Passenger rail in the United States is undergoing a quiet transformation. DMUs (diesel multiple units) — both FRA- (Federal Railroad Administration) compliant and non-compliant — are emerging as niche players that eventually could have significant impact on the regional rail market.

Transit systems in North Carolina, Texas, Colorado, Utah, Illinois, California and up to a dozen other states are considering the use of DMUs.

The major advantage of the DMU over traditional light rail is that it can run on existing tracks by sharing right-of-way with freight trains. Also, it doesn't require electrification with overhead wires and the construction of substations to provide the electricity. This removes a substantial hurdle in development costs.

Because they are self-propelled, DMUs don't require locomotives and often can be coupled together to form different configurations depending on service requirements. In addition, they're bi-directional, so reversing direction at the end of the run is simplified.

A good starting point
"It's a good starter program for agencies that want to use existing infrastructure," says Tom Janaky, vice president of sales for Colorado Railcar, a manufacturer of FRA-compliant DMUs in Fort Lupton, Colo.

In February, an FRA-compliant DMU built by Colorado Railcar began revenue service at the South Florida Regional Transportation Authority.

It's part of a three-vehicle demonstration project sponsored by the FRA and the Florida Department of Transportation (FDOT). Two other DMUs (a standard double-decker and a low-floor double-decker) will also be put into service under the contract. The FRA and FDOT acquired the three vehicles in a joint procurement.

Janaky says he's seeing growing interest in compliant DMUs, but concedes that funding continues to be an issue and could handcuff the growth of the market. Two proposed rail projects — in Austin, Texas, and Denver — are contingent upon the results of sales tax initiatives that will be decided by voters on Nov. 2.

TTA's experiment
In Raleigh, N.C., Triangle Transit Authority (TTA) is nearing completion of an equipment order that could spawn a host of followers. The TTA is in the final stages of a procurement of 12 bi-directional married pairs of FRA-compliant DMUs for a 28-mile line that's expected to begin revenue service in mid-2008.

At press time, the agency was requesting best-and-final offers from railcar manufacturers who had successfully cleared the earlier hurdles. Thomas Janssen, TTA's vehicle engineer, said the agency worked with seven railcar manufacturers during the review cycle and received proposals from many, though not all, of them. "That was a good sign," he says. "It showed that they [the railcar manufacturers] were interested. They did not try to give us something off the shelf and say, 'Take it or leave it.'"

The reason that TTA was concerned about manufacturer interest is simple. Its order of 24 railcars is small, especially when you consider that interested European and Asian railcar manufacturers don't yet make an FRA-compliant DMU.

To meet the TTA's specifications, they would have to modify the design of an existing product, either a DMU or EMU (electric multiple unit), to meet the FRA's standards. That's an investment that some railcar builders are reluctant to make.

Working in TTA's favor, however, is the possibility that Metra, the commuter rail line serving northeast Illinois, is considering a large order of DMUs in the next few years for its STARline project. Large, in this case, amounts to 30 DMUs and 60 trailers. "That's helped us," Janssen says. "It's definitely a substantial order."

The project also boasts a versatile design-platform approach. "We kept our spec open to allow some sort of 'standard' design that might work for many agencies," Janssen says. "This has great potential to save costs for future orders."

In the past, many transit agencies preferred to put their own design signature on light rail vehicles. "This, of course, added costs as every new order was a new design," Janssen says.

It's not surprising that other transit agencies are closely watching the developments at TTA. Janssen says as many as 10 transit agencies have expressed interest in buying vehicles from this procurement under an option agreement. Of those, three properties are "very interested" in buying option vehicles, he says.

Many other systems are taking a wait-and-see attitude. "They want to see if it works for us," Janssen says. "DMUs are not new to this country, but they have been problematic in the past. I'm hoping that we're not just a guinea pig. Hopefully, there's a new rail design era starting here."

Werner Katerkamp, a senior associate with Booz Allen Hamilton, believes DMUs have a healthy future in the U.S. market, but agrees with Janssen that the success of TTA's rail system will influence agencies considering this option. "My personal interpretation is that we'll see DMU equipment taking off," he says. "But we'll have to see what the future holds."

