Imagine if you could launch faster passenger train service on a dedicated right of way for half the cost of traditional high speed rail – or speed up conventional service by 30% while still running at 79 mph.
It’s possible, a startup company claims, to slash transit times by eliminating the station stops that pull down average train speeds. American Solar Rail proposes building autonomous, self-propelled, battery-electric passenger cars that would function as rolling stations.
The EMDI cars would pick up passengers at conventional stations, then deliver them to the passenger train on the fly. Passengers who want to get off at the next station would then board the EMDI, which would uncouple from the train and make the station stop, where the process would repeat itself.
A passenger route using the EMDI system and a top speed of 125 mph could achieve similar transit times as a true high speed line with maximum speeds of 180 to 220 mph, ASR founder Robert Green says.
“They’ve got that big throttle. They want to go,” he says of proponents of true high speed rail. “They don’t have a way to measure the impact of not having to stop. That’s what we did and we found it was a gold mine of time.”
Green examined a proposed high-speed route between Jacksonville, Fla., and Atlanta that would include stops at Savannah and Macon, Ga. The route was outlined in Georgia’s 2015 state rail plan.
The transit time using conventional high-speed equipment on a 180-mph to 220-mph dedicated, 368-mile right of way would be 2 hours, 49 minutes, with an average speed of 131 mph, Green says.
Over the same route, an EMDI system with a top speed of 125 mph would produce a transit time of 2 hours, 58 minutes with an average speed of 123.8 mph, he says.
Although the EMDI transit time would be slightly slower than a true high speed system, ASR estimates it would come at a far lower cost to build: $19.7 million per mile for the 125-mph route with EMDI service compared to $41.4 million per mile for the 220-mph conventional high speed route.
“Everybody’s talking about we need better high-speed rail in this country, and this helps,” Green says.
Using EMDI – which stands for EMbark/DIsembark – also would cut transit times by as much as 30% in regular 79-mph Amtrak service, Green says. “We’re going to bring efficiency, effectiveness, and lower cost because we can do more with 80 miles an hour,” he says.
The EMDI batteries would be recharged during station stops, using low-cost electricity generated from solar panels along the railroad right of way. Green, an entrepreneur with more than a dozen patents, has been involved in the development of solar farms in the Southeast.
ASR has received a patent for the EMID and commissioned a study of the concept at MxV Rail in Pueblo, Colo. Much of the necessary technology exists in some form, MxV Rail noted, but has yet to be applied to railroads.
“The EMDI concept does not present any barrier to implementation that cannot be surmounted. There are, however, many technical and regulatory challenges associated with the EMDI concept that would have to be solved to achieve a functional system,” according to MxV Rail’s October 2023 report.
Chief among them: Safety issues related to the EMDI catching and coupling with a passenger train.
“Current train control concepts work on the principle of fail-safe train operation and train spacing, which require automatically stopping the train in the event of any train control failure. The spacing between consecutive trains is set by signal separation or the braking distance of the train. The EMDI concept shifts this paradigm,” MxV Rail notes. “The concept will need to meet the current fail-safe standards for train operations and be capable of fail-safe encroachment of the EMDI vehicle to less than braking distance from the train, particularly during coupling. This will be the key challenge regarding the fulfillment of the regulatory requirements for fail-safe train operations.”
MxV Rail recommended that ASR create a technical advisory board to address technical and regulatory issues.
Green and ASR Chief Marketing Officer Warren Getler have met with officials from the Federal Railroad Administration, the U.S. Department of Transportation, the Georgia Department of Transportation, and congressional staffers.
The company is currently seeking funding from private investors. The initial funding round would support the construction and testing of two EMDI prototypes.
Amtrak declined to comment. The Rail Passengers Association did not respond to a request for comment.
A slip-coach was a specially equipped car in the UK that was dropped from a through train so it could coast to a stop under the control of a guard (brakeman) aboard the car. Last used around 1960.
I first read of a similar idea many years ago (late 70s or early 80s), so I don’t think this is new. I DO think the idea has some merit, though I question the average speed assumptions. They suggest an average speed of 123.8 mph, with a top speed of 125 mph. Maybe on a dedicated line with no freight interference.
Or you could run a two-tier service between all-stops trains and limited-stops trains. A motorized “slip-coach” might work better than boarding between two trains at speed, you uncouple on the fly with the slip-coach powering itself into a station siding, to then be picked-up on the fly by a return train. But, I like the tried-and-true first idea better.