chapter2 - railway industry overview

8/11/2019 Chapter2 - Railway Industry Overview

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AMERICAN RAILWAY ENGINEERING ANDMAINTENANCE OF WAY ASSOCIATIONPractical Guide to Railway Engineering

Railway IndustryOverview

Chapter

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A R E M A C O M M I T T E E 2 4 – E D U C A T I O N & T R A I N I N G

Railway Industry Overview

Paul Li, P Eng.

UMA Engineering, LTD.Edmonton, AB. T5S 1G3

[email protected]

Maxwell B. Mitchell, P.E.

Norfolk Southern Railway (Retired) Trion, GA 30753-1703

[email protected]

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C H A P T E R 2 – R A I L W A Y I N D U S T R Y O V E R V I E W

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Railway IndustryOverview

2.1 Introductionhe railway industry encompasses not only the operating railway companiesand transit authorities, but also the various government regulatory agencies,railway associations, professional organizations, manufacturers and suppliersof locomotives, railcars, maintenance work equipment and track materials,

consultants, contractors, educational institutes and, most important of all, the shippingcustomers.

The information in this chapter is of a general nature and may be considered as typicalof the industry. However, each railway company is unique and as such it must be

understood what is included in this chapter may not be correct for a particularcompany.

2.2 Railway CompaniesGovernment owned freight railways are nowadays limited to some regional lines wheretransportation service must be protected for the economic well being of thecommunities. Passenger railways, on the other hand, are generally owned bygovernments. Transcontinental services, such as the Amtrak or VIA Rail in Canada,are corporations solely owned by the respective Federal Governments. These

passenger railway companies normally do not own the trackage infrastructures. Exceptfor certain connecting routes and dedicated high-speed corridors, they merely operatethe passenger equipment on existing tracks owned by freight railways. Local rapidtransit systems are usually operated as public utilities by the individual municipalities ortransit authorities on their own trackage. Commuter services may be operated bygovernment agencies or private sector on either their own or other railway ownedtrackage.

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Freight railways in North America, including those owned by government, are usuallyincorporated as separate legal entities from their owning shareholders. The majorrailroads are usually owned by public companies with shares traded through the

various stock exchanges. Due to their age, most of these companies were incorporated

under special charters or acts of Congress. Private companies, the shares of which arenot openly traded, may own the smaller regional or short line railroads.

2.2.1 Organization of a Railway Company

An incorporated railway is governed through a Board of Directors appointed by theshareholders at the Annual General Meetings (AGM) together with a public auditor.

The Board of Directors normally meets once a month to decide on corporate issues,budget and major fund appropriation. Day-to-day business is handled by the ChiefOperating Officer (COO), Company Secretary, and Chief Financial Officer (CFO)

reporting to the Chief Executive Officer (CEO) who is the President of the company. These four senior executives at the corporate level may be appointed by the Board ofDirectors or shareholders at the AGM as stipulated in the corporate by-laws.

The COO heads the operation of the railway. Except for the Class 1 railways, theCEO and COO are often one and the same person. Under the COO, there are fourmajor departments. These are the Transportation, Engineering, Mechanical, andMarketing departments. There are other smaller yet important ancillary departmentsunder the COO that help run the company. These are the Human Resources,Industrial Relations, Labor Relations, Safety and Loss Control, Occupational HealthServices, Supply Management (purchasing), Real Estate, Public Affairs and PoliceDepartments. The Corporate Affairs, Legal and Regulatory Affairs departmentsusually report to the Company Secretary while the Financial Planning, Budget, Costing,

Accounting, Taxation, Internal Auditing and Information Technology (IT)departments report to the CFO. The IT department’s reporting to the CFO ispossibly due to the history of computers being first introduced in railways foraccounting purposes. The Investor Relations department usually reports directly to theCEO.

As the major railways’ networks span thousands of miles or even across the continent,the operating departments (Transportation, Maintenance of Way and Structures,Communications and Signals, and Mechanical) are normally structured in various levelsof geographic control. In the past, it was common to see four levels of management,e.g. the Headquarters, Regions, Divisions and Subdivisions. Supervisors and managersof the different operating departments reported upwards level-by-level, independent ofthe other departments, to the three separate headquarter chiefs. There was nomarketing function in those days with all sales handled by the station agents reportingthrough the Transportation Department.

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Modern communication facilities have allowed the railways to reduce the levels ofgeographic control down to two or three. Some railways have changed their reportingrelation from the former line organization (single line up different department) to afunctional organization where the different operating departments within the same

geographic level report to one General Manager of Operations. The operatingdepartments of Transportation, Maintenance of Way and Structures, Communicationsand Signals and Mechanical transform into functions within one “OperationsDepartment,” so to speak. These railroads believe that this type of organizationpromotes cooperation among the operating departments and improves operations.However, many railroads have retained the departmental line reporting structure asoutlined in the above paragraph. The departments of such railroads do work closely

with their counterparts in the other departments.

Transportation Department

The Transportation Department is responsible for train operations on lines and interminals as well as tracking the locations of all locomotives and rolling stock (loadsand empties). Terminal operation includes supervising of yard crews in the breakingup of arrived trains, marshaling traffic into different destination blocks, and the makingup of departing trains. Line operation includes the supervision of Rail TrafficControllers (train dispatchers and tower operators) and train crews (locomotiveengineers, conductors and trainmen) to ensure on time delivery of trains. While theyard and train crews report to the front line transportation supervisors and terminaloperations coordinators (trainmasters and yardmasters), crew calling for duty is done insome railways through a Crew Management Center. The conductor is the head of thetrain crew and responsible for the complete train while the locomotive engineer isresponsible for the operation of the locomotives and train handling. In the absence ofthe conductor, the locomotive engineer is in charge of the train. In the past,locomotive engineers reported to the master mechanics because of the specializedtrade knowledge required to operate the locomotives. Nowadays, locomotiveengineers report to the transportation supervisors. Passenger and Commuter/Transitrailways include a Passenger Operations Department to handle the logistics associated

with transporting people including train scheduling, information dissemination,ticketing and stations, as well as the operations of large passenger terminals. Rail trafficcontrollers (dispatchers) report through a separate line of supervisors in the Rail TrafficControl Centers. With the advance of communication technology, many railways havecentralized their former local dispatching centers under one roof for the entirenetwork.

The traditional function of Traffic Systems in tracking locations of loads has beenreplaced electronically by the universal Automatic Equipment Identification (AEI)system adopted in North America. However, some car-checkers are still required toassist the yardmaster in locating specific cars within major terminals.

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The chief of transportation at the headquarters level is now responsible only fornetwork operations, centralized rail traffic control, motive power control, carmanagement, traffic system service reliability, service design, Operating Practices (rulesand training) and network capacity planning.

Engineering Department

The Engineering Department is responsible for the maintenance and construction ofplant infrastructures, including track, roadbed, right-of-way, bridges, drainage culverts,buildings, signal plant, communication systems and electric traction systems.

Much smaller crews covering larger territories now replace former sizable localmaintenance of way crews. Their work consists mainly of small day-to-daymaintenance repairs such as defective rail change out behind rail test cars, correctingtrack geometry defects found by the Track Geometry Car, and emergency repairsnecessitated by adverse weather conditions and derailments. The track supervisors(roadmasters) are responsible for track inspection and workforce management. Muchof the reporting is now commonly done in the field with a portable computer or usingthe touch-tone pad of a telephone.

Large mechanized production crews that may travel over sizeable portions of therailroad, for the most part, now perform programmed or out-of-face rail and tierenewal work.

The Bridge and Building Group (B&B) is generally responsible for the track carryingbridges, occasional overhead roadway bridges, under track culverts, and roadway signs.In the past, the B&B forces also were responsible for the railway’s buildings, hence, the

building portion in the name. However, for the most part, contractors on many freightrailroads handle the building maintenance function. On many commuter and transitproperties, the Bridge and Building Department continues to be responsible for stationbuildings and platform structures.

The Work Equipment Group maintains and performs heavy repairs for track andbridge maintenance machines used by the Maintenance of Way and Structuresdepartment as well as signal & communications and electrical traction equipment. Thisgroup may even design and build machines that the supply industry does not offer theindustry.

