WAC 296-52-67090
Initiation systems. (1) General
initiation rules.
(a) Training and supervision.
(i) The blaster in charge must provide adequate
on-the-job training and supervision in the safe use of
initiation systems.
(ii) All members of the blasting crew must be instructed,
by the blaster in charge, in the safe use of the initiation
system to be used and its system components.
(b) Manufacturer recommendations. All initiation systems
and system components must be used in accordance with
manufacturer recommendations and instructions.
(c) Vehicle use precautions.
(i) Explosives bulk trucks or other vehicles operated on
a blast site cannot tread on:
(A) Tubing
(B) Connectors
OR
(C) Any surface delay component
(ii) If a vehicle must pass over loaded blast holes.
Precautions must be made to consolidate tubing, connectors, or
any surface delay component at the collar of the hole to
prevent vehicle contact.
(d) Connecting the firing line. Firing lines cannot be
connected to the blast initiating device until all personnel
are:
(i) Accounted for
(ii) Removed from the blast danger area
OR
Are in a blast shelter or other location that provides
equivalent protection
(e) Visual inspection. The blaster in charge must
visually inspect the initiation system to make sure it is
assembled according to the manufacturer's recommendations,
before firing the shot.
(f) Explosives not used:
(i) Unused detonators or short capped fuses cannot be
placed in holes that may be used for blasting.
(ii) Unused detonators must be removed from the work area
and disposed of or stored in a licensed magazine.
(iii) Loose cartridges of explosives, detonators,
primers, and capped fuses that are not used by the end of the
work shift must be returned to and locked in their magazines.
(2) Nonelectric initiation systems.
(a) Shock tube lines. When a nonelectric shock tube
initiation system is used:
(i) Spools of shock tube lines cannot be spooled from
trucks or equipment.
(ii) The shock tube line must:
(A) Be free of knots and tight kinks
(B) Be free of cuts or abrasions that could expose the
core to moisture
(C) Not be stretched
(D) Be neat and orderly
(iii) Tie ins must be kept neat and clean.
(iv) Unused lead line must be sealed to prevent moisture
and dirt from entering the tube.
(v) Care must be taken to avoid hitting the tube with a
shovel when the shock tube is being covered.
(vi) The end of the detonator must be pointed toward the
front of the shot to minimize the chance of shrapnel flying to
the rear of the blast where the shock tube will be lit.
(i) Be secured properly in surface connector blocks.
(ii) Never exceed the rated capacity of tubes in surface
connector blocks.
(c) Splicing line. A knot must be tied in the tubes to
take the strain off of the splice.
(d) Detonator cord. If a detonator cord is used for
surface tie in:
(i) All lines must be kept taut.
(ii) Connections to nonelectrical units must be at ninety
degree angles.
(e) Equipment and personnel.
(i) Equipment cannot roll over shock tubes.
(ii) All unnecessary equipment and personnel must be
removed from the blast area during loading.
(3) Electric initiating systems.
(a) Survey of extraneous currents. A survey to evaluate
extraneous currents must be conducted:
(i) By the blaster in charge before adopting any system
of electrical firing.
(ii) To eliminate all currents before holes are loaded.
(b) Detonator compatibility, style, function, and
manufacture. In any single blast using electric detonators,
all detonators must be:
(i) Compatible with each other.
(ii) Of the same style or function.
(iii) From the same manufacturer.
(c) Wire capacity and gauge.
(i) Connecting wires and lead wires must:
(A) Be insulated single solid wires with sufficient
current carrying capacity
(B) Not be less than twenty gauge (American wire gauge)
solid core insulated wire
(ii) Firing line or lead wires must:
(A) Be made of solid single wires with sufficient current
carrying capacity
(B) Not be less than fourteen gauge (American wire gauge)
solid core insulated wire
Note:
Bus wires, depends on the size of the blast, fourteen gauge (American wire gauge) copper is recommended.
(d) Lead wires.
(i) Shunting. You must shunt the ends of lead wires that
will be connected to a firing device by twisting them together
before they are connected to leg or connecting wires.
(ii) Control. The blaster in charge must keep control of
shunted lead wires until loading is completed and the leg
wires are attached.
(iii) Attachment. Lead wires must be attached by the
blaster in charge when it is time to fire the shot.
(e) Detonator leg wires. Electric detonator leg wires
must:
(i) Be kept shunted (short circuited) until they are
connected into the circuit for firing.
(ii) Not be separated (except for testing) until all
holes are loaded and the loader is ready to connect the leg
wires to the connecting or lead wires.
(f) Circuits.
(i) Blasting circuits or power circuits must be used in
electric blasting and according to the electric detonator
manufacturer's recommendations.
(ii) Care must be taken to make sure an adequate quantity
of delivered current is available according to the
manufacturer's recommendations, when firing a circuit of
electric detonators.
(iii) A power circuit used for firing electric detonators
cannot be grounded.
(iv) The firing switch must be designed so the firing
lines to the detonator circuit automatically short circuit
when the switch is in the "off" position.
(v) The firing switch must be locked in the "open" or
"off" position at all times, except when firing from a power
circuit.
(g) Firing line insulation. The insulation on all firing
lines must be adequate and in good condition when firing
electrically.
(h) Testing.
(i) The firing line must be checked at the terminals with
an approved testing device before being connected to the
blasting machine or other power sources.
(ii) The circuit, including all detonators, must be
tested with an approved testing device before being connected
to the firing line.
(i) Switch keys. The blaster in charge is the only
person who is allowed to have firing switch keys in their
possession.
(j) Blasting machines. A nonelectric system must be used
if these requirements cannot be satisfied:
(i) Blasting machines must be in good condition.
(ii) The efficiency of the blasting machine must be
tested periodically to make sure it delivers power at its
rated capacity.
(iii) Responsible person.
• The blaster in charge must be in charge of blasting
machines
• The blaster in charge must connect the lead wires to
the blasting machine and must fire the shot
(iv) Connections.
• When firing with blasting machines, connections must be
made according to the manufacturer of the electric detonator's
recommendations
• All connections must be made from the drill hole back
to the source of the firing current
• Lead wires must remain shunted and not connected to the
blasting machine or other source of current until the charge
is ready to fire
• The number of electric detonators connected to a
blasting machine cannot exceed the blasting machine's rated
capacity
(v) Series circuit. In primary blasting, a series
circuit cannot contain more detonators than the manufacturer's
recommended limits for electric detonators.
(vi) Circuit testing. A blaster in charge must use
blasting testers specifically designed to test circuits to
charged holes.
(vii) Blasting near power lines. Whenever lead or
blasting wires could be thrown over live overhead powerlines,
communication lines, utility services, or other services or
structures by the force of an explosion, care must be taken to
make sure:
(A) The total length of wires are short enough so they
will not hit the lines
(B) The wires are securely anchored to the ground
(C) The owners or operators of the utilities in the blast
area are notified
(viii) Disconnecting lead wires. After firing an
electric blast from a blasting machine, lead wires must be
immediately disconnected from the machine and short-circuited.