Track warrant

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A track warrant is a set of instructions issued to a train crew authorizing specific train movements. The system is widely used in North America.[ citation needed ] The warrant is issued by the train dispatcher and delivered to the train crew via radio. The train crew copies the instructions onto a pre-printed paper form and reads back the warrant to ensure that nothing was misunderstood. [1]

Train A series of coupled vehicles for transporting cargo/passengers

A train is a form of transport consisting of a series of connected vehicles that generally runs along a rail track to transport cargo or passengers. The word "train" comes from the Old French trahiner, derived from the Latin trahere meaning "to pull" or "to draw".

Train dispatcher profession

A train dispatcher (US), rail traffic controller (Canada), train controller (Australia) or signalman (UK), is employed by a railroad to direct and facilitate the movement of trains over an assigned territory, which is usually part, or all, of a railroad operating division. The dispatcher is also responsible for cost effective movement of trains and other on-track railroad equipment to optimize physical (trains) and human resource (crews) assets.

Contents

Operation

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 (known as "Box 6" on a standard form), although the track warrants remain 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. [2] [ better source needed ]

Train station Railway facility where trains regularly stop to load or unload passengers and/or freight

A train station, railway station, railroad station, or depot is a railway facility or area where trains regularly stop to load or unload passengers or freight. It generally consists of at least one track-side platform and a station building (depot) providing such ancillary services as ticket sales and waiting rooms. If a station is on a single-track line, it often has a passing loop to facilitate traffic movements. The smallest stations are most often referred to as "stops" or, in some parts of the world, as "halts".

Railroad switch railroad turnout

A railroad switch (AE), turnout, or [set of] points (BE) is a mechanical installation enabling railway trains to be guided from one track to another, such as at a railway junction or where a spur or siding branches off.

Track warrants usually allow a train to move in one direction only—a "Proceed" instruction. Sometimes a train may also be given authorizing movements in either direction, called a "Work between" instruction. However, only one train can have a section of track at one particular time if moving in the same direction. If there are two trains moving in the same direction, the leading train must give up the track before the trailing train can obtain a track warrant for that territory. For example, if Train 56 has a track warrant to proceed in the northbound direction from MP (milepost) 14 to MP 77 and there is a train following, then Train 56 must give up a portion or all of its warrant before the following train can be issued the track that Train 56 has already cleared. Many times this is accomplished by the dispatcher asking the leading train for their milepost location and then issuing a warrant up to that point to the trailing train. Continuing the previous example, if Train 56 is clear of MP 50, the dispatcher can issue a warrant to the trailing train up to MP 50, but not beyond it. Once a train has received a new track warrant or has left track warrant territory they will release the entirety of their warrant back to the dispatcher. [3] [ better source needed ]

Maintenance of Way crews receive track bulletins (usually called "Form A", "Form B" or "Form C") 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. [4]

Comparison with Direct Traffic Control

Track Warrant Control is similar to yet distinct from the concept of Direct Traffic Control (DTC), appearing later as railroads migrated fully from older forms of Train order operation. DTC was designed to facilitate the movement of trains using concepts of blocks and sidings previously used with Train Orders. DTC is only a mechanism to transfer movement authority and can only work within an arrangement of predefined blocks. [5] Track Warrant systems appropriate the remaining responsibility of Train Order systems to notify operating personnel of safety directives that include things like temporary speed restrictions, tracks out of service, etc. and combines them with the movement authority function of DTC. Furthermore Track Warrants are not limited to fixed blocks and can be issued and released from almost any explicitly identified landmark along the rail line. [6]

Train order operation signalling system based on timetable and manual train orders

Train order operation, or more accurately timetable and train order operation, is a largely obsolete system by which the railroads of North America conveyed operating instructions before the days of centralized traffic control, direct traffic control, and the use of track warrants conveyed by radio. The system used a set of rules when direct communication between train dispatchers and trains was limited or non-existent. Trains would follow a predetermined operating plan, known as the timetable, unless superseded by train orders conveyed to the train from the dispatcher, through local intermediaries. Train order operation was a system that required minimum human overhead in an era before widespread use of technology-based automation. It was the most practical way for railroads with limited capital resources, or lines with limited traffic, to operate. To this day, a large number of short lines, heritage railways, and railroad museums continue to use Train Order operation.

