Recommended Safe
Working Practices
Orica Seismic Products
Recommended Safe
Working Practices
Orica Seismic Products
October 2008
Contents
Introduction
Handling Explosives
4
Description of Explosive Materials
6
Properties
7
Explosive Safety
Fires
9
Static Electricity
9
Radio Frequency Energy
9
Other Communication Devices
10
Lightning
10
Stray Currents
10
Explosive Products
Geogel™ Seismic Gelatin Dynamites
11
Osx 8 Cast Boosters
12
Osx 5 Emulsion Explosives
13
Osd™ Seismic Electric Detonators
14
Oseis Seismic Electronic Detonators
16
Cordtex Detonating Cord
18
™
™
™
™
Product Use
Handling Detonators
19
Shock, Impact and Friction
19
Preparing Charges
19
Priming Charges
20
Loading Charges
25
Shooting/Detonating
27
Potential Problems
1
Blowouts/Delayed Blowouts
29
Some Factors in Exposure
29
Some Basic Preventions in Exposure
29
Misfires
30
Abandoning a Misfired Charge
31
Recommended Safe Working Practices – Orica Seismic Products
Specialty Applications
Proximity to Pipelines
32
Pattern Shooting
32
Surface Shooting
34
Seismic Cleanup
35
Prevention of Blasting Accidents
A Summary of Actions for the Prevention of Blasting Accidents
37
i.
Storage of Explosive Materials
37
ii.
Collection of Explosive Materials and
Transportation to the Line
38
iii.
Preparation of Charge
38
iv.
Handling of Detonators
39
v.
Priming of Charge
40
vi.
Loading of Charge
40
vii. Shooting
41
viii. Use of Detonating Cords
41
ix.
42
Use of Explosives on Surface
Disclaimer
44
Copyright
44
References and Acknowledgements
44
Contents
2
Introduction
The advice in this booklet is offered gratis with the main objective
of keeping seismic workers free from harm as a result of accidents caused
by irregular or improper use of explosive materials. The precautions are
based on the collective experience of many individuals and organizations,
and the advice is given in good faith as representing the soundest safety
advice in the use of Orica Explosives.
None of the guidelines suggested in this booklet are intended to supersede
or countermand any Federal, State, Provincial, Territorial, Municipal and
company regulations that must be followed in the use of explosive materials.
It is the blaster’s responsibility to ensure that all aspects of the seismic blasting
operation are carried out in a safe manner. This includes designation of a safe work
area, as well as safe procedures for explosives storage, handling, preparing, priming,
loading and shooting.
Persons undertaking drilling/loading or blasting operations within the seismic industry
must be qualified, certified and trained in the following or be under the direct
supervision of a person with the following qualification, certification and training:
• Seismic Blaster Safety Training or local equivalent
• Minimum 18 years of age (regulatory dependent)
• Minimum six months experience in seismic blasting operations
• Ability to communicate effectively in the English language, both orally and
in writing (country dependent)
• Be physically capable of safely carrying out the duties of a blaster
• Blasters must obtain and maintain a personal log of all blasting work that they have
performed, if required by regulations or company policy
THE BLASTING AREA is generally defined as the area extending at least 50 meters
(165 ft) in all directions from a place where explosives are being prepared or fired,
or where unexploded charges are known or believed to be.
The Minimum Seismic Industry Safe Distance is 30 meters (100 ft). This is
the recognized safe distance for blasting. No one should be within this zone while
blasting, including the blaster.
The Critical Work Zone being 15 meters (50 ft) in all directions from the shot point,
meaning:
• No smoking
• No radio transmitting
• No cell phones/pagers
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Recommended Safe Working Practices – Orica Seismic Products
The Critical Work Zone applies 100% of the time to open flame and smoking.
Regarding Radio Frequency (RF) Transmitting, the zone applies when the explosive
product is not secured within the appropriate magazines. The minimum seismic
industry recognized time delay to approach the shot point after firing is 30 seconds
or more. This is to protect blasters and helpers (anyone in the blasting zone) from
delayed blowouts.
The safe work practices discussed in this document essentially set a minimum
standard for seismic blasting operations. You should also check with your supervisor
as your company may have additional safe work practices that you should operate
under. These would include, but not be limited to:
• Handling explosives
• Handling detonators
• Preparing charges
• Priming charges
• Loading charges
• Shooting
Remember, one small error with explosives
could be fatal to you or others around you!
Handling Explosives
Explosives used in commercial blasting operations are a combination of various
substances and mixtures that produce a rapid exothermic reaction when initiated.
The explosive ingredients are either a molecular explosive where the fuels and
oxidizers are on the same molecule, such as with TNT or a physical mixture of solid
and/or liquid oxidizers and fuels such as in emulsion explosives.
A detonation is a specific type of explosion consisting of an exothermic reaction,
which is always associated with a shock wave. This shock wave in rock becomes
a sound wave travelling through the earth. This is actually the only part of the
explosion process of interest in seismic work. A secondary pressure is generated;
by the gasses generated in the detonation. This gas pressure, which is usually
less than 60% of the strength of the shock pressure helps move rock in blasting
applications such as mining and quarrying.
The detonation is a self-sustaining chemical reaction that will consume any explosive
in its path at a very high velocity. Once initiated, the detonation wave will continue
until the explosives are consumed. The reaction generally occurs between 5,000
to 7,500 meters/second (16,404 to 24,606 ft/sec.), virtually instantaneous, with
seismic explosives.
Introduction
4
Explosives are routinely initiated by the shock effect of a detonator or another
explosive. Explosives are sensitive to heat, shock (impact), or friction so they must
be protected from these things to prevent premature, unintended or accidental
detonation.
The explosives used for seismic exploration are either of the dynamite-type
(nitroglycerine with oxidizing salts and solid fuel components), non-nitroglycerine
explosives which; are generally emulsions or watergels and molecular types (Pentolite)
which are combinations of ingredients that are individually explosive materials, such
as PETN and TNT. Emulsions and watergels are aqueous explosives (water based)
which contain fine mixtures of explosive ingredients which are either emulsified
to form a ‘mayonnaise’ like explosive or crossed linked to form a ‘gel’ like explosive.
Seismic exploration with explosive materials is carried out using several techniques.
One of those methods is the use of shot holes that are drilled and loaded with
explosive materials. When the explosive material is detonated, the resulting seismic
waves are reflected or refracted by various geological structures located as deep
as several miles below the earth’s surface. These waves are detected by sensitive
geophones placed on the earth’s surface and are recorded on magnetic tapes or other
media for subsequent data processing to determine subsurface geological structures.
Certain kinds of structures are favourable for the accumulation of gas and oil.
Thanks to extensive research and experience, modern explosives are safe when used
properly. Standards and precautions for storage and use should be well known and
can be incorporated into codes that are understandable, enforceable and effective.
During seismic exploration a blasting machine sends an electrical signal to the
detonator, which is sufficient to activate it. The detonator explosion, in turn, initiates
an explosion of the main explosive charge. Detonation of an explosive charge
produces a shock wave with a sudden release of hot gases with four common effects:
• Fragmentation of material
• Displacement of material
• Vibration of ground (seismic)
• Concussion (air blast/noise)
When incorporating the use of explosive materials into a seismic operation, careful
consideration must be given to the product type, characteristics and long-term
implications in the event of a misfire. Different explosive and detonator types are
better suited to different data acquisition requirements, work site conditions, and
terrain. Orica can assist in providing technical knowledge to help determine the best
product for the seismic operation.
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Recommended Safe Working Practices – Orica Seismic Products
Description of Explosive Materials
Detonator
A seismic detonator is a small metal tube with two wires that emerge from a plug.
These wires may be twisted together or encased in a shunt to ensure that the circuit
is closed in the case of Electric Seismic electric detonators or supplied unshunted
in the case of Oseis™ electronic detonators.
Explosive Charge
Seismic explosive charges may be in a strong rigid package or plastic cartridge. They
can be brightly coloured or wrapped in heavy brown paper. Explosives are produced
in a wide range of strengths and detonation velocities.
Detonating Cord
A small component of seismic work makes use of reinforced detonating cord.
This is a strong cord, which can be made of various materials such as braided
textiles, waterproofing compounds and plastics with a slim explosive core.
