Vehicle and Implement Woods
Tests were made by the U.S. Forest Service to obtain a better knowledge of the mechanical properties of the woods at present used in the manufacture of vehicles and implements and of those which might be substituted for them. Tests were made upon the following materials: hickory buggy spokes ([see Fig. 5]); hickory and red oak buggy shafts; wagon tongues; Douglas fir and southern pine cultivator poles.
Details of the tests and results may be found in:
| Cir. 142, | U.S.F.S.: | Tests on vehicle and implement woods. |
Cross-arms
In tests by the U.S. Forest Service on cross-arms a special apparatus was devised in which the load was distributed along the arm as in actual practice. The load was applied by rods passing through the pinholes in the arms. Nuts on these rods pulled down on the wooden bearing-blocks shaped to fit the upper side of the arm. The lower ends of these rods were attached to a system of equalizing levers, so arranged that the load at each pinhole would be the same. In all the tests the load was applied vertically by means of the static machine.
| Cir. 204, | U.S.F.S.: | Strength tests of cross-arms. |