Demolition Safety and Transportation (Chapter 3) Flashcards
- For calculating MSD, When do you refer table 6-2?
When charge weight is more than 27 lbs and less than 500 lbs
- In temporary storage, how explosive should be stacked?
Explosive should:
Weigh no more than 500 lbs per pile
Placed no less than 140 feet apart
- What is minimum distance from energized power lines required to prepare electric blasting cap?
At least 155m
- To ensure circulation of air, what is minimum distance from top of stack to ceiling or cover?
No less than 18 inches
- To ensure circulation of air, what is minimum distance from bottom of stack to earth flooring?
No less than 3 inches
- Where are blasting caps stored during transportation?
Transfer in separate location from the explosives
How do you calculate MSD when charge weight is more than 500 lbs?
Meters = 100 x cube root of N.E.W
Feet =300 x cube root of N.E.W
(Bare Charges in the Open)
- Described the requirements for time fuse test burn, and how many times should be conducted?
At minimum 3 ft test burn. Do not use the first or last 6” of time fuse from a new or partially used roll (moisture) Book answer is every 24 hrs. However it should be conducted every hour.
- Premature detonation of electric blasting caps may be induced by:
Radio Radar TV signal Lightning Static electricity
- What are the some considerations in demolition safety?
a) Maintain Control of all initiation source at all times (i.e. RAMS transmitter, electrical blasting machines, etc.)
b) Suspend blasting operations during electrical storms
- What is the first step you take when conducting a continuity check?
Ground yourself
- What is SADD?
Rules for storing explosives: Safety Accessibility Dryness Drainage
Safety is most important
- How many people requires to conduct explosive transportation?
Use only minimum number of personnel necessary to accomplish the mission
- How many fire extinguishers you must have when you transporting explosive and what are they?
2, Class B/C
- What is the MSD for charges that less than 27 lbs?
300 meter
- Can you destroy blasting cap with burning method?
NO. Blasting cap destroy by only detonation
- What is formula for DET Cord N.E.W?
Length in feet x 54 grains per foot x RE Factor = total grains of explosives
Grains / 7000 = NET EXPLOSIVE WEIGHT IN LBS
- When placing electrical blasting caps in a metal container (like an ammo can), how much overlap should be on the lid ?
Minimum ½ inches overlap
- How long should you wait to clear a nonelectric misfire and electric misfire?
Non-electric: 30 minutes
Electric: Immediately
- What is the preferred method of disposing of explosive?
Burning
- Can you use BLASTING CAPS underground?
No, Do not use blasting caps underground, use DET Cord or M151/M152 boosters
- When burning explosive what must you do?
Calculate Minimum Safety Distance
Ensure stacked pules will not exceed 2000 lbs or more than 3 inches thick
Where should you not carry blasting caps?
Pockets or in any uncontrolled container
What should you do before un-shunting wires on an electric blasting cap?
Ground yourself
What should you do after a time fuse test burn?
Upon completion of test, mark roll with Your name, DTG, test burn time, then tie half knot in non-working end
RE factor for Det Cord
1.66
What should you avoid when working with Det cord?
Sharp bends, loops, kinks as well as stepping on the cord (Any of these can change the path of detonation and/or cause a cut in the cord)
What type of charge are the MSD’s for in this chapter?
Bare Charge in the Open
Non-electric Misfire Causes
Moisture in M7 Cap, M700 Time Fuse, Det Cord
Failure to seat M700 into M7 or M60/M81
Failure to properly seat the blasting cap into the cap well or explosive
Debris in the M7
Non-electric clearing procedures for aboveground charges
Wait 30 mins
Place a primed 1 lb charge next to misfired charge
Move to MSD, detonate
Non-electric clearing procedures for failure to initiate det cord branch line, line main, or ring main
Wait 30 mins
Attach a new initiating set
Move to MSD, detonate
Non-electric clearing procedures for buried charges
Wait 30 mins
Remove tamping to within 1ft, place a primed 2 lb charge on top
Move to MSD, detonate
If digging over charge is impractical, dig 1 ft to side at same depth
Electric Misfire Causes
Inoperable power source, damaged or weak batteries
Inadequate power source for number of caps and length of firing wire has too much resistance
Improper connections
Grounds in system
Electric Misfire Prevention
Make one individual responsible for all electrical wiring
Check: All connections, grounding of wires, number of caps does not exceed capacity of power source
Electric Misfire Clearing Procedures
Make another attempt to fire
Check connections, blasting machine, power source
Disconnect power source, use another if available
If second attempt fails, shunt wires
Inspect the entire circuit for wire breaks or short circuits
Do not attempt to remove or handle cap, place a primed 1lb charge next to misfired charge
Move to MSD, detonate
PERSON IN CHARGE WILL CLEAR MISFIRE WITH POWERSOURCE
Should the responsibility for loading, storing, and transporting explosives be divided?
No
Where should you park when transporting explosives?
Revetted Areas
How fast should you drive when transporting explosives?
35 mph
Should you refuel when transporting explosives?
No, except in emergencies
If blasting caps or other initiators must be transported in the same vehicle with other explosives, where should they be carried?
In the cab or the truck in an approved ammunition container
Types of permanent earth covered magazines for storage of explosives
Igloo
Steel-Arced
Hillside
Subsurface
Destruction Procedures for Detonation
Place charges on top of pile, every 4-5 feet
Rule for cutting shock tube
Never use crimpers
