BUMPING POST FOR RAILWAY TRACKS.
The post is a 15-in. steel I-beam, resting on a base plate 3⁄4-in. thick, and supported by anchor rods 13⁄4 ins. diameter, with upset ends held by nuts on a heavy forging bolted to the top of the post. These rods extend forward and outward to clear the rails, and then pass vertically through a 4 × 6-in. angle iron crosstie, and an ordinary wooden tie, extending down to an anchor block or deadman buried in the ground 61⁄2 ft. below the top of the rail.
Vertical braces or spreaders are fitted between the anchor timber and a longitudinal timber under the ties, so as to prevent the loosening of the anchor rods when the post is struck. The rods are held in position against the rails by steel forgings bolted to the rail with 1-in. turned bolts. An oak striking block, 12 × 12 ins., 3 ft. long, is bolted between angle iron brackets on the face of the post.
Fig. 290.
Front View.
Fig. 291.
Side View.
Scale, 3 in. = 1 ft.
To Read Working Drawings.
One of the advantages resulting from a knowledge of practical draughting is, that it enables a mechanic to read a drawing when given him as a guide for his work. It is getting every day more general among draughtsmen to figure exactly and minutely every part of their drawings which are made to a scale.
Drawings are almost always made “finished size,” that is, the dimensions are for the work when it is completed. Consequently all the figures written on the different parts indicate the exact size of the work when finished, without any regard to the size of the drawing itself, which may be made to any reduced and convenient scale.