Pamphlet Volume 10-11 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1917 Excerpt: ...charges within I0 or l2 inches of the desired depth. The exact depth may be ascertained by trial shots. The greatest depth it is practicable to blast at one shot is about 6 feet. If a deeper ditch is wanted, blast a second time in the bottom of the first excavation. (See table on page 98 for depths for charges.) The blasting out of very large canals should proceed along these lines. They involve no principles not explained for the making of small ditches. A channel 35 feet wide and 6 feet deep that was excavated by blasting. The water has smoothed the sides a little, but in the main the big)ditch looks in the picture as it looked after the blast which opened it. The cost of such ditching can e figured accurately in advance when dimensions are known, the kind of soil and its condition considered, and the cost of explosions at hand. (Athens, Ga.) One line or row of charges frequently will make a ditch up to I0 feet wide and 6 feet deep. To make wider ditches use 2 or more rows. Usually 2 rows of charges will be needed for ditches between 8 and I2 feet wide if less than 4 to 6 feet deep, and 3 rows for ditches l2 to l8 feet wide. Wide Ditches The lines or rows of charges should be placed about 4 feet apart, except where the charges consist of more than 4 cartridges and are close together in the rows on account of transmitted detonation, when the rows may be as much as 6 feet apart. In blasting out very wide and shallow ditches or canals, it sometimes is of advantage to load 2 rows with light charges rather than to attempt to blast out cartridge loading tor very small ditch. Single-row loading for larze dnch--i lunr onol are nee ed, more row: of chargol. 06 the ditch to the required width with one row heavily loaded. The heavy charges might dig deeper tha...