Leaving a lighter footprint

Erica LoPresti, on behalf of Terramac, USA, describes how crawler carriers are redefining productivity for pipeline construction.

While standard wheeled and steel track carriers have traditionally been the go-to solution for most material transport applications in North America, oil and gas pipeline contractors were

finding that productivity suffered when these heavy haulers became stuck in wet ground conditions. In addition, the footprint of these machines often caused enough soil damage in transit to warrant calling for remedial repair work, which led to project cost overruns.

Companies such as Terramac, a leading US manufacturer of innovative rubber track crawler carriers, have discovered a revolutionary and productive solution to handle these challenges, with the introduction of new rubber track technology. While rubber tracks have long been used in smaller material delivery vehicles, such as fork lifts and front

loaders, these latest innovations have expanded the use of rubber tracks to crawler carriers.

“Crawler carriers are designed for the kind of terrain that chassis trucks and other vehicles cannot handle due to ground conditions, grade or working angles,” says Mike Crimaldi, CEO of Terramac. “A unique flotation design of the units’ rubber tracks lets the vehicle exert minimum ground pressure at full capacity. This leaves a minimal footprint for less soil disturbance and provides reduced slippage for the toughest weather and terrain conditions.”

Conquering the ability to tackle tough terrain soon led to outfitting these rubber tracked carriers for specific oil and gas pipeline applications, in order to further enhance jobsite productivity. Manufacturers have engineered crawler carriers to allow for a limitless number of application customisations.

As the multipurpose carrier is constructed with a frame that can easily accommodate customisations, it is able to

support various types of specialised oil and gas pipeline equipment for the job at hand. Terramac can customise electrical power sources, frame adjustments and hydraulics to suit any attachment without altering the unit’s chassis.

The result is the ability to take workers, equipment and raw materials to any jobsite, even those in remote locations, to complete pipeline projects on time and on budget. The top uses for crawler carriers in the oil and gas pipeline industry are discussed in this article.

Transporting crew membersTransporting workers to and from a jobsite can be challenging, but personnel crawler carriers make it a cinch. Personnel carriers are utilised throughout the entire pipeline project – from the clearing crews to the final reclamation crews – for their ability to transport the maximum amount of workers with one vehicle and minimum trips. These units are widely used on remote jobsites as they easily manoeuvre over rough, soft and steep ground conditions to transport crews along pipeline spreads efficiently and safely.

“The personnel crawler carriers are great to get out to wherever we need to go, and we go to some tough locations to get to the pipelines,” notes Jeff Wade, Owner of Ace Pipeline. “One carrier can take up to 25 crew members plus all their tools and meals safely out to the job and back. No more multiple vehicles getting in the way or getting stuck trying to get through. They can be enclosed with heaters to protect them from the elements. That makes a big difference.”

Many personnel carriers up to the 9 t size class can accommodate anywhere from 10 - 25 people with cabin configurations for safety and comfort.

Right-of-way clearingAn area must be established for the path of the pipeline, as well as for the transport of equipment and material during

the construction process. Crawler carriers are frequently used during the clearing process to aid in removing trees and bush from the pipeline right-of-way (ROW).

“A new process I’ve seen more of recently are pipeline crews grinding and mulching the trees and brush while they’re clearing,” says Jesse Whittaker, Regional Sales Manager at Terramac. “Crawler carriers are then used to remove the mulch from the ROW since the units’ rubber tracks can easily conquer the terrain with minimal disruption to the soil.”

Site investigationCrawler carriers can be used for potholing to identify existing pipelines before laying new ones, which is a critical step. This process has been improved with the use of hydro/vacuum excavation units mounted onto rubber track crawler carriers.

“The utilisation of the crawler carrier with a hydro excavation unit

Figure 1. Configured with a personnel carrier, units transport crews to remote pipeline jobsites.

Figure 2. Units outfitted with a flatbed make mat hauling easy on the pipeline ROW.

World Pipelines / REPRINTED FROM NORTH AMERICA 2017

allows customers to have easier access in the rougher, more treacherous terrain,” explains John Lucki, Vice President of Operations at Cross Country Infrastructure Services. “Combining these two units into one machine provides safer, faster and more cost-effective exposure of the pipelines, which makes a positive impact on the customer’s bottom line.”

Crawler carriers are widely used for this application for their nimble movement on all terrain types, unlike wheeled semi-trucks that were previously used.

HaulingFlatbed crawler carriers lead the way on oil and gas pipeline jobsites by hauling mats to be laid in preparation for heavier equipment to come through, while dump bed carriers that are fully loaded exert a very low PSI.

The bed versatility allows these units to haul various types of materials, including crib blocks to set pipe on during the welding phase and sandbags to pad the pipe in the trench. And with the ability to manoeuvre in all types of terrain, crawler carriers can easily haul material on asphalt roads without damaging the surface.

