On the rails

According to the Association of American Railroads (AAR), each day, US railroads deliver an average of five million tons of goods and serve almost every industrial, wholesale, retail, and resource-based sector. The government estimates that this means 56 tons of freight are moved per person in America each year – a figure it expects to increase more than 33% over the next 30 years.

Unlike highways, the majority of the 140,000 mile US railroads are privately owned and maintained, which requires a huge, and sustained, level of investment.

Over the past 35 years, the AAR says railroad companies have spent approximately $600 billion of their own funds to maintain and improve tracks, bridges, locomotives, freight cars, and other infrastructure and equipment. However, over the same period, freight rates have dropped by more than 40%, which means the average shipper can move nearly double the amount of freight for the same price they paid in 1980. Clearly this helps to keep US farmers, manufacturers and energy suppliers competitive, but it also brings profitability issues for the rail operators.

Freight railroads are now facing additional challenges, in the shape of federal regulatory emissions legislation, with the introduction of Tier 4 mandates that came into effect on January 1 2015. The aim of the legislation is to significantly cut emissions of particles and oxides of nitrogen (NOx) compared to Tier 3 levels. The chart depicts the progressive reduction of NOx and PM limits for newly built engines in line haul operation.  While different limits have applied for remanufactured locomotives in Tier 0 through Tier 3, these differences have been removed for Tier 4.

Environmental Protection Agency locomotive emissions regulations, line haul cycle

OEMs work to meet Tier 4

The stringent Tier 4 emission standards call for the single-largest emission reduction in rail history. Two of the biggest OEMs, General Electric (GE) and Electro-Motive Diesel (EMD), which is part of Caterpillar, have been working hard to develop new locomotives that can meet the new limits. Since the equivalent of Tier 4 requirements have already been achieved in on-highway vehicles, it was logical for these companies to leverage technology from across their businesses as they redesigned their engines. 

GE says it has invested 10 years and $600 million in the development if its Tier 4 offering - the GE Evolution Series Tier 4. This is a 12-cylinder turbocharged engine with advanced air to air cooling, common rail injection and exhaust gas recirculation, which the OEM says meets the new stringent limits without urea-based aftertreatment. Available now, this new engine runs on ultra low sulphur diesel fuel, takes 430 gallons of lubricating oil and has 14 oil filters, which have been designed for 184 day capacity. 

EMD has unveiled the SD70ACe-T4 locomotive, powered by the new EMD 1010 engine, which has been designed to meet the tighter emissions requirements. Although EMD is keeping details of its Tier 4 engine under wraps, they have reported that it is a 12 cylinder four-stroke, which again meets the emissions requirements without the use of urea. The company currently expects it to be available by mid-2016.

New Tier 4 engines will run at higher temperatures and higher pressures than their predecessors, which means they will require advanced lubricants.

Longer drain intervals

The challenge for today’s railroad lubricant is to deliver good engine protection and to keep engines clean over long drain intervals.  The drain intervals for railroad lubricants are determined by the results of in-service testing and a number of parameters, including base number, acid number, soot and metals, are used to monitor oil quality.

Over time, contaminants and by-products accumulate in the oil, which can result in it reaching any one of the condemning limits, triggering an oil change. To keep costs down and utilisation rates up, it is desirable for these oil changes to coincide with the six-monthly locomotive safety inspections required by the Federal Railroad Administration (FRA), which means oils must offer a minimum 184 day oil drain interval (ODI).

To add further value, railroad oils must be capable of reliable operation until the subsequent inspection after a further 184 days. Oils that last less than 184 days are undesirable since they force the locomotive out of service for an oil change, representing a greater cost than any savings gained from reduced oil use. It is essential for extended drain oils to achieve 184 days ODI with a high degree of confidence so that the condemning limits for used oil analysis are not exceeded.

By selecting superior quality engine oils operators can prevent unscheduled oil changes, confidently extend ODIs to 184 days and reduce overall oil use and maintenance costs.

Reaping the benefits

The most obvious benefits of enabling locomotives to easily meet their scheduled oil drain interval is that less oil is purchased and less time is spent changing it, which directly reduces operational costs. Less obvious benefits come from the potential to reduce rolling stock, track space and depreciation since there will no longer be a need to re-power trains whose locomotive has been unexpectedly condemned. Alternatively, operators could choose to maintain fleet size and use the extra capacity to acquire new business.

Infineum has developed specific railroad engine oils based on salicylate technology, which are flexible enough to meet the needs of the latest Tier 4 engines and the requirements of operators in other geographies such as South Africa, the Middle East, India and South America. These railroad products allow extended drain intervals, enabling engines to stay reliably in service for longer, which can help operators to maximise profitability.

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