513 EM 385-1-1 Chapters 23-29

Sections

29-8. General Requirements.

General Instructions

Obtain written permission from the USACE supervisor/KO or COR before bringing explosives to the jobsite. The Blaster-in-Charge must manage the transport, handling, storage, and use of explosives.
Display warning signs at access points to the blasting area and halt operations during thunderstorms or dust storms. Implement controls to prevent accidental discharge from extraneous electricity.
Notify operators/owners and take safety measures before blasting near overhead power lines or other structures. Use specific systems to detect and handle lightning or static electrical discharges.

Blasting and Detonation Procedures

The Blaster-in-Charge is responsible for directing and supervising all loading and firing activities. Use electric or non-electric blasting machines, and follow manufacturers' instructions for initiating blasts.
Utilize appropriate types of detonators and connectors for delayed blasts. After firing, immediately disconnect and lock the switches, and the Blaster must keep possession of the keys.
Ensure the use of insulated solid core wires and determine a safe distance for the blaster from the blast, considering various factors such as geology, blast pattern, and explosive material.

Blasting Machines

Operate, maintain, test, and inspect blasting machines as per manufacturer’s instructions. Secure the machines to limit access to the Blaster only.
Connect the firing line to the blasting machine or power source only when ready to fire, after checking with an approved blasting instrument.

Blasting Power Supply

Use a double-pole double-throw switch for the blasting switch, ensuring it's ungrounded, UL listed, enclosed, and can shunt the firing lines when open.
Install a grounded switch and a lightning gap of at least 15 feet (4.6 m) between the blasting and power switches. Use appropriate cable, plug, and receptacle for connections.

Storage of Explosives

Store explosives as per the ESSP on a DoD installation, or according to ATF P 5400.7 on a non-DoD installation.
Maintain two copies of an accurate running inventory of all explosives and blasting agents, one at the magazine and one in a separate facility at least 50 feet (15.2 m) away.

Knowledge Check Choose the best answer for the question.

29-6. After blasting, who must keep possession of the blasting keys?

A Qualified Person (QP)

The Blaster-in-Charge

The Blaster

The Blast Supervisor

You forgot to answer the question!

EM 385-1-1 Paragraph 29-8 (a.–d.).

29-8. General Requirements. (a.–d.).

a.  General. (29-8.a)

(1)  Prerequisites.  Obtain written permission from the USACE supervisor/KO or COR before bringing explosive materials onto the jobsite.  Periodic replenishment of previously approved supplies does not require re-approval.

(2)  A Blaster-in-Charge must oversee the transporting, handling, storing, and use of explosives, blasting agents, and blasting equipment.  Blasters must work under the supervision of the Blaster-in-Charge.

(3)  Provide warning signs at points of access to blasting area.

(4)  Discontinue operations involving the handling or use of explosive materials and move personnel to a safe area during the approach or progress of a thunderstorm or dust storm.  Establish and implement controls to prevent accidental discharge of electric blasting caps from extraneous electricity.

(5)  Do not perform blasting operations near overhead power lines, communications lines, utility services, or other structures until the operators and/or owners have been notified and measures for safe control have been taken.

(6)  The Blaster-in-Charge will direct and supervise all loading and firing.

(7)  Use a positive system to detect and measure the probability of lightning or massive static electrical discharges.

(8)  Follow procedures in the Master Blasting Plan when lightning or static hazard is present or when a static detection device indicates a potential hazard.

(9)  Use an electric blasting machine or a properly designed power source to initiate any blasts fired by electric detonators.

(a)  Use a blasting machine or starting device according to the manufacturer’s instructions to initiate any blasts fired by non-electric detonators.

(b)  Use an approved non-electrical initiation system according to the manufacturer’s instructions and system requirements when blasting near radar or radio transmission facilities or near electrical energy sources where testing has shown that RF energy or stray electrical current may present a hazard from electrical blasting.

(10) Initiate detonating cord by non-electric detonator (cap and fuse), electric detonator, shock tube detonator or gas-initiated detonator according to the manufacturer's instructions.

(11) Use delayed electric detonators, non-electric delay detonators, detonating cord connectors, or electronic detonators for all delayed blasts according to the manufacturer's instructions.

(12) After firing the shot, immediately disconnect the cable between the switches and lock both switches in the open position.

(13)  The Blaster must keep possession of the keys to the blaster at all times.

(14)  Use appropriately sized insulated solid core wires in good condition for all lines.

(15) Provide sufficient firing line to permit the blaster to be located at a safe distance from the blast.  Consider the following factors when determining the safe distance of the blast area:

(a)  Geology or material to be blasted.

(b)  Blast pattern.

(d)  Previous blasting experience at the site.

(e)  Delay system, powder factor, and pounds per delay.

(f)  Type and amount of explosive material.

(g)  Type and amount of stemming.

(16)  Do not operate mechanized equipment (including drills) within 50 feet (15.2 m) of a loaded hole, unless blasting mats or back covering are placed.

(17)  The use of black powder is prohibited.

(18) All refuse from explosive loading, such as empty boxes, paper, and fiber packing, may not be reused for any purpose.  Obliterate all explosive markings and dispose of the refuse at an approved location or make it unusable by a method approved by the USACE supervisor or accepted by the KO or COR.

b.  Blasting Machines. (29-8.b)

(1)  Operate, maintain, test (prior to use and periodically thereafter), and inspect blasting machines according to the manufacturer’s instructions.

(2)  Secure blasting machines so they are accessible only to the Blaster.  Only the
    Blaster is permitted to connect the leading wire to the machine.

(3)  Do not connect any firing line to a blasting machine or other power source until the shot is to be fired. The firing line must be checked with an approved blasting instrument before being connected to the blasting machine or other power source.

c.  Blasting Power Supply.  When energy for blasting is taken from power circuits, the voltage must not exceed 550 volts.  (29-8.c)

(1)  The blasting switch must be an ungrounded UL (or other NRTL) listed, enclosed, and externally operated double-pole double-throw switch that will shunt the firing lines when locked in the open position.

(2)  Install a grounded switch between the blasting switch and the power circuit at a distance not less than 15 feet (4.6 m) from the blasting switch.

(3)  Provide a lightning gap of at least 15 feet (4.6 m) between the two switches. Use cable, plug, and receptacle to make the gap connection.

d.  Storage of Explosives.  (29-8.d)

(1)  When on a DoD installation, store explosives according to the requirements of the ESSP.

(2)  When on a non-DoD installation, store explosives according to the requirements of ATF P 5400.7.

(3)  Keep two copies of an accurate running inventory of all explosives and blasting agents stored at the project site.  Keep one at the magazine and one in a facility which is at least 50 feet (15.2 m) from the magazine.