Ala. Admin. Code r. 480-3-4-.18

Current through Register Vol. 43, No. 1, October 31, 2024

Section 480-3-4-.18 - Blasting (General)

(1) All blasting including blasting of boulders shall be done at the end of the shift, except that blasting may be done during the shift if blasting houses are provided and used for the protection of shot firers and other persons in the quarry; these houses shall be built of timbers not less than 7" x 9", or equivalent, erected a safe distance from any point where blasting is done.

(2) All blasting should be done electrically or with detonating fuse.

(3) Primers

(a) Primers shall be made up near the working place by competent men experienced in handling explosives. Such persons shall also load, assist in loading or supervise the loading or charging of drill holes.

(b) Primers should be prepared by inserting the detonator in the side of the cartridge and making one or more half hitches around the cartridge with the fuse, or by inserting the detonator in the side or end of the cartridge and tying the fuse to the cartridge. Holes made in the primer cartridge for the purpose of inserting the detonator shall be made with a wooden or soft metal skewer.

(4) Tamping

(a) In tamping holes only a wooden tamping bar, or block having no exposed metal parts shall be used. Before charging drill holes, except well holes, they shall be thoroughly cleaned. Explosives shall not be violently tamped in the drill hole, but may be firmly charged, except that undue pressure shall not be used against the primer cartridge when placing it in the drill hole. The primer cartridge shall not be slit.

(5) Explosives

(a) Explosives shall not be brought to the working place more than one hour before charging operations begin and shall be kept in a place safe from danger of ignition or detonation by electrical wiring, mechanical equipment or loose rock.

(6) Stemming

(a) When a drill hole has been charged with explosives, it shall be filled to the collar with stemmings material, as nearly free from rock or grit as practical. Rock dust, free running sand or moist sand, clay or loam is recommended. The stemming material shall be well tamped. For well drilled holes stone screenings of 1/4 inch and down are recommended.

(6) Charging

(a) No charging operations shall be carried on in working places where rock falling from the face or rolling rock is likely to endanger the charging operations. Working places shall be made safe for charging operations before charging is begun. Charging of explosives shall only be done at a safe distance from drilling and loading operations.

(b) Fuse igniters of the "hot wire" type or punk or their equivalent shall be used for igniting safety fuse.

(c) Mis-fires shall be reported to the quarry or pit foreman, and no person shall return to the vicinity of the suspected mis-fire until thirty (30) minutes has elapsed in the case of fuse blasting and until fifteen (15) minutes has elapsed in the case of electrical blasting. No regular quarry or pit operations shall be conducted in the area of a known mis-fired hole. Mis-fires, (except in the case of well holes), shall be reblasted by inserting a new primer in drill hole. In such case stemming or tamping material may be washed from the drill hole with water before inserting the new primer.

(7) Mis-fires

(a) If not possible or safe to insert a new primer, a new hole may be drilled under the personal supervision of the pit or quarry foreman, and such hole shall be started not less than 2 feet from the original drill hole and shall be drilled at such an angle as to eliminate all danger of meeting or coming closer than 2 feet of the original drill hole. In the case of sprung holes the new drill hole shall be placed and carried at such an angle that there will be no possibility of its meeting any part of the mis-fire charge, provided that, in case of a mis-fired well drilled hole it shall not be disturbed nor any attempt made to fire it without permission of the superintendent or quarry foreman.

(b) If explosives are found in "bootlegs" or "guns," they shall be treated as misfired shots. All pit or quarry operations in any working place shall be alerted if explosive is found in the muck pile, and such work shall be continued with caution until there is reasonable certainty that all of the unexploded powder in the muck pile has been recovered.

Such recovered explosive shall be removed and destroyed, following procedure recommended by the explosive manufacturers. Any left over explosive, capped fuse, or detonators, remaining after charging the drill holes, shall be returned to the distributing magazine.

(c) Boulders which must be broken by blasting, shall be block-holed and "adobe," "plaster" or "mud-capped" shots shall be prohibited, except that such shots may be permitted where no means of drilling such boulders is available, provided that they shall then be fired under supervision of the pit or quarry foreman or his assistant.

(d) All electric power within an unsafe distance of the place to be blasted shall be cut off during loading of holes.

(8) Springing

(a) Where drill holes are sprung, the temperature of the chamber shall be determined before placing the final charge and no hole shall be loaded with the final charge until the chamber has been cooled to 800^ F. No drill holes shall be sprung when adjacent to a loaded sprung hole.

(b) Cartridges shall not be forced into drill holes. Cartridges shall be placed in drill holes in the original wrapper.

(9) Detonator Strength

(a) Where detonators are used, nothing less than number 6 detonators or electric detonators shall be used to explode charges.

Author: Department of Industrial Relations

Ala. Admin. Code r. 480-3-4-.18

Prior to October 1, 1982, this regulation was designated as General Rule 18.

Statutory Authority:Code of Ala. 1975, § 25-2-2(3)