Track warrant
From Wikipedia, the free encyclopedia
Track warrants are systematized permissions used on some rail lines to authorize use of the main line instead of signals. Train crews receive track warrants by radio, phone, or electronic transmission from a dispatcher. Track warrants are issued granting main track use between two named points (i.e. milepost sign, station, and or any fixed physical point, such as a switch). The dispatcher may also issue time constraints (*box 6), although the track warrants remains in effect until cleared by a member of the receiving crew. Track warrants are sometimes used in conjunction with a block signal system to provide rear-end protection against following trains. Track warrants are usually given allowing a train to move in one direction only (proceed), sometimes they may also be given authorizing movements in either direction (work between).
Maintenance crews also receive track warrants (usually called "Form B's") in order to perform track work that would otherwise be interrupted by passing trains. This is done by providing the maintenance crew with a form or protection, or allowing work to be done behind a passing train.
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[edit] Xboxes
Most track warrants in the U.S. follow a standard form as suggested by the General Code of Operating Rules, consisting of several "Xboxes" to mark specific notes or conditions for a warrant. These vary from temporary speed restrictions to rules regarding meeting other trains.
- Box 1- Void on a previous warrant
- Box 2- Proceed from point to point
- Box 3- Proceed from point to point (cont.)
- Box 4- Work between certain limits
- Box 5- Not in effect until ____
- Box 6- Authority expires at ____
- Box 7- Not in effect until after the arrival of ____ at ____
- Box 8- Hold main track at last named point
- Box 9- Do not foul limits ahead of ____
- Box 10- Clear main track at last named point
- Box 11- Between ____ and ____ make all movements at restricted speed: limits occupied by train
- Box 12- Between ____ and ____ make all movements at restricted speed: limits occupied by men or equipment
- Box 13- Do not exceed ____ mph between _____ and ____
- Box 14- Do not exceed ____ mph between _____ and ____
- Box 15- Flag protection not required against following trains on same track
- Box 16- Track bulletins in effect
- Box 17 and 18- Other specific instructions
[edit] Use
As an example, the BNSF Railway uses track warrants on the "El Paso Sub" line which runs from Belen, New Mexico to El Paso, Texas, with the dispatcher in Fort Worth, Texas. Track warrants are used on the railroad's Harbor Subdivision in Southern California as well, though infrequently since operations on the line were reduced in 2002. There are no electrical signals on either route. Some smaller Class II railroads, such as the Iowa Interstate Railroad, and many Class III railroads are dispatched completely by track warrant.