Communications and Signals are responsible for maintaining the in-house telephoneand radio communications system, the active wayside train control signals, the rail-highway grade crossing signals and dispatcher centers.

For electrically powered railways, the Electrical Traction department is also a separateengineering function, which maintains the electric traction system including

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substations, electrical distribution system, power management systems and requiredbonding and grounding.

The Engineering Services (Design and Construction) function looks after all the

technical services, such as liaison with regulatory agencies, surveying, design, drafting,tendering and contract administration to facilitate construction work. They also handleall applications for wire, pipe and road crossings, industrial private tracks and 3rd partyconstruction.

For those railroads where all departments report to a General Manager Operations, theChief Engineer at headquarters is primarily responsible for engineering standards,research and development, maintenance practice, centralized design functions (track,signals and communications systems, bridges and structures, etc.) and prioritizing themaintenance and capital budget among division needs. For those railroads where thedepartments report through their own departmental chain of command, the respectiveheadquarters Engineering Department Chief Engineer is responsible for the abovefunctions as well as the program maintenance functions, structure maintenance andrenewal, signal upgrades and installations, and track, bridge, culvert and signalinspections.

Mechanical Department

The Mechanical (Motive Power and Equipment) Department at the division level isresponsible for scheduled maintenance, inspections and repair of locomotives androlling stock. Day-to-day maintenance of locomotives includes basic inspection,fueling, sanding, changing brake shoes, flushing out toilets and washing. Minor repairsto railcars include changing out wheels, air hoses and brake shoes. Major repairs tolocomotives and fleet conversion of railcars are now mostly done at the “back shops”under headquarters’ control. With some railways, the car mechanics responsible forinbound and outbound inspections of trains now report to the TransportationDepartment. The Mechanical department may also be responsible for the majority ofthe MOW rolling stock.

The Mechanical Chief is responsible for equipment standards, maintenance practicesfor motive power and rolling stocks, and the major repair shops.

Marketing Department

The Marketing Department concentrates on research and development of variousmarket sectors (e.g., coal, sulphur, potash, fertilizer, grain, agricultural products, metaland minerals, timber, pulp and paper, automotive, merchandising and intermodal) andrevenue growth. The Industrial Development group handles the negotiations withcustomers in the construction of private trackage. The other functions of Marketinginclude customer services, account management, quality assurance and operation

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interface. With some railways, operations of the intermodal terminals and cargo flowalso report to the Marketing Department.

2.3 Regulatory Agencies andRailway Associations

2.3.1 Regulatory Agencies

United States

The Surface Transportation Board (STB) regulates railroads regarding mergers in theUnited States. Additionally, the STB has the power to issue directed service orders toone railroad to operate another, or a portion of another railroad that is no longercapable of operating on its own. Such operations normally continue until such time aseither an acquisition is made or it is determined to discontinue service all together. Inthe early 1980's, railroads were deregulated in the rate-making arena and Federalapproval is not required for the raising or lowering of rates. Railroads may now enterinto rate contracts with customers.

In the operations area, the Federal Railroad Administration (FRA), a part of theDepartment of Transportation, regulates the railway industry. Among the things thatthe FRA regulates are locomotive and rolling stock inspections and brake tests, trainoperating procedures, radio communications procedures, track and signal safetystandards, fall protection, as well as employee on-track safety. Additionally, theOccupational Safety and Health Administration (OSHA) regulates work place safety ofrailroads in areas that the FRA does not have specific regulations unless the FRA hasmade a determination that regulations are not needed in that specific area.

Additionally, in the United States, the National Transportation Safety Board (NTSB) ischarged with investigating all major train accidents and the issuance of cause findingsas well as recommendations for the prevention of future occurrences. The NTSB’srecommendations are not binding unless the FRA adopts them. However, with veryfew exceptions, even if the FRA does not adopt the recommendations, the companyon which the train accident occurred will adopt the NTSB’s recommendations in at

least some modified form.Other governmental authorities exerting regulatory control over the railways includestate agencies, state Departments of Transportation (DOT), commerce commissionsand local governmental entities empowered to enact local ordinances.

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Canada

In Canada, the Canadian Transportation Agency (CTA), Transport Canada (TC), andthe Transportation Safety Board (TSB) regulate the Federally Regulated Railways, the

railways that are inter-provincial. Intra-provincial railroads are provincially regulated. The CTA addresses rate disputes, switching disputes, cost appropriations disputes(fencing, installation of crossing warning systems, etc.). They listen to both sides,consult with Transport Canada, and make determinations within sixty days of hearingthe dispute.

TC regulates railroads at the federal level in a similar manner as the FRA does in theUnited States except for on-track safety or fall protection. While the regulations in thetwo countries are not identical, they are similar. On-track safety and fall protection areregulated by Labour Canada. Transport Canada requires that affected railways adoptand comply with the AREMA Communications and Signals Manual of RecommendedPractice recommendations.

TSB, similar to the NTSB in the United States, investigates serious train accidents.Recommendations of the TSB are reviewed and sometimes worked into existing rulesor operating practices.

Many provinces adopt some or most of the Federal regulations/rules regarding theintra-provincial railroads. Other provinces have completely separate regulations forrailroads under their jurisdiction.

2.3.2 Railroad Associations There are numerous railway associations that address the various functional areas ofthe railway industry.

AAR and RAC

The Association of American Railroads (AAR) is the industry lobbying association ofthe major freight railroads in United States, Canada and Mexico, as well as Amtrak.

The AAR, working closely with Congressional and government leaders, helpsformulate the framework of railroad operations in North America. It fosterscooperation among railways and helps set operating rules, regulations on the handlingof inter-line traffic and interchange standards for railway equipment. The Railway

Association of Canada (RAC), with 55 freight, passenger, commuter and tourist railwaymembers, is the counterpart of AAR in Canada. For more information on AAR andRAC, visit www.aar.org and www.railcan.ca.

The AAR also provides railroad information exchange services through RAILINC,one of its two subsidiaries. Transportation Technology Center, Inc. (TTCI) is the

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other AAR subsidiary. With its 48 miles of test track in Pueblo, CO, TTCI focuses onresearch programs that will enhance railroad safety, reliability and productivity.

AREMA

The American Railway Engineering and Maintenance-of-Way Association (AREMA)is the organization that represents the engineering function of the North Americanrailroads. This organization was the result of the merger in 1997 of the AmericanRailway Engineering Association (AREA), the American Railway Bridge and Building

Association, and the Roadmasters and Maintenance of Way Association. In 1998, theCommunications and Signals group that had been a part of the Association of

American Railroads (AAR) joined AREMA, thus bringing all of the engineeringfunctions under a single umbrella. The AREMA mission is centered about thedevelopment and advancement of both technical and practical knowledge andrecommended practices pertaining to the design, construction and maintenance of

railway infrastructure. One of the primary tasks of the 26 committees making up AREMA is the development and updating of the recommended practices provided inthe AREMA Manual for Railway Engineering. For more information, visit

www.arema.org.

REMSA

On the supply side is the Railway Engineering-Maintenance Suppliers Association(REMSA). This association consists of many of the vendors that supply the productsand services that the railway engineering departments need. REMSA was created in1965 by the merger of the Association of Track and Structures Suppliers and theNational Railway Appliances Association. The association represents companies andindividuals who manufacture or sell maintenance-of-way equipment, products, andservices, or are engineers, contractors and consultants working in construction and/ormaintenance of railway transportation facilities. The mission of REMSA is to provideglobal business development opportunities to members; to transfer knowledge aboutmarkets, products and the industry to members and their customers, and to supportgovernment initiatives that advance the North American railroad industry. For moreinformation, visit www.remsa.org.

RSSI

Railway Systems Suppliers, Inc. (RSSI) is a trade association serving the

communication and signal segment of the rail transportation industry. RSSI continuesto grow with over 250 member companies. The primary effort of RSSI each year is toorganize and manage a trade show for its member companies to exhibit their productsand services. The association was incorporated in 1966 as the Railway Signal andCommunication Suppliers Association Inc. Previous to that time it existed as twoseparate entities, one for the signal area and one dealing in the communications area ofthe railroad industry. Although records are vague for the years previous to 1966, there

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are indications that one or both of these entities were in existence as far back as 1906.In 1972 the corporate name was changed to Railway Systems Suppliers, Inc. Thegoverning body of the RSSI is made up of fourteen directors from fourteen membercompanies and meets five times a year. For more information, visit www.rssi.org.