Explosive products used in conducting seismic operations are expected to function
as per Orica specifications if handled and stored properly. Every shot point that is
drilled and loaded is intended to detonate. The way explosives are handled contributes
significantly to the prevention of misfired charges. To reduce the probability
of a misfire, the following are suggested:
• Always follow Orica’s recommendations for the safe use of product and its
limitations, (Orica best practices)
• Never handle or use explosive materials unless qualified, trained and certified
or under the direct supervision of a person who is qualified, certified and trained
• Always be completely familiar with the required safe work procedures and
regulations for the area in which you are operating
• Never investigate the contents of a detonator
• Never pull wires, coupling device, plastic tubing, or detonating cord out of any
detonator
• Never take apart or alter the contents of any explosive material
• Never expose explosive materials to sources of heat exceeding 66ºC (150ºF) or to an
open flame, unless such materials or procedures
for their use have been recommended by the manufacturer
• Never strike explosive materials with, or allow them to be hit by, objects other than
those required in loading
• Never subject explosive materials to excessive impact or friction
Introduction
6
Explosives should never be struck, thrown, dropped, kicked, or otherwise subjected
to any form of impact, shock or friction. The results of impact testing on explosives can
vary. A negative response in a given number of tests is no guarantee that a positive
response cannot eventually be obtained. Whether in cases or as individual cartridges,
explosives should not be ‘shocked’ in any manner.
Individual cases of explosives should never be slid across a floor. This applies friction
to the bottom of the case; which could be disastrous with some forms of explosives
in the event that leakage has occurred unnoticed to the point where the bottom
of the case is affected. This could occur if explosives have undergone several extreme
temperature cycles (i.e. seasonal changes). This usually applies to explosives several
years old. In the event that you observe any signs of leakage or liquid on explosives,
the on-site supervisor should be notified. Any liquid observed is almost always water
of condensation, but it is best to work safe.
If nitroglycerine (NG) is suspected to have contaminated a storage or transportation
area, the area should be treated with ‘NG-destroyer’ under the supervision of the
manufacturer or distributor. NG-destroyer is a mixture of materials that when applied
to a contaminated area neutralizes the explosive effects of the NG.
Explosives can be destroyed, if necessary, by burning or by detonation. There are
very specific procedures for this. Unwanted explosives should only be disposed
of by, or under the supervision of an experienced blaster. Contact your Orica
explosives supplier for technical recommendations regarding product destruction.
Properties
For general use, explosive products should:
• Remain intact and sensitive during storage and use
• Not freeze or break down chemically (i.e. dissociate) under normal temperatures
• Be suitably packaged for the intended use
• Be safe to handle, transport and store
• Upon initiation, detonate properly
• Possess the following properties:
– adequate strength for the intended use
– high velocity of detonation under high hydrostatic pressure
– suitable density for the particular application
– adequate water protection
– minimal fumes produced, particularly in confined areas
– long shelf life under severe climate conditions
Note: Although some seismic emulsions are designed
to break down over time, they must never be intentionally
abandoned without proper regulatory documentation.
7
Recommended Safe Working Practices – Orica Seismic Products
Seismic explosives have some unique requirements:
• Products must be supplied in a strong rigid package or cartridge which will not
collapse when pushed to depth through mud or sand
• Water resistance must be particularly good especially under hydrostatic pressure
of a column of water for extended times before firing
• Products must be capable of detonating at full velocity while under hydrostatic
pressure
• The rate of reaction, known as velocity of detonation (VOD), should be at least
5,000 meters per second, (16,404 ft per second)
Explosives must never be knowingly abandoned anywhere,
anytime, for any reason. This is a serious offence!!
If you find abandoned explosives, do not touch them. Contact your supervisor or
the party manager who will notify the appropriate authorities. There are reporting
requirements for misfired/abandoned holes specific to Federal, State, Province,
County, Territory etc. It is the responsibility of each individual company to
maintain records of misfires/abandoned holes.
Introduction
8
Explosive Safety
Explosives are sensitive to heat, shock (impact), or friction so they must be
protected from these things to prevent premature or accidental detonation.
Fires
A detonator involved in a fire will almost certainly explode; this result from the effect
heat has on the explosive components inside a detonator. In normal use it is heat
from the internal firing mechanisms within the detonator that initiates the base
charge. Because detonators are sensitive to elevated temperatures not normally seen
in handling and storage they should not be exposed to fire.
Static Electricity
The most likely source of an accident with electric detonators in seismic work
is static electricity.
Everyone develops static charges on their body, which can be released at any time
by touching a conductor of electricity. The seismic detonator is protected from static
charges to a certain extent by a preferred static discharge-path inside the detonator.
However, the surest way to prevent accidental detonation of electric detonators by
static electricity is to keep the legwires shunted (i.e. wires touching, circuit closed, etc.).
Since static electricity is the most likely cause of an accident, you should take
precautions to avoid static build up. Here are six points to keep in mind:
• Wear only natural fiber outer clothing. Do not wear synthetic outerwear, such
as polyester that helps generate and hold static electricity
• Ground yourself frequently by touching clean metal surfaces. Always do this
immediately before handling detonators
• Avoid friction. Never let lead wires slide through your hands
• Never put detonators in your pockets
• Never throw legwires as they could pick up static charge in the air
• Never handle detonators during severe dust, snow or electrical storms
Radio Frequency Energy
Detonators can be initiated by radio frequency transmission in the vicinity of the
detonator. Tables of distances are available in all regulations, relating transmitter
power (i.e. watts) to safe distances from detonators. The best rule in seismic
is to avoid all radio transmission when handling detonators. In addition, you
can minimize the possibility of radio transmission problems by keeping detonator
legwires close to the ground to avoid forming an antenna. Keep the doors
of portable containers closed when not in use. Upon the approach of a vehicle, cease
handling detonators until you are satisfied that the occupant(s) are not transmitting
on any radio or cell phone and that radios and cell phones are turned off.
9
Recommended Safe Working Practices – Orica Seismic Products
Note: Please refer to the IME Safety Library Publication –
20 on RF when working with detonators on or near roads
or road allowances and post appropriate warnings.
Other Communication Devices
The licensed blaster on-site controls a blast area of 50 meters (165 ft) around the
point where explosive devices are being prepared for firing. Therefore, no low
wattage transmitting or receiving devices shall be within this 50 meter (165 ft)
area even if they are shut-off. This includes cellular phones, pagers and GPS vehicle
navigation systems.
Lightning
In view of the intense electrical energy associated with lightning in an approaching
thunderstorm all explosive work should cease. Workers should remove themselves
to a safe area until the storm has passed. These storms can produce enough energy
to pose a serious hazard by the threat of lightning hitting the ground near the
explosives and potentially initiating them. This recommendation applies for all types
of seismic detonators and explosives.
Stray Currents
Stray currents can be avoided by making sure that detonator leads, do not contact
electrical conductors.
By far the most important rule when working with Seismic electric detonators is:
KEEP YOUR SHUNT ON!
Always ensure that legwires are touching and that good
contact will be maintained until you are ready to test or
shoot. As long as wires are shunted, the circuit is closed and
there is a minimized chance of accidental initiation.
Explosive Safety
10
Explosive Products
Geogel™ Seismic Gelatin Dynamites
High Velocity Seismic gelatins are specifically formulated to withstand high
hydrostatic pressure and provide both excellent water resistance and lengthy storage
periods. These products may be packaged in either paper or plastic cartridges. The
plastic is designed to increase the life of the product in the borehole if not punched.
Explosives containing nitroglycerine (NG) may cause headaches for some people
if vapours are inhaled, or if the substance contacts exposed skin. Always handle
explosives in well-ventilated areas and use protective gloves. Allow NG magazines
to ventilate for a minimum of 15 minutes prior to entering. Other health hazards,
which can be associated with a detonation, are the yellowish red brown nitrous oxide
fumes that can be harmful, if inhaled. Always ensure the cloud has dissipated before
approaching the shot hole. This is usually more prevalent during blowouts.
Geogel™
Orica’s NG based seismic explosive, Geogel™ is a gelatin dynamite. It has very good
water resistance in plastic and stores well at most temperatures and humidity’s.
Density is 1.43 g/cc and velocity of detonation is over 6100 m/s (20,000 f/s) even
under high hydrostatic heads. It is specially formulated to allow punching with
relative ease at very low temperatures. Check Orica’s product data sheets for
recommended shelf life for storage.
Geogel™ comes in two forms:
Geogel™ FAST-LOK™ is packaged in rigid plastic shells with wide threads, which
can be threaded together to construct larger charges and spiral wound paper.
