Pennsylvania Code › Title 34 - LABOR AND INDUSTRY › Part I - Department of Labor and Industry › Chapter 43 - TUNNEL CONSTRUCTION AND COMPRESSED AIR WORK › Subchapter A - TUNNEL CONSTRUCTION AND WORK IN COMPRESSED AIR › TUNNEL CONSTRUCTION › Section 43.26 - Blasting

Current through Register Vol. 54, No. 28, July 13, 2024
(a) There shall be
					 one blaster in charge of blasting in each section.
(b) No one who has not received a permit from
					 the Department shall be employed as a blaster anywhere within the jurisdiction
					 of the Department.
(c) The
					 explosives used shall be such as to cause the least amount of injurious
					 gases.
(d) No blaster shall attempt
					 to use any frozen dynamite. No quantity greater than is sufficient for daily
					 use shall be artificially thawed at one time. Only approved methods of thawing
					 shall be permitted.
(e) Except in
					 cases of instantaneous blasting by electricity, a blaster shall count the
					 number of shots exploding when he fires a round of holes. If there are any
					 misfires, he shall remain until the misfires have been exploded or holes made
					 safe.
(f) If a fuse is used,
					 misfires shall not be approached, even for purposes of inspection, until three
					 hours have elapsed. If electric blasting caps are used, misfires shall not be
					 approached, even for purposes of inspection, until 15 minutes have
					 elapsed.
(g) Whenever feasible, a
					 charge that has failed to explode shall be exploded by inserting a new primer
					 in the hold on the old charge and detonating the primer.
(h) The blaster shall use only hardwood rods
					 for tamping. He shall not tamp or load any hole with a metal bar, nor shall the
					 wooden rod have any metal parts.
(i) Firing shall be done by safety fuse or
					 approved battery or from an electric current of not over 250 volts, if an
					 approved switch is used. Other methods of firing may be permitted upon approval
					 by the Department.
(j) When firing
					 by electricity from power or lighting wires in any tunnel, an approved switch
					 shall be furnished with the lever down when in the "off" position. The switch
					 shall be fixed in a locked box, to which no person shall have access except the
					 blaster. There shall be flexible leads of connecting wires at least five feet
					 in length with one end attached to the incoming lines and the other end
					 provided with plugs that may be connected to the switch on the inside
					 shot-firing circuit when firing and that shall at all times be connected to an
					 effective ground. After blasting, the switch lever shall be pulled out, the
					 wires disconnected and the box locked before any person shall be allowed to
					 return, and shall remain locked until again ready to blast. Blasting wires
					 shall be laid on the opposite side of the tunnel from the lighting and power
					 wires.
(k) Before the loading of
					 holes, all powerlines and electric light wires shall be disconnected at a point
					 outside the blasting switch. After explosives are taken in, preparatory to
					 blasting, no current by grounding of power or bonded rails shall be allowed
					 beyond the blasting switch. Under no circumstances shall ground current be used
					 for exploding blasts.
(l) The
					 blaster shall cause a sufficient warning to be sounded and shall be responsible
					 to see that all persons retreat to safe shelter before he sets off the blast,
					 and shall also see that no one returns until he reports it safe. He shall
					 report to the tunnel foreman and furnish names of all persons refusing to obey
					 his caution.
(m) No person shall be
					 allowed to deepen holes that have previously contained explosives.
(n) All wires in broken rock shall be
					 carefully traced and a search made for unexploded cartridges.
(o) Whenever blasting is done at points
					 liable to break through to where other men are at work, the foreman or person
					 in charge shall, before any holes are loaded, give warning of danger to all
					 persons working where the blasts may break through, and he shall not allow any
					 holes to be charged until warning is acknowledged and the men are
					 removed.
(p) When testing circuits
					 through charged holes, blasters shall use sufficient leading wires to be at a
					 safe distance and shall use only approved types of galvanometers. No tests of
					 circuits in charged holes shall be made until men are removed to a safe
					 distance.
(q) No blasts shall be
					 fired with fuse in vertical or steep shafts.
(r) In shaft sinking where the electric
					 current is used for firing, a separate switch not controlling any electric
					 lights shall be used for blasting. Proper safeguards similar to those in
					 tunnels shall be followed in order to insure against premature
					 firing.