This corresponds to a working pull of 33 and 66 lbs. per inch of width respectively.

Example.—What width double belt will be required to transmit 50 horse power travelling at a speed of 3,000 feet per minute?

The horse power transmitted by each inch width of double belt travelling at the stated speed is

( 1 × 3,000 / 1,000 ) × 2 = 6,

hence the width of belt required to transmit 50 horse power is

50 ÷ 6 = 8.33, say 8 inches.

Ques. At what velocity should a belt be run?

Ans. At from 3,000 to 5,000 feet per minute.

Ques. How may the greatest amount of power transmitting capacity be obtained from belts?

Ans. By covering the pulleys with leather.