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Whats Next for Locomotives?

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It seems like railroads have been part of America forever, although its really closer to 180 years. Children wish for electric train sets, and every department store seems to put a model train in its Christmas display. Even our musical heritage includes many tunes about trains and the engineers who drive them. Given our love affair with trains, lets look at railroads, locomotives and especially the lubricants that move them.

Think that North Americas railroads are past their prime? Think again. They have about 167,000 miles of track – the largest rail system in the world. They carry about 40 percent of Americas freight and do it profitably, efficiently and while using far less fuel than trucks.

The 1980s and 1990s saw a number of North American railroads file for bankruptcy and others swallowed by mergers. Left today are nine so-called Class 1 major rail freight systems, five in the United States and two each in Canada and Mexico. They are BNSF Railway, Canadian National Railway and Canadian Pacific, CSX Transportation, Ferrocarril Mexicano, Kansas City Southern Railway and its KCS de Mexico subsidiary, Norfolk Southern, and Union Pacific Railroad.

Industry data indicate that railroads can move a ton of cargo an average of 469 miles on one gallon of diesel fuel. (By comparison, says Robert Braswell of the American Trucking Association, the average on-highway rig moves one ton of cargo about 209 miles per gallon of diesel.) Of course trucks have the advantage of being able to move on local roads. They form a very good symbiotic relationship with the railroads, which cost-effectively deliver large quantities of cargo to terminal locations for onward distribution.

According to the Association of American Railroads, the largest volume of products shipped by rail in 2011 was coal, which accounted for over 40 percent of the total tonnage. Next came chemicals and allied products (10 percent), then mixed shipments of intermodal (piggyback) containers (6 percent). Other principal products carried are shown above.

Coal may be fading as a rail consumer, however. Coals primary use is as a fuel for electric power plants. Exports of metallurgical and thermal coal remain robust for certain Class 1 railroads, and the state of the global economy will influence this element. But a combination of more stringent emissions requirements on coal and the boom in natural gas production has resulted in more power generators using natural gas. This has cut into coal production, shipping and use. Hence, the biggest source of shipping tonnage and about 25 percent of gross revenues for the railroads is under a lot of pressure. Where this goes in the future will have a significant impact on railroad operations and their viability.

The power to move people and products over the rails comes from locomotives. Originally powered by steam, locomotive engines transitioned to diesel power after World War II. Currently, there are about 24,000 locomotives operating in North Americas railway network, 70 percent of which are in line-haul service. Short-haul and switching engines make up the remainder.

Engine builders General Electric (GE) and Electro-Motive Diesel (EMD) dominate the Class 1 locomotive fleet, with about equal shares. The latter, originally part of General Motors, became part of Caterpillar subsidiary Progress Rail Services in April 2010.

Most railroad locomotives operate using an electromo-tive proces: Their engines burn fuel to run an alternator, which provides electricity to the traction motors which power the driver wheels. However, some low-power, low-speed applications (e.g. switching engines) use a mechanical drive consisting of fluid couplings leading to a planetary-type gear box, which in turn delivers power to the driving wheels.

Fred Girshick, senior rail-road technologist and rail-road industry liaison at Infineum USA in Linden, N.J., offers some idea of the differences between a locomotive engine and an on-highway heavy-duty diesel engine. He points out that a Class 1 locomotive can have 10 times the horsepower, 12 times the displacement and 20 times the torque of its highway rival (see below).

Historically, U.S. railroads have used engine oils designed to control deposits and neutralize the harsh, sulfuric acids formed during combustion, which get into the locomotives crankcase from blowby. A major factor in this has been the fuel used. Fifty years ago, No. 4-D diesel was the choice due to its low cost. However, refiners began to produce less 4-D in favor of 2-D, a fuel more favored for commercial applications. So 2-D diesel fuel was the standard until the introduction of ultra-low-sulfur diesel (with 15 ppm max. sulfur) in June 2006. As fuel refiners made the change, so did railroads; they adopted ULSD around the same general time as the on-highway diesel fleet.

Oil marketing to the rail-roads has changed as well. For years the major oil companies supplied the lubricant and fuel needs of the major railroads. However, service counts for a great deal with railroads, where emergency night and weekend deliveries to remote sites are par for the course. Some independent lubricant suppliers have taken on the task and have enjoyed long and successful relationships with these customers.

One such supplier is Red Giant Oil, which has sold lubricants and other products to farmers and farm equipment dealers in the Midwest since 1910. In 1959, Red Giant purchased Searle Petroleum Co., which had been in business since 1889. In the mid 1980s, Red Giant/Searle says, it became the first independent lubricant company to begin selling new railroad engine oil to Class 1 railroads. Today, the company says it is the largest supplier of railroad engine oil in North America, serving the likes of BNSF and Union Pacific, as well as Kansas City Southern and many regional and short lines.

David Bills, vice president of Red Giant in Council Bluffs, Iowa, says that its philosophy of total cost of ownership appeals to rail-road operators. The company has dedicated blending systems to make and ship the zinc-free engine oils (more on that later) that GE and EMD locomotives require, and is dedicated to fast, efficient supply of products anywhere their railroad customers need it. He notes that short lead times are cru-cial to the railroads, since a locomotive that is stopped doesnt generate revenue.

Focusing on service, Bills adds, has allowed Red Giant to branch out from engine oils into supplying the other railroad requirements, including greases, hydraulic oils and other petroleum products.

Randy Morgan from BNSF agrees that service is paramount. A successful supplier to the BNSF would be attentive to our requests, supportive of our needs and the supplier of the product with best value, he told LubesnGreases. Best value [means] best price, delivery as requested, and quality as specified.

