specified by the purchaser. The poles described here are considered as simple cantilever members subject to transverse loads only. Modification of the requirements may be necessary if the poles are to be used for other types of construction.
Requirements for the preservative treatment of poles are not included in the standard. These requirements are detailed in other standards (for example those of the American Wood-Preservers' Association and American Society for Testing Materials) and in customer specifications. However, exceptions are made to this exclusion of those cases where conditioning the wood for treatment or where the actual process of preservation could reduce the fiber stresses below standard specifications (8,000 PSI) and as a consequence necessitate a change in the minimum 6 ft from the butt dimension given.
The species, the length and class of poles, the type of treatment (including seasoning details, if seasoning is desired), and complete details for roofing, gaining, boring and branding, not included in this standard, must be given in purchase orders.
Complete detailed instructions must be given to the supplier whenever the requirements of this standard are modified to meet special conditions.

Material Requirements
All poles must be cut from live southern pine timber: Longleaf Pine (Pinus palustris), Shortleaf Pine (Pinus echinata), Loblolly Pine (Pinus taeda) and Slash Pine (Pinus elliottii).

Prohibited Defects
Cross breaks (cracks).
Decay -- except as permitted for firm red heart, defective butts and decayed knots.
Dead streaks.
Holes -- open or plugged, except holes for test purposes, which shall be plugged.
Hollow butts or tops -- except as permitted under hollow pith centers and defective butts.
Marine borer damage.
Nails, spikes and other metal not specifically authorized by the purchaser.

Permitted Defects
Firm Red Heart. Firm red heart not accompanied by softening or other disintegration (decay) of the wood is permitted.
Hollow Pith Centers. Hollow pith centers in tops or butts and in knots are permitted in poles that are to be given full-length treatment.
Sap Stain. Sap stain not accompanied by softening or other disintegration (decay) of the wood is permitted.
Scars. Turpentine acid face scars are permitted anywhere on the pole surface.

Limited Defects
Bark Inclusions. Depressions containing bark inclusions must be no more than 2 inches deep, measured from the surface of the pole.
Compression Wood. The outer 1 inch of all poles shall be free from compression wood visible on either end.
Defective Butts. Hollowing in the butt caused by "splinter pulling" in felling the tree is permitted, provided that the area of such a hollow is less than 10% of the butt area.
Insect Damage. Insect damage, consisting of holes 1/16 inch or less in diameter, or surface scoring or channeling is permitted. All other forms of insect damage are prohibited.
Knots. The diameter of any single knot and the sum of knot diameters in any l-ft section shall not exceed the limits of Table 7. Type II "decayed knots" are permitted.
Scars (Cat face). No pole shall have a scar or turpentine cat face located within 2 ft of the ground line. Turpentine scars need be trimmed only to the extent necessary for examination for evidence of fungus infection and insect damage. Other sound scars are permitted elsewhere on the pole surface, provided they are smoothly trimmed and do not interfere with the cutting of any gain, and provided that:
(A) The circumference at any point on trimmed surfaces located between the butt and 2 ft below the ground line is not less than the minimum circumference specified at 6 ft from the butt for the class and length of the of pole; and
(B) The depth of the trimmed scar is not more than 2 inches, if the diameter is 10 inches or less or 1/5 the pole diameter at the location of the scar if the diameter is more than 10 inches.
Shakes. Shakes in the butt surface which are not closer than 2 inches to the side surface of the pole are permitted, provided they do not extend to the ground line. Shakes or a combination of connected shakes which are closer than 2 inches to the side surface of the pole are permitted, provided they do not extend farther than 2 ft from the butt surface and do not have an opening wider than ,/8 inch. Shakes in the top surface are permitted in poles that are to be given full-length preservative treatment, provided that the diameter of the shake is not greater than 1/2 the diameter of the top of the pole.
Shape. Poles shall be free from short crooks. A pole may have sweep subject to the following limitations.
(A) Where sweep is in one plane and one direction only--
1.For poles 50 ft and shorter, a straight line joining the surface of the pole at the ground line and the edge
of the pole at the top, in 90% or more of an inspection lot, shall not be distant from the surface of the pole at any point more than 1 inch for each 10 ft of length between these points. In the remainder of the inspection lot (10%) the poles may have a deviation of 1 inch for each 6 ft of length when measured as above.
2.Poles 55 ft and longer shall meet the 1 inch in 10 ft requirements in 75% or more of an inspection lot. In the remainder of the lot (25%) the poles may have a deviation of 1 inch for each 6 ft of length when measured as above.
(B) Where sweep is in two planes (double sweep), or in two directions in one plane (reverse sweep) a straight line connecting the mid-point at the ground line with the mid-point at the top shall not at any intermediate point pass through the surface of the pole.
Spiral Grain. Spiral grain (twist grain) is permitted as follows:
Length of Pole (ft)  Maximum Twist of Grain Permitted
30 and shorter 1 complete twist in any 10 ft
35-45, inclusive 1 complete twist in any 16 ft
50 and longer 1 complete twist in any 20 ft