2.4 Operations of Railways

2.4.1 Safety First in Railway Operations

The safety of operations, being the safety of employees and train operations, is the firstpriority of railroads. No one should be exposed to unnecessary hazards and risks.Responsibility for safety cannot be transferred. Each employee and contractor of arailroad must accept this principal and each is personally held accountable for hisactions. Safety is a condition of working on a railroad.

Railway transportation entails the movement of heavy equipment carrying people andgoods, some of which can be hazardous or even flammable. An accident inflicts notonly property damage but also personal injuries, occasionally fatal. Where longstretches of track are destroyed by a derailment, it may take days to restore traffic.

The business of railways has been deregulated by governments, but not the safety ofoperations. On issues regarding safety of operations, although the railways areprovided with the opportunity to self-regulate, they remain reportable to the FRA or

Transport Canada. Except for minor incidents involving no personal injury, propertydamage or hazardous material release, all accidents must be reported to regulatingagencies. These regulating agencies have authority to issue temporary speedrestrictions or even suspend operations until the investigation is completed and thecause of the accident determined.

The investors and customers are also concerned about the railways’ safety records. Wall Street analysts include the railway’s safety performance in their evaluation of thecompany’s value. Potential customers, particularly those in the petroleum andchemical industries, commonly evaluate accident records of the railways on theproposed routes before choosing a carrier. The business success of a railway dependsgreatly on its safety performance.

The Safety and Loss Control Department of a railway is generally set up as a functionindependent of line operations but often reporting directly to the COO. This set-up isto ensure that safety is never compromised by economy of operations. The Safety andLoss Control Department provides safety training, performs safety audits, makesrecommendations for safety improvement, keeps records of all accidents, and ensuresinvestigations are done impartially. However, unless safety is ingrained in each and

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every employee, no Safety Department can make a railway safe. The safety processmust be ingrained in all departments from the department head down to each andevery employee as well as contractor/consultant employee with all employees takingresponsibility and accountability for safety.

2.4.2 Bibles of the Railways for Safe Operations

In order to achieve the capacity to move the required amount of traffic safely andproductively under all weather conditions, every railway must have certain “bibles” toregulate its operations. These are:

The Operating Rules, which are generally adopted from either:

The General Code of Operating Rules (GCOR) by the Association of American Railways (ARR), or

The Canadian Rail Operating Rules (CROR) by the Railway Association ofCanada,

The NORAC Operating Rules used by some New England & Eastern UnitedStates Railways,

Norfolk Southern Operating Rules,

CSX Operating Rules,

The General Operating Instructions (GOI),

Current Timetable and Terminal Operating Manuals, including specialinstructions and subdivision instructions,

General Bulletin Orders (GBO) and Daily Operating Bulletins (DOB).

Each railway requires its operating employees to be re-trained and re-qualified atregular intervals ranging from one year in the United States to one to three years inCanada.

Railway Engineering Departments, the Federal Railroad Administration (FRA) in theUnited States and Transport Canada in Canada issue additional instructions thatregulate how maintenance and construction of the components that make up thephysical elements of the railway structure are to be maintained and/or performed,including but not limited to:

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MOW Rules or Chief Engineers Instructions/Standard Practice Circulars(SPC’s).

FRA Track Safety Standards.

Transport Canada Track Safety Rules.

FRA Rules and Regulations Governing Railroad Signal and Train ControlSystems.

FRA Fall Protection (Workplace Safety).

FRA On-Track Safety (Workplace Safety).

The AREMA Manual for Railway Engineering, the AREMA Portfolio of TrackworkPlans and the AREMA Communications & Signals Manual of Recommended

Practices provide industry recommended practices associated with design, constructionand maintenance of railway track, bridges, signal and communication systems,roadway, roadway related facilities and electric traction systems.

2.4.3 Tracks and Authority of Movements

Tracks are divided into “main tracks” and “other than main tracks” based on the levelof control required for train or engine movements.

The main track is the track extending through yards and between stations, upon whichtrains or engine are authorized and governed by one or more methods of control. Themain track must not be occupied without authority or protection. The term“mainline” is not defined in the rulebooks and generally refers to the series ofsubdivisions on which most of the traffic is carried, as opposed to secondary lines andbranch lines.

Portions of the main track may be designated by limit signs in the field and/or bytimetable or special instructions that permit certain types of movements withoutspecific authority. Certain speed restrictions normally apply. These limits are oftencalled “Yard Limits”.

Occupancy of “Other Than Main Tracks” does not require authority from a

dispatcher/rail traffic controller (RTC) or tower operator. This class of tracks includesall tracks other than the main tracks or sidings. Safety of movement on these tracksdepends on the locomotive engineer looking out for other movements, obstructions,and people working on the tracks. The Rule Book therefore requires that trains orengines on “Other Than Main Tracks” must move at a speed that allows them to stop

within half the range of vision short of train, engine, or railroad equipment fouling the

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track, stop signal or derail or switch lined improperly or a maximum of 20 MPH, whichever is less (Restricted Speed).

There is one other type of track, Sidings and Signaled Tracks, that can either be

controlled under main track rules or “other than main track” rules. A siding is definedas “a track auxiliary to the main track, for meeting or passing trains, which is sodesignated in the timetable.” General bulletin orders (GBOs), train orders, or dailyoperating bulletins (DOBs) and track bulletins are instructions regarding trackcondition restrictions and other information which affect the safety and movement ofa train or engine. Signaled siding and signaled tracks, on which main track rules apply,are usually listed in the subdivision instructions of timetables. Note that signaledsidings or tracks refer to those tracks where the entire trackage is bonded with trackcircuits and signaled, not just the turnouts.

In the United States, trackage may be designated as “FRA Excepted Track” by theowner. This trackage is exempt from the FRA Track Safety Standards with theexception of maintenance of required track inspection frequencies and maximumpermissible gage. The maximum permissible speed operated on these tracks must notexceed 10 mph. The operation of revenue passenger trains or freight trains with morethan 5 placarded cars (hazardous material) is not allowed. (See Chapter 3 Basic Track –

Track Geometry for more information and requirements associated with Excepted Track.)

2.4.4 Speeds

Speed is a vital yet conflicting factor in the transportation business. Higher speedsimprove capacity and productivity but increase the safety risk and maintenance costs.Each railway goes through strenuous analysis to establish the maximum permissiblespeeds on its network of main tracks to balance the effect of safety and maintenancecosts against capacity and productivity. Compliance to the speed restrictions ismandatory to the well-being, of not only the company, but also its operatingemployees.

The maximum permissible speeds or zone speeds on main tracks are shown in thesubdivision instructions in the timetable. Separate speeds are usually specified forpassenger, freight, and express trains. Different speeds may also be allowed foropposing train directions and tracks.

Within a speed zone or designated subdivision, there are usually temporary speedrestrictions (TSR) and permanent speed restrictions (PSR). PSR are listed in thetimetable with the maximum permissible speeds operated over the subdivision andmay have signs along the track, dependent upon the carrier. TSR are usuallydesignated by bulletins.

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At locations where main tracks are connected with turnouts or intersecting each other with diamond crossings (railroad crossings at grade), movements usually have to slowdown to a speed that can be safely accommodated by the turnouts or crossings. Onnon-signaled tracks, the speed restrictions are listed as PSR in the timetable. On

signaled tracks, the signals are designed to indicate the maximum permissible speed ofthe movement through the turnouts and interlocking. Unlike the traffic lights on citystreets, railway signal systems are capable of displaying dozens of different instructionsto the trains through various combinations (up to a hundred for some railways) ofcolor lights, relative positions of the lights, and use of marker plates. These differentsignal aspects are designed to provide speed instructions, not only for that particularsignal location, but also for the second or even third signal further down the track.

Operable speeds over track are also defined by the FRA Track Safety Standards in theUnited States and the Transport Canada Track Safety Rules. Speeds are defined by theClass of Track (Class 1 through 5) and High Speed (Class 6 through 9) in the UnitedStates and Classes 1 through 6 in Canada. Permissible operating speeds are limited byperformance criteria in a number of track oriented parameters. (See Chapter 3 – Basic

Track, Track Geometry for more detail.)