It is available in the following sizes:
0.125 kg (0.28 lb)
Spiral wound paper
0.25 kg (0.55 lb)
Spiral wound paper
0.5 kg (1.1 lb)
Spiral wound paper
1.0 kg (2.2 lb)
Spiral wound paper
2.0 kg (4.4 lb)
Spiral wound paper
2.0 kg (4.4 lb)
Fast-Lok™ Plastic
It is available in 60 mm (2³⁄8 in) by 2.0 kg (4.4 lb) Fast-Lok™ plastic shells, suitable
for coupled charges in standard augured holes.
Geogel™ products are reliable under the most severe temperatures and hydrostatic
pressures. Geogel™ can be detonated in tight patterns or in closely spaced holes and
shot sequentially with no adverse effect on the charges in adjacent holes. To preclude
sympathetic detonation when using Geogel™, minimum separation distances are
recommended.
11
Recommended Safe Working Practices – Orica Seismic Products
Charge Size
Separation
1 kg (2.2 lb)
0.8 m (2.6 ft)
5 kg (11 lb)
1.4 m (4.5 ft)
10 kg (22 lb)
1.8 m (6 ft)
20 kg (44 lb)
2.3 m (7.5 ft)
50 kg (110 lb)
3.3 m (11 ft)
These distances allow for ground conditions, but angle of drilling could cause
significant error in the small distances between charges.
Osx™ 8 Cast Boosters
An explosive charge composed of a cast mixture of explosive materials, such as TNT,
PETN, RDX or HMX that may contain aluminum or other constituents depending
on the formulation of the product. The cast boosters, in paper or plastic shells,
have a long shelf life when properly stored in approved magazines. The charges
have extended exposure life (in a borehole), which can be reduced by degrading
technologies.
Osx™ 8 L
The Osx™ 8 L series of seismic explosives are specifically designed as a consistent,
reliable high-energy source for seismic exploration applications and consists of
a plastic shell filled with the required mass of cast molecular explosives. The
modular plastic shells provide a means of coupling the boosters together. The sizes
available include 0.5 kg (1.1 Ib), 1.0 kg (2.2Ib), 2.0 kg (4.4Ib) and 2.5 kg (5.5Ib). Twin
longitudinal tunnels are cast into the explosive to accommodate conventional Electric
Seismic detonators or Oseis™ electronic detonators.
Figure 1: Geogel™
Figure 2: Osx™ 8L Cast Boosters
Explosive Products
12
Osx™ 5 Emulsion Explosives
Water-in-oil emulsion explosives consist of minute sized droplets of an aqueous solution
of inorganic oxidizer salts that are surrounded by a very thin layer of a continuous
oil phase medium, which is stabilized with an emulsifying agent to prevent liquid
separation. The outer layer of oil provides excellent water resistance, which is further
improved; by the thick spiral wound paper, plastic film or plastic shell.
Emulsion explosives generally have a shelf life of one to two years for inventory
purposes after which time they will begin to degrade. Check Orica’s product data
sheets for recommended shelf life for storage.
The sensitivity of emulsions is dependent on either a chemical sensitizing ingredient
or the incorporation of voids. These voids are either normal air, gas or hallow
micro spheres. The explosive properties are entirely dependent on the chemical
ingredients of the emulsion. The oxidizer is in the form of very small (micron-sized)
supersaturated droplets surrounded by an oil/wax blend and stabilized by surfactants.
Ammonium Nitrate is the major ingredient in the oxidizer solution.
There are three mechanisms that will desensitize emulsions. The first is crystallization,
which will occur slowly under all conditions of temperature and temperature cycling.
The other two will occur when loaded in wet conditions. When exposed to water,
the emulsion will slowly ‘absorb’ water (analogous to osmosis biological systems);
at some water level in the 20% range, the emulsion will become insensitive to a
detonator. At the same time, the water will leach the oxidizer solution out of the
emulsion, which will also desensitize the emulsion. The time taken to desensitize will
depend critically on the conditions in the hole and the integrity of the packaging.
Magnagel™ (Osx™ 5)
A safer alternative to traditional dynamites, Magnagel™ (Osx™ 5) is an emulsion with
very low sensitivity to shock. Since Magnagel™ (Osx™ 5) contains no PETN-TNT,
no nitroglycerin or related nitrate esters, and no other self-explosive ingredients
of any kind, it is unquestionably the safest product
on the market. The emulsion detonates solely because of
the manner in which the oxidizers and fuels are intimately
combined and stabilized during manufacture. This product
is packaged in rigid plastic shells to withstand the toughest
loading situations. The Fast-Lok™ shell design is available in
three sizes, plus an additional two sizes in the straight plastic
shells. This combination of sizes makes it easy for the crew to
deliver any desired charge weight.
With a density of 1.18 g/cc and a velocity of detonation of
5400 m/s (17,700 f/s) Magnagel™ (Osx™ 5) performs similar
to seismic dynamites.
Figure 3: Magnagel™
13
Recommended Safe Working Practices – Orica Seismic Products
Magnagel™ (Osx™ 5) is available in the following sizes:
0.125 kg (0.28 Ib)
Plastic
0.25 kg (0.55 lb)
Plastic
0.5 kg (1.1 lb)
Fast-Lok™ Plastic
1.0 kg (2.2 lb)
Fast-Lok™ Plastic
2.0 kg (4.4 lb)
Fast-Lok™ Plastic
The shock pressure required to break the glass micro balloons is about 500 psi
(3400 kPa). If Magnagel™ (Osx™ 5) must be shot sequentially, minimum separation
distances should be applied.
Charge Size
Separation
1 kg (2.2 lb)
5 m (16 ft)
5 kg (11 lb)
6.5 m (21 ft)
10 kg (22 lb)
8 m (26 ft)
These distances allow for variance in ground conditions, but it may be necessary
to allow for the effect of drilling off-vertical holes.
Osd™ Seismic Electric Detonators
A seismic electric detonator has a small metal tube sealed at the open end by
a polymer plug. Two wires emerge from this plug. These are the legwires, usually
in the form duplex wire (two wires attached together). The ends of the legwires are
placed together so that they are shunted (touching). The bare wires may be twisted
together or in contact with each other and encased in a shunt material to ensure that
the wires are electrically in contact and the circuit is closed.
Figure 4: Osd™ Seismic Electric Detonator
Inside the detonator, the wires are joined by a bridge wire; similar to the filament
in a light bulb. The bridge wire is located in either a loose initiating charge or in a more
compact format called a match head where the initiating charge is coated over the
bridge wire similar to a match head. When current is passed through the detonator
leads, the bridge wire heats up to ignite the initiating charge of the match head. The
flame front from this ignition then initiates detonation of the primary charge and then
the base charge. This entire sequence of events usually occurs in one millisecond or less.
Explosive Products
14
Figure 5: Conventional seismic electric detonator cross section
The total explosives content of most seismic electric detonators is less than one
gram but they are usually considered high strength detonators capable of initiating
detonator sensitive explosive charges. When the base charge is detonated inside a
cartridge of explosives, it sends out a shock wave, which causes the explosives to
detonate. Shock pressure and heat are the main effects which initiate the reaction
in the explosives.
To provide an accurate time break signal at the recording instrument, it is essential
there be minimal time lag between breaking the bridge wire of the detonator and
the detonation. Seismic electric detonators are designed to meet this requirement.
Other features important for seismic work include:
• Excellent water resistance under high hydrostatic pressures and a long
in-hole storage
• Reliable performance unaffected by extreme temperatures
• Design features to minimize static electricity hazards
• Shunted legwires to help protect against stray electric currents
• High strength base charge for reliable initiation of explosive charges
• Corrosion resistant aluminum shell to withstand prolonged in-hole exposure
• Heavy gauge legwires for rough loading conditions
• Polymer legwire insulation designed specially for use at very low temperatures
• Bright colored insulation for high visibility
Even when the detonators cease to function with an electric impulse, the explosive
compositions will remain as a potential hazard and should be handled appropriately.
