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Loram Maintenance of Way Inc.'s RG400 Series of rail grinders incorporate increased available horsepower, advanced grind control systems, more stones and higher grind speeds. The idea: maximize available track time and ensure a cost-effective production grind program. Photo: Loram Maintenance of Way
Rail is a huge expenditure for railroads, so extending rail life is crucial. Minimizing the potential for derailments is also critical. Many railroads grind rail to restore the profile and, as a result, extend rail life and improve ride quality.
Some of the large freight railroads figured on doing a lot of grinding this year — for example, both CSX and Norfolk Southern Railway planned to grind 18,000 pass miles, according to surveys they submitted for Progressive Railroading’s 2016 MOW Spending Report, which was published in April.
How often they grind varies. So does the equipment they use to do it.
Certainly, rail-grinding technology continues to evolve. What are suppliers offering these days? What’s new? What’s tried and true?
For answers, Progressive Railroading recently reached out to a cross-section of rail-grinding suppliers and service providers. Technology updates from six suppliers follow.
As a part of its rail life-cycle strategy, Vossloh North America offers a newly developed high-performance milling (HPM) system designed to eliminate “even larger rail defects in an efficient manner,” the company says. Milling prevents premature and cost-intensive rail replacements. Depending on the remaining height of the rail head and the amount of lateral wear, the HPM system can extend the life cycle of a rail up to 300 percent, the company says.
Capable of removing up to 3 millimeters from the rail’s running surface, the milling machine needs only a single pass for in-depth removal of rail defects and precise rail reprofiling, the company says. The machine’s working speed of nearly 1.24 mph is faster than previous systems (0.43 mph).
A fine milling assembly is arranged vertically to the track and “improves the quality of the rail surface in terms of residual waviness,” the company says. After processing, surface roughness is less than 3 micrometers. The synchronized working mode of the main and fine milling units ensures that milling follows the direction of travel. The new finishing technology also ensures that the HPM system remains free of grinding; furthermore, the process produces neither dust nor sparks. Any milling swarf is vacuumed off and collected in a swarf bunker, which makes the system suitable for use in spaces with an increased risk of fire.
The modular track milling trains can be tailored to suit market and customer requirements. The train, which can use its own tractive power or be towed by a locomotive, can achieve a speed of up to 75 mph during transfers.
Meanwhile, Modern Track Machinery recently commissioned its first hi-rail mobile grinding truck in the U.S. market — for the Honolulu Authority for Rapid Transportation for the 20-mile passenger-rail system the agency is building on the island of Oahu.
The Geismar model V2R 800 M consists of an eight-stone rail grinding module coupled to a hi-rail truck. Designed to address corrugation, the hi-rail mobile grinding truck provides preventive grinding and scale removal, and can grind embedded girder rail and road crossings. Its design also enables it to be used under catenary systems.
The module has two independent heads containing two stones each, enabling users to set grinding angles as required. The unit comes with a built-in dust collection system to contain dust and spoils generated during the grinding operation. The module is radio controlled, enabling operators to closely monitor the grinding process.
“We feel that it is a real advantage for railroads and transits to have the ability to be mobile while addressing their spot grinding,” company officials said. “This unit can quickly set on at crossings, access the work site, deploy the module in under 10 minutes, complete the grinding requirements, and ultimately clear track while minimizing track outages. This unit not being rail-bound reduces required track time to move from location to location.”
And with the Geismar model V2R 800 M, company officials believe they’ve “addressed a niche in the grinding market” to enable customers to address spot needs that exist beyond “traditional grinding programs.”
Officials at Harsco Rail, too, continue to invest in rail grinding technology — the company recently introduced Dynamic Pattern Generation. This enhancement provides the grinder with a mechanism to orient grinding motors based on measured rail profile, desired rail shape (template) and the resulting metal removal effort, the company says.
