Op-ed: A battery-operated train is the best alternative to the Dinky

The Pop-Up Metro train.

By Kip Cherry

The Railroad Redevelopment Corporation (RDC), whose chairman is Henry Posner of the Princeton University class of 1977, has gone live with a new concept in rail service. The Pittsburgh headquartered firm, which owns and operates railroads around the world, sees a profitable market in redeveloping light density railroad lines in the United States, starting with the Princeton Branch, and its powerful connection to the Northeast Corridor. 

Mr. Posner has brought into the U.S. stunning orange and black remanufactured former London subway cars that are running in a demonstration project in central Pennsylvania.  Focused on sustainable and efficient transportation, these battery-operated railcars are remanufactured by Vivarail, a British company in which RDC is a shareholder. This exciting new option will work on the Dinky’s existing rails. These railcars offer benefits that cannot be matched by so-called Bus Rapid Transit or any other bus alternative. Mr. Posner’s hope is that the Princeton Branch will be just the first of many shortlines around the United States to use this technology.

Mr. Posner is calling his demonstration project Pop-Up Metro. It is set up at Rockhill Furnace, Pa., about three hours from Princeton. Designed to operate at typical speeds of 60 miles per hour, the Pop-Up Metro deals with Federal safety regulations and NJ Transit purchasing practices. The concept is to show how well the equipment will operate on the existing Dinky rails while gaining cost savings and critical greenhouse and pollution reductions.

Last year, as all mass transit struggled with the pandemic, NJ Transit initiated a “transitway study” to determine the future of service on the Dinky line. The study parameters seem calculated to support a claim that aging equipment changes will make rail service impractical and that the only alternative is some form of a bus alternative.

Because of this, some have argued that the real goal of the study is to make the case for replacing rail service with some iteration of BRT service. Hopefully that isn’t true. In any event, Mr. Posner has made a major investment to show what the Pop-Up Metro can do.

The sustainability of the new train is critical. The train batteries will also allow for the removal of the Dinky catenary, which some people think is dangerous and unsightly. This will also eliminate ongoing costly and difficult maintenance of the catenary. RDC would initially rely on commercially generated power, but options include renewable power through existing solar fields, or potentially a community solar installation on a new warehouse rooftop.  Renewable power will then be sent to PSE&G which, in return, will be in a position to power the batteries.

The Vivarail interiors are comfortable, outfitted with Wifi, and can be easily maintained.  Routine repairs can be accomplished on-site. Any heavy repairs can be done by contractors off-site. The cars, which originally arrived at Rockhill Furnace by truck, can be moved easily by truck. There are no immediate plans for autonomous train operation, but this option will be evaluated as the technology moves forward. Such an option would further enhance safety and reduce onboard personnel and costs.  And there is also the simple value in using existing trackage. The Pop-Up Metro can be placed into service quickly, with no new infrastructure investment. This strengthens the Princeton Branch’s position as part of the national railroad network.

Critical to the long-term success of any revitalized Princeton line is reliable, fast service to trains on the Northeast Corridor.  The current service has been far from reliable.  At the beginning of Princeton University’s fall semester, Dinky service was curtailed for almost a week because of mechanical problems, just as students and vacationers were returning to the university and the greater Princeton community. Reliable service will allow travelers to shape their needs around the service and will also allow residents to establish long-term employment and business operation plans with the assurance that there is easy transportation to the Northeast Corridor.  And those presently using other modes of transportation will be encouraged to return to using the Dinky and allow Princeton businesses to take advantage of opportunities to bring people from other places to take advantage of retail,  entertainment, and educational opportunities in Princeton.

Another new source of ridership could come from the University’s own growth, including its new Innovation hub that is intended to spur growth in new innovative enterprises in coordination with area colleges and universities, and could be an important factor in the growth in Princeton’s commercial district with its new hotel and other initiatives.

Because the door configuration of the new cars will allow for quick exit and entry onto the train, there are other new opportunities for added ridership. The fast on-and-off time will make an additional transit-oriented development stop feasible without a significant increase in total train travel time. This will allow for investment at a site to be chosen to include residential, office, and commercial uses with easy access to Route 1.  More importantly, a new transit stop near Route 1 could be designed to be a hub for area employers, allowing for easy van pickup by new area warehousing employers, as well as employers at the Carnegie Center, points along Alexander Street, other employers along Route 1, and the hospital. A new stop would reduce regional congestion with its attendant environmental costs, just as new area warehouses begin to take on thousands of new employees. 