15
Recommended Safe Working Practices – Orica Seismic Products
Oseis™ Seismic Electronic Detonators
The communication capability of Oseis™ electronic detonators provides a security
feature not found in standard electric detonator technologies. Oseis™ detonators can
communicate specific information about the status of the detonator either prior
to loading or post loading the detonator into a blast hole. The communication
features of the system offer the ability to ‘interrogate’ the entire system prior to
charging and firing a blast. The Oseis™ detonator system uses digital communication
protocols, blast keys, and logic circuits that can prevent accidental initiation due to
operator error or unauthorized use. These features provide a higher level of blast site
security and can prevent misuse of the product. The detonator incorporates additional
internal components designed to provide increased protection against accidental
initiation from extraneous electrical energy (static, stray current, radio frequency, etc.).
Unlike a standard electric detonator, the igniter or firing device inside an Oseis™
detonator is physically separated from the leads by a circuit board or electronic
assembly. It is because of this design difference that traditional safety testing equipment
such as a blaster’s galvanometer as well as shunting practices cannot be applied to
electronic detonators. Shunting however does not cause any complications in the use
of electronic detonators and the field recommendation to always shunt still applies.
Refer to the Institute of Makers of Explosives (IME) Safety Library Publication
12 (SLP 12) for the definition of ‘shunting’ and its applicability to both Electric
and Electronic detonator systems.
Figure 6: Conventional electric detonator and electronic detonator cross section
Explosive Products
16
Oseis™
The Orica Seismic Electronic Initiating System, Oseis™, consists of electronic detonators,
Oseis™ Tester and Oseis™ Shooter control equipment with trigger interface and
software. The system was designed specifically for geophysical exploration and can
be used for both single and pattern firing applications in challenging environments.
The Oseis™ Detonator is a high strength, super accurate electronic detonator capable
of in field programming of delayed or instantaneous firing times. Through its capability
of two-way communication the detonator functionally can be checked via the
control equipment anytime from loading to firing. Protection structures built into the
electronic circuitry provide a high level of protection against stray current, over-voltage,
static electricity and electromagnetic induction not present in conventional electric
detonators.
Figure 7: Oseis™ Detonator
The Oseis™ Tester is a multi function device used during loading to perform detonator
function, identification and positioning tasks. The Oseis™ Tester checks for full
detonator function, including measurement of any current leakage, and displays user
warning messages. The Oseis™ Tester reads and stores the unique detonator identity
number (Det-ID) to memory and allows for entering line and shot point location.
Figure 8: Oseis™ Tester, Oseis™ Shooter and Oseis™ Trigger Cable
17
Recommended Safe Working Practices – Orica Seismic Products
To fire the shot, the Oseis™ Shooter is connected to the conventional seismic shooting
system via the Oseis™ trigger cable. The Oseis™ Shooter is protected by a personalized
identification number (PIN) to prevent use by unauthorized personnel. Oseis™
Detonators can only be programmed and fired by Oseis™ Shooters, which provide the
required firing energy and digital information. The final firing command to the Oseis™
Detonator is given by the Oseis™ Shooter upon receipt of a dedicated trigger signal.
The trigger signal is sent by the firing command from a conventional seismic shooting
system. The time between recept of the trigger signal to the detonator firing is a
constant 20 ms +/– 0.075 ms.
Oseis™ software is available as an information management system for explosives
loading and shooting operations. The software can provide the ability to track
operational status by reconciling detonator testing history with loading location
via imported survey and shooting plans. It can provide the ability to confirm and
report blasthole shooting and final explosive consumption. This information can be
integrated into customer management systems or provide additional quality control
and regulatory compliance documentation.
Cordtex™ Detonating Cord
A small proportion of seismic work makes use of a reinforced detonating cord,
ranging from 10 – 50 grains/foot, (2 – 10.2 grams/meter). This is actually a very
physically strong cord made of braided textiles and plastics with a slim PETN
explosive core. Cordtex™ detonating cord is typically used to initiate explosive charges
directly when the shot point is closer than 60 m, (196.8 ft) from power lines. Other
reasons for using detonating cord include client requests, landowner concerns and
environmental considerations. The detonating cord is initiated at or just beneath
the surface by a short length Seismic Electric detonator attached to the cord. The
reason detonating cord is used near power lines is to avoid having long lengths of
copper wire being thrown up onto the power lines in the event of hole blowout.
Sometimes the detonating cord is used in surface blasting to initiate the charge
(Poulter Method). The detonating cord used in seismic blasting operations detonates
around 6000 to 7000 meters per second (19,700 to 23,000 ft/sec). Cordtex™
detonating cord has a very long shelf life if stored properly (5 to 10 years). PETN
(Pentaerythritol Tetranitrate) is the molecular explosive used in most detonating cords
and is essentially insoluble in water. Water will desensitize PETN but it is still capable
of detonation if a strong initiator is used. For example if an end of detonating cord
is allowed to become wet it may not initiate with a detonator placed along side
of the detonating cord at the wet section. If a dry section of the detonating cord
is detonated it will shoot through a wet section of the cord. The plastic protective
coverings are designed to provide a long service life under a variety of conditions.
Explosive Products
18
Product Use
Handling Detonators
Seven conditions which could cause accidental initiation of a seismic detonator include:
• Shock (impact)
• Heat
• Friction
• Static electricity
• Radio frequency energy
• Lightning
• Stray currents
Shock, Impact and Friction
Shock, impact and friction may be applied to and prematurely detonate detonators
by tampering with the metal tube of the detonator (i.e. hammering, prying with
sharp tools, etc.). Another potential means of applying friction would be pulling the
legwires out of the detonator. This may also cause accidental initiation. Detonators
must never be abandoned anywhere, anytime, for any reason! There have been
many accidents with detonators caused by children finding and attempting to open
them. All detonators must be accounted for at all times.
Preparing Charges
Only the number of cartridges of explosives required for a given shot hole shall be
removed from the portable container at that shot hole. Explosives and detonators
shall remain in the portable containers until the hole is completely ready to load.
Only a brass T-bar punch or equivalent is permitted for punching explosive
cartridges. Even this T-bar punch should not be used with excessive force; only the
force produced by reasonable pushing is acceptable. Never hammer a punch and
never use any tools to help force the T-bar punch into the explosive. Steel tools, such
as screwdrivers, must never be used for punching. If an explosive appears to be too
hard to punch using a reasonable pushing force, do not attempt to heat the explosive
‘to thaw it out.’ Even at -40°C, explosives should be capable of being punched
without resorting to mechanical means. Never place explosives close to heating
devices. Notify the on-site supervisor if explosives cannot be punched.
Use caution when punching the explosive cartridge as the punch can penetrate through
and into your hand. Always use appropriate personal protective equipment (PPE).
If there is a requirement to cut cartridges, do so only with a brass knife on a soft
surface, away from other explosives (i.e. never in magazines or portable containers).
Uncertified helpers, whenever handling, preparing or firing charges must
always be under direct visual supervision of the certified blaster. It is an
industry recognized practice that no one is allowed to drill alone.
19
Recommended Safe Working Practices – Orica Seismic Products
Priming Charges
Only the exact number of detonators required for a given shot hole shall be removed
from the portable container at that shot hole.
Primed charges must never be made up in advance. Exposure to a primed charge
should be minimized. This can be done by priming the charge; just before loading,
and then loading the hole immediately. A primed charge must never be stored
anywhere or transported on any vehicle.
Before priming, ground yourself and ensure the detonator is securely shunted.
Minimum force should be required to place a detonator in the charge. The detonator
should be placed in the lower half of the cartridge to avoid contact with the loading
pole or stinger point. If there is a capwell, insert the detonator in it.
Figure 9: Insertion of detonator into capwell
Where required to punch, make the punch-hole only slightly longer than the
detonator, and position it so that the exploding-end of the detonator will be in the
center of the cartridge. Never punch across the cartridge so that the detonator
is actually touching the side. This could result in detonation failures.
Figure 10: Improper detonator alignment
Product Use
20
After priming, the detonator should be secured by making at least two half hitches
around the cartridge with the legwires. Never drag primed charges by the legwires.
Figure 11: Secured detonator wires around the charge
Priming the Charge:
• Always insert the detonator completely into the hole in the explosive material
or capwell
• Always point the end of the detonator in the direction of the main explosive charge
• Never punch across the explosive; if the detonator is touching the other side
it could result in a detonation failure
• Use two half hitches with legwire to secure detonator in order to take tension
off the detonator when loading
• Never pull the legwires too tightly. This may break the wires or damage
the insulation
• Never drag a primed charge by the legwires as they may snap or tear slightly,
rendering the cap useless or generate a static charge build up
• Never prime the charge before the shot hole is ready to be loaded
Priming a charge is the moment of greatest hazard in
blasting!