In the past, grinders used “canned” patterns with predefined motor orientation and contact pressure, primarily varying the speed of grinder travel, the company says. With Dynamic Pattern Generation, grinding motor orientation and contact pressure can be changed (along with grinder travel speed) for a specific grinding segment using simulation technology to achieve the desired depth of metal removal at the proper location on the rail.
The simulation is performed iteratively to define the number of passes the grinder must take in each direction and the motor orientation at each pass — this is “particularly effective” for smaller grinders that do not have enough grinding motors to achieve full rail head coverage in one grinder pass, the company says. The chart at left shows one example of the results of applying this technology.
Railroads around the world continue to increase grinding requirements to predefined metrics while ensuring the proper rail profile is left behind and corrugation/surface defects are removed. They want maximum grinding speed and optimal metal removal. Dynamic Pattern Generation and real-time monitoring provide this capability, the company says.
Noise can be an important issue for transit-rail systems to control. Officials at Plasser American Corp., which offers GWM Rail Grinding Machines for rail grinding of tracks and turnouts, say they’ve addressed the issue by using a special method of rail rectification: acoustic grinding using oscillating grinding stones. The method achieves an “immediate reduction of the noise” with reductions up to 12 decibels, the company says.
The grinding process is achieved by the back and forth oscillating movement of the grinding units (six grinding stones per unit), and also by the continuous forward motion of the machine. A waterspraying unit ensures a dust- and spark-free work process.
Optimum rail surface quality can be achieved by using oscillating grinding technology, the company says. When using rotating disks, a periodic chatter mark area usually remains after grinding. To remove these chatter marks, the company recommends a final oscillating grinding pass.
When treating rail with milling machines, the company also recommends performing a final grinding pass using the oscillating grinding method to achieve a smooth rail surface.
Another application for the grinding machine is the treatment of new rails. Long-term studies carried out by several railroads have concluded that when preventive grinding is performed, corrugations occur “far later than on untreated new rails,” the company says.
Plasser offers a variety of self-propelled machines with up to five grinding units per rail, each carrying six oscillating grinding stones that adapt to the rail profile and apply the correct (hydraulically adjustable) vertical load to the rails, the company says.
Other equipment providers also offer a variety of machines to help railroads meet specific rail grinding needs.
For example, Loram Maintenance of Way Inc. offers the Loram RGS Specialty Grinder. The switch and crossing grinder/spot grinder grinds at speeds up to 12 mph; grinding angles can address all grinding conditions. Operators can reduce power to grind motors as needed to vary surface finish. Features include a Tier II-compliant engine capable of achieving “industry-leading fuel efficiency and corresponding low emissions,” the company says; a robust dust collection system designed to lessen environmental impact; and environmentally friendly and flame-resistant hydraulic fluid.
The company also offers the Loram RG400 Series Grinder, which is a high-production grinder. The company’s high-production grinders can grind at speeds up to 20 mph. The units provide deeper cutting angle capabilities, which make the grinder suitable for use in all rail conditions, the company says. Other features include:
• sophisticated grinding controls designed to ensure accurate metal removal; • advanced horsepower controls for consistent metal removal performance; • an improved traction system for better performance in grades; • auto machine lubrication, which reduces maintenance and enhances machine accuracy; • high-capacity, walk-around water cars designed to provide improved fire suppression and a safer work environment for Loram and railroad personnel; • state-of-the-art rail measurement and vision systems; • environmentally friendly and flame resistant hydraulic fluid; • a Tier II-compliant engine; and • a robust dust collection system. Railtech Matweld also has a unit to bring to the rail-grinding discussion. The Railtech Matweld Head-Wash Grinder (HWG) is a hydraulic powered, track mounted machine designed to efficiently grind the ball of the rail in preparation for the company’s Head-Wash Repair Weld (HWR). The idea: provide a precision grind to complement the HWR process in defect removal.
The compact and lightweight grinder allows for quick on-track setup and breakdown, and the ergonomic profile enables operators to “quickly and comfortably” grind the ball to the appropriate depth and width, the company says. Email comments or questions to firstname.lastname@example.org