Thursday, September 27, 2012

Glide path to efficiency

Written by  Mischa Wanek-Libman, Engineering Editor
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Friction modification has morphed from art to science. Suppliers are spending a lot of time in the lab developing and testing products for proper lubricity, and that can withstand the temperatures and pressures of the wheel/rail interface.

Biobased lubricants

Environmental Lubricants Manufacturing, Inc. (ELM) has added microwave-based grease manufacturing capabilities, which is expected to reduce the production cost of its petroleum level rail curve grease products. According to ELM, microwave-based grease manufacturing was invented at the University of Northern Iowa, and licensed to Marion Mixers in Iowa. ELM has been testing a production size unit for the past three years. This year, ELM added two 40,000-pound grease reaction vessels to work with two microwave transmitters at 150 kW total energy input.

“Offering better performance and biodegradability for products grown here in the U.S. and matching the cost of petroleum greases is welcome news to the industry,” said Dr. Lou Honary, founding director of UNI/NABL Center and chairman and president of ELM.

Honary says that biobased greases not only provide superior metal-metal separation at the point of contact in rolling stock, but they also tend to remediate soil contaminated with non-renewable greases. The soil bacterial activity due to the presence of biobased materials creates an environment that helps in breaking down contaminants.

Alan Burgess, ELM operations manager, said “Our products are now being offered through a major nationwide distributor, making it easier for railroads to get biobased grease. Plews & Edelmann Company has the UltraLube brand of grease and other lubricants available in all retail stores, as well as having distribution sites for pails, drums, and totes of rail curve grease in various parts of the country.”

ELM has tested its products in the field and has worked with TTCI to test products. This year, ELM’s products are part of a comparative test of rail curve greases in a DOT sponsored project at the University of Northern Iowa.

“We work with biobased oil suppliers to use vegetable oils most suited for industrial lubricants. This brings the resources of seed companies and companies that chemically modify renewable oils for use in our products,” said Mike Jensen, ELM product manager.

UltraLube Rail Curve Greases and Switch Plate Lubricants, which has exclusive rights to ELM’s soy compound, says its products provide increased lubricity to reduce wheel and track wear and improve fuel efficiency.

“Rail curve greases also contain advanced extreme pressure additives to guard against wheel and rail wear and are available with added molybdenum disulphide, which offers enhanced effects for greater protection. The greases are formulated to resist port plugging in wiping bars and provide longer carry down track from the lubricator. They offer better gauge face coefficient of friction and less migration to the top of the rail than petroleum-based grease,” said Dave Babics, senior product manager for lubrication products. “Our switch plate lubricants are formulated with natural seed oil and proprietary additives to protect switches from wear, rust, and corrosion. Designed to be poured, brushed, wiped, or sprayed, the lubricant prevents against dust and dirt buildup, while resisting washout from rain or melting ice.”

Continued product evolution

The engineering teams at L.B. Foster Friction Management have invested significant resources in further improving the company’s equipment in the areas of performance, efficiency, and reliability.

“This includes the refinement of our PROTECTOR® trackside system’s real-time electronic controls to provide a precise, guaranteed volumetric output of friction control media (lubricants at the gauge face and KELTRACK® at the top rail) over a wide range of operational, physical and environmental conditions. Attention to the finest details has led to improvements in the internal design of our applicator bars, resulting in further improvements with respect to robustness, simplicity and maintainability,” said Kevin Oldknow, vice president, technology and business development.

Oldknow notes that the digital world’s evolution has created an expectation among customers to have remote information available in order to make intelligent decisions in the management and deployment of constrained maintenance resources.

“With this in mind, we have made further investments in the core communication technologies used to transmit remote performance monitoring (RPM) data and in the web-based applications used to leverage this data for insights in decision-making. We now have systems deployed on several continents in both the northern and southern hemispheres that are working seamlessly with the local telecommunications networks and protocols to transmit data back to a central server where our customers can conveniently monitor the health and performance of their systems and establish active alerts to notify them whenever conditions change,” said Oldknow.

