Maintenance of Way: R&D at TTCI

By Walter Weart

In October 2008, the Association of American Railroads (AAR), Railinc and the Transportation Technology Center Inc. (TTCI) issued a report titled "Railroad Industry Priority Technology Goals and Directions for the Next 20 Years," which was written to serve as the industry's research-and-development roadmap.

A section of the report covers track and structures, classifying a range of industry R&D goals as "useful," "necessary" or "essential." Among the essential: accident reduction, onboard/in-track condition monitoring, increased rail life and reduced track component lifecycle cost.

Some of the work the industry's doing to achieve those goals was on full display March 15 and 16 during TTCI's 16th Annual AAR Research Review. The event attracted more than 400 attendees to the Pueblo Convention Center and TTCI's test site in Pueblo, Colo.

On the warm and breezy morning of March 16, railroad representatives and vendors made their way around TTCI's Facility for Accelerated Service Testing (FAST) high-tonnage track loop to view experiments being conducted under AAR's Strategic Research Initiatives program. Wearing steel-toed boots, safety vests, hard hats and safety glasses, attendees were able to catch a glimpse of some of the R&D/test progress that's already been made on a wide range of rail, tie, fastener, special trackwork and maintenance-of-way technique fronts.

A New Generation of Rail

For example, researchers currently are using a 17,000-ton test train on the FAST loop, which was built to test the effects of increased axle loads on track structure and rolling stock.

Among the items subject to test: a new generation of premium rail supplied by U.S. companies, including Evraz Rocky Mountain Steel and ArcelorMittal, as well as European, Japanese and Chinese firms.

Intermediate hardness rail is being tested, as well.

"This new rail is being subjected to testing here before being tested at two outside locations, one on the Union Pacific and the other on the Norfolk Southern," says Semih Kalay, TTCI's vice president of technology, adding that initial results have been "very good."

The UP segment, which is in the Powder River Basin, features gentle curves and concrete ties. The NS site is at Blue Mountain, a ridge that forms the eastern edge of the Appalachian Mountains; the location features 10-degree curves and wood ties.

Talking (and Testing) Ties

Speaking of ties: Crossties of various shapes and materials are being tested at TTCI as part of the industry-wide aim to reduce track component lifecycle costs.

Currently under analysis is a "half frame" concrete tie from Austrian-based Schwellenwerk und Steuerungstechnik Linz GmbH.

The ties feature shoulders under both rails; ties with two and four fasteners per rail are being tested for possible application with heavy axle loads and significant curves.

A tie developed by Germany's ThyssenKrupp AG also was recently installed in the FAST loop for testing.

"[The Y-steel tie] is mainly used in tight curves down to 150m where CWR tracks often show problems of moving during different rail temperatures," said Thomas Schlender, VP of MRT Track & Services Co. Inc., a joint venture comprising Atlantic Track & Turnout Co. and ThyssenKrupp GfT Gleistechnik GmbH, via e-mail. "Another advantage of this tie will be its limited height, which was often required for track renewals in tunnel sections."

Other track components under test at TTCI include switches — particularly flange bearing frogs and switch points.

"We have been researching both flange bearing switches and crossings here, and also monitoring switches and diamonds installed in revenue service," says Kalay, adding that he expects to see an increase in the FRA-allowable speed of trains that operate over these installations from 10 mph to 25 mph.

Moveable frogs are being tested, as well. They offer longer service life because there's no flangeway subject to wear; the lack of a flangeway also provides a smoother ride, says David Davis, TTCI's senior scientist. The moveable frog in service at TTCI had been installed for about three months as of press time and had been subjected to about 60 million gross tons.

"Both the Union Pacific and the BNSF are using moveable frog switches in mainline service and, depending on the type of switch — such as No. 30 — can operate through them at about 50 mph," says Davis.

Meanwhile, researchers are exploring methods to modify the switch point profile to reduce stress and the chipping away of material at the tip of the point — two new designs are being evaluated, Kalay says. And the search for a better point fit in the rail profile also continues.

Not all of the work at the test track involves track components. Researchers also are exploring ways to improve MOW practices.

"We are monitoring implementation of preventive rail grinding and the use of friction control on both the gauge and head of the rail," says Kalay.

The goal: extend rail life by as much as two times, he says. So far, so good: As of mid-March, 1.3 billion gross ton miles had been accumulated on a two-degree curve with no defects and significant reduction in rail wear using the techniques, Kalay says.

TTCI researchers also have been busy developing new inspection techniques at the Rail Defect Test Track. They've already learned that there's plenty of room for improvement, particularly below the rail head. Help could be on the way in the form of ground penetrating radar, which is being used to probe below the crosstie into the ballast and subgrade. The system detects underground moisture problems long before symptoms become visible at the surface, Kalay says.

Another promising technique: a combination of laser and ultrasonic technology to inspect 98 percent of the rail at speeds up to 20 mph.

"We are looking at non-contact testing in the laboratory and in the field, with reliability an issue," says Kalay, adding that TTCI is working with Aerospace Corp. to refine the process.

Another "essential" goal according to the 2008 report is accident reduction. From 2004 to 2009, newer steel combined with better car and rail inspection techniques have reduced derailments due to broken rails by 15 percent, Kalay says.

The R&D progress will continue incrementally.

"We continue to work with the railroads, looking at the major areas outlined in the report, such as shared track and higher-speed passenger trains on freight railroads," says Kalay.

Walter Weart is a Denver-based free-lance writer