Mine Safety

1. Denr administrative
order 2000-98
MINE SAFETY | EM 412
SECTION 46 DREDGING
[ J o C h ]

2. ● WHAT IS DREDGING?
● HOW DOES IT WORK?
● WHEN TO DREDGE?
● SAFETY OPERATIONS
Section 46 dredging

3. ● WHAT IS DREDGING?
Dredging is the recovery
of mined materials from under water.
One method of placer mining.
Section 46 dredging

4. ● HOW DOES IT WORK?
DREDGER
1. mechanical
2. hydraulic
1 bucket ladder dredge
2 grab dredge
3 dipper and backhoe dredge
4 plain suction dredge
5 cutter dredge
6 trailing suction hopper dredge
Section 46 dredging

6. RULE 454:
All safety rules regarding
the operation of chain-and-bucket
excavations shall apply.
*trench is defined as a narrow underground excavation >15 ft
https://www.osha.gov/Publications/trench_excavation_fs.html
Section 46 dredging
General Trenching and Excavation Rules
● Keep heavy equipment away from trench edges.
● Keep surcharge loads at least 2 feet (0.6 meters) from
trench edges.
● Know where underground utilities are located.
● Test for low oxygen, hazardous fumes and toxic gases.
● Inspect trenches at the start of each shift.
● Inspect trenches following a rainstorm.
● Do not work under raised loads.

7. RULE 455:
During service, each floating dredge pump
installations shall have at least two (2)
rowboats in good condition, one of which
shall be floating and ready. The life saving
appliances shall be hanged conspicuously
around the sides of floating dredge pumps.
*conspicuous means to be easily noticed
Section 46 dredging

8. RULE 456:
A rope line shall be provided along
the sides of the dredge pontoon
at a convenient distance above
the water line for grasp line of
anyone who may accidentally fall
into the water.
*pontoon means a flat-bottomed boat
Section 46 dredging

9. RULE 457:
At least two (2) sets of
life-saving appliances per
twenty (20) meters of deck
length shall be placed at
conspicuous points along
the sides of the dredge and
shall be provided with sign
boards.
Section 46 dredging

10. RULE 458:
Each dredge shall be served by at least
two (2) row boats ready with oars,
one of them floating at the side of the
lantern mounted at the bow.
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11. RULE 459:
Before any operation on a dredge is
started, the corresponding signals shall be
given such as starting up, shutdown,
shiftover, etc.
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12. RULE 460:
While the dredge is in operation, it shall be
prohibited to:
a. Pass through the bucket carrying frame or move
along it;
b. Climb into a bucket or chain link, nor enter the
discharge batch, or remain at the bow of the
pontoon or near the bucket slot when the bucket
chain frame is raised high; and
c. Use of mooring ropes to reach the bank or over
the pontoon or gangway to the bank.
Section 46 dredging

13. RULE 461:
A trap or gangway of firm
construction shall be suspended
between the dredge and the bank to
facilitate movements.
RULE 462:
No gangway or trap shall be
raised or lowered when there is a
person on it.
*gangway is a raised platform or walkway providing a passage
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14. RULE 463:
A gangway fitted with
handrails shall be
provided for movement
of personnel
to and from the roof and
upper deck.
Section 46 dredging

15. MISCELLANEOUS
GINGINEERS
BLOCK 2X2