The Problem:
Installing two large diameter casings under the Burlington Northern/Santa
Fe Railroad for the expansion of a golf course. Safety was a major
concern since the track was traveled by up to 120 trains each day.
In addition, the expansion would also be adding more hike and bike
trails in the area, so the safety of pedestrians eliminated the
option of an above ground crossing.
The Solution:
Middlecreek Mining Corporation knew that large diameter casings
under the railroad tracks provided the best solution and they
chose Permalok Steel Casing. For the first tunnel, Permalok
delivered four 21-foot joints of 120" O. D. casing. When
the initial tool configuration of segmented ram cones could
not stand up to the amount of stress placed on it, Permalok
fabricated a 120" pipe adapter that resembled an inverted
bell, which proved to be much more successful.
After learning new lessons on the smaller installation, the
crew began to work on the 138" job. Permalok provided pipe
for the larger tunnel that had an O. D. of 138" and a 1.5" wall
thickness. Each 21-foot joint weighed 46,000 lbs.
When installation was complete, the pipe forming the 148-foot
long tunnel weighed 323,000 lbs., and when the final casing segment
was in place, a new large diameter pipe ramming record was established. |