Methods of Operation and Signal Systems Learning Objectives
Methods of Operation and Signal Systems
Learning Objectives • Understand the various methods of operation and signal systems used on today’s railroads. 2
CAUTION The following presentation was developed to provide general information only. For detailed compliance information please refer to 49 CFR 236 – Rules, Standards and Instructions, Subpart D and the S&TC technical manual. It is recommended that each employee refer to appropriate manuals and regulations when dealing with any specific issue. 3
Information The FRA Rules, Standards, and Instructions are considered to be the minimum standard allowed for the installation, inspection, maintenance, and repair of signal and train control systems, devices, and appliances. Each railroad may adopt more stringent standards. Refer to your railroad’s signal standard and instruction manual for further guidance.
Method Of Operation & Signal Systems The following presentation contains generic descriptions of different railroad methods of operation to be used for study purposes only. If questions arise regarding a specific railroad’s method of operation please consult the appropriate timetable, FRA regulation 49 CFR 236. 0, or your supervisor further guidance. 5
Method Of Operation & Signal Systems • Method of Operation and Signal Systems. 6
Method Of Operation & Signal Systems Two trains which are not in the same place at the same time cannot collide! 7
Method Of Operation & Signal Systems “Method of Operation” is a term which is best defined as the means by which a train has authority for movement. The method and the specified limits are usually listed in the railroad’s timetable for each district or subdivision. 8
Method Of Operation & Signal Systems “Signal System” is a term which refers to the type of system (or systems) in use on a specified territory. Signal systems, interlockings and special signal arrangements are listed in the railroad’s timetable for each district or subdivision. 9
Non-signal Operating Systems • • • Yard Limits Timetable Operation Train Order Manual Block System Track Warrant/Track Permit Direct Traffic Control 10
Automatic Block Signals • Automatic Block System (ABS) • Multiple Track (Current of Traffic) • Absolute Permissive Block 11
Operation by Signal Indication • Intelockings • Traffic Control System 12
Yard Limits Within yard limits, the main track may be used by trains or engines, not protecting (note: no flag protection) against other trains or engines. Engines must give way to trains as soon as practicable upon their approach. Movements within yard limits must be made at restricted speed, unless the main track is known to be clear by a block signal displaying a clear (e. g. green) as part of its aspect. 13
Non-signal (Dark) territory What is the allowable speed here? Refer to 49 CFR 236. 0 14
Timetable Operation • Timetable operation is a system where train movements are authorized by being scheduled in the timetable. • Any deviations from the timetable (delayed, extra, or annulