(The following article by John Stilgoe was posted on the Boston Globe website on March 27.)
BOSTON — Commuter rail passengers might be safer going home. Morning MBTA commuter trains operate with locomotives that push trains to Boston. At way stations, passengers board from the side, all along the train, but at South Station the only exit lies at the end of track. Positioning the locomotive at the rear of inbound trains and the front of outbound ones saves South Station passengers a few steps twice daily. But over the years, outbound trains may prove safer, simply because massive locomotives lead them across road crossings.
MBTA commuter trains operate in push-pull mode. Invented more than a century ago in steam-engine days, the technique is simple. Half of the time, the engineer sits in the locomotive and controls it normally as it pulls coaches. The rest of the time he stands at the opposite end of the train, and remotely controls the locomotive pushing the cars. Well into the 20th century, railroad companies experimented with steam locomotives pushing passenger trains. While a fireman stood in the locomotive shoveling coal, the engineer operated the locomotive from the far end of the train, controlling speed, applying brakes, and blowing the whistle. Electric-powered coaches, much like MBTA subway cars but operating from overhead wires, supplanted push-pull steam operation around New York and several other cities. Later, self-propelled diesel-electric rail cars replaced traditional passenger trains.
South-of-Boston old-timers may remember the silver rail-diesel cars built by the Budd Company and operated over Old Colony tracks by the New Haven Railroad. In the 1950s, the cars, called RDC, worried commuters accustomed to passenger trains pulled by locomotives.
The self-propelled cars, even when operated in multiples, seemed less likely to withstand grade-crossing collisions. But 1950s RDCs moved slowly along weedy tracks, and proved themselves safe in a handful of collisions. They satisfied riders while cutting operating costs.
Unlike steam locomotives, RDCs did not need to be turned around at each end of the line and coupled back to trains, a labor-intensive, time- and space-consuming operation. Old-timers may also remember the turntable at Greenbush, and the Whitman turntable historic site is next to the town’s MBTA station. But railroad management was happy to get rid of steam locomotives and turntables. First-generation diesel locomotives also required turntables, but bidirectional diesels soon replaced them. After the middle 1960s engineers at the end of the line merely swiveled their seats, but they still had to uncouple diesels, move along coaches on parallel tracks, and couple to opposite ends of cars before heading back.
Late 1950s push-pull technology enabled railroads to leave locomotives attached to trains. Financially strapped railroads saw push-pull as a way to cut jobs and increase efficiency. But some passengers worried about the implications of heavy locomotives pushing trains.
Experiments with toy trains make anyone wonder about the real thing. Pulling a toy train across a table is easy, despite the lack of tracks. The cars follow the locomotive. Pushing the train proves awkward, since the cars sprawl in every direction. Once off the rails, a modern push-pull in push mode is likely to wreck seriously — as a recent California train disaster proved — because the mass of the heavy locomotive at its rear slams the coaches into objects along the tracks.
Only reinforced coaches operate as cab cars. Federal Railroad Administration regulations require that cab cars have the same longitudinal strength as ordinary diesel locomotives. The cars have strengthened end bracing too, partly as a result of studies of 1970s Boston-area RDC collisions.
Federal Railroad Administration documents make clear that cab cars are lighter than traditional locomotives and their occupants may face significantly higher risks of death and injury than passengers in locomotive-pulled trains. In the 1980s the railroad administration began to worry. In August 1981, an MBTA push-pull train in push mode collided with another train in Beverly, killing an engineer and injuring 28 passengers. In November 1987 another MBTA train in push mode suffered a collision in Boston, injuring 223. In February 1996, in Secaucus, N.J., a push-mode train hit another commuter train, killing one and injuring 162, almost all of them aboard the pushed train. A week later, a nearly empty push-mode commuter train hit an Amtrak express pulled by two locomotives traveling at 125 miles per hour. The 11 fatalities and 13 injuries aboard the push-mode train happened mostly in the cab car. Following the 1996 collisions the administration required changes in push-pull train operation, including directing transit authorities to review putting passengers in any car other than the leading cab car until all seats are occupied.
MBTA commuter lines west and south of Boston operate according to the highest possible safety standards, in part because they are new. Signaling systems produce a level of safety and operating efficiency recognized worldwide, but do little to solve the grade-crossing danger. Recent collisions in Britain and California make clear that any vehicle on the tracks may derail any train. If the train is a push-pull one speeding along in push mode, the heavy locomotive at its rear is likely to scatter the cars ahead of it. The cab car may crumple, and the bi-level cars behind it may snap at stairways and other points as they flip on their sides.
Push-pull trains do lower operating costs, but in the end their price may prove higher than passengers expect. It seems a simple matter to install detectors at every grade crossing to warn engineers of obstacles ahead that could kill.
Norwell resident John Stilgoe is Orchard Professor in the History of Landscape at Harvard University.