This section is from the book "Elementary Principles Carpentry", by Thomas Tredgold. Also available from Amazon: Elementary Principles Of Carpentry.
131. The rules for beams fixed at one end and loaded at the other are precisely the same as those for beams supported at both ends, except that a different constant number must be used; viz. the constant d in the following Table, or the constant number c for beams supported at both ends must be divided by 4. If the weight be uniformly diffused over the length, the beam will bear double the weight that would break it when applied in the middle.
Kind of Wood. | Specific gravity. | Length in feet. | Breadth in inches. | Depth in inches. | Deflection at the time of fracture in inches. | Weight that broke the piece in lbs. | Values of constant d. | Experimentalist. |
English oak........... | .922 | 4 | 2 | 2 | .. | 266 | 133 | Beaufoy. |
" ...... | .. | 4 | 2 | 2 | .. | 210 | 105 | " |
Dantzic oak........... | .854 | 4 | 2 | 2 | .. | 196 | 98 | " |
Beech................... | .700 | 3 | 2 | 2 | 11 | 401 | 150 | Barlow. |
" ............. | .740 | 2 | 1 | 2 | 5 | 352 | 176 | " |
Ash ................... | .658 | 3 | 2 | 2 | 11 1/2 | 436 | 163 | " |
" ................... | .730 | 2 | 1 | 2 | 6 | 321 | 160 | " |
" green ........... | .858 | 5 | 2 | 2 | 16 | 239 | 149 | Peake and Barrallier. |
Teak, old, dry .. | .606 | 5 | 2 | 2 | 12 1/2 | 257 | 161 | " |
Dantzic fir, wet | .648 | 5 | 2 | 2 | 12 1/2 | 157 | 97 | " |
Riga fir ........... | .537 | 4 | 2 | 2 | .. | 210 | 105 | Beaufoy. |
" dry ........... | .633 | 5 | 2 | 2 | 14 | 153 | 93 | Peake and Barrallier. |
" dry ............ | .636 | 2 | 3 | 3 | .. | 1974 | 146 | |
Red pine .............. | .589 | 2 | 3 | 3 | .. | 1753 | 129 | " |
Virginian yellow pine .. .. | .522 | 5 | 2 | 2 | 11 3/4 | 147 | 92 | Peake and Barrallier. |
Canadian white pine .. .. | .618 | 5 | 2 | 2 | 18 3/4 | 122 | 76 | " |
Pitch pine.............. | ... | 4 | 2 | 2 | ... | 270 | 135 | Beaufoy. |
Larch, dry ............ | .526 | 5 | 2 | 2 | 16 1/4 | 162 | 101 | Peake and Barrallier. |
American spruce | .537 | 2 | 3 | 3 | 2 | 1652 | 122 | Fincham. |
Kowrie (N. Zea-land) .. .. | .629 | 2 | 3 | 3 | ... | 2044 | 151 | " |
Saul (India) ..... | .880 | ... | ... | ... | ... | .. | 220 | Skinner. |
 
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