T-Junction
Dig 13
11/24/01 and 11/25/01
Only 80.58' to go!
Diggers: John Bowles, Greg Buckley, Bill Copeland, Tim Fuller, Rick Hines,
Seokbin Lim, Dave McCool, Jeff Page, Kerry Rowland, Eddie Simmons, Carl Wagner,
Chris Wolters
Four blasts were completed. The depth gained was 5.5 feet
Blast 14 Drilling went well using a drill and compressor
provided by David McCool. Six holes were drilled to between 2'10" and
3'. Total drill time was 50 minutes. The holes were loaded with 1
stick of dynamite and 24 inches of power split. After the blast the depth
measurement showed that we had only removed 6 inches. After pushing the
loose material down the hole we found a foot thick shelf with a cavity below.
The blast had blown out above and below a stubborn foot thick layer.
Blast 15 We jack hammered the layer down to about 10
inches thick and then drilled 6 8" holes. The holes were loaded with
a doubled over stick of 16" power split. After blasting and jack
hammering we whittled the layer down to 6 to 10 inches at the lip of the 9-inch
hole.
Blast 16 Determined to get the stubborn layer we
drilled 18 new 8" holes. We drilled at about a 20-degree angle at the
perimeter of our 30" hole to avoid breaking into the void below. 23
sticks of 16" power split were looped into the new and old holes. A
foot of dirt was pack on top to help direct the energy into the stubborn layer.
The blast was the most spectacular so far, sending a column of mud 100 feet into
the air. More importantly the ledge was reduced to two triangles on
opposite sides of the hole that were removed with the jackhammer. One
large hunch of the ledge measuring 6 by 6 by 16" was removed. The
rock, per our resident geologist, is a type of sandy limestone. Nearly all
of the CaCO3 has been dissolved and replaced by SiO2. The rock would
crumble into table salt sized grains of transparent quartz. After squaring
up the hole, the total depth gained for blast 14, 15, and 16 was 2.6 feet.&nb
sp;
Blast 17 Eddie drilled 6 4-foot deep holes in 36
minutes using our compressor and Dave's drill. Dave loaded them with all
the explosive we had left. Each hole got two sticks of dynamite, 1.5 or 2
sticks of power split and a third stick of dynamite on top. This produced
another spectacular blast throwing rock 100' into the air. We were hoping
to gain 4' but instead got a respectable pull of 2.9 feet.
A photo of the Sunday crew is attached. Several people have reported
trouble downloading the "Blast 16"
photo. I will try to send the
Blast 16 photo later.
Next Dig will be Saturday and Sunday, 12/1 and 12/2. Please call or email
as early as possible to sign up for next weekend or any future weekend.
Rick
913 897 4258