2.4.5 Rail Traffic Control Systems

Before any communication device was available, train movements were by fleetoperations, that is, all trains ran in one direction until all had arrived, then they operatedin the opposite direction. Next came operations by timetable schedules, which allowedtrains to operate in both directions. Trains were classified by superiority to determine

which train would take the siding at a meet. The lower class train had to wait at thesiding until the higher class train had arrived or its schedule became ineffective after 12hours. With the installation of telegraph lines, a system of train dispatching by“timetable and train orders” was rapidly adopted due to its ability to handle non-scheduled or “extra” trains. The train order process is safe but time consuming. Inorder to achieve higher capacity, railways have evolved into more efficient trafficcontrol systems, with or without signal control.

Most of the former train order rules have been eliminated and replaced withoccupancy control system (OCS) rules in the CROR (Canada), or with track warrantcontrol (TWC) or direct traffic control (DTC) rules in the GCOR (US). Thesemodern non-signaled systems are modified train order systems that take advantage of

the high-tech radio communication and computers.

Radio Communication of Train Orders

A train order, clearance, authority or instruction that is required to be in writing can betransmitted by voice radio communication from the dispatcher/operator or in Canada,the rail traffic controller (RTC), to the train and copied in writing by a member of the

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train crew, usually on a pre-printed form. The crew member copying the order mustrepeat the order to the dispatcher/operator or RTC, word for word from the copy.

The dispatcher/operator or RTC checks the repeat against his/her written order forcorrectness, underscoring each word and digit as it is repeated. If correct, the

dispatcher/operator or RTC will respond complete, the time and the initials of thedispatcher/operator or RTC, which are recorded by the crew member. The order isnot complete and must not be acted upon until the crew member has acknowledgedby repeating the complete time and the initials of the dispatcher/operator or RTC tothe dispatcher/operator or RTC and an OK is given by the dispatcher or RTC.

Train Spacing and Block Separation

When trains were dispatched by timetable and train orders, a train following another inthe same direction relied on time spacing and flag protection to prevent rear-endcollisions. A train was not allowed to depart a station less than five or ten minutes,

depending on the road, after a preceding train in non-signaled territories had departed.If a train slowed down, the flagman in the caboose had to light and throw off five orten-minute fusees to signal the following train to immediately reduce speed torestricted speed. If the train stopped, the flagman had to scramble back a sufficientdistance to protect the train.

Rear-end collision can be prevented by dividing the track into “blocks” and allowingonly one train in each block at a time. The early Manual Block Signal (MBS) systemhad operators stationed at each block entrance to manually set the block signals toindicate whether the block was occupied or not. The early signals consisted of a blackball hoisted on a pole, with the high position indicating “proceed,” hence the term“high ball.” This later evolved into the use of “semaphore” arms and to the currentcolor lights that can be set by dispatchers hundreds of miles away.

The automatic block signal (ABS) system was developed after Dr. William Robinsoninvented the track circuit in 1872. The ABS system is mainly used for directionaloperations on two or more tracks with designated current of traffic or on relativelylow-density single tracks.

Track Circuit

Insulated joints are used to separate the track circuit of each block from another. Abattery powered low voltage direct current is passed through the two rails from one

end of a block to energize a relay at the other end of the block. The energized relaycoil picks up the iron relay armature to close the “proceed” signal circuit, which ispowered by another battery. When the track is occupied, the wheels shunt the trackcircuit, taking current away from the relay. With the relay coil not energized, thearmature drops by gravitational force (no spring used in railway relays) and opens the“proceed” signal circuit to give a “stop” indication. The track circuit is a fail safedesign and is often referred to as the Vital Circuit. If any of the components fail, such

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as a rail break, the circuit drops to indicate a “stop” signal. This is the basic one-blocksignal plant. Current systems are more sophisticated, using complicated interlockedswitching logic to provide multi-block indications.

Signal Block Length

The single block system is not practical as all trains, not knowing whether the nextblock is occupied or not, must slow down such that they are prepared to stop at theend of each block. The current ABS systems use “two-block, three-indication” as aminimum standard. With the two-block, three indication system, each block must beat least as long as the longest normal stopping distance for any train on the route,travelling at its maximum authorized speed. When a block is occupied, the signal intothis block automatically drops to a “stop” or “restricting” indication, allowing afollowing train to proceed only at restricted speed. (On some roads, this may be a“stop and proceed” indication requiring a train to stop before being permitted to

proceed at restricted speed.) The signal into the block immediately following theoccupied block changes to an “approach” indication when the block is vacated. An“approach,” allows a following train to proceed into this first vacant block but requiresit to slow down preparing to stop at the next signal. The signal into the second vacantblock (i.e., if both blocks are not occupied) would give an unrestricted “clear”indication, allowing a train to proceed at track speed. In order to move trains alongsmoothly without slowing down due to receiving an approach indication, the trainsmust be spaced two blocks or two braking-distances apart. The excess train spacing isone braking distance.

To increase line capacity, more and more railways are changing to a three-block, four-indication system by dividing the existing block lengths into halves. The four-indication system requires the use of an additional secondary approach signal indicationsuch as an “advance approach,” which indicates to be prepared to stop at the secondsignal ahead. The three-block separation, each block being only half the brakingdistance, allows trains to be spaced at one and one-half the braking distance apart.

The purpose of automatic block signals is to prevent rear-end collision. The ABSsystem is best suited for double or multi track territories with designated “current oftraffic,” normally running on the right-hand track. Passing of a slow train by anothertrain in the same direction is impossible by ABS alone. When passing is needed, or

when track work or serious delay requires left-hand movements against the current oftraffic, clearances (train orders) are issued. Nowadays, any remaining ABS systems are

mostly operated within OCS or TWC rules.

Centralized Traffic Control

On single track territories or double track sections where crossing over is allowed,there is no current of traffic. The common signaled system used in such a territory isthe centralized traffic control (CTC) system. The requirement for an absolute “stop”

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(instead of the permissive “stop and proceed”) and wait for train meets or passesnecessitate the use of “controlled signals” at sidings, junctions or crossovers in doubletrack sections. These controlled signals and the associated switches are lined andlocked by dispatchers remotely located in a centralized rail traffic control (RTC) center

often hundreds of miles away.

All turnouts within a CTC territory are circuit controlled and interlocked with othertrack circuits. Turnouts at controlled locations (sidings, junctions and crossovers) areoften equipped with “dual control switches.” A dual control switch is normally poweroperated remotely by the dispatchers and electrically locked, but can be released by aqualified employee for manual operation in the field. Other turnouts (to industrialspurs, private tracks or some low traffic branch lines) between controlled signals arenormally hand operated and equipped with either an “electric lock” (old regulations) ora standard key lock.

Authority to enter a CTC main track (or re-enter after having cleared one) at acontrolled location is by signal indication. The train crew (engineer or conductor)requests permission verbally by radio communication with the dispatcher. Afterensuring that there is no conflicting movement, the dispatcher lines the switch and setsthe signals (remotely) to authorize the train to proceed. For entry through anelectrically locked switch between signals, the dispatcher gives permission to the train.

Controls for a CTC section of track are located on a panel (or recently on a computerscreen) at the dispatcher’s desk with a diagram of the trackage and lights (or indicators)showing the locations of all trains. The dispatcher makes plans for train movementsand sends his instructions to the interlocking plants at the ends of each siding byturning a knob, pushing a button, or the use of a computer keyboard. Control of the

signals and switches in an extended territory over only two line wires (or recently bymicrowave) was made possible with pulse-code technology developed in the 1930’s. These are the “non-vital” circuits that can use up-to-date electronics to speed up,simplify and reduce the cost of transmitting information. The vital-circuit relays in thefield control and interlock switches, signals and track circuits to ensure safety ofmovements. When the switch points are lined or the signals have cleared, a message issent back from the field location to the dispatcher console to confirm that the action iscomplete.

