| white | 3,880 | 5,970 | 1,131,000 | .77 | 5.2 | 14.9 | | Hemlock | 3,410 | 5,770 | 917,000 | .73 | 6.6 | 12.9 | | Pine, lodgepole | 3,080 | 5,130 | 1,015,000 | .54 | 5.1 | 7.4 | | longleaf | 5,090 | 8,630 | 1,662,000 | .88 | 8.1 | 34.8 | | red | 3,740 | 6,430 | 1,384,000 | .59 | 5.8 | 28.0 | | shortleaf | 4,360 | 7,710 | 1,395,000 | | | | | sugar | 3,330 | 5,270 | 966,000 | .66 | 5.0 | 11.6 | | west, yellow | 3,180 | 5,180 | 1,111,000 | .52 | 4.3 | 15.6 | | White | 3,410 | 5,310 | 1,073,000 | .62 | 5.9 | 13.3 | | Redwood | 4,530 | 6,560 | 1,024,000 | | | | | Spruce, | | | | | | | | Engelmann | 2,740 | 4,550 | 866,000 | .50 | 4.8 | 6.1 | | red | 3,440 | 5,820 | 1,143,000 | .62 | 6.0 | | | white | 3,160 | 5,200 | 968,000 | .58 | 6.6 | | | Tamarack | 4,200 | 7,170 | 1,236,000 | .84 | 7.2 | 30.0 | |-------------------------------------------------------------------------------------| _Kinds of Loads_ There are various ways in which beams are loaded, of which the following are the most important: (1) ~Uniform load~ occurs where the load is spread evenly over the beam. (2) ~Concentrated load~ occurs where the load is applied at single point or points. (3) ~Live~ or ~immediate load~ is one of momentary or short duration at any one point, such as occurs in crossing a bridge. (4) ~Dead~ or ~permanent load~ is one of constant and indeterminate duration, as books on a shelf. In the case of a bridge the weight of the structure itself is the dead load. All large beams support a uniform dead load consisting of their own weight. The effect of dead load on a wooden beam may be two or more times that produced by an immediate load of the same weight. Loads greater than the elastic limit are unsafe and will generally result in rupture if continued long enough. A beam may be considered safe under permanent load when the deflections diminish during equal successive periods of time. A continual increase in deflection indicates an unsafe load which is almost certain to rupture the beam eventually.