Splits and Checks.
(A) In the top. A split or a combination of two single checks (each check terminating at the pith center and separated by not less than 1/6 of the circumference) having one or both portions located in a vertical plane within 30 degrees of the top bolt hole shall not extend downward along the pole more than 6 inches. All other combinations of check or split shall not extend downward along the pole more than 12 inches.
(B) In the butt. A split or a combination of two single checks, as defined above, shall not extend upward along the pole more than 2 ft.

Table 7.--Limits of Knot Size
Maximum Sizes Permitted, inches
 Diameter of Any Single 
Knot (inches)
Sum of Diameters of All
Knots Greater than 0.5 inch
in Any 1-ft Section (inches)
Length of Pole classes
45 ft and shorter
lower half of length   8
upper half of length 5 8
50 ft and longer
lower half of length 4 10
upper half of length 6 6 10

Poles less than 50 ft long shall not be more than 3 inches shorter or 6 inches longer than nominal length. Poles 50 ft long or more shall be not more than 6 inches shorter or 12 inches longer than nominal length.
Length shall be measured between the extreme ends of the pole.

The minimum circumference at 6 ft from the butt and at the top, for each length and class of pole are listed in Table 8. The circumference at 6 ft from the butt of the pole shall be not more than 7 inches or 20% larger than the specified minimum, whichever is greater.
The top dimensional requirement shall apply at a point corresponding to the minimum length permitted for the pole.

The true circumference class shall be determined as follows: measure the circumference at 6 ft from the butt. This dimension will determine the tree class of the pole, provided that its top (measured at the minimum length point) is large enough. Otherwise, the circumference at the top will determine the true class provided that the circumference at 6 ft from the butt does not exceed the specified minimum by more than 7 inches or 20%, whichever is greater.

Table 8.--Circumference Specifications for the Various Classes of Creosoted Southern Pine Poles
of pole 
Distance of 
ground line 
from butt* 
Pole Class
1 2 3 4 5 6 7 9 10
Minimum top circumference (inches)
27 25 23 21 19 17 15 15 12
Minimum circumference six foot from butt (inches)
20 4 31.0 29.0 27.0 25.0 23.0 21.0 19.5 17.5 14.0
25 5 33.5 31.5 29.5 27.5 25.5 23.0 21.5 19.5 15.0
30 5.5 36.5 34.0 32.0 29.5 27.5 25.0 23.5 20.5
35 6 39.0 36.5 34.0 31.5 29.0 27.0 25.0
40 6 41.0 38.5 36.0 33.5 31.0 28.5 26.5
45 6.5 43.0 40.5 37.5 35.0 32.5 30.0 28.0
50 7 45.0 42.0 39.0 36.5 34.0 31.5 29.0
55 7.5 46.5 43.5 40.5 38.0 35.0 32.5
60 8 48.0 45.0 42.0 39.0 36.0 33.5
65 8.5 49.5 46.5 43.5 40.5 37.5
70 9 51.0 48.0 45.0 41.5 38.5
75 9.5 52.5 49.0 46.0 43.0
80 10 54.0 50.5 47.0 44.0
85 10.5 55.0 51.5 48.0
90 11 56.0 53.0 49.0
95 11 57.0 54.0 50.0
100 11 58.5 55.0 51.0
105 12 59.5 56.0 52.0
110 12 60.5 57.0 53.0
115 12 61.5 58.0
120 12 62.5 59.0
125 12 63.5 59.5
*For use in applying specifications which require a definition of "ground line."

Table 9.--Diameter Specifications for the Various Classes of Creosoted Southern Pine Poles*
Length of 
pole (Feet)
Pole Class
1 2 3 4 5 6 7
Minimum top diameter (inches)
8.8 8.1 7.5 6.9 6.2 5.6 5.0
Minimum diameter six feet from butt (inches)
16 -- -- -- -- -- 7.2 6.8
18 -- -- -- -- -- 7.7 7.2
20 -- -- -- -- -- 8.0 7.5
25 -- -- -- 10.8 10.0 9.0 8.2
30 -- -- -- 11.4 10.6 9.7 9.0
35 -- -- 13.0 12.1 11.3 10.4 9.6
40 15.6 14.6 13.6 12.8 11.9 11.0 --
45 16.4 15.3 14.2 13.4 12.4 11.5 --
50 17.1 16.0 14.8 14.0 12.9 -- --
55 17.7 16.6 15.4 14.5 13.5 -- --
60 18.2 17.2 16.0 15.0 13.9 -- --
*Diameters to the nearest one-tenth inch obtained by converting circumference specifications, assuming all poles to be round.