In between sidings, opposing train movements are not possible on the single track, butfollowing movements in the same direction are allowed. The single track between twosidings usually includes absolute permissive block (APB) circuits that function withintermediate block signals between the sidings. These circuits can determine thedirection of a train and drop all opposing signals from one siding to the next to red assoon as the train heads out onto the single track. The circuits also allow signals behindthe train to clear as it moves from block to block, allowing following train movements.Most major railways have installed “intermediate signals” between sidings or controlled

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signals to facilitate fleeting of trains. Spacing of intermediate signals has the sameeffect on line capacity as previously discussed for ABS.

Single track with CTC is considered to have about 70% of the capacity of ABS double-

track. With longer trains and heavier loading in recent years, many railways aretrimming their excess capacity by converting most of their ABS double-track to single-track CTC with long sidings and high-speed turnouts for better asset utilization andimproved flexibility in handling train speed differential.

Additional Information

For further information about timetables and signal systems, see Chapter 7 of thisPractical Guide to Railway Engineering [or Chapter 7 of The Railroad What It Is, What ItDoes, by John Armstrong ].

2.5 Railway Cars

2.5.1 Freight CarsMost freight cars are configured as a car body (to carry the freight) sitting on twotrucks, each with two axles. A pair of steel wheels is semi-permanently attached to asteel axle with the wheel flanges installed on the gauge side and the wheel tread on thefield sides. A set of roller bearings (or journal box in older railcars) is bolted to eachend of the wheel-axle, which the truck frame straddles. The truck frame consists oftwo side frames connected by a bolster beam. Two or three coil springs between thebolster and the side frame serve to dampen the shock during motion. Brake riggingunder the truck frame connects the brakes to the brake cylinder. At the center of thebolster, there is a cast integral truck center plate and a center pin. The car body sits oneach center plate and is connected to the center plate by the pin. Two roller bearingsand housings on each side of the bolster serve to facilitate and limit the swivel of thetruck allowing the railcar to negotiate through curves.

As freight cars are interchanged from railway to railway throughout the continent, theymay require repair at any time or location. All replacement parts for the undercarriage,including the wheel/truck assembly, brake system, and drawbar/coupler assembly, arestandardized with few variations. This eliminates the necessity for each railway to

maintain an enormous inventory of replacement parts and work force “know how” torepair the different types of cars from different owners. Furthermore, these parts aredesigned for easy removal and replacement to minimize delays to traffic enroute. Thisstandardization is promoted by the AAR.

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Although the basic configuration of the freight railcars never changed over years, thecar bodies have evolved considerably according to the specific requirement for thedifferent commodities carried.

Boxcars

The old boxcar, as the name implies, is a plain wooden box on wheels to protect thelading (cargo) from the weather. A sliding door on each side facilitates loading andunloading of goods. Newer boxcars are made of steel in various lengths with doors oflarger sizes or types to allow access by forklifts. Some are equipped with interiorbulkheads to restrain loads. Boxcars are the general vehicles for carrying packagedgoods that require protection from rain or snow. The most common types of goodscarried are pulp and paper, plywood and OSB boards, packaged non-perishable foodproducts and consumer merchandise.

Insulated Boxcars and Mechanical Reefers

Insulated boxcars are used for short haul of perishable produce. For longer haul,refrigerator cars (commonly known as reefers) are used. These are insulated steelboxcars with a mechanical refrigeration device to control the temperature.

Intermodal Cars – Piggyback Trailers and Containers

Consumer goods and food produce are normally shipped from the manufacturers andproducers on rail in boxcars over long distances to major distribution centers. Fromthere, these goods are trans-loaded onto highway trucks for final delivery to the shopsor retailers. With the development of tractor-trailers, most of these goods are nowloaded straight into trailers. To realize the economy of long haul by rail, these trailersare lifted onto flat deck railcars in an intermodal terminal near the origin and shippedby express trains to another intermodal terminal near the distribution centers. Thistype of intermodal traffic is generally known as trailers on flat cars (TOFC).

A recent development in rail transportation of trailers is to eliminate the use of railcars. The specially equipped trailers are positioned on special bogies on the track andcoupled together. As this type of train is much lighter than the normal intermodaltrains, specialized smaller motive power units can be used. This type of service hasbecome so reliable that some carriers operate them over long distances of 1,000 ormore miles.

With much ocean freight now switched to the use of containers, import and exportmerchandise is carried in standard 20 foot or 40 foot long containers. On thehighways, these containers are carried on flat deck trailers. On rails, these containersare loaded onto flat cars. This is termed containers on flat cars (COFC) intermodaltraffic. Double-stacking of these containers on specialized intermodal flatcars allowsshipping of two or four containers on one platform. A loaded double-stack car is over

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20 feet tall above top of rail and is significantly taller than the standard 15-foot heightof most railcars. More and more domestic merchandise is now also shipped indomestic containers, which are longer than the ocean freight containers.

Double-stacked intermodal trains have become one of the most important parts ofrailway business. This is the fastest growing traffic despite severe competition withhighway trucks. Except for the pulp, paper and lumber boards, most boxcar traffic hasnow been replaced by the TOFC or COFC traffic. Some of the trailers or containersare also equipped with a mechanical refrigerating device for temperature control likethe reefers. Intermodal flatcars are often coupled permanently in packs of 2, 3, 4 or 5platforms. Some multi-pack intermodal platforms are articulately connected with bogytrucks, i.e., two platforms sharing the same railway truck.

Flat Cars

Flat cars are one of the earliest types of railcars and used for carrying commodities withlengthy dimensions such as timber logs, cut lumber, pipes and other long finishedmetal products. The easy accessibility also makes flatcars an ideal carrier forconstruction equipment, machinery and any dimensional loads.

General service flat cars usually have a wood deck to facilitate nailed-down anchoragefor loads. Other flat cars are specially modified for carrying certain types of goods, suchas the built-in center beam and bulkhead ends for carrying lumber and wood products.

TOFC and COFC are other modifications to flat cars.

Auto Rack Cars

Another modification to the flat car is the development of bi-level and tri-level carriersfor finished automobiles. These auto rack cars carry 12 to 18 automobiles each,making it economical to transport finished autos for long distances at low rates. Theauto racks are now fully enclosed to minimize damage and vandalism.

Gondola Cars

Another common type of railcar is the gondola car. These are open metal wagons on wheels to facilitate top loading. Some gondola cars are equipped with removablecovers to protect the cargo from rain and snow. To prevent contamination of theenvironment by the fine dust, soft covers or spray coatings may be used. The early

gondola wagons were five to six feet deep. As the strength of drawbars and couplersincreased, the gondola wagons increased in height to carry more tonnage per car. Theshallow gondola cars are normally used for heavy commodities such as rocks, metalproducts and metal scraps. The tall gondolas are used for carrying loose bulkcommodities such as coal, sulphur, potash, grain, plastic pellets, woodchips andsawdust. Most tall gondolas used for carrying these loose bulk commodities are builtor modified as hopper cars.

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Hopper Cars

Hopper cars are gondola cars built with hopper doors at the bottom to facilitate gravityoff-loading. The interior side walls of most hopper cars are sloped (in individual

compartments) to funnel the contents through the hopper doors. Some coveredhoppers, such as those carrying grain or cement, may be cylindrically shaped withsmaller openings on the top for loading.

Rotary Gondola/Hopper Cars

For certain commodities, portable devices may be used to shake or vibrate the hoppercars to promote faster off-loading. Some gondola and hopper cars are equipped withrotary couplers so that the whole railcar may be rotated on its side to shake the ladingoff the top.

Tank Cars

Tank cars are cylindrical in shape. Commodities carried are usually in a liquid state,such as petroleum and chemicals, including liquefied petroleum (LP) gases and moltensulphur. As the contents carried in tank cars are usually hazardous or under highpressure to maintain its liquid state, the design and construction of these cars isstringently controlled. Some are built to maintain structural integrity to prevent leakageeven after derailment. Handling and switching procedures, including the relativeposition of these cars in a train, are strictly regulated. Switching of certain loaded tankcars over the hump yard is not allowed.

Maintenance-of-Way Cars

The typical maintenance-of-way department will posses a number of specialty cars forpurposes of performing maintenance and construction related work. These carsinclude air-dumps for side depositing of fill material and rip-rap for bank stabilization,ballast hoppers for depositing controlled amounts of ballast through a variety ofcontrolled bottom dump doors, idler flat cars for rail cranes, Continuous Welded Railtrains for unloading or loading of CWR, specialized trailer or camp cars for housinglarge production gangs, wire cars for installation of overhead catenary wire in electrifiedterritory, conventional gondola cars for hauling rail and ties and box cars for specialtymobile storage of materials.

