CORDAGE.
Ropes, cables, and all other descriptions of cordage are distinguished by their circumference, thus a two-inch rope means a rope two inches in circumference.
To find the weight of a rope.
First method.—Multiply the length in fathoms by the square of the circumference, and divide the product by 480 for the weight in cwts.
Example.—Required the weight of 110 fathoms of 3-inch rope.
3 × 3 × 110 = 990, which divided by 480, gives 2 cwt. 7 lb. Weight required.
Second method.—Divide the square of the circumference by 4, the quotient will give the weight, in pounds, per fathom.
Example.—What is the weight of a 3-inch rope per fathom?
32 ÷ 4 = 2¼ lb. Weight required.