To the Editor:

Let me state up front that I support rail and public transit, and have contributed my time to national rail lobbies that promote improvement in rail and transit service and infrastructure. That said, there are some constraints to the state’s proposal to add diesel multi-units (DMUs) to the Fairmount branch line that are not being openly stated.

First, diesel multi-units (DMUs) are not a new idea.  Trains manufactured by the Budd Rail Company known as “Budd Liners” were the work horse of the New York&New Haven as well as the Boston & Maine railroads through the 1950s and 1960s. Their counterpart is the electric multi-unit (EMU, and not the bird) that is in popular use by both US and European commuter railroads.

It is important to understand that there are no USA companies manufacturing DMU train sets at this time.  The last company to do so was Colorado Railcar, which ended operations in 2008, its assets transferred to US Railcar, a procurement operation with no manufacturing facilities.

This raises questions of dealing with the “Buy America” Act requiring a percentage of final assembly of such trains to be facilitated on US soil and employ US workers. Unless the state can obtain an exemption from this law, any manufacturer chosen will first have to gear up a manufacturing facility for final assembly.

DMUs will also require the development of a repair facility where these units can be serviced. A DMU unit is both a locomotive and passenger coach, and has to be serviced on specific schedules. A new fleet that is different from the current locomotive-powered trains also raises questions of where such DMU units can be stored when not in use. As of now, the MBTA is all but out of real estate to store its trains when not in use.

Many neighborhood activists seeking to develop the Fairmount branch into a subway line should abandon that idea and embrace the rail configuration in place. Federal Railroad Administration (FRA) regulations forbid the mix of subway trains and heavy-weight trains, such as the commuter trains and occasional freight train that operate on the Fairmount branch. This is due to differences in speed allowances and crash, which are quite different. Subway and “heavy rail” trains must also be “grade separated” on different tracks as one may find along the Southwest Corridor segment of the MBTA’s Orange Line and commuter rail line as found in Jamaica Plain. Grade separating this branch as it enters the current South Bay rail yard in South Boston would be akin to another “Big Dig.”

So... to somewhat quote the Seinfeld TV series... “No subway for you!”
As to scheduling more trains, that also has some limitations. FRA regulations govern how frequent heavy trains (which include DMUs) may operate on a set of tracks, and how close they can be to each other during operation.  The system is very much akin to air traffic control for airplanes.  Each segment of track or “block” considers the weight of the train, its speed, and space between trains.  On lighter-weight and slower-speed subway trains, this may only be a distance of a few hundred yards, but on heavy weight trains it is measured in miles.

This does not mean that DMU service or more frequent trains are not possible. They are. However, we should not be lulled into some false idea that this proposed DMU service will manifest overnight. We are talking several years into the future, at the very least.

In the meantime, the current rail service on the Fairmount branch should be looked at for new and creative ways that will serve the riding public. For example, reconnecting it to the Northeast Corridor (NEC) at Readville opens up a whole host of possibilities.

D. M. Kirkpatrick, Roslindale, MA.