The company has been further broadening the application and usage of next-generation friction modifier materials, such as KELTRACK ER (Enhanced Retentivity) to deliver top of rail friction control benefits at dramatically reduced application settings (i.e., material usage rates). L.B. Foster says it has also brought a new and more technologically sophisticated material to the domain of traction enhancement with the commercial release of Alleviate™ traction gel, which acts to combat low adhesion conditions caused by, for example, organic pastes occurring at the wheel/rail interface during the fall leaf season.

“Our focus remains on providing our customers with products and services that add value. Friction at the wheel/rail interface manifests itself in a surprisingly diverse range of phenomena that are meaningful to the railway operator,” said Oldknow. “Correspondingly, management of friction at this interface provides a diverse range of benefits to the operator in optimizing productivity. As an example, the extension in rail life that is provided by an effective friction management program improves both the economics and utilization of the infrastructure. Economic improvements come from a straightforward reduction in rail replacement rate, while utilization is improved when fewer time slots are occupied by rail change out activities. The same arguments apply to track maintenance activities in general, such as fastener replacement and re-gauging.”

Oldknow notes fuel savings also play a major role in delivering verifiable benefits to the industry. He says that over the past several years it has been demonstrated that a territory-wide approach to friction management (including Kelsan™ AutoPilot™ train mounted top of rail friction control) can provide measurable reductions in locomotive diesel usage in both highly curved, and shallow curved/tangent track territories.

“The theoretical work to understand this through wheel rail contact analysis and simulations is just now catching up to the point where these widespread savings can be rigorously understood and explained. The net result is a substantial improvement in fuel efficiency over broad territories,” said Oldknow.

The company also points to mitigation of rolling contact fatigue (RCF) through effective friction management as another area in which operational efficiencies can be improved. Noting, when the growth rate of RCF (and wear) is slowed, rail surface and profile conditions can be managed with less effort and metal removal via grinding. In addition to the further extension in rail life that this provides, there is an additional impact in which grinding resources become more effective (for example the same number of grinders can cover a wider portion of the network under resource constrained conditions).

“As we continue our efforts toward maximizing the effectiveness of our products, we have a long history of working very closely with the customer base, as well as third-party research institutes (for example, the AAR-TTCI and NRC-CSTT) and consultants, to ensure that our products and technologies meet and exceed the expectations of the industry in providing reliable, quantitative benefits. A significant body of research, for example, has been carried out over many years to quantify the benefits of KELTRACK for friction control at the top of rail/wheel tread interface. This research has included exhaustive work to verify the safety of KELTRACK (versus lubricants) from the standpoints of locomotive adhesion and braking effort, as well as verifying the compatibility of this material with signaling systems, sanding, and ultrasonic testing,” said Oldknow.

Developing a system

Loram Maintenance of Way, Inc., is currently working on a new and improved friction modification delivery system. The new system is flexible enough to work with a variety of friction modifiers of different viscosities and at a large temperature range, which gives the customer more options on unit placement.

“This system will allow us to vary quantity of friction modifier based on the needs of the customer,” explains Jon Behrens, integration manager at Loram. “This variability allows us to skip more or less axles and reduce waste base on train traffic.”

The company also offers YardGlide for use in hump yards to reduce the rolling resistance of the cars after they come through the retarders. This reduction in rolling resistance allows the cars to reach their final destination at a slower speed, reducing the impact loading during coupling and preventing the cars from stopping short. Loram has integrated the YardGlide system in with the hump yard controller, which allows the yard controller to increase or decrease the amount of friction modifier based on destination in the yard. The yard controller can also shut the unit off when running a switcher locomotive through.

TracGlide is Loram’s locomotive mounted system for friction management. The system works to reduce the friction of the wheels on the trailing cars. The friction modifier is fully consumed by the end of the consist, which increases the train fuel efficiency and helps increase the speed of the train traveling up grades.

“Loram continues to invest in research and development,” said Behrens. “We have a scale test model of a wheel and rail to provide research into new friction modifier and the benefits. Once the lab has provided samples, we then partner with a railroad to perform real-world testing.”