Schnabel Cars

Schnabel cars are designed to carry large,heavy loads. These cars separate into twoparts with the load becoming an integral partof the car, as it is attached back together for

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shipment. The car illustrated is just a small version of the many types of Schnabel carsthat have been built.

2.5.2 Hazardous CommoditiesGovernment regulations require that all railcars carrying hazardous or dangerouscommodities display a placard indicating the type of content carried or previouslycarried (residual in empties). Movements of these cars on a train must also beaccompanied with documentation for emergency cleanup instructions. If thedocument for a certain car is missing, the train can only move at restricted speed to thenext nearest location where the car can be set out.

2.5.3 Passenger Cars

Unlike freight cars, passenger cars are designed and built for the safe and comfortablecarriage of people. The interior of passenger cars is usually specially laid out ascoaches, sleepers, dining cars, sightseeing domes and baggage cars. Passenger cars inurban transit systems are designed to accommodate both sitting and standingpassengers to achieve maximum capacity.

Over the years, there has been much improvement to passenger cars. The mostsignificant improvements are in the body structure and under-carriage in thesuspension system. New passenger cars are designed to remain upright afterderailment and have stringent crash worthiness requirements. Some cars are designed

with a suspension mechanism to automatically tilt the car on curves so that the

passenger train may be operated at a higher speed than normally acceptable to olderequipment.

The fastest presently operating passenger train is the French TGV at approximately200 mph. The Japanese bullet train and the Swedish tilt train operate at about 120mph. Scientists are developing new propulsion systems, such as magnetic levitation, toraise the speeds of passenger trains to a higher plateau.

2.6 Locomotives In North America, all steam locomotives of the old railroad age were long ago replaced

with diesel or electric locomotives, except for a few tour trains. Unlike the steamlocomotive, the mechanical energy developed by the diesel engine is used to generateelectrical power to drive the traction motors at the driving axles and the air compressorto maintain the air-brake system. The proper term should actually be diesel-electriclocomotives. Electric locomotives do not have the diesel engines and draw electricalenergy directly from the overhead power distribution system or a third rail at the track

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level. (See Chapter 9, Railway Electrification.) Unlike in Europe, use of electriclocomotives in North America is almost exclusively for urban transit. Practically allfreight railways in America use diesel-electric locomotives.

There are different makes and models of diesel-electric locomotives in various sizesand shapes. Those used in passenger services are more streamlined in shape for high-speed operations. Dual mode locomotives are utilized on some passenger andcommuter railways. These locomotives have the capability of operating as a straightelectric locomotive in electrified territory or as a straight diesel locomotive where theoverhead electrical propulsive system is not available. The most important factors inclassifying locomotives are:

Horse-power of the engines,

Maximum tractive effort developed,

Weight of the locomotives,

Running gear ratio, and

Number of driving axles.

Trains require little energy to move the goods over level distance, but significantlymore energy to move uphill (or braking energy downhill) even on the gentlest grade.

At 15 mph, the extra energy required to lift a train to an elevation 200 feet higher, would move the same train about 21 miles at the same speed if it were on level track.

Grade is highly significant for a heavy train. A train powered at 1.5 hp per ton, whichcould make 60 mph on level track, will slow to about 22 mph on a 1% grade and to 10mph on a 2% grade. The same train will eventually stall, as the grade gets steeper.Railways actually seldom use much more than 0.5 hp per ton to move their heavytrains.

2.6.1 Horsepower (hp) and Tractive Effort

Horsepower is a measure of the rate of doing work. One horsepower = 550 ft-lbs. persecond or 375 lb-miles per hour. At zero speed, horsepower is also zero. The rated

maximum horsepower of most diesel engines is developed between 800 and 1000 rpm. The available crankshaft hp is converted (by a generator, alternator or rectifier) toelectricity. After using part of the gross hp to power the cooling fans, blowers, airbrake compressor, etc., the remaining horsepower drives the wheel axles via thetraction motors. With the modern diesel electric locomotives, normally 82% of thediesel horsepower is available for traction.

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The tractive effort (in pounds) available from a locomotive can be roughly calculatedas:

Tractive Effort (lbs.) = Horsepower X (308)

Speed (mph) Where 308 is 82% of 375 lb-miles per hour per hp. For example, a 3000 hplocomotive will have approximately 74,000 lbs. tractive effort at 12.5 mph.

2.6.2 Tractive Force and Adhesion

It is the tractive force at the locomotive driving wheels (drivers) at the rail that startsand moves tonnage up various grades. The maximum tractive force that can bedeveloped at the rail is equal to the weight on drivers multiplied by the adhesion(coefficient of friction) of the wheels on the rail.

The primary factors, among others, affecting adhesion are rail condition and speed. Adhesion decreases as speed increases. At about 10 mph, adhesion varies from lessthan 10% on slimy, wet rail to about 40% on dry, sanded rail. In general, with the aidof the sanders, approximately 25% adhesion is usually available.

As all the wheels on most diesel locomotives are driving wheels, the weight of thelocomotives must be about four times the tractive force developed. The HHP (highhorsepower) units for main line service weigh about 195 tons each on 6 axles. Themaximum tractive force is therefore approximately 97,000 lb. per locomotive or 16,000lb. per axle; that is, if there is enough horsepower at the wheel rims to develop the

tractive effort.

2.6.3 Drawbar Pull

After some of the tractive effort is used to move the locomotive itself, the remainingeffort, in the form of “drawbar pull,” is used to move the rest of the train. As the trainspeed increases, the tractive effort from the locomotives decreases and the drawbarpull available to move the train also decreases.

Due to the limited strength of drawbars and coupler knuckles, the number oflocomotives or motorized axles that can be used in the head end of a train is restricted.

Although rated with a minimum strength of 350,000 lb. (general service coupler madeof Grade B steel), coupler knuckle failure may happen at 250,000 lb. due to age and wear. Grade E knuckles used on some captive services may have an ultimate strengthof 650,000 lb.

To avoid the risk of drawbar failure enroute, it is recommended to limit the number ofmotorized axles in a locomotive consist to 18 (three 6-axle units). If more tractive

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effort is required to move the tonnage of a train, the option of in-train motive powershould be considered.

2.6.4 Train Resistance Train resistance, the force required to move a train, is the sum of the rolling resistanceon tangent level track, grade resistance and curve resistance of the locomotives andcars. Other resistances due to wind velocity, tunnels or different train marshalling willnot be discussed here.

Rolling Resistance

Rolling Resistance is the sum of the forces that must be overcome by the tractive effortof the locomotive to move a railway vehicle on level tangent track in still air at aconstant speed. These resistive forces include:

Rolling friction between wheels and rail that depends mainly on the quality oftrack.

Bearing resistance, which varies with the weight on each axle and, at low speed,the type, design and lubrication of the bearing.

Train dynamic forces that include the effects of friction and impact betweenthe wheel flanges against the gauge side of the rail and those due to sway,concussion, buff and slack-action. The rail-flange forces vary with speed andquality of the wheel tread and rail, as well as the tracking effect of the trucks.

Air resistance that varies directly with the cross-sectional area, length and shapeof the vehicle and the square of its speed.

In general, rolling resistance of a train, R (in lb.), can be calculated using an empiricalexpression as follows:

R = A + B V + C D V 2

where A, B, C & D are coefficients defining the different resistive forces that are eitherindependent, dependent or affected by the square of the train speed V.

Davis Formula

The first empirical formula to compute rolling resistance was developed by W.L. Davisin 1926. The original Davis formula provided satisfactory results for older equipment

with journal bearings within the speed range between 5 and 40 mph. Roller bearings,increased dimensions, heavier loadings, higher train speeds and changes to trackstructure have made it necessary to modify the coefficients proposed by Davis. Since

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then, there had been various modifications. Interested readers may refer to Section 2.1of Chapter 16 in the AREMA Manual for Railway Engineering for more information.

Starting Resistance

The resistance caused by friction within a railway vehicle’s wheel bearings can besignificantly higher at starting than when the vehicle is moving. Depending on the typeof bearings, weight per axle and the temperature of the bearing, starting resistance canrange from 5 to 50 lb/ton. The ambient temperature and the duration of the stop asshown below affect temperature of the bearing.