Manufacturing Requirements
Bark Removal
Outer bark shall be completely removed from all poles. On all poles, no patch of inner bark more than 1 inch wide shall be left on the pole surface between the butt and 2 ft below the ground line. On poles that are to be given full-length treatment, no patch of inner bark larger than 1 inch wide and 6 inches long shall be left on the pole surface between the top and 2 ft below the ground line. On poles that are to be butt treated, no patch of inner bark larger than 1 inch wide and 6 ft long shall be left on the pole surface between point 1 ft above and 2 ft below ground line.

All poles shall be neatly sawed at the top and the butt along a plane which shall not be out of square with the axis of the pole by more than 2 inches per foot of diameter of the sawed surface. Beveling at the edge of the sawed butt surface not more than 1/12 the butt diameter in width or an equivalent area unsymmetrically located is permitted.

Completely overgrown knots, rising more than 1 inch above the pole surface, branch stubs, and partially overgrown knots shall be trimmed close. Completely overgrown knots less than 1 inch high need not be trimmed. Trimming may be done by shaving machine or by hand.

If shaving is used, the depth of cut shall not be more than necessary to remove inner bark and to trim smoothly and closely all branch stubs and overgrown knots. There shall be no abrupt change in the contour of the pole surface between the ground line and the above ground sections. The lower 2 ft of poles may be trimmed to remove wood fibers causing butt flare, provided sufficient sapwood remains to obtain the customer's minimum penetration requirement.

Marking and Code Letters
The following information shall be burn-branded legibly and permanently on the face and the butt of each pole or included on a metal tag affixed thereto.
1.The supplier's code or trademark.
2.The plant location and year of treatment.
3.Code letters denoting the pole species and preservative used.
4.The true circumference-class numeral and numerals showing the length of the pole.

Metal tags (noncorrosive) attached to the butt of the pole shall be securely affixed to serve the intended purpose.

Storage and Handling
When it is necessary to hold poles in storage, they shall be stacked on treated or other non-decaying skids of such dimensions, and so arranged as to support the poles without producing noticeable distortion of any of them. The height of the piles shall be limited to avoid damage to poles on the bottom layers.
Poles shall be piled and supported in such a manner that all poles are at least 1 ft above the general ground level and any vegetation growing on it. No decayed or decaying wood shall be permitted to remain underneath stored piles.

Poles shall not be dragged along the ground. Cant hooks, pole tongs or other pointed tools shall not be applied to the ground line section of any pole.

Mechanical Damage
Poles are not acceptable if they contain indentations attributed to loading or handling slings that are 1/4 inch or more deep over 20% or more of the pole circumference, or more than 1/2 inch deep at any point. Other indentations or abrasions, for example, fork lift damage, chain-saw damage, etc. shall not be more than 1/10 the pole diameter at the point of damage up to a maximum of 1 inch. Such damage is permitted in an oversized section, where the excess of wood shall be taken into consideration in evaluating the effects of the damage. In any case, the circumference for a given class is still required to be not less than specification minimum.

