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

The penetration per blow will be 2
40 or .05 feet; and the formula for the second case

(1000
1000 + 500)² × 500 × 6
.05 = 48,000 lbs.

Of which one tenth or one twelfth only is the maximum load which should be placed upon the pile permanently. The surest test of the power of a pile is to load it temporarily, when the time and place admit.

Perronet considered fifty tons, or 112,000 lbs. as not too great for a twelve inch pile; and allowed twenty-five tons for a pile of nine inches in diameter.

That the point of the pile may not be shattered by contact with the hard earth, an iron shoe is sometimes fitted to the lower end; and that the head may not split, an iron ring is driven on to the top.

The force of the blow given by a ram depends upon the weight of the ram or monkey, and upon the velocity at which it strikes the pile; the velocity depends upon the height from which it falls. The velocities of bodies falling freely being as the times, and the spaces fallen through as the squares of the times, we have the following rules; and from them the table succeeding.

Given the velocity of a body to find the space through which it must fall,

(Velocity in feet per second
8)² = space in feet.

Thus a weight to acquire a velocity of two hundred feet per second, must fall through a height of

(200
8)² = 625 feet.