Standard instructions used in track warrants

Most track warrants in the U.S. follow a standard form as suggested by the General Code of Operating Rules [7] , consisting of several standard instructions to mark specific notes or conditions for a warrant. These vary from temporary speed restrictions to rules regarding meeting other trains.

Form (document) document with blank spaces/fields for insertion of required or requested information. A device for collecting data.

A form is a document with spaces in which to write or select, for a series of documents with similar contents. The documents usually have the printed parts in common, except, possibly, for a serial number.

The General Code of Operating Rules (GCOR) is a set of operating rules for railroads in the United States. The GCOR is used by Class I railroads west of the Chicago, most of the Class II railroads, and many Short-line railroads.

Some railroad systems, such as Rail America, use additional boxes:[ citation needed ]

Non-GCOR Track Warrant systems include the NORAC Form D Control System (DCS) which was later partly adopted by CSX to supplant its older DTC system.[ citation needed ]

Use of track warrants on specific railroads

The BNSF Railway uses track warrants on its El Paso Subdivision which runs from Belen, New Mexico to El Paso, Texas, with the dispatcher in Fort Worth, Texas. There are no electrical signals on the route. BNSF also uses TWC (Track Warrant Control) on its Forsyth Subdivision between Jones Jct. (a suburb of Billings, Montana) and Hysham, Montana. Unlike the El Paso Subdivision, ABS is used. And on the Madill Subdivision between Denison, TX and Irving, TX with an ABS signal overlay on the northern ten or so miles between Denison and Sherman, TX. Track Warrant Control is also used in many other lower to medium traffic volume sections of the BNSF system, sometimes with an automatic block signal system overlay, and on the other class one railroads as well. Some smaller Class II railroads, such as the Iowa Interstate Railroad, and many Class III railroads are dispatched completely by track warrant.

Canadian railways use a similar system called Occupancy Control System (OCS), in which movements are controlled via clearances issued over the radio from the Rail Traffic Controller to the train. The system is in wide use on lines that aren't installed with centralized traffic control (CTC).

See also

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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. 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.

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The Callahan Subdivision is a CSX Transportation railroad subdivision within the Jacksonville Division on the former Seaboard Air Line Railroad. The sub extends northward 20 miles from Baldwin, Florida, where the Jacksonville Terminal Subdivision's S Line and Tallahassee Subdivision meet just north of Baldwin Yard, a classification yard. According to Jacksonville Division Timetable Number 4 published in 2005, the sub runs from milepost SM 0.18 to milepost SM 20.0, where it joins the Nahunta Subdivision, a former Atlantic Coast Line Railroad, in Callahan, Florida. The line serves as a bypass to Jacksonville.

The BNSF Avard Subdivision runs 177 miles (285 km) of track between Tulsa, Oklahoma, starting at milepost (MP) 425.2, to Avard, Oklahoma, MP 602, where it meets the BNSF Panhandle Sub.

References

  1. ↑ Solomon, Brian (2010). Railroad Signaling. Minneapolis, Minnesota: Voyageur Press. p. 135. ISBN   978-0-7603-3881-0.
  2. ↑ GCOR Sixth Edition Section 14
  3. ↑ GCOR Sixth Edition Section 14.3
  4. ↑ GCOR Sixth Edition Section 14.5
  5. ↑ GCOR Sixth Edition Section 16
  6. ↑ CSX Operating Rules 2007 Edition: Rules 170-175, 180-183
  7. ↑ GCOR Sixth Edition section 14.0


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