Spike-pulling tests apply to problems of railroad maintenance, and the results are used to compare the spike-holding powers of various woods, both untreated and treated with different preservatives, and the efficiency of various forms of spikes. Special tests are also made in which the spike is subjected to a transverse load applied repetitively by a blow.
For details of tests and results see:
| Cir. 38, | U.S.F.S.: | Instructions to engineers of timber tests, p. 26. | ||
| Cir. 46, | U.S.F.S.: | Holding force of railroad spikes in wooden ties. | ||
| Bul. 118, | U.S.F.S.: | Prolonging the life of cross-ties, pp. 37-40. |
Packing Boxes
Special tests on the strength of packing boxes of various woods have been made by the U.S. Forest Service to determine the merits of different kinds of woods as box material with the view of substituting new kinds for the more expensive ones now in use. The methods of tests consisted in applying a load along the diagonal of a box, an action similar to that which occurs when a box is dropped on one of its corners. The load was measured at each one-fourth inch in deflection, and notes were made of the primary and subsequent failures.
For details of tests and results, see:
| Cir. 47, | U.S.F.S.: | Strength of packing boxes of various woods. | ||
| Cir. 214, | U.S.F.S.: | Tests of packing boxes of various forms. |