Handbook of Railroad Construction; For the use of American engineers. / Containing the necessary rules, tables, and formulæ for the location, construction, equipment, and management of railroads, as built in the United States.

by George L. Vose

BALLASTING.

Where gravel is used for the ballasting of the road-bed, it shall be of a quality satisfactory to the engineer, and shall be spread upon the road-bed to the width and depth required. When broken stone is used, it shall be of durable quality, and shall be broken so as to pass through a ring of three inches in diameter. The quantity will be measured in the road-bed as finished, and the contractor will be required to keep the ditches trimmed and clear.

RIP-RAP, OR RUBBLE SLOPES.

The first party shall distribute rubble stone over the slopes of earth embankments, whenever required to do so, to protect said slopes from the action of water. Such stone to be arranged by competent hands, and laid to such thickness, and with stones of such size, as shall be directed. Where the contractor has rock in the neighboring cuttings which is available, it shall be reserved and applied to this purpose; and when not, good rock shall be obtained where the contractor can conveniently get it.

MEASUREMENTS.

All earth or rock necessarily moved to complete the grading of this contract according to direction, will be measured in excavation only; and if the contractor (with the consent of the engineer,) should find it convenient to waste earth from an excavation, instead of carrying it to its proper embankment, and to borrow at some nearer point earth for said embankment to replace that which was wasted, he shall be paid for the earth from the original excavation in the order of its most economical arrangement for the second parties. All earth moved from borrowing pits shall also be measured in excavation only.

78. Specification for Masonry.

FIRST CLASS MASONRY.

First class masonry will apply to bridge abutments exceeding twenty-five feet in height, to the ring stones of arches, and to the piers of bridges in running water. The stone shall be laid at the rate of one header to two stretchers, disposed so as to make efficient bond. No header to be less than forty inches long, and no stretcher to be less than eighteen inches in width. No stone less than twelve inches in thickness, no stone to have a greater height than width, all stones to be placed upon the natural bed. The masonry throughout to have hammer dressed beds and joints. Vertical joints to be continued back at least ten inches from the face of the wall. The mortar joints on the face not to exceed one fourth of an inch in thickness. The stone to be laid with regard to breaking joints in the adjoining courses. The stone must be dressed complete before laying, and not be moved after being placed in the mortar. The face will not be tooled, but only roughly hewed, except for one half inch from the beds and joints, where it will be hammered. The ring stones of arches shall have beds to conform to the radius of the arch, with the end joints vertical, and be made to set smoothly on the centering, with the beds with the proper inclination. Each stone must extend through the whole thickness of the arch, and not be less than eight inches thick on the intrados. No spawls or pinners will be admitted. The ring stone shall be dimension work, according to the plans furnished, the beds and joints being truly dressed, but the faces left rough.

All first class work shall be carefully laid in good cement mortar, (see Art. Cement). Each stone before being laid shall be carefully cleaned and moistened; and masonry built in hot weather shall be protected from the sun as fast as laid, by covering with boards. Copings shall be built of stone of equal thickness, neatly dressed and laid.