MSHA - Interactive Training - JTA Spiders

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	Blasting
	Contact: Palmer.Melvin@dol.gov

1. Conduct pre-blast meeting

Review weather conditions

Communicate number of holes

Information from supervisor for communication purposes only

Calculate bags per hole

Calculate 3.94 lbs of anfo per linear foot

Discuss reasons to turn electronic devices off i.e. 2-way radio

Discuss reasons to avoid stepping on detonator cords

Minimize foot traffic in blast area and no motorized vehicles

Review reaons to always face the highwall (Don't turn your back to the ledge)

Discuss stemming process

One shovel of coarse stone and one shovel of fines/chips (layered)

Remind Driller to communicate every hour with supervisor of status

Communicate any needs and status of the Driller

Note: This is very important for those working alone

2. Complete Blaster's log

Log must be completed in it's entirety

Enter date

Enter time

Enter name of quarry

Enter specific location of face (north, south, east, west)

Describe weather conditions

Wind (speed, direction)

Clouds

Enter blaster's name

Enter number of holes

Enter depth of holes

Enter spacing of holes

Enter spacing of burden

Enter amount of 25 ms 700 ms detonators

Enter amount of boosters

Enter amount of detonating cord

Enter amount of 17 ms delays

Sketch drill pattern

Burden, spacing, face

Enter total number of anfo bags

Enter number of pounds of anfo per hole

Enter time of detonation

Note any misfires

3. Site preparation

Deliver stemming materials to blast site (front-end loader operator)

Request made by blaster or supervisor

Locate or place blaster's shed behind or to the side of shot

Blaster shed must be constructed of a minimuym of 3/8" steel; place 300 - 500 eet away from blasting area away from blasting area

Place and/or check for proper signage

Signs are for general public and employees; Signs should be written in both English and Spanish

4. Loading the hole

Loading done by two persons

Best practice (time)

Load holes closest to the face and work your way back

Spot the explosives around the hole

Place anfo on one side of hole

Place booster on opposite side on hole

Place detonator on free side of hole

Slide detonator through booster and fasten in second hole in the booster

Follow proper task training according to manufacturer instructions

Lower detonator and booster into the hole

Pour anfo into hole

Measure depth of anfo with wooden pole

This should be done by a second person

Stop adding anfo at 10' from top of hole or maximum of 3 bags for a 35' hole

Different hole depths will require different calculations

Place stemming into hole

Place one shovel of coarse and one shovel of fine

Stemming must be level with top of hole

Repeat process for each hole

Never leave blast site unattended

5. Unusual occurrences

Misfire

Notify affected workers

Re-initiate blast notification

Check connections and reconnect the 700 ms detonators

Run new primer cord to blaster's shed

Repeat blast notification procedures

Blast

Repeat post-blast procedures

Lost hole

Cancel the hole (back fill hole)

To prevent misdirection of blast energy

Return explosives to inventory

Note cancelled hole on blaster's log

X-thru explosives used or note "cancel"

Approaching storm

Stop loading

Evacuate

Secure area

Column shift

Treat as a misfire

Wash explosives from hole

6. Post blast procedures

Prohibit entrance to site for 30 minutes

Release access roads

Resume business activities as normal

Return to blast area after 30 minutes

Check area for misfires; avoid gas exposure created by blast

Visually check 700 ms for visible detonation

Look for cap to be blown

Will be opened up with black powder; Last one on each row indicates detonation

7. Blast notification

Notify all equipment operators with radios to barricade roads

Notify scale house to contact fire department

Remove all personnel from blast area (at least 1000' from site)

Call shot firer and instruct him to prime the blast

Radio each check point for final confirmation

Licensed blaster will make a final check and initiate blast

8. Connecting the shot

Clear area except for authorized personnel

Remove van and all equipment

Run detonating cord to blasters shed

Make primer cord and blast hole connections

Refer to blasters chart

Walk the blast site after all connections are made

Title

Blasting

Subject

Company

Author

debbie combs

Version

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