Dark territory

Dark territory is a term used in the North American railroad industry to describe a section of running track not controlled by signals. Train movements in dark territory were previously handled by timetable and train order operation, but since the widespread adoption of two way radio communications these have been replaced by track warrants and direct traffic control, with train dispatchers managing train movements directly.^[1] Today most dark territory consists of lightly used secondary branch lines and industrial tracks with speeds ranging between 25 miles per hour (40 km/h) and 40 miles per hour (64 km/h); however, there do exist a small minority of main lines that fall into the category. The term can also apply to automatic signaled lines where trains are running against the normal flow of traffic.

Safety concerns

The primary safety concerns with dark territory stems from the lack of any form of direct or indirect train detection along the route. Train detection systems such as track circuits not only alert other trains to the presence of a potential hazard, but can also alert dispatchers or other monitoring systems to the same. Dark territory also lacks the ability to control or lock switches onto the main track, detect misaligned switches, broken rails or runaway rail cars. In most cases these drawbacks are mitigated by the light traffic and low speed of the trains in dark territory, but a runaway train (such as the crude oil unit train in 2013's Lac-Mégantic derailment) will not respect limits on speed and is not detectable by rail traffic controllers on a line with no signals or track circuits.^[2]

The total reliance on manual procedures to ensure safety has occasionally resulted in train wrecks, some with fatalities, due to either miscommunication or oversight on the part of operating personnel.^[1] In 1948 the Interstate Commerce Commission set a nationwide speed limit of 60 miles per hour (97 km/h) for trains not protected by some kind of block system (including manual block and track warrants) and in 2012 this was expanded to include all lines considered dark territory. Since 1991 the National Transportation Safety Board (NTSB) had recommended that railroads be required to install new forms of signaling technology, such as positive train control (PTC), that can stop trains from exceeding their procedural authorities and warn them of improperly lined switches.^[3] In 2008 Congress passed a law requiring installation of PTC technology on parts of the U.S. rail network, including some dark territory, by 2016,^[4][5] although as of 2012 none of the proposed implementations have been rolled out on a regular basis for freight trains.

On specific railroads

BNSF Railway

The Gateway Subdivision of BNSF Railway, in California and Oregon, is unsignalled and operates with track warrant control (TWC), as is the El Paso Subdivision located in Southern New Mexico. The Phoenix Subdivision is an approximately 200-mile-long mainline subdivision running north/south in Arizona operating under verbal track warrant.^[6]

Dakota, Minnesota and Eastern Railroad

The Waseca Subdivision of the Dakota, Minnesota and Eastern Railroad, a 103 mile (166 km) freight line in Minnesota, is not signalled and uses TWC.^[7] Several other portions of the railroad converted to signalled operation in 2008.^[8]

Iowa, Chicago and Eastern Railroad

Most of the Owatonna Subdivision of the Iowa, Chicago and Eastern Railroad, a 124 mile (200 km) freight line in Iowa and Minnesota, is not signalled. The line is operated with TWC.^[7]

Long Island Rail Road

The Long Island Rail Road (LIRR) in New York, the nation's second busiest commuter railroad, still operates two (formerly three) sections of track in dark territory. The Montauk Branch between the Speonk station and Montauk operate under manual block, as does the ex-LIRR Lower Montauk Branch further west on the branch in Queens, where the LIRR discontinued passenger service in November 2012 as a result of having to install positive train control on most of the LIRR. The Main Line between Ronkonkoma and Greenport also operates without any signalling or Automatic Train Control system. Train crews must receive permission from the Block Operator to traverse those sections of the railroad in the form of train orders, in addition to strictly adhering to the rules and special instructions of the railroad's timetable.

Union Pacific Railroad

The Union Pacific Railroad uses dark territory on the Sharon Springs Subdivision in western Kansas, the Lost Springs Subdivision between Herington, Kansas, and Wichita, Kansas, the Brownsville Subdivision in south Texas, as well as on several under-used lines in the Greater Los Angeles Area.

In popular culture

In Breaking Bad, season 5, episode 5, "Dead Freight", Lydia gives Walt, Jesse and Mike details about a train that travels through a dark territory in McKinley County, New Mexico, that's also a telecom dead zone, so the team can steal a large quantity of methylamine, undetected.^[9]

See also

• General Code of Operating Rules
• Glossary of rail transport terms
• North American railway signaling
• Runaway train

References