Expanded footprint

The SKF Lubrication Business Unit’s flagship Lincoln wayside gauge face applicator continues its evolution based on customer needs.

“The applicator has the same Lincoln Pump-To-Port™ technology and now can be installed quickly by only one person. Applicators that are easy to remove and reinstall during rail maintenance are beneficial when dealing with tight track maintenance windows,” said Eric Nieman, rail lubrication product manager, SKF Lubrication Business Unit. “Another new product is the Lincoln SLID top-of-rail applicator, which squirts (not sprays) friction modifier in predetermined quantities to an exact position on the rail. Friction modifiers now can be measured and placed precisely, thus dampening noise from the stick-slip effect, reducing waste of expensive material and reducing environmental contamination.”

Nieman notes there have been advances in the SKF EasyRail on board systems, which are mounted on board the locomotive or rail vehicle and spray greases or friction modifiers onto the wheel flanges or the top of rail. The smart controllers optimize the sprayed quantity by triggering lubrication based on curve, distance, time, and direction inputs.

“From a tribology point of view, wheel/rail contact is no different than a roller bearing. Track and wheel wear rates and noise emissions can be reduced by applying lubricant to the wheel/rail interface to reduce friction. By applying the precise amount of lubricant at the proper time, our customers realize reduced track and wheel maintenance, while minimizing costs associated with friction modifiers and greases,” said Nieman.

Since the acquisition of Lincoln by the SKF Group in 2010, the two brands have combined their extensive research and development efforts to ensure continued innovation in the global market.

“Customers benefit from the SKF Life Cycle Management approach to reduce total cost of ownership and maximize productivity through every stage, from specification and design to operation and maintenance,” said Nieman.

Linear lubrication

Robolube Industries, Inc., has completed in-house testing of its new Linear Wayside Lubrication System and is now in the final testing stage with the system, which has been installed on Class I main line track.

“The Robolube Linear System uses only one ounce of grease per train, utilizing the ‘Field Proven’ Robolube technology in providing a hirail application of lubricant to the gauge face in a wayside lubrication configuration,” said Bob Pieper, president of Robolube.

Pieper says the minimal amount of grease used means less maintenance, optimal grease displacement/consumption, reduction or elimination of hazardous mats, and minimal waste.

“Since there is absolutely no contact with trains, the unit can be mounted at the ideal location; which is in the apex of the curve. Here, lubricant is best applied for carry down the rail and there is virtually no cast from centrifugal forces of the wheels, eliminating waste and environmental issues. The design also allows for quick removal and installation for track maintenance and servicing,” said Pieper.

Learning from different markets

Whitmore has completed the acquisition of QHi Rail Ltd., a U.K.-based wayside lubricator equipment company. According to Bruce Wise, Director of Railroad Sales for Whitmore Rail, the acquisition will allow Whitmore Rail to offer customers a complete lubrication system. The company is busy adapting existing QHi equipment to the North and South American rail markets.“The North America freight environment is much more rugged and the equipment needs to stand up to that,” said Wise. “Our system has the ability to adjust for changes temperature. The output of our unit is much more consistent across a range of temperatures.”

Whitmore Rail has also developed two new lubricants, RailArmor, for rail curves and SwitchArmor. Both were developed based on Whitmore’s experience in other industries.

“Because we are in other market segments outside of railroads, such as mining, we’ve been able to use technology from our mining lubricants and apply it toward our rail curve grease. It’s performed well,” said Wise.

Wise also mentioned that the company worked closely with Class I railroads in RailArmor’s development in “tough” field locations.

Partnering with the railroads is key to Whitmore Rail’s research and development efforts and the company recognizes that it is a two-way street. While the railroads allow field-testing of lubricants on their property, Whitmore Rail allows the railroads access to its lab facilities. Whitmore Rail currently has a major freight railroad using its climate-controlled test chamber, which can simulate cold weather conditions in a controlled environment, for comparative testing of both lubricants and equipment.

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