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 Span being	150	feet,
The Rise	20	feet,
The Panel	15	feet,
Weight per foot of bridge and load	3,000	lbs.

The half number of panels is five; the diagonals of which, neglecting fractions, are

√20² + 15² = 25 feet,

√20² + 30² = 37 feet,

√20² + 45² = 49 feet,

√20² + 60² = 64 feet,

√20² + 75² = 78 feet.

The weight upon each of these sets of braces, is the weight of the length of one panel; which, in the present case, is 3,000 × 15 = 45,000 lbs. As there is a brace under each chord stick, and assuming four sticks in each chord, we divide by eight, and have, in round numbers, 6,000 lbs. per brace; and correcting for inclination, as follows, we have the numbers below.

20 : 25 :: 6000 : 10000

20 : 37 :: 6000 : 15000