Type of Bearings Above Freezing Below Freezing

Journal Bearing 25 lb/ton 35 lb/ton

Roller Bearing 5 lb/ton 15 lb/ton

Starting resistance is generally not much of a problem with the very large tractive effortavailable with modern diesel locomotives, except on steeper grades. If necessary, thelocomotive engineer can bunch up the train first, then start the train one car at a time.

The cars already moving will help start the ones to the rear. This is called “takingslack” to start.

Grade Resistance

Grade Resistance is the force required to overcome gradient and is equal to 20 lb. perton per percent grade. This force is derived from the resolution of force vectors and isindependent of train speed. An up grade produces a resistive force while a down gradeproduces an accelerating (negative resistive) force. A train moving up a long tangent of1% grade at 10 mph, a speed that most tonnage trains slow down to at ruling gradelocations, will have a train resistance coefficient of 22.4 to 23.5 lb. per ton with thegrade resistance accounted for over 85% of the total.

Curve Resistance

Curve Resistance is an estimate of the added resistance a locomotive or car must

overcome when operating through a horizontal curve. The exact details of themechanics contributing to curve resistance are not easy to define. It is generallyaccepted in the railway industry that curve resistance is approximately the same as a0.04% up grade per degree of curvature (which equals 0.8 lb. per ton per degree ofcurvature) for standard gauge tracks. At very slow speeds, say 1 or 2 mph, the curveresistance is closer to 1.0 lb. (or 0.05% up grade) per ton per degree of curve.

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2.6.5 Compensated GradeIt is a common practice to describe curvature and grade together as compensatedgrade. Compensated grade is the algebraic total of the track gradient and the

equivalent grade of the curve.

Gc = G + D c * 0.04

Where G c = compensated grade in %

G = track gradient in %

Dc = degree of curvature in decimal number

The track gradient “G” is positive for up grade and negative for down grade. Theequivalent grade of a curve is always positive; i.e., at +0.04% per degree of curve withtangent tracks as 0.00%. The combined resistance due to track geometry can thus becalculated by converting the compensated grade at 20 lb. per ton per percent grade asshown below.

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Track Gradient

Degree ofCurvature

CompensatedGrade

Grade and CurveResistance

+ 0.44 % 3 û 45’ + 0.59 % + 11.8 lb/ton

+ 0.50 % Tangent + 0.50 % + 10.0 lb/ton

- 0.73 % Tangent - 0.73 % - 14.6 lb/ton

- 0.73 % 4û 30’ - 0.55 % - 11.0 lb/ton

Note that curves on down grades help reduce the accelerating force of coal trainscoming down from the mines. In railway operations, keeping a train under controlover a long stretch of steep down grade poses a much bigger problem than poweringthe same train uphill.

2.6.6 Acceleration and Balance Speed

It takes about 100 lb. force to accelerate a mass of 1 ton at the rate of 1 mph persecond. The total tractive force, "F" (lb.), required to accelerate a train of "W" tons(locomotive and cars) at the rate of "A" mph per sec. can thus be calculatedapproximately as:

F (lb.) = 100 W (ton) A (mph/sec)

After a portion of the drawbar pull is used to overcome the train resistance, the excessis used to accelerate the train. Rolling resistance for a train increases as the speedincreases. At the same time, the tractive effort of the locomotive (and thus thedrawbar force) decreases as the speed increases. As the available drawbar forcedecreases, the accelerating rate drops. For a train operating on a long stretch ofconsistent grade, there is an equilibrium point when the total drawbar pull is equal tothe total train resistance. At this point or speed, the train will accelerate no more. Thisis the “balance speed” (or balancing speed) of the particular train on that particulargrade.

If the grade resistance increases after the balance speed is reached, the train will slowdown to another balance speed for the increased grade. If the grade keeps onincreasing, the train will slow to a speed that the locomotive cannot sustain and willstall.

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At any given speed that the train is to maintain, there is a maximum tonnage that alocomotive can pull up a specified grade. This is the tonnage rating of the locomotivefor the specified grade.

2.6.7 Tonnage Ratings of Locomotives

Most railways publish “Tonnage Ratings” for their locomotive fleet. These ratingsindicate the maximum tonnage that a specific locomotive can haul over a giventerritory at a specified minimum speed.

Obviously, no single rating can be used for assigning maximum tonnage where thenumber of cars (axles) and their weights vary from train to train. A system has beendeveloped and used on most railways, which makes it possible to express tonnageratings without regard to the weight of the cars in a train.

2.6.8 Ruling Grade

On any particular section of railway, the ruling grade (compensated) determines howmuch tonnage can be hauled. This is the particular point on the section at which thecombined grade and curve resistance makes the train pull hardest and, therefore, ruleshow much tonnage can be hauled by a locomotive consist. It is not at the samelocation for both directions, and may not be the same location for all trains.

2.6.9 Momentum Grade

The ruling grade may not be the steepest grade on the section. A short grade does notaffect the whole train length at the same time. A short incline may be run as amomentum grade, if conditions are such that trains can get a good run for the hill. Ifthe velocity head of the train at the foot of the grade is higher than the actual rise, theincline is a momentum grade. Velocity head, h in feet, can be calculated as:

h (ft) = v 2 / ( 2 g ) where v = train speed in ft/sec at foot of grade,& g = gravitational acceleration, or

h (ft) = 0.03 V 2 where V = train speed in mph at foot of grade

Conversely, if the velocity head, h, is less than the actual rise in feet, the grade isconsidered as a ruling grade. The effects of train length must be considered in theabove calculation to ensure a good portion of the train is over the hill when the

velocity head is depleted.

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2.6.10 Power to Stop

In moving traffic over a railway, power to stop can be more important than tractiveforce, bigger cars or stronger couplers. In order to maximize the capacity of theexisting line, trains are run as close as possible (with minimum headway) at reasonablespeed without running into each other. That takes reliable braking power.

The air brake used in railway cars is a fail-safe, reversed action system. Plainlydescribed, the brakes on each car are released when the brake pipe pressure is chargedup and maintained (80 to 90 psi for most freight train operations) throughout the trainby the air compressors on the locomotives (or from a yard air plant prior to departure).

The train brakes are actuated by a controlled reduction (minimum 10 psi reduction toavoid sticking brakes on release) of the brake pipe pressure. This reduction causes the

valve on each car to release air from the auxiliary reservoir (charged up at the same

time as the train line) to build up pressure in the brake cylinder, applying the brakes.Each pound of reduction in brake pipe pressure will build up approximately 2.5 psipressure in the brake cylinder. At 85 psi brake pipe pressure, a full service reduction of25 psi will produce approximately 60 psi in the brake cylinder. At this point, thepressures in the reservoir and cylinder are equal, and any further reduction will have nofurther effect.

There is a second “emergency” reservoir on each car. With an emergency application,the brake valve opens the brake pipe wide. The resulting rapid rate of brake pipepressure reduction causes the car valves to dump the air of both auxiliary andemergency reservoirs into the brake cylinder. The resulting brake cylinder pressure isapproximately 20% higher than that of a full service application. The rate ofapplication back through the train is as fast as 900 ft. per second.

The braking power is dissipated as heat at the brake shoes and wheels. On long steepgrades, it is necessary to release the brakes intermittently or stop the train to cool the

wheels. Increasing or recharging the brake pipe pressure from the locomotives releasesbrakes. Increasing the brake pipe pressure will cause the brake valve to completelyexhaust the brake cylinders and recharge the reservoirs. As it takes time to rechargethe system, the train is momentarily without brakes after a full service application orseries of smaller reductions.

Although the locomotives have independent brakes (straight air system used mainly for

controlling slack and during switching operations) and some locomotives are equipped with dynamic brakes, to prevent jack-knifing, most of the braking force has to be fromthe train brakes. In mountainous territory, keeping the heavy trains under controlshould be the key concern in grade designs.

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2.7 Traffic Systems The railway business is the business of transporting people and goods. Thetransportation of people (the most precious commodity of all) requires the higheststandards for safety, comfort and speed. Passenger trains are always operated asscheduled trains with the highest priority at the fastest speed that is safe for the trackconditions and type of passenger equipment used. Operations of passenger trainsideally are within minutes of the schedules.

