The Mississippi River Valley Alluvial Aquifer — a primary water source for small towns, rural water systems and farm irrigation in eastern Arkansas — is running dry. According to the Army Corps of Engineers’ website, a project study in the mid-1980s pointed out, and further studies have since shown, the region’s groundwater resources are rapidly shrinking.
As part of its plan to preserve and protect the Alluvial Aquifer – and the deeper, more recently tapped Sparta Aquifer – the Army Corps of Engineers is constructing an irrigation system that will bring more than 100 billion gallons of water annually from the White River at DeValls Bluff to about 250,000 acres of farmland in Arkansas, Lonoke, Monroe and Prairie counties.
The system will include a $26-million pump station and 1.5 miles of pipe, supplied by AMERICAN SpiralWeld Pipe, in Columbia, South Carolina, to carry water from the Grand Prairie Pump Station to a 100-acre reservoir, where it will be distributed to area farms.
From the pump station, two 120-inch-diameter spiral-welded steel pipelines will split into four 84-inch pipelines, which will then each split into 42-inch pipelines. The 120-inch wye fittings to split the 120-inch pipelines were a first for AMERICAN SpiralWeld. “We have made and shipped 120-inch pipe and fittings, but none of this magnitude with these dimensional challenges,” said Kyle Couture, assistant manager of Customer Service for AMERICAN Ductile Iron Pipe and SpiralWeld Pipe.
“The width of the fittings could not exceed 18 feet, the maximum allowed width for transport by truck through states including South Carolina, Georgia, Alabama, Mississippi and Arkansas. The fittings are 17 feet and 3 inches.”
The challenge began with the design of the fittings. “The width of the fittings could not exceed 18 feet, the maximum allowed width for transport by truck through states including South Carolina, Georgia, Alabama, Mississippi and Arkansas,” Couture said. “The fittings are 17 feet and 3 inches.”
In addition to width, there were also height restrictions to ensure fittings would clear underpasses, bridges and train trestles during transport. And then there was the challenge of positioning the load on the trailer. “AMERICAN SpiralWeld Technical Systems created 3D computer models to use in identifying the center of gravity of the pipe sections, and then determining their correct positioning on the truck,” said Patrick Hook, vice president of Operations for AMERICAN SpiralWeld.
A specially designed steel rack was constructed to cradle the pipe and fitting sections during shipment. “Getting the design of this rack right was critical,” Hook said, “and it was especially difficult because the fittings were not centered side-to-side on the trailer. This was a major accomplishment for our team.”
Manufacture of the fittings was equally as challenging. The size of the 84-inch wye outlets, connected at acute 45-degree angles to the 120-inch pipe, meant the plant’s computer-operated cutting machine couldn’t be used to cut the pipe. Again, computer modeling was used. “The cut of each outlet was modeled on a computer, the cut dimensions were transferred to the 84-inch pipe in 3-inch increments, and then the pipe was cut by hand,” Hook said.
Prior to cutting the 84-inch hole in the 120-inch pipe, braces were tacked in place to stabilize and maintain the shape of the 120-inch pipe after the cut. “This was necessary because the cut made a hole in the 120-inch pipe that was 85 inches tall and 121 inches wide,” Hook said.
Technical Systems designed special lugs for handling the fittings during fabrication and loading, and to secure the fittings to the trailer for shipment. “These lugs proved invaluable during the fabrication process to rotate and move the large fittings into various positions for welding,” Hook said.
Technical Systems also designed special fork lift adapters, made in-house by the Fabrication Department, to keep the fittings from rotating as they were being moved through the plant during manufacturing. “It was quite spectacular to see,” Hook said.
Once constructed and nestled in the steel rack for transport, the journey began from Columbia, South Carolina, to DeValls Bluff, Arkansas. The route was driven and mapped ahead of time to determine the best roads to travel. “The jobsite is in a very rural part of Arkansas,” Couture said. “The route included a lot of two-lane back roads, a challenge for a shipment that takes up one-and-a-half highway lanes.”
The shipment of each fitting would require a great deal of logistical planning by AMERICAN’s Traffic Department in coordination with AMERICAN SpiralWeld’s Shipping Department. Each of the five states crossed, from South Carolina to Arkansas, required a written request and compliance with state-enforced regulations for hauling such large pieces.
“Alabama, for instance, required us to cross the state between midnight and 6 a.m.,” Couture said. “Other states restricted us to daylight hours. All states required us to have escorts; some required escorts by state troopers. Alabama also required documentation of reasons why the fittings could not be transported by another means, such as rail or waterway.”
After successful delivery of the first fitting, the specially made steel rack used to cradle the fitting was hauled back to South Carolina and loaded with the second 120-inch wye fitting, which was then transported in the same manner to the jobsite.
AMERICAN SpiralWeld Pipe is a division of AMERICAN Cast Iron Pipe Company, headquartered in Birmingham, Alabama. In addition to spiral-welded steel pipe for water and wastewater transmission, the company manufactures ductile iron pipe, valves and hydrants for the waterworks industry and ERW steel pipe for the oil and gas industries. The company’s diversified product line also includes static castings and high-performance fire pumps.