The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1920-07-22
HOW THE BIG YUKON
DREDGE WAS RAISED
Feat Without Prece-
dent in History
of Dredging
NO DAMAGE TO HULL
Success the Result of Careful
Planning and Efficiency
in Management

"NHE precision OF proceeding o
hte crews working like drill
teams, on a practiced SEIZED
ule which was the marked
feature of the successful raising
of the large steel dredge OF
the Yukon Gold company at Murray
on July 18TH following several weeks
of intensive preparation, has brought
out many inquiries as to the methods
employed, and the Miner has the fol-
lowing description to offer of the
unique performance.
The Problem and Its Solution.
The dredge was sunk early in June
during the night in its pond 25 feet
deep. The problem was complicated
by the great 1OOO-ton mass of steel
and machinery resting on an uneven
bottom listed Is degrees from star
board to port. Although guyed and
anchored in all directions with %
steel cables soon after sinking, the
dredge would have tipped completely
over had it been merely pumped out
without observing some hundreds of
special precautions. One of the prin-
cipal preparations was the lowering of
the pond water, which was accom-
plished by blasting and scraping a
deep canal nearly 1000 feet long, and
also by diverting the waters of Pritch-
ard creek. To help prevent the dredge
from tipping over and sinking deep on
the high side when it righted itself
r,F
high as possible by the diver under
the starboard side of the hull
Precautions to Prevent Tipping.
The steel cables or guy lines from
the high superstructure were made
adjustable on the shore on both sides
of the dredge, crews at each of these
stations pulled in or let out on these
lines by means of hand winches and
heavy tackle and gradually pulled the
dredge over to a level position as she
grew lighter from pumping out her
load of water, and raised up. The
was further complicated
by the seven outside pontoons or
extra compartments which surround
the hull, requiring seven individual
pump suctions in addition to the
various main pumping units used to
unwater the hull. Thirteen suctions
were used altogether.
On account of the great danger of
the dredge tipping entirely over due
to the high side of the hull being emp
tied first and floating, many strong
cables were attached to this star
board side. To assist these guys, about
100 tons of water were left as ballast
in the pontoons or water tight COM
partments on this extreme starboard
side of the hull. When the dredge fin
ally came up all lines were held tight
to keep the boat level, but this would
not suffice without the quick pump
ing out of the water in the three star
board pontoons. which was accom-
plished with celebrity by a group of
small pumps which were set up on
wheels with long power cables to per-
nit of their being moved rapidly to
various positions
Raised on the 18th.
All preparations were complete on
July Sth. On the 9Th a trial run was
made, and the dredge brought nearly
o the surface, but as the pumps were /
not giving perfect service that day
With their long suctions, Zone 16-inch |
pump sucking p feet), it was decided |
q postpone complete flotation until
could be further tighten
ID. On account of electrical storms !
md consequent hazard of power in
erruptions, the crews we're laid off /
until the 18th, as even a S-minute
power interruption at the critical time |
when the dredge came to the surface, |
night have resulted in it's sinking in
more serious position on the uneven
POTION.
At a m. July 18th all pumps were
tarted, and nearly half a million gal .
ons of water rapidly pumped out of
he hull. This included considerable
due to pressure of water
through small cracks deeply sub
merged, in the wooden deck and wood
N filters around the deck beams. How
YER the leakage had been reduced to
bout one hundredth of it's former
-olume by an original scheme of
jumping several tons of sawdust
through a centrifugal pump and water
cts into all those cracks which were J.
to stoppage by hand work
r divers efforts. Several tons of
manure were applied by the diver in