Definitions of Terms
The following definitions shall apply to the terms used in this standard.
Check. The lengthwise separation of the wood that usually extends across the rings of annual growth and commonly results from stresses set up in wood during seasoning.
Compression Wood. Abnormal wood formed on the lower side of branches and inclined trunks of softwood trees. Compression wood is identified by (1) its relatively wide annual rings, usually eccentric; (2) relatively large amount of summerwood, sometimes more than 50% of the width of the annual rings in which it occurs; and (3) its lack of demarcation between springwood and summerwood in the same annual rings. Compression wood, compared with normal wood, shrinks excessively lengthwise.
Cross Break. A separation of the wood cells across the grain. Such breaks may be due to internal strains resulting from unequal longitudinal shrinkage or to external forces.
Dead Streak. An area, devoid of bark, resulting from progressive destruction of the growth cells of wood and bark at the edges of the streak. On a pole, a dead streak is characterized by a discolored weathered appearance and by lack of evidence of overgrowth along the edges of the deadened surface.
Decay. The decomposition of wood substance by fungi.
Decay, advanced (or typical). The older stage of decay in which the destruction is readily recognized because the wood has become punky, soft and spongy, stringy, ring-shaked, pitted, crumbly or, in poles not stored or rafted in water, is in a soggy condition. Decided discoloration or bleaching of the rotted wood is often apparent.
Decay, incipient. The early state of decay that has not proceeded far enough to soften or otherwise perceptibly impair the hardness of the wood. It is usually accompanied by a slight discoloration or bleaching of the wood.
Decayed Knot. A knot containing decay. Two types of decayed knot are recognized.
Type I--Knots containing soft or loose fibers (decay) which may extend the full length of the knot into the pole and which are associated with heart rot.
Type II--Knots containing soft or loose fibers (decay) which are not associated with heart rot.
Face of Pole. The concave side of greatest curvature in poles with sweep in one plane and one direction, or the side of greatest curvature between ground line and top in poles having reverse or double sweep.
Groundline Section. That portion of a pole between 1 ft above and 2 ft below the ground line, as defined in the pole dimension tables.
Hollow Heart. A void in the heartwood caused by decay or insect attack.
Hollow Pith Center. A small hole at the pith center of the trunk or of a knot caused by disintegration of the pith (small soft core occurring in the structural center of a tree or branch).
Insect Damage. Damage resulting from the boring into the pole by insects or insect larvae. Scoring or channeling of the pole surface is not classed as insect damage.
Kiln Drying. Drying by the use of heated air in batch or progressive-type kilns.
Knot Diameter. The diameter of a knot on the surface of the pole measured in a direction at right angles to the lengthwise axis of the pole. The sapwood as well as the heartwood portion of a knot shall be included in the measurement.
Red Heart. A condition caused by a fungus, Fomes pini, that occurs in the living tree. It is characterized in the early stages of infection by a reddish or brownish color in the heartwood (known as "firm red heart"). Later the wood of the living tree disintegrates (decays) in small, usually distinct, areas that develop into white-lined pockets.
Sap Stain. A discoloration of the sapwood, caused by the action of certain molds and fungi, that is not accompanied by softening or other disintegration of the wood.
Scar. A depression in the pole's surface resulting from a wound where healing has not reestablished the pole's normal cross section.
Scar, Turpentine Acid Face. An area in the lower portion of a southern pine pole where bark hack removal with acid applied has caused resin to flow. No removal of sapwood has occurred.
Scar, Turpentine Cat Face. A depression in the surface of a southern pine pole resulting from a wood hack into the sapwood, where healing has not reestablished the pole's normal cross section.
Shake. A separation along the grain, the greater part of which occurs between the rings of annual growth.
Short Crook. A localized deviation from straightness which, within any section 5 ft long or less, is more than 1/2 the mean diameter of the crooked section.
Spiral-grained (twist-grained) Wood. Wood in which the fibers take a spiral course about the trunk of a tree instead of a vertical course. The spiral may extend in a right-handed or left-handed direction around the tree trunk. Spiral grain is a form of cross grain.
Split. A lengthwise separation of the wood due to the tearing apart of the wood cells.
Steam Conditioning. Subjecting poles in a closed vessel to steam prior to treatment.
Sweep. Deviation of a pole from straightness.

Appendix B
Grading Bourbon Stave and Heading Bolts
All bolts must be split from live, sound, straight-grained White Oak timber (preferably 16 to 20 inches in diameter) and must be free of all defects, such as knots, heart checks, bird pecks, streaks, shake, cat faces, worm holes, water soak, bows or crooks.

(Figure 18)

Requirements for Stave Bolts
No. 1 stave bolts must square up 5 inches of heartwood and measure 39 inches long.
No. 2 stave bolts include all bolts not squaring 5 inches of redwood and with a minimum of 5 1/2 inches of redwood from sap to apex.

(Figure 19)
(Figure 20)

Requirements for Heading Bolts
No. 1 heading bolts must be 15 to 18 inches from corner to comer, and 8 inches deep from heart to sap.
No. 2 heading bolts must be 11 to 15 inches from corner to corner, and a minimum of 6 1/2 inches from heart to sap.

Rules for Inspections of Bourbon Stave Bolts
Bolts must be split from sound straight-grained White Oak timber and must be free from all defects, such as knots, heart checks, bird pecks, streaks, shake, cat faces, worm holes, water soak, bows or crooks.
Green bolts must have the following dimensions: 39 inches long, 5 inches to 8 inches wide from heart to sap.
Bolts must average 6 inches deep and can be 5 inches to 8 inches deep clear of sap.
Bolts will be measured in ricks 4 ft high and 8 ft long.

Rules for Inspection of Bourbon Heading Bolts
Bolts must be split from sound, straight-grained White Oak timber 20 inches and up, and must be free from all defects, such as knots, heart checks, bird pecks, streaks, shake, cat faces, worm holes, water soak, bows or crooks.
Green bolts must have the following dimensions: 23 inches long, 6 inches and wider from heart to sap.
Bolts must average 8 inches deep, and can be 6 inches and deeper clear of sap.
Bolts will be measured in ricks 4 ft high and 8 ft long.

(Figure 21)
(Figure 22)
(Figure 23)