ST Pipeline completed construction of the 109 km Big Sandy Pipeline, traversing rugged mountain terrain, in 2008, with the pipeline officially opened in April this year. ST Pipeline was contracted by Equitrans L.P. to build the $US154 million, 20 inch diameter natural gas pipeline, which aims to relieve summer capacity constraints that were restricting gas production in the eastern Kentucky Basin.

Building a pipeline in the rugged mountains of eastern Kentucky required four-wheel drive vehicles to get up and down the 50 per cent slopes and also required the ALLU SM Screener-Crusher to prepare the blasted and excavated sandstone for use as structural fill material. The ALLU SM Screener-Crusher is a specialty attachment for loaders, excavators, and backhoes. The device has rotating discs with hammers that pulverise and size material.

ALLU dealer Leslie Equipment sold eight of the ALLU SM Screener-Crushers to ST Pipeline for use on the Big Sandy Pipeline where the terrain was so steep that steel cable winches connected to Deere JD700JLGP and CAT D8T bulldozers had to be used to hold 68,000 lb John Deere 240CLC and 270CLC excavators onto the mountain-sides.

ST Pipeline used six, 80 inch wide ALLU Model SMH-317 units and two, 101 inch wide ALLU Model SMH-423 unit Screener-Crusher attachments. The SMH-317 is equipped with three chain-driven drums with 40 mm disc spacing and hammers, and is driven by a two-way hydraulic drive system; the SMH-423 has four drums. For the Big Sandy Pipeline, ST Pipeline used the ALLU attachments on Deere excavators leased from Leslie Equipment.

“Given the steepness of this terrain and the difficulty of moving materials up to the job site, we had to find something that could give us useable structural fill in place,” said Jim Shafer, owner of ST Pipeline.

“I found information about the ALLU equipment on the internet and called Red Bailes at Leslie Equipment to get more information.”

Mr Shafer’s team used the ALLU SM Screener-Crushers for several different jobs, including to prepare excavated soils and rock for use in pipeline saddles and ditch line barriers; to temporarily anchor the installed pipe; and, to backfill the pipe prior to final grading.

“These ALLU attachments were just what we needed to keep up with our goal of installing 2,000 linear feet of pipe per day.”

Multipurpose uses for ALLU attachments

The Big Sandy Pipeline was installed in mostly a white sandstone geology, which frequently required blasting of rock. The construction right-of-way was only 30 m wide with steep drop-offs on either side.

The primary purpose of the ALLU SM Screener-Crusher was to backfill the pipe after installation. The unit can quickly pick up 2.3 cubic metres of excavated soil and deliver screened fill onto the pipeline without damaging it. The excavator operator then empties larger rocks out of the bucket before picking up the next load.

Mr Shafer’s team also used the ALLU SM Screener-Crusher to prepare the blasted and excavated rock for use in pipe saddles (soil-filled burlap bags that supported the pipeline) and in ditch line barriers – known as water breakers.

The water breakers were also made up of soil-filled burlap bags that were stacked to form walls around the pipeline. They were designed to slow the water flow in the pipeline trench on steep slopes so as to prevent washout of the soil around the pipe. The workers from ST Pipeline used the ALLU SM Screener-Crusher to prepare excavated backfill and then fill the burlap bags by hand.

“I am extremely satisfied with my ALLU equipment,” said Mr Shafer. “I’ve been installing pipelines for over 40 years and I’ve never seen anything so efficient.”