On time delivery of freight trains is also vital to the success of a railway, particularly forhigh value commodities and traffic extremely competitive with highway trucks. Inorder to keep inventory cost low, customers dealing in high value commodities, such asthe automotive industry, normally keep minimum inventory to meet demands orproduction schedules. They do not tolerate late delivery by more than a few hours.

Merchandise and intermodal traffic are highly competitive with other modes oftransportation. The railways must handle this traffic with high priority in order toremain in the market place. Intermodal and automotive trains are operated as corescheduled express trains. These trains are designed to bypass as many terminals aspossible and provided with enough horsepower to operate at the maximum allowedspeeds. On time delivery must be achieved within a couple hours of the schedules.

Bulk commodities such as coal, sulphur and grain are normally shipped in unit trains with no switching between origins and destinations. In exchange for economy offreight rates, the shippers normally will tolerate some delay except when the trains haveto make a direct connection for a certain ship at the seaport. These heavy tonnagetrains seldom achieve track speed on uphill grades. Bulk trains are usually operated onan as-required basis using available track time windows between core trains. Schedulesfor these trains are usually zero based; i.e., the clock starts ticking when the traindeparts at the origin.

Manifest trains handling all other commodities are operated as quasi-core scheduledtrains. Schedules for these trains are normally planned 48 to 72 hours ahead based ontraffic availability by the Network Operations Control and confirmed 24 hours prior todepartures. Traffic on these trains normally requires switching at intermediateterminals for train connections. The railways usually have a certain amount offlexibility in handling this traffic and a delay of up to 12 hours may be acceptable.

Wayfreights or road switchers are the work trains that spot and switch traffic forcustomers along the line and within terminals. The labor cost to operate a switcher ona main line subdivision is usually the highest among all trains. While through trainsmay be operated with a reduced crew (engineer and conductor), road switchers requirea full crew (1 or 2 additional trainmen) to line switches and derails, apply and releasehandbrakes, perform walking inspection of cars and air-brake system and to protectpushing movements. The simple “hook and haul” activities of a road switcher, picking

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up (say 5) loads and re-spotting empties at an industry on a line with sidings 20 minutesapart, will take approximately an hour of the main track time.

The window required for on-line switching significantly impacts the capacity of the

main track to handle through trains. When a road switcher occupies the main track while picking up or spotting loads/empties at an industry, all through freights aredelayed from running through the block. In most cases, the dispatcher may choose todelay and hold the road switcher at the nearest siding until there is an adequate windowfor the switcher to complete its work and clear the block. On a medium traffic linehandling 20 through freights per day, the average delay to a switcher waiting at a sidingfor the one-hour window is approximately 45 minutes to an hour. The total switchertime to serve this industry is therefore 1.75 to 2 hours.

The duration that a train crew may work on a one-way trip is usually limited bygovernment regulations or collective labor agreement to 12 hours. After deducting 2.5hours at the initial terminal for making up the train in the order that cars will beswitched, 3 hours road time and another half hour to tie-up at the final terminal, thereis usually not much time left for actual switching and waiting for work windows.

2.7.1 Priority of Trains

Based on market demand, railways prioritize the dispatching of their trains as follows:

Passenger trains Priority 1

Express intermodal and auto trains Priority 2

Manifest trains Priority 3

Wayfreight and road switchers Priority 3

Bulk trains contracted for specific delivery intervals Priority 3

Other bulk unit trains Priority 4

Other railroads may prioritize their trains differently.

On double track territories, where each track is signaled for traffic in one directiononly, trains operate according to designated current of traffic, except during track

outage or work blocks. In this situation, trains do not have to stop for meets. If alltrains running in the same direction operate at the same speed, they do not have tostop for passes either. Unfortunately, trains do operate at different speeds by design tomeet the market requirements. On single track territories, which make up the majorityof the North American network, trains have to stop and wait for meets and passes.

In the decision as to which train will take the siding and wait for a meet or pass, thefirst factor considered by the train dispatcher is usually the priority of the trains.

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Consider the situation where a double-stack intermodal train is closely followed (say 2blocks apart) by a higher speed passenger train and has to meet a slow moving heavybulk train between sidings A and B. If all these trains are on schedule, the likelydecision by the train dispatcher would be to put both the intermodal train and the bulk

train in the two sidings and let the passenger train pass. The intermodal train would bethe next one cleared onto the main track, while the bulk train remains delayed in thesiding until both other trains have gone by. The dispatcher’s decision may vary if thepassenger train is ahead of schedule or if the computer’s “meet-pass planner routine”advises that such decision would introduce significant delays to other trains in theterritory beyond acceptable limits.

The railways usually have three different maximum allowed speeds specified for thesame class of track, with the fastest speed for passenger trains, the middle one forexpress trains and the slowest speed for all other freight trains. If all trains on asegment of track are operated at the same speed, higher speeds will allow more trainsto move through the segment. Train delays at sidings for meets are inherent andunavoidable with single-track territories. The amount of total train delays between twosidings is related to the running time between the sidings, the efficiency of the signalsystem and the number of trains operated per day. Train delays at sidings to let othertrains pass are caused by speed differentials between trains in the same direction. Thegreater the speed differential between trains, the more trains that will be delayed “in thehole” to let the high-speed train by. Speed differential in the same direction, therefore,introduces more train delays and reduces the capacity of the line segment.

2.7.2 Effects of Sharing Tracks by Freight and

Passenger Trains vs. Track of Single Use There is a physical limit as to how many trains could be put through a segment ofsingle track, depending on the siding grid time, signal system and dispatchingefficiency. If one “channel” of the available capacity is required for each normalthrough freight, it is generally believed that a conventional passenger train will need 2channels, while an express train requires 1.5 channels. A passenger train takes up to 2channels of the available capacity only if it is running at 3-inch unbalance (regardingcurve elevation) over the normal freights. If the passenger train uses specialtyequipment and operates at speeds significantly higher than the freight trains, it will takeup more capacity from the line. It may therefore be advantageous to operate high-speed passenger trains on dedicated tracks when there are enough trains to justify theinfrastructure investment. There are also other safety advantages to operatingpassenger trains on dedicated tracks. The heavy long freight trains, particularly thebulk trains, kick the track out of line and surface a lot faster than the light passengertrains. The out-of-surface track does not affect the slow moving freights as much asthe fast passenger trains. If a track is jointly used by freights with passenger trains, the

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safety and comfort level required for the passengers will necessitate more frequenttrack re-surfacing than if the track is used for freight alone.

2.7.3 Overcoming the Delays that Occur in FreightYards

Freight Yards are necessary in the railway business in order to originate, transport andterminate shipments of freight. However, they can be real handicaps in that theyinherently cause delays to freight in transit, thereby upsetting shippers. Railways oftenspend large sums of money both to construct efficient, high-speed main tracks and toget trains over the road as rapidly as practicable. But when these trains arrive interminals, the cars they brought may sit idle awaiting switching and departure to theirdestinations.

In order to eliminate such delays, railways will often "mainline" trains at intermediateterminals rather than "yard" them there. In this process, locomotives are fueled andserviced on a main track, or on a track immediately adjacent thereto. Air brake testscan also be made there if required. Engine and train crews are changed at the samelocation, thereby minimizing a yard's effects on a train while taking advantage of itsservice capabilities and personnel.

If a train does not require fueling and servicing, crews are sometimes changed at asiding outlying a terminal, with personnel being transported by van or carryall. Thenthe train, with its new crew, simply "runs" the terminal as if it did not exist, savingmany hours or even days of delay.

When a train is run essentially intact over more than one railway, then the samelocomotive consist is often run through on all of the railways. This requires the abilityto change the frequencies of onboard radio equipment to match those of the railroadsbeing operated on. Preserving the continuity of a train (and its air brake line) reducesthe number of required air brake tests, also saving time. Intermodal trains usually travelfrom and to facilities specifically constructed to handle truck trailers and containers. Atthese facilities, the switching of trailers and containers (on chassis) is handled on thepavement by hostler or dray tractors. This rapid handling makes this servicecompetitive with straight truck transport.

chapter2 - railway industry overview

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