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July, 1917 THE MARINE REVIEW oe Table I Average Strength Values for Structural Timbers GREEN MATERIAL Taken from United States Forest Service Bulletin 108 Relative Relative Fiber strength stiffness —Knots in stringers tested— stress based on based on Vol. I Vol. Vol. IIil Weight at Modulus Modulus modulus modulus ; (See Fig. 14) Cross per elastic of of of of section No. Rings etft: limit rupture Elas- rupture. elasticity. Less 1% Less 1% Less 1% under of per Moisture oven- per per ticity Douglas Douglas than in. than in, than in. test. tests inch content. dry. sq.in, Sq. in. pers: fir==-100! fir == 100). 31% and 1% and 1% and Per sq. in. percent. percent. in. over ins Over in. over Species In. cent Lbs. Lbs. Lbs. lbs. Per cent Per cent Douglas fir 8xl6 134 10.9 31.8.4 28.9 4,282 6,605 1,611 100.0 100.0 1.2 0.5 17 O.7.- 7 1050 3.3 (132) (133) 12x12 Long- . 10x16 . leaf 8x16 13 14.6 29.2 35.4 3,855 6,437 1,466 97.4 91.0 0.4 O52 0.5 0.2 4.0 5 Geen as pine 6x16 (12) ‘ ; 6x10 Short- 8x16 z leaf 8x14 33 12.3 48.4 31.4 3,376 5,948 1,546 90.0 96.0 0.4 0.1 One Oik 2.4 1:2 pine 8x12 (31) (31) Western : hemlock 8x16 27 17;:6 41.9 28.1 3,761 5,821 1,489 S8ebes 92.4 0.7 0.7 P5 0.4 3.4 253 Loblolly 8x16 78 6.2 58.0 31.2 3,266 5,568 1,467 84.4 91.1 0.2 0.2 0.3 0.7 4.6 Be7. pine 5x12 (68) (55) (55) Western 8x16 : larch 8x12 43 23.9 50.5 28.7 3,677 5,562 1,364 84.2 84.6 0.9 0.2 2.3 0.6 10.9 i3 8x16. Redwood 6x12 30 1935 90.2 23.3 4,323 5,327 1,202 80.6 74.6 0.9 Od 2e 156 1.3 8.3 3.6 7x 9 Tamarack 6x12 11 16.7 56.9 fos ee 3,231 4,984 1,268 75:5 78.7 0.9 0.4 1.4 0.4 8.4 0.7 Norway, : . pine 6x12 11 13.2 52.1 252 2,897. 3,767 1,042 57.0 64.7 2.5 1.8 2.8 2.5 14.0 8.7 Note—Subscript numbers indicate number of tests when different from that shown in column “Number of Tests.”’ Table II Average Strength Values for Structural Timbers AIR-SEASONED MATERIAL : Taken from United States Forest Service Bulletin 108 Relative Relative Fiber . strength stiffness —Knots in stringers tested— stress : based on based on Vol. I . Vol. 11 - Vol. III Weight at Modulus Modulus modulus modulus (See Fig. 14) Cross per elastic of of of of ; section No. Rings Cinett: limit rupture Elas- rupture. elasticity. Less 1% Less 14% Less 1% under of per Moisture oven- per per ticity Douglas Douglas’ than in. than in. than bs eas test. tests inch content. dry. sq.in. sq.in. per fir=100 fr=100 1% and 1% ang) a and Per sq.in. percent. percent. in. “over in. over in. over Species In. cent Lbs. Lbs. Lbs. lbs. Per cent Per cent Douglas fir 8x16 64 15.2 20.9 Zhes 4,931 7,142 1,641 100.0 100.0 0.5 0.1 1.2 0.2. 12.1 0.9 Long- 8x16 leaf 6x16 Bd, 12:57, 21.6 38.6 3,793 5,957 1,720 83.6 104.8 None None None None None None pine 6x10 (6) : Short- 8x16 leaf 8x14 9 12.3 16.3 oat 5,186 7,033 1,782 98.5 108.6 None None 0.2 0.5 2.8 1.6 pine 8x12 ‘Western hemlock 8x16 31 17:5 Lid. 28.4 4,828 7,109 1.805 99.6 110.0 0.3 0.1 1.6 0.5 8.0 0.7 (30) (30) 8x16 s Loblolly 6x16 21 655 21s 33.4 3,706 6,259 152k 87.7 92.7 OUae Ad 0.4 0.8 2.8 3.4 pine 6x10 é : 8x 8 Western 8x16 : larch 8x12 36 23.0 18.2 29.8 3,904 6,534 1,561 91.5 95.1 1.8 0.3 3-2 0.6 19.4 1.6 8x16 % Redwood 6x12 12 18.1 173 2230 3,747 4,573 946 64.1 57.6 0.1 None 0.8 0.3 3.0 123 7x 9 (7) (7) ; Tamarack 6x12 4 16.6 23.4 30.8 3,643 5,865 1,385 82.3 84.4 1.8 None 0.8 None 18.0 0.5 Norwey pine 6x12 4 18 17.0 26.4 2,928 5.255 1,103 Toh 67.2 35 1:5 2.3 Oo 17S 9.3 Note—Subscript numbers indicate number of tests when different from that shown in column ‘‘Number of Tests.” Pc ee air eeainaeiSuED pease sl FSielGiesaeS See ID NTIS