After the shot hole is ready to load, the explosive charges are primed with
a detonator.
21
Recommended Safe Working Practices – Orica Seismic Products
Priming Geogel™ explosives without a detonator well
1
Punch a hole upwards at about 45 degrees
on the side of the cartridge about one-third
from the bottom end with an approved
brass punch.
2
The hole should be only marginally bigger than
the detonator.
3
Insert a shunted Osd™ Electric Seismic
detonator or an Oseis™ Electronic detonator
into the hole so that the entire casing is
submerged in the charge.
4
Secure the detonator with at least two halfhitches around the cartridge with the legwires.
5
Couple any additional charge required, preassembled, on to the primed charge.
Couple a drive point onto the bottom end to check any upward movement of the charge.
Product Use
22
Priming Magnagel (Osx™ 5) explosives with a detonator well
1
Insert a shunted Osd™ Electric Seismic
detonator or an Oseis™ Electronic detonator
into the detonator well at the bottom of
the cartridge.
2
Withdraw the Osd™ Electric Seismic detonator
or an Oseis™ Electronic detonator legwires
upwards past the threads and through the
single recessed channel provided.
3
Secure the legwires with at least two halfhitches around the cartridge. Couple any
additional charge required, preassembled,
on to the primed cartridge while holding the
legwires secure in the recessed channel.
4
Couple a drive point on to the bottom end
to check any upward movement of the charge,
taking care that the detonator leads remain
in the recessed channel if the drive point
is being attached to the primed cartridge.
Cordtex™ XTL™ (48 gr/ft, 10.2 g/m) is used to prime charges that are located close to
power lines.
23
Recommended Safe Working Practices – Orica Seismic Products
Priming Geogel™ with Cordtex™ XTL
Punch a hole clean through the cartridge about a third from the top and sloping
downwards about 45 degrees opposite to the first hole.
Thread the Cordtex™ XTL downwards through the upper hole, then downwards
through the lower hole.
Figure 12: Securing cord via a knot
Tie a secure knot outside the lower end of the bottom hole to prevent the Cordtex™
XTL from slipping out.
Couple any additional charge required, preassembled, onto the primed cartridge.
Couple a drive point onto the bottom end to check any upward movement
of the charge.
Priming Magnagel™ (Osx™ 5) with Cordtex™ XTL
Pierce the top of the detonator well and push at least 25 cm (10 in) of Cordtex™ XTL
into the emulsion.
Withdraw the Cordtex™ XTL upwards past the threads through the single recessed
channel provided, making sure the cord does not move out of the detonator well.
Secure the Cordtex™ XTL by half-hitching once, just above the level, which the drive
point will reach.
Figure 13: Secured detonating cord around the charge
Product Use
24
Note: When using Cordtex™ XTL to initiate a multiple-shell charge
of Magnagel™ (Osx™ 5), only the uppermost shell in the hole should be
primed. Cordtex™ XTL should not be fed alongside the charge past the top
shell because it may adversely affect the detonation properties of emulsion.
Couple any additional charge required, preassemble, on to the primed charge while
holding the Cordtex™ XTL secure in the recessed channel.
Couple a drive point on to the bottom end of the cartridge to check any upward
movement of the charge, taking care that the Cordtex™ XTL remains in the recessed
channel if the drive point is being attached to the primed charge.
Loading Charges
Loading
• Always check each shot hole to ensure it is safe for loading
• Always take precautions to prevent the accumulation of static electric charges
• Never force explosive materials into a shot hole
• Never drop-load a charge
• Always tamp with non-sparking, anti-static tamping poles and pole extension
fittings
• Never tamp violently
• Never kink or damage detonating cord, coupling devices or wires of detonator
when tamping
• After the hole is loaded, always test the circuit for continuity and proper resistance
using a blasting galvanometer or an instrument specifically designed for testing
electric or electronic detonators and circuits containing them
• Always ensure that the lead wires of electric or electronic detonators are shunted
to prevent accidental detonation
• If the detonator is dead, immediately load another primed charge on top
• Drillers should demonstrate proper loading procedures to new helpers and instruct
them in areas of more difficult drilling formations
• Drillers must never move up to the next hole leaving the helper to load the shot
hole on his or her own
All charges require the use of a sand point, to anchor the charge and to prevent
movement. A stinger point or overshot and loading pole must be used to push the
charge down the hole.
25
Recommended Safe Working Practices – Orica Seismic Products
Figure 14: Sand point and stringer point / loading pole
If loading charges in excess of 10 kg (22 Ib), and loading poles are not required,
another method to lower the charge (i.e. binder twine) must be used in accordance
with the applicable regulations.
After loading, an approved blasting galvanometer or Oseis™ tester must be used
to confirm the continuity of the detonator(s) at each shot point while the hole is still
open. If the circuit is open or current leakage is measured in the case of electronic
detonators (i.e. broken legwires), immediately load another primed charge on
top of the first charge to ensure that the first charge can be detonated. Ensure the
actual charge is logged. If the above procedure is unsuccessful then the location
of the charge must be appropriately marked and logged. If reloading the hole is
not possible use the approved separation distances to locate and drill a new hole.
Procedures for misfires should include provisions for smaller sized charges to be used
for detonation and proper notification.
Note: When using Oseis™ Electronic Detonators the manufacturer’s
approved Oseis™ ‘Tester’ shall be used at the time of loading (prior to
stemming) and after the shothole is stemmed. This is to make sure that
the detonator down-lines were not damaged while stemming the shothole.
After testing detonators, re-shunt or twist the legwire ends together.
Never use a galvanometer or electronic tester that is not approved for blasting.
Where it is possible or likely that detonator legwire will break, double cap/prime
or use a downline of detonating cord (i.e. insert an additional detonator).
All drill cuttings or other material not required to fill the hole must be spread evenly
over the ground surrounding the hole unless otherwise dictated by regulations
or the permit.
A log must be maintained of all loading and shooting conducted. Information should
be logged immediately after loading each shot.
Product Use
26
Figure 15: Explosives inventory log book
All hazards must be carefully logged to warn shooters of possible danger. This may
include short-drilled holes, explosive cartridges stuck at shallow depth, loose rock at
or near surface and any loading poles or other equipment left in the shot hole.
Refer to your company’s specific procedures for dealing with charges, which have not
been successfully loaded.
Recognized industry practice is that any shallow holes shall be clearly identified
(i.e. flagging, signage or excess detonator wire bundled and visible at the surface).
Shooting/Detonating
• Always fire electric and electronic detonators with firing currents as recommended
by Orica
• Always keep electric and electronic detonator wires or lead wires disconnected
from the power source and shunted until ready to test or fire
• Never attempt to cut and splice leads unless specifically recommended by Orica
• Never use a blasting machine or firing line that appears to be damaged or poorly
maintained
• Never use blasting machines that are designed for electronic detonators with
electric detonators or vice versa unless specifically designed for that purpose
• Never mix electric and electronic detonators in the same shot hole or blasting circuit
• Never use other manufacturers equipment with Orica Oseis™ detonators
• Never mix electric or electronic detonators from different manufacturers in the
same shot hole or blasting circuit
• Always check that the circuit is complete with an approved galvanometer, blasting
machine, or electronic ‘Tester’ before firing
• Always ensure legwire ends are clean before connecting
• Always follow Orica’s warnings and instructions for hook-up and firing procedures
and safety precautions
27
Recommended Safe Working Practices – Orica Seismic Products
Prior to hooking up detonator legwires, make sure the following precautions have
been adequately dealt with:
• Check the hole number, line number and check for a pattern
• Never lean over the hole while hooking the legwires
• Always discharge static electricity before unshunting the legwires
• Helper must keep back at least 30 meters (100 ft)
• Know what the charge depth is prior to arming the Oseis™ shooter or seismic
shooting system
Do not transmit by radio from the time that hook-up is started until it is complete and
all personnel are in a safe position. This area is considered The Critical Work Zone.
Shunts should not be removed or the detonator should not be unshunted until ready
to make the final connections. Make sure connecting wire ends are clean. Ensure that
the firing line is of clean, insulated and undamaged suitable cable. The line should be
laid along the ground with connections slightly elevated to prevent current leakage
into the ground.
Ensure the circuit is complete, using an approved blasting galvanometer or an Oseis™
‘Tester’ before firing.