“With crawler carriers, contractors are able to effortlessly transport materials and supplies to jobsites while minimising environmental damage,” says Matt Slater, Director of Sales at Terramac. “Our full line of straight frame units feature heavy duty carrying capacities. These units are also offered with three standard options, flatbeds, convertible dump-to-flat beds and rock dump beds, allowing contractors to haul the heaviest materials including dirt, mud and rocks to any jobsite.”

Pipeline stringingTransporting pipe to be laid along the ROW requires the utmost attention to detail. Crawler carriers equipped with a specialised fifth wheel attachment simplify the pipeline stringing process by pulling the stringing trailer. These specialised carrier units allow the stringing crew to efficiently string the pipe from end to end along the ROW, eliminating the need for using heavy haulers that become stuck in adverse ground conditions or cause soil damage in transit. Flatbed carriers can also be utilised during this process to haul pipe to the jobsite in preparation for being laid.

Furthermore, crawler carriers with fuel tanks provide fuel for the entire fleet of equipment while working along the ROW; this increases productivity as machinery does not need to travel from the jobsite to a main road or equipment yard for refuelling.

Welding pipeCrawler carriers are often used as all terrain welding systems. After pipelines are aligned, the sections need to be welded together and prepared for placement into the trenches. The low ground pressure and off-road capability of a rubber track crawler carrier allows the unit to tackle challenging ground conditions in order to reach the worksite, while carrying the welding system required to finish the job.

In addition, crawler carriers can be configured with a crane to help the welding crew pick up and hold a line clamp while tack welding the pipe into place. The crane is also useful for holding up a canopy to provide the crew shade during the welding process and keep sun glare out of their welding hoods.

Slater explains that the Terramac RT9 equipped with a tack welder unit is able to deliver power for up to four welders at one time while also providing the shaded canopy necessary for teams to perfect their welds. He concludes by noting that this specialty unit has become highly useful on the pipeline jobsites of Terramac customers.

Figure 3. Courtney Construction uses the Terramac RT9 crawler carrier with two tack welding units working on a 10 in. and 12 in. pipeline.

Figure 4. Rotating functionality enables the Terramac RT14R to haul and dump materials in confined spaces with ease.

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Sandblasting/coatingCrawler carriers equipped with sandblasting rigs, air compressors and sandblast pots, make cleaning and coating a simple process for maintaining a pipeline over time. These specialised carrier units allow crews to sandblast the welds and remove any of the initial coating that could have been damaged during the welding process. The pipeline is blasted back down to the bare metal and prepped for a final coating of corrosion resistant epoxy.

ReclamationRestoring land to its original state is the last part of a job, and reaching jobsites in need of reclamation has a reputation of being problematic. However, this important step is made easy with crawler carriers equipped with specialised restoration equipment, such as hydroseeders.

“The hydroseeder allows the environmental crew to follow up the clean-up crew and spray the seed mix for erosion control with very little foot print and less disturbance on the surrounding soil,” says Billy Evans, General Manager of Shafer Equipment. “The crews can finish the job with little evidence they were ever there working.”

Due to the flotation from its rubber tracks, a crawler carrier will leave a minimal footprint, while the hydroseeder attachment allows users to seed, fertilize and mulch in one simple process. Crawler carriers with water tanks are also used to supply the hydroseeding crew with a steady supply of water to increase production. Other restoration attachment options include broadcast seeders, bark blowers and straw blowers.

Slip remediationBreakthroughs in gaining the ability to conquer any type of terrain has led to other innovative developments for haulers.

Tighter spaces create limited productivity due to a lack of manoeuvrability while offloading materials using standard straight frame technology.

To enable the crawler carrier to haul and dump materials at any angle, an innovative rugged upper frame with a unique 360˚ functionality was developed. This rotational solution has dramatically saved time by eliminating the need for the driver to navigate the truck into a dumping position through a series of start and stop manoeuvres. Instead, a simple touch of the switch rotates the bed into the desired position to deliver the material to the exact location without any adjustment of track positioning.

“360˚ rotating carriers are ideal for working on pipeline slip remediation projects where space is very limited,” says Kenny Newhouse of K&N Contracting. “If a hillside slip occurs after the reclamation process, these rotating carriers can easily manoeuvre in the confined area to get the slip repaired with minimal ground disturbance.”

An additional application for rotating crawler carriers is padding the pipeline; sand bags, cribbing or other material can be dumped directly into the trench, rather than left on the side. And, mat hauling on steep inclines with a rotating unit provides less wear on the undercarriage and increases the life of the machine.

“This unique rotational functionality allows materials to be offloaded faster than standard straight frame models,” says Whittaker. “Our RT14R rotating unit provides contractors with a versatile solution to tackle a range of applications while improving efficiency and cost savings. The amount of time saved adds up quickly when you factor in how many loads are being hauled on a daily basis.”

World Pipelines / REPRINTED FROM NORTH AMERICA 2017