For break-in of a new engine, the railroads often use a monograde SAE 40 engine oil having a typical Kinematic Viscosity of 15 cSt at 100 degrees C. But they generally operate their fleets on SAE 20W-40 (KV 15.3 cSt), which accounts for about 90 percent of the business.

Approvals for railroad engine oils are managed by the additive suppliers, who do the test work and present the data to the engine manufacturers for approval. Additive suppliers also facilitate the submissions necessary for oil companies to gain OEM approvals and to meet individual railroad fresh oil specifications.

Tom Gallagher, global rail-road technical liaison for San Ramon, Calif.-based Chevron Oronite, says the history of railroad engine oil advances have been driven by changes in engine design to meet increased power output requirements, coupled with the need to reduce emissions. There also have been in-cylinder modifications that improve combustion and operational efficiencies.

Railroad engine oils have their own classification system referred to as generations and maintained by the Locomotive Maintenance Officers Association. A key focus in their development, both Gallagher and Infineums Girshick point out, is the oils base number or BN, a meaurement of its ability to fight acids and oxidation. BN may rise or fall, depending on LMOA members needs, but other changes in locomotive equipment also can present challenges for the oil and additive companies (above).

Chevron Oronite and Infineum each emphasize that 2015 will be a pivotal year for railroads, engines and lubricants. This is when the latest emissions requirements, EPA Tier 4, come into force.

Both agree that the introduction of emissions control equipment, such as exhaust gas recirculation, to these engines will be one of the most significant changes. These are the same phased-in emissions regulations that on-highway truck operators have faced since 2000, and are now meeting.

As Girshick points out, Tier 4 places greater demands on locomotive engines, just as it does for trucks. In addition to new engine designs that are expected (see table, page 38), the overall railroad fleet is undergoing modernization to higher horsepower, and locomotives are expected to supply improved haulage-ability, as the railroaders call it. The goal is to have longer maintenance intervals with engines that have more stringent emissions and lower oil consumption. That is not a formula for success unless engine lubricants keep pace.

Fortunately, additive suppliers say, the experience gained from on highway engine oil development translates into railroad engine oil development, especially in the area of handling EGR soot, which is different from combustion soot.

One of the big factors in formulating oils for these engines is the sulfur content of the fuel used. The original railroad engine fuels contained sulfur in excess of 5,000 ppm. When they were burned, the sulfur combined with any water that was present to create highly acidic materials which needed to be neutralized. As engines improved and other factors such as longer maintenance intervals increased the stress on engine oils, the answer often was to increase BN in the oils. Eventually BN peaked at 17 to combat sulfurous acids.

LMOA Generation 6 oils were introduced into this market in 2008, with an official 2009 effective date. These oils were designed for use with <500 ppm sulfur fuels, which permitted a return to lower BN.

Meanwhile, <15 ppm sulfur fuels were introduced for on-highway use in 2006. Since refiners dont want to make too many fuel cuts, <15 ppm became the standard fuel used by U.S. railroads as well. Hence, BN levels were reduced to the 9 to 10 range, while BN retention, as measured in used oil analysis trending, was improved in order to align with locomotive maintenance intervals and used oil condemning limits.

LMOA Generation 7 is in the works now, and it is difficult to say where BN will land. These formulations will need to effectively address established locomotive maintenance intervals, lower oil consumption rates, emissions mandates and modified engine operating conditions.

Of course, BN isnt the only requirement for rail-road engine oils. Because of the amount of soot generated, good dispersency is a must-have, as well as antioxidants and anti-foam. Since 90 percent of the in-service engine oils are SAE 20W-40 grade, a small amount of viscosity index improver is used as well. Dosages are relatively low, and shear stability is similar to on-highway diesel engine oils.

Antiwear is a unique case. Earlier EMD locomotives have silverplated wrist-pin bearings and do not do well with zinc-containing additives. Specifically, they will pit and corrode very early, resulting in field problems and premature bearing failures. Many of these older engines are still in service, so railroad engine oils use zinc-free antiwear additives to achieve backwards compatibility for the full range of engines in the market.

While GE engines do not have the silver wrist-pin bearing issue, the OEM is comfortable with non-zinc formulations and supports them for uniformity of oil selection by the railroads. Plus, the likely introduction of exhaust after-treatment equipment onboard EPA Tier 4 certified locomotives favors the continued use of non-zinc engine oil formulations to mimize catalyst poisoning concerns.

Base stocks used in current formulations are either API Group I or Group II, with no decided preference from the engine manufacturers. Besides the issue of cost, the key is to formulate a finished oil that has at least 12.0 mm2/sec kinematic viscosity at 100 degrees C.

There is an additional requirement that the high-temperature high-shear (HTHS) viscosity be at least 10.9 mPa.s at 100 C after shearing, as measured by ASTM method D6278. Obviously, boundary layer viscosity is a critical issue for the high horsepower, medium-speed engines powering the locomotive fleets of North America.

Railroads represent a major part of the North American economy, moving millions of tons of freight annually. They have been through hard times but have again found traction. They will continue to be an integral part of the scene for years to come.

Thats something Abbie Culberson, marketing specialist with Oronite, finds cheering. She rides a train to work every day and loves the ease of it. She loves the sound of the train, the way it rocks, even the noise of the brakes when it pulls into the station and the chime of bells at the crossings. Her commuter train often passes freight trains, and she thinks, They sure do move a lot of product.

Next time youre stopped at a crossing waiting for the train to pass, take a moment to remember that, and how it affects your life. The wait wont be so long or frustrating.

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