Always make sure that all personnel are safe from harm before shooting. Assume
that the charge may be just under the surface (i.e. a floater) such that dangerous
flyrock could be thrown around.
Figure 16: Shot hole blowout
The industry minimum safe distance from a shot point is 30 meters (100 ft).
Never shoot when anyone is less than 30 meters (100 ft) from the hole!
Product Use
28
Potential Problems
Blowouts/Delayed Blowouts
Always wait the required time prior to approaching a fired shot hole.
Always approach a hole with caution after the charge has been detonated.
Be prepared for a delayed blowout.
Delayed blowouts may only occur a small percentage of the time, however, the
exposure/risk to the blasters (and blasters helpers) is significant to warrant that some
basic safe work procedures be created/used by industry.
The most obvious exposure is when a blaster (or helper) approaches the shot point,
after blasting, in order to trash/clean the shot point.
There may be little or no warning for a significant delayed blowout to occur.
Some Factors in Exposure
• Recognize that the critical work zone is 15 meters (50 ft) in all directions around
the shot point
• Recognize that the blaster is directly responsible for the blasting area, which
is 50 meters (165 ft) in all directions around the shot point
• That natural gas pockets form near the surface in some areas
• That soft, wet or frozen ground conditions can contribute to delayed blowout
problems
• Poor loading procedures, specifically plugging of the shot hole
Some Basic Preventions in Exposure
• That the blaster and helper MUST maintain a safe distance outside the critical work
zone, maintaining a minimum distance of 30 meters (100 ft) (from shot point)
while blasting
• That a minimum of 30 seconds after detonation should be observed before
approaching the shot point
• To observe ground conditions, and remember that they may be a factor in delayed
blowouts
• That the helpers must be specifically trained and supervised, while working around
the shot point(s)
• That drill crew(s) be trained and supervised in proper tamping methods, and that
additional precautions be taken in areas where further exposure may be a concern
29
Recommended Safe Working Practices – Orica Seismic Products
Misfires
A blaster who suspects that a misfire has occurred must ensure that no one returns
to, or approaches the blasting area for 15 minutes (electric detonators) and
30 minutes (electronic detonators) or for the period recommended by
the manufacturer of the explosive. Note: Most manufacturers follow IME
recommendations (IME Safety Library Publication – SLP 17 on Misfires)
Misfires should be dealt with as promptly as possible to eliminate the potential
hazard of any misfired hole being accidentally initiated. A thorough risk assessment
must be conducted to determine the safest, most effective way to deal with the
misfire.
Since misfires occur under varied conditions and are caused by different factors, it is
impossible to offer detailed instruction to cover every situation. Due to the potential
hazards involved, only persons who are certified, trained and experienced in the use
of explosive materials should handle misfired charges.
If a misfire occurs involving the use of an electric or electronic detonator, ALWAYS
wait the required regulatory time before entering the 30 metre (100 ft) safe zone
to check the hole. When the hole is checked, do the following:
• Disconnect the firing line from the blasting machine
• Shunt the legwires
• Secure the blasting machine
Following the regulated waiting period, the blaster and the absolute minimum
number of competent, experience personnel required to assess the situation may
approach the misfired hole.
Some of the more frequent causes of misfires are:
• Improper loading practices
• Damage to legwires of electric and electronic detonators
• Improper series or parallel connections (pattern shooting)
• Insufficient or excessive electric current
The safest and surest way to dispose of any misfired explosive material is by
detonation (providing there is sufficient burden or cover to contain the blast).
Before taking any such action the following should be observed:
• Have the blaster make an evaluation to determine the amount and location of any
misfired explosive material and the condition of the ground surrounding the misfire
• Have the blaster check the electric or electronic detonator circuit using an approved
galvanometer or electronic detonator ‘Tester’. Misfires attributable to malfunctions
of the electrical circuit may be reconnected and fired if the holes have sufficient
burden. If more than one hole fails to fire, the problem may be the failure of the
blasting machine. In this case, the detonators may still be functional and the holes
can be refired
Potential Problems
30
• If detonating cord is involved in a misfire, check any lines coming out of the hole and
if they appear to be intact, reconnect them and attempt to refire the misfired hole
• If a hole has not detonated, there will still be explosive materials in the hole,
which can be re-primed and fired. If the shot hole is open, it may be possible
to place a fresh charge on top of the existing charge in the hole
• In holes where the cuttings have been removed and the shot hole is open and
accessible, a new charge can be placed in the hole and the hole refired
• Never drill in a shot hole that was previously loaded with explosive materials.
Initiation can occur if unexploded material is struck by a steel drill bit or stem
• Never extract or attempt to extract a detonator or any explosive material from
a loaded shot hole without carrying out an approved Risk Assessment
• A thorough investigation should always be conducted of all misfire incidents so the
cause can be determined and corrective action can be taken to prevent recurrence.
Abandoning a Misfired Charge
If following a thorough risk assessment and the results determine that the misfired
charge cannot be safety detonated, that it is located in an isolated location, and will
not pose a risk to the area where it is located, the charge may be abandoned. All
regulatory requirements regarding abandoning misfired charges must be followed
in the abandonment process.
Basic requirements for abandoning a misfired charge include but are not limited to:
• The detonator lead wires must be cut and placed in the drill hole beneath the
surface
• The surface must be covered with drill cuttings
• A Lost Hole Marker must be placed in or beside the shot hole
• Lost Hole Markers are available through local explosive suppliers
• The seismic contractor must keep a permanent record of the misfire, including
information on the location, explosive type and depth
Required reports must be submitted to appropriate regulatory agencies.
31
Recommended Safe Working Practices – Orica Seismic Products
Specialty Applications
Proximity to Pipelines
If the charge is within regulated distances, the company must go through the risk
assessment with the pipeline company. It is generally safer to abandon the hole in a
permanent manner (bentonite top to bottom) than to detonate it or remove it. Written
agreement should be obtained from the pipeline company and landowner if applicable.
Liability for the charge always remains with the company responsible for the
program. However if the charge is detonated, the same company is liable for any
future pipeline defects in that geographic location.
Pattern Shooting
Most seismic programs have a single hole at each shot point, but sometimes twohole or three-hole patters are used. In some areas, this provides better records.
Patterns of holes are shot simultaneously at each shot point after connecting the
legwires in series. Note: Multiple Oseis™ Seismic Electronic Detonators are always
connected in parallel.
Figure 17: Osd™ Seismic Electric Detonators in series, Oseis™ Electronic Detonators in parallel
Osd™ Seismic Electric Detonators; are designed to be connected in series. They should
never be hooked up in parallel. In practice, patterns are usually connected in series by
using a specially spliced firing line, but single-strand insulated connecting wire can be
used if suitable firing line is not available.
Specialty Applications
32
Detonating Cord
• Always use detonating cord matched to the blasting methods and type of explosive
materials being used
• Always handle detonating cord as carefully as other explosive materials
• Always cut the detonating cord from the spool before loading the rest of the
explosive material (proper tools are required to cut cord)
• Always make tight connections, following manufacturer’s directions
• Always attach detonators to detonating cord with tape or methods recommended
by the manufacturer
• Always attach the detonator initiating the detonating cord at least six inches from
the cut end of the detonating cord
• Never make loops, kinks, or sharp angles in the cord which might direct the cord
back toward the oncoming line of detonation and possibly cause a cut-off
• Never damage detonating cord prior to firing
• Never use damaged detonating cord
• Never cut detonating cord with devices such as scissors, plier type cutters, cap
crimpers or similar instruments
Detonating cord is used when shot holes are located within 60 meters (~200 ft)
of any overhead power line.
Detonating cord can be used to initiate most charges by lacing it through two holes
punched downwards across the charge by a brass punch and knotted to secure.
Emulsions can be primed by pushing cord into the capwell and half-hitching near
the bottom threads to secure. Orica’s recommended priming procedures must be
followed.
Cut the detonating cord from the spool as soon as the hole is loaded. Detonating
cords should be cut only with non-ferrous anvil type shears, available from Orica
or its distributors. The cut ends should then be secured with electrical tape to prevent
spillage of the explosive contents.
Never do any work with detonating cords in magazines or portable containers.
Detonating cords must never be cut on a hard surface, nor should they be cut by
impacting with an axe or other sharp blow. Detonating cord is an explosive
and should never be used for anything other than its intended purpose.