DMU 'light' emerges
FRA compliance is not always necessary. For example, the River Line at New Jersey Transit uses non-compliant DMUs that are structured more like light rail vehicles than commuter cars.

The River Line, which connects Trenton and Camden along the Delaware River, put the DMU vehicles into revenue service in March along an existing and enhanced right-of-way.

The line spans 34.5 miles with 20 stations. The 20 railcars in service were manufactured by Bombardier Transportation.

Because some of the line is street running, the smaller, lighter DMUs were chosen over the heavier, less maneuverable FRA-compliant vehicles. The intention was to create a rail line that operates like light rail, but without the electrification.

DMU shows versatility
"Depending on the service, there is a place for both FRA-compliant and non-compliant DMUs," says Chuck Wochele, vice president of business development for Alstom Transportation. He says Alstom is closely following the progress of DMUs in the U.S. and has targeted both the compliant and non-compliant markets.

Frank Guzzo, director of trains business unit in North America for Siemens Transportation, agrees with Wochele's assessment. "There's a market for both DMU concepts," he says, "especially when you look at the rising cost of building a light rail line today compared to 10 or 15 years ago."

Key to the entry of railcar manufacturers into this market will be the appearance of high-volume orders, like Metra's.

"This market has been developing for 20 years or so," says Ray Metz, vice president of sales of intercity and regional rail for Bombardier. "We've followed it, and we're interested in it."

Metz says Bombardier has designed an FRA-compliant vehicle that would meet market requirements. "We're just waiting for a project opportunity that is of sufficient size to justify us going forward," he says. "With Metra, in particular, there could be a critical mass that really kicks off an interest in these types of DMUs."

To meet market demand, Colorado Railcar's Janaky says his company is developing a DMU that can operate on freight tracks and then transfer to light rail tracks.

Another DMU strategy
New Jersey's River Line is only one example of a non-compliant DMU service.

In San Diego County, Calif., the North County Transit District (NCTD) has selected a non-compliant DMU for its Sprinter line, a 22-mile system with 15 stations, that's quite a bit different from the River Line car.

The agency, based in Oceanside, selected a mid-sized non-compliant DMU built by Siemens that's widely used in Europe. The modifications for use in Oceanside include additional air conditioning capacity and heavier braking performance.

"It was close to off-the-shelf equipment with a few minor changes," says Don Bullock, NCTD's manager of capital construction.

The branch line that will be used for the Sprinter is also used for freight service. Normally, this would require that the passenger railcars meet FRA standards, but the agency was able to guarantee time separation and received a shared-use waiver. "The freight line will be operating from 11 p.m. to 4 a.m., and we'll provide our service during the day," Bullock says.

This waiver allowed NCTD to look at non-compliant alternatives. Although several railcar manufacturers participated in the industry review process, few chose to submit a bid. "There were two difficulties we faced: One, this DMU is a new animal in the United States. And, two, we only ordered 12 vehicles and a $50 million contract probably barely hits the radar screen with these guys," Bullock says.

Buy America exemption
Because federal funds will be used for the purchase of the railcars, NCTD had to meet Buy America requirements. But the agency was able to get an exemption because no U.S. manufacturers submitted a bid. "That was one of the fastest things I've ever seen out of the FTA," Bullock says.

Passenger capacity per vehicle is approximately 220, with 125 seated and 95 standing. "That's 440 per consist, which is much higher than our ridership project would require initially," Bullock says.

The DMU will be powered by two turbocharged, intercooled six-cylinder diesel engines connected to a five-speed automatic transmission with integrated torque converter and retarder.

Revenue service is expected to start at the end of 2007. NCTD officials expect more than 10,000 riders per day initially. Some of the ridership will be generated by students attending three colleges along the line. According to Bullock, a survey suggests that most of the riders will be people taking care of errands rather than commuters.

Station design has been kept consistently simple, Bullock says, because of the desire to control costs and to reduce any competitiveness among the cities served.