It’s been said that great things can be done when men and mountains meet. The same was proven true for the McElroy Talon™ and a glacier-topped mountain in Alaska that came calling last spring.
A pipeline solution
There are nearly 50 hydropower facilities in Alaska, but the Bradley Lake Hydroelectric Plant is the largest. It provides 10% of the state’s renewable energy, but the Homer Electric Association’s goal is to boost that to 18%. To make that happen, they needed to increase its power capacity and to do that they needed more water in Bradley Lake. Plans were made to construct a massive 10,000’ HDPE pipeline that would divert glacier runoff from Battle Creek to Bradley Lake, but the steep, rugged terrain and the remote location on the Kenai Peninsula about 27 miles from Homer, Alaska, wouldn’t make it easy. Just to get there was a feat in itself. From Homer, the only way to reach the jobsite was by plane, helicopter or boat depending on the rise of the tide. The big equipment was delivered by barge.
A revolutionary machine
The design of the Talon — McElroy’s largest fusion machine — was inspired by the increasing use of pipe up to 2000mm. McElroy looked for a safer, more efficient way to fuse large-diameter pipe because the bigger the pipe, the higher it must be loaded up and over into a traditional fusion machine which requires the assistance of large, onsite material-handling equipment. The solution was to turn the machine upside down and incorporate a unique jaw design that allows it to drive over pipe and lift it up from the ground, position it to be fused and move from joint to joint down the pipeline. This new method for handling pipe which launched in 2013 provides a safer, more efficient way to fuse large pipe.
Proving its capabilities
While designed to fuse large-diameter pipe in the most challenging situations, the relatively new Talon had not yet experienced the kinds of geographic challenges the Kenai Mountains presented. Prior jobs had been mostly flat and straight; this one featured steep grades upwards at 17% and downwards of 18% with tight corners all around.
The 1600mm (63”) HDPE pipeline would be fused up the side of a mountain on a very narrow roadway that was not much wider than the Talon itself. The job application at Bradley Lake was the main reason GMC Contracting decided to buy the self-contained Talon fusion machine from ISCO Industries. GMC of Anchorage, is a civil contractor that has been in business for decades focused largely on underground pipe fusion work and site development.
“We were really excited about landing this job with Orion Contracting,” said Todd Bethard, Vice President of GMC and a civil engineer. “The pipe itself was at first a bit daunting but things turned out pretty well.”
GMC saw that there wasn’t going to be a lot of room on the narrow road for moving a generator around and pulling a conventional rolling fusion machine up the mountain with a dozer.
“It would just mean more equipment required and we really needed to be able to provide access at times up to the dam itself … so with all that equipment cluttering the way we just figured it was going to be too difficult,” Bethard said.
Because of the Talon’s ability to load pipe from the ground and track upwards on rough terrain, it was believed that it was the only machine that could handle the demands of the job.
It was definitely a big job but Bethard said they received great support from ISCO and McElroy, and, thankfully, they didn’t have to contend with altitude challenges despite the terrain. Prior to the job, McElroy provided hands-on training on the Talon and GMC’s operators picked it up quickly.
“It’s a big fusion machine, but it’s still a fusion machine,” said Matt Hennigan, a Training Specialist with McElroy University.
Rotating teams from McElroy provided onsite technical assistance once the job started while others worked behind the scenes at home to troubleshoot via the Talon’s remote interface as well as the Crew App. Cell connectivity was often poor but overcome by everyone’s determination to resolve issues as quickly as possible and a team effort to complete the project successfully and productively.
Taken into consideration in the analysis of joint reports was the pipe thickness of the Borouge PE100 DR21 pipe which varied from 3” to 3.75” which added to the alignment, heat soak and cool time. Initial test fusions were conducted to undergo bend back testing. It was decided to remove all the internal bead formations to create a smooth surface and check for proper alignment.
Fusions began at the base of the mountain with McElroy’s MegaMc® 1600 and the Talon joining two 40’ sticks of pipe together. A flatbed truck moved these 20,000-pound, 80’ sections up the mountain. Once they were staged, the Talon was placed on a low-loading trailer for the 9-mile trip up the mountain to begin fusing.
Talon for the win
Despite the enormity of the pipe, the pipeline was fused with minimal pipe support. An easier jobsite setup along with the Talon’s ability to more easily align the pipe and move from joint to joint made all the difference.
Brandon Jackman, Sustaining Engineering Manager at McElroy, tracked the Talon’s productivity. He was pleased to report its ability to fuse four joints a day and that there were more than a dozen days where they were making five or six fusions a day. Water was flowing in the pipeline in July after taking less than two months to complete which beat the time allotted for fusion.
Altogether the Talon performed 155 fusions, and 120 of those were high on that mountain.