In the unlikely event that you must connect two ends of detonating cord together,
use only a non-slip knot such as a square knot
33
Recommended Safe Working Practices – Orica Seismic Products
Surface Shooting
• To ensure every hole is detonated, the patterns must be connected in series
• Always use a specially designed firing line. If however, there are just a few patterns
and a line is not available, lead wire can be used
Seismic data may be obtained using surface methods but these shots would be
isolated and site-specific. Most importantly, they should be implemented by a
qualified field supervisor and/or the manufacturer’s technical personnel.
Orica’s instructions are specific to each product and must be reviewed prior
to surface shooting.
Key Safety Considerations for Surface Shooting
Crew members, must take all necessary precautions to avoid starting forest fires.
Three explosives configurations, which have potential, for initiating fires are:
• Exposed blaster (i.e. metal casing exposed)
• Concentrations of detonating cord in one place (i.e. wound around stakes)
• Exposed ends of detonating cord (i.e. cut ends which have not been taped
to cover the explosive core
Only one qualified blaster should be recognized as the chief blaster for a surface
operation. This blaster will have complete control over the explosives operation
and all personnel movement in the blasting area.
Before priming a surface charge the blaster should conduct the following
procedures in the proper sequence:
• Shunt one end of the firing line and secure this for connection to the blasting
machine later
• The blaster should shield or protect the seismic detonator, (in the ground, behind
a tree or on the ground with the base charge pointing away from himself), then
remove the shunt and securely connect the short detonator legwires (usually
3 meters /10 ft) to the shunted firing line in effect making a long shunted circuit
• This long detonator circuit can now be used to safely prime the surface charge
Never unshunt the legwires of a detonator close to another surface charge. Always
connect the legwires to a shunted firing line before priming a charge to maximize
protection against static electricity and minimize exposure to unintended explosive
detonation.
Surface charges, which are laid out but will not be detonated immediately, must
be guarded.
Specialty Applications
34
Blast warning signals must be sounded before detonation of surface shots.
As a possible example refer to the following table:
Before the blast
After the blast
12 short whistle signals must be
sounded at one second interval.
One long whistle signal
(minimum 5 seconds) to signify the
blasting area is safe be re-entered.
Two minutes pause between the last
warning signal and initiating the blast.
Seismic Cleanup
The seismic industry is committed to working alongside landowners, residents,
communities and other stakeholders to build and maintain long-term, mutually
beneficial relationships. Cleanup operations are one of the ways that the industry
demonstrates this commitment. Cleanup may be conducted as the seismic program
is being completed or in the case of some winter operations, cleanup is conducted
in the spring after the snow has melted. The intended purpose of cleanup is to
remove any residual garbage, which may have been left behind because of snow
cover, wind or oversight.
Although the magazine keeper maintains diligent inventory controls on each seismic
program, on rare occasion a cleanup crew may encounter a detonator, explosive
charge, primed charge or detonating cord above ground. Explosive materials found
on the surface should be considered live and extreme caution must be exercised as
follows:
• Do not touch, handle, move or disturb the product
• Document the exact legal land location, landscape indicators, permit tags or leave
a visible marker that will be easy to find
• Establish a 100 meter (330 ft) perimeter using flagging, barriers or guards to ensure
no entry
• No radios, cell phones or other transmitting devices are permitted within the
established perimeter
• The on-site supervisor must be notified immediately
• A person who is certified, trained and experienced in the handling of explosives
materials must be engaged to determine the appropriate course of action
• Copies of the chaining notes and drills logs should be reviewed for charge size and
depth at the time of drilling
• Actions must follow all regulatory requirements, safe work practices and in some
areas, local bylaws may also apply
35
Recommended Safe Working Practices – Orica Seismic Products
• If for safety reasons, it is determined that the charge must be relocated to
be destroyed, all transportation will be carried out in accordance with the
Transportation of Dangerous Goods, Clear Language Regulations, Transport
Canada, ATF and DOT requirements
• Use only an approved blasting machine, if required for disposal purposes
Specialty Applications
36
Prevention of Blasting Accidents
A Summary of Actions for the Prevention of Blasting Accidents
I. Storage of Explosive Materials
37
1.
Keep all unnecessary sources of heat or fire away from magazines.
NO SMOKING in or near magazines.
2.
Do not store or leave any combustible materials within 8 m (25 ft)
of magazines. Keep grass close to magazines cut very short.
3.
Store explosives only in authorized explosives magazines.
4.
Keep explosive magazines free from grit or dirt. Sweep magazines clean with
a whisk broom daily if magazines are used daily.
5.
Store only authorized explosives in explosives magazines. (No metal tools or
equipment, no oil, paint, gasoline, etc.).
6.
Never store explosives near a heat source, such as radiators, stoves,
steam-pipes, etc.
7.
Detonating cords are explosives and should be stored in explosives magazines.
8.
Store detonators only in authorized detonator magazines.
9.
Never store detonators in the same magazine as explosives.
10.
Keep detonator magazines clean and tidy on a daily basis if magazines are
used daily.
11.
Do not store anything other than detonators in detonator magazines.
12.
On receiving new stock, relocate current stock to the front of the magazine
so that oldest stock is always used first.
13.
Do not overload magazines. Stack cases so they cannot fall.
14.
In loading, unloading or shifting cases, handle explosive materials as though
they were breakable goods. Do not throw, drop, jolt, slide or kick cases.
15.
Magazines must be locked at all times and access to keys controlled.
Recommended Safe Working Practices – Orica Seismic Products
II. Collection of Explosive Materials and Transportation to the Line
1.
Check that day-boxes are clean and free from dirt, grit, crumbs of explosives
and any other extraneous materials before loading.
2.
Collect requirements from the explosives and detonator magazines and ensure
these magazines are securely locked before leaving.
3.
Handle both explosives and detonators as though these were breakable goods.
Do not throw, drop, jolt, slide or kick cases.
4.
Secure cases neatly in the appropriate day-boxes prior to transporting.
5.
Place explosives only in the explosives compartment and place detonators only
in the detonator compartment.
6.
Never transport anything other than explosives or detonators in the day-boxes.
(No loose metal objects, no supplies of any kind other than the explosive
materials).
7.
Lock day-boxes securely before leaving.
8.
Drive vehicles containing explosives and detonators in such a manner as
to minimize bumping, jolting and load movement of the explosives contents.
III. Preparation of Charge
1.
After drilling the shot hole, remove only the number of explosive cartridges
for that shot. Couple charges if necessary. Do not make up more charges than
required to be loaded and fired in one shot.
2.
Handle charges carefully. Do not drop or throw cartridges on the ground.
3.
Use only an approved brass priming punch to make a cavity for the detonator.
4.
Do not use screwdrivers or any other steel implements for punching.
Never Place Charges near Exhausts!
5.
Do not use undue force in punching. Do not hammer punches. Do not swing
axes or other steel implements at cartridges. Do not swing cartridges at sharp
objects. Do not spear cartridges with stinger-points.
NOTE: If powder appears too hard to punch by applying a reasonable amount
of steady pressure on the punch, report to the party manager who will contact
the manufacturer.
6.
Do not punch a cartridge near the top where the detonator might come
in contact with the loading pole.
7.
If required to cut powder, do this only with an approved brass knife. Cut only
on a soft surface, such as the ground or on wood, (not on a metal surface).
Clean up any fragments of powder, and drop them down the borehole.
Never cut cartridges in magazines or day-boxes.
Prevention of Blasting Accidents
38
IV. Handling of Detonators
1.
Keep detonators away from open flame, sparks, or heat sources.
NO SMOKING.
2.
Avoid impact on detonators. Do not attempt to pry detonators open
to investigate the contents. Do not attempt to pull the legwires out
of the detonators.
3.
Wear only natural fiber outer clothing. Synthetics, such as nylon, generate
static energy.
4.
Ground yourself whenever possible to bleed away static charges prior
to handling detonators. Many simple actions such as sliding off a vehicle
seat can generate static.
5.
Avoid excessive friction with plastics. Do not let legwires slide through
your hands.
Keep your shunt on
6.
Minimize handling of detonators. Leave in containers until required. Do not
carry detonators in your pockets.
7.
Do not throw legwires through the air.
8.
Do not handle detonators during severe dust, snow or electric storms.
9.
Do not transmit on any radio when handling detonators. (RF energy can initiate
detonators under certain circumstances).
10.