Mr. Posner’s Pop-Up Metro on the Dinky line also preserves the option of providing rail freight to carry waste, recyclables, and oversized cargo. Freight could be moved at night so that it doesn’t interrupt regular passenger service. Negotiations could also be undertaken on parking fees and efforts could be made to effectuate a popular campus gathering spot at the Dinky Plaza in association with the Wawa, which would benefit passengers, students, and community members alike.  This also creates possibilities such as a van service with Princeton merchants and various entertainment modes.

Much more could be said about the potential of Mr. Posner’s Vivarail cars if placed into operation through a public-private partnership with rail know-how and a commitment to locally-focused, reliable, and efficient service.  Such an effort would be consistent with Princeton University’s own targets of reducing campus greenhouse gas emissions to zero by 2046. Mr. Posner’s new train is an opportunity for NJ Transit’s Transitway Study process to give the Princeton Branch a real chance to continue as a dedicated rail line that will support future regional economic growth.  

Most recently, Vivarail made a historic run during the COP26UN Climate Change conference in Glasgow, with the first electric train crossing the iconic bridge over the Firth of Forth. Prince Charles visited the train and spent time learning about battery technology and RDC’s plans for introducing more UK battery technology to the United States through its Pop-Up Metro initiative. Mr. Posner also officially announced the order of a second train from Vivarail for Pop-Up Metro at the climate conference.

Kip Cherry, a planner, is a member of Save the Dinky. She is the only member of the 44-person Princeton Transitway stakeholders’ group representing a citizen group.

Princeton University alumnus Henry Posner (center) with Prince Charles (left), who had a chance to see the battery-powered train in action in Scotland.


  1. Great briefing, Kip Cherry! And three cheers for Mr. Posner to remember his college town for this project. Putting his money where his mouth is!

  2. This 1100 word near-ad for Vivarail asserts it would be better than a system of electric buses to connect the Junction with Princeton, but doesn’t explain how.
    How would Vivarail offer a no-transfer connection to the Princeton Shopping Center and other neighborhoods in town? How would Vivarail have lower personnel costs and more flexible crew scheduling? How would it “surge” to meet extra demand on Reunion Weekend? An electric bus system could do all of those things, and better adjust to future needs than a fixed route train system.
    Check out the 4 proposed alternatives–Google njtransit princetontransitway and click on the presentation link in the first paragraph.

  3. From the headline and section, this is clearly labeled as an editorial and not a news article. But seriously, how many people want to sit on a bus that makes stops throughout town to get to Princeton Junction given how bad traffic is? You would just be encouraging more people to take Uber to the junction. The FreeB replacement often takes an hour to make it around town. The electric bus system you want so bad could connect with the train, dropping passengers off at the train station. Crazy idea! Because if we keep the train then the university can’t have its land grab!

  4. What on earth is the point of this? That railroad is already electrified. We don’t need silly battery trains, we just need modern electric rail cars. There is no justification for using batteries on electrified route.

  5. Because as the writer points out, this would remove the cantenary wires. For various reasons officials and the university would like them gone, including for safety reasons. A drunk Princeton University student once was eletrocuted and sucessfully sued, for example.

  6. How to waste taxpayer money as quickly as possible. Let’s start another task force that can rule by unanimous quorum despite public pushback.

  7. How many people use the “free” transportation? Or is it called self-funded now. Another “free” mode of transportation in Princeton:

    “Finally Council will consider a resolution to extend the current contract for operation of the free Muni bus service for another two weeks, to December 13. The current contract with WeDriveU Inc. was for an interim period of four months at a cost of $44,000. The additional two weeks will add $5,500 to that contract.”

  8. It’s not environmental to replace an electric train with a battery powered train. We have the best of all possible worlds currently. It’s a huge mistake to replace it with off-grid transportation.

  9. Ryan N. you don’t seem to have looked carefully at this. Some points in favour of adopting these lightweight battery cars for the branch – which are just another form of electrification:

    1) Cantenary copper wires and fixed supports won’t need to be replaced – saving many dollars.
    2) The much lower weight of these cars (70-75 tonnes in total) will reduce the total amount of electricity needed to provide the service.
    3) The lower weight will reduce the need for track maintenance, saving more money.
    4) Regenerated electricity from braking saves even more money.
    5) The batteries can be charged fully overnight when electricity rates are much lower.
    6) The modular traction components can be swapped in situ.

    The current Arrow cars from the 1970s I understand will soon be rendered obsolete, so it is quite likely any like-for-like replacements will be very expensive as a non-standard type.

    I suspect that something like these battery units will be the only way to retain this short line.

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