Keep legwires close to the ground to minimize any antenna effect for RF pick-up.
11.
Avoid any contact between detonators or legwires and any source of power,
(electric cables, etc.). Avoid unnecessary contact with any conductor of
electricity, (fences, etc.).
MOST IMPORTANT. Never remove the shunt or separate the duplex wires
of detonators (electric and electronic) until a primed charge is safely in the hole,
or until absolutely necessary.
Never make up charges ahead of time
39
Recommended Safe Working Practices – Orica Seismic Products
V. Priming of Charge
1.
Remove only the number of detonators required for the shot point at hand.
2.
Check that the detonator (electric and electronic) is securely shunted.
If you have any doubt, twist wire ends together.
3.
Do not start priming until the hole is ready to load.
4.
Prime the charge by inserting the detonator firmly into the detonator cavity.
Never force the detonator into the charge. Enlarge the cavity if necessary but
never attempt to enlarge the detonator well of cast booster charges such
as Osx™ 8.
5.
Secure the detonator by making two half-hitches with the legwires around
the cartridge.
6.
Never prime charges in advance of your immediate requirements.
7.
Never transport a primed charge on a vehicle.
8.
Never drag primed charges by the detonator legwires.
VI. Loading of Charge
1.
Use drive points to anchor the charge and to prevent upward movement.
2.
Re-check that the shunt is secure before starting to load.
3.
Lower the charge slowly into the hole. If force is required to lower the
charge apply even pressure on the loading pole. Do not hammer charges with
loading poles.
4.
Use only approved wooden loading poles.
5.
Never drop-load a primed cartridge.
6.
Never drop-load cartridges on top of a primed cartridge.
7.
Check circuit continuity with an approved galvanometer or circuit tester,
but only after the charge is loaded to depth and additionally after stemming.
8.
Close day-boxes before proceeding to the next shot point.
9.
When the day’s work is complete, return any unused explosives and detonators
to the magazine in their original cases.
10.
Make sure magazines are locked.
Prevention of Blasting Accidents
40
VII. Shooting
1.
Do not remove protective legwire shunts or untwist the wires end of electric
detonators until ready to make final connections.
2.
Make sure all wire ends are bright and clean before making connections.
3.
Do not transmit on any radio until ready to fire.
4.
Keep the firing circuit insulated from the ground or other conductors such
as bare wires, rails, pipes, etc.
5.
Keep all electric wires or cables away from the blasting area until ready
to prepare and fire the shot.
Never prime charges before completing the hole
6.
Ensure that the blasting machine is incapable of dispensing an electrical charge
before making connections. Touch firing-cable ends together to equalize any
potential difference.
7.
Test circuits of all detonators using only an approved blasting galvanometer
or Tester.
8.
Withdraw all personnel to a safe distance and/or take cover before shooting.
Charges might be shallower than intended which could cause cratering and
dangerous flyrock.
9.
In the unlikely event that a charge is thrown from the hole, do not approach
the charge until you are sure it is not burning.
10.
Approach a hole with caution even after the charge has detonated.
Always be prepared for delayed blowout.
VIII. Use of Detonating Cords
41
1.
Cut detonating cord only with approved non-sparking anvil type shears.
2.
Tape ends of cut cords to contain the explosive powder.
3.
Never cut cords in magazines or day-boxes.
4.
Never cut cords on a metal surface with a knife.
5.
Never use any form of impact to cut cord.
6.
Never use cords for any purpose other than an explosive charge.
(Do not use cord for bootlaces, tying parcels, securing equipment, belt, etc).
Recommended Safe Working Practices – Orica Seismic Products
IX. Use of Explosives on Surface
This refers particularly to the use of ‘saddlebag’ explosive packs suspended on lath
and interconnected by detonating cord in the traditional POULTER method of seismic
shooting. It also includes use of any linear explosives or any surface configuration.
Caution: Be aware of fire hazards
In any work with explosive materials on the surface, in dry forested or grassy areas,
there is a risk of starting fires. This risk can be minimized by avoiding the use of
naked detonators and/or concentrations of detonating cord. However, it is strongly
recommended that crews carry fire-extinguishing equipment to quench any fires
before they can spread.
1.
All crew members operating less than 500 meters (1700 ft) from the shooting
crew should wear suitable hearing protection.
2.
Shooting crew should wear hard hats, suitable hearing protection and safety
glasses.
3.
Line crews, preload crew and shooting crew should all have radios for proper
spread control where line of sight is not possible.
4.
The shooter shall be recognized as the ‘chief blaster’ and shall have complete
control over the explosive operation and all personnel movement in the
blasting area.
5.
All personnel should maintain a 100 – 150 meter (330 – 500 ft) distance
from the explosives on the spread. Distance depends on the amount of
explosives used.
6.
When laying out explosives patterns, never overlap patterns from adjacent
shot points.
7.
Never lay out more than one pattern at a time unless a minimum distance
of 15 meters (50 ft) can be maintained between patterns. Never interconnect
patterns by cord, even temporarily.
8.
Do not wind cord around explosive packs on stakes. This could cause cut-offs
and/or fires.
9.
Always tape the cut ends of cord to prevent spillage of both the explosives and
fire retardant chemicals.
10.
Do not lay rocks, stumps or any other debris on the explosive packs or linear
explosives. These could become projectiles.
11.
When placing explosive packs along the trunkline, assure equidistant placement
with intimate contact to the cord.
Prevention of Blasting Accidents
42
43
12.
Always carry detonators in a light aluminum, or other non-sparking metal
box which will hold one or two cartons. This will protect the detonators from
physical damage and from stray electric currents or RF transmission energy.
13.
Only one person, the ‘Chief Blaster’, shall have control over the seismic
detonators. Never assign the arming duties to two people.
14.
All personnel on the spread should be accounted for visually or by radio before
priming the charge.
15.
The detonator should be used to prime a point charge directly and the point
charge will then initiate the trunkline. Assure that the detonator is fully within
the point charge so that the detonator body will be totally consumed in the
detonation. Shooting exposed detonators could cause forest fires.
16.
Should a trail or cut line intersect the explosive pattern a guard with a radio
should be stationed both ways on the trail at a safe distance to eliminate
the possibility of trappers, hunters, hikers or animals walking up on the line
unexpectedly.
17.
Immediately after a personnel check, radio silence must be requested until the
charge is primed and hooked up to the blasting machine.
18.
Always disconnect the firing line from the blasting machine and twist the wires
together to act as a shunt, before connecting to the detonator leads. Touch the
firing ends together to ensure that no potential difference exists before making
final connections.
19.
The circuit should be tested only after the shooter has returned to the blasting
machine.
20.
Do not leave surface patterns laid out overnight.
Recommended Safe Working Practices – Orica Seismic Products
Disclaimer
The information contained herein is based on experience and is believed to be accurate and up to date as at
the date of its preparation. However, uses and conditions of use are not within the manufacturer’s control
and users should determine the suitability of such products and methods of use for their purposes. Neither
the manufacturer nor the seller makes any warranty of any kind, express or implied, statutory or otherwise,
except that the products described herein shall conform to the manufacturer’s or seller’s specifications. The
manufacturer and the seller expressly disclaim all other warranties, INCLUDING, WITHOUT LIMITATION,
WARRANTIES CONCERNING MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Under no
circumstances shall the manufacturer or the seller be liable for indirect, special, consequential, or incidental
damages including, without limitation, damages for lost or anticipated profits.
Trade Marks and Copyright
The word Orica, the Ring device and the Orica mark are trademarks of Orica group Companies.
Osx, Osd, Oseis, Geogel, Magnagel, and Cordtex are trademarks of Orica Explosives Technology Pty Ltd.
ACN 075 659 353, 1 Nicholson Street, East Melbourne, Victoria, Australia. All copyright in these materials
belongs to Orica. This copyright is protected by Australian and international copyright laws.
References and Acknowledgements
Seismic Exploration, Dr. Ian Ross, Orica Canada Inc. Retired
Canadian Association of Geophysical Contractors (CAGC)
Mike Barbe, Orica USA Inc. Retired
Safety Library Publications 17 & 20, The Institute of Makers of Explosives
Explosives and Rock Blasting, The Atlas Powder Company
Richard Randall, Orica USA Inc.
Clem Bennett, Orica USA Inc.
Disclaimer, Copyright, References and Acknowledgements
44
For contact information please visit our website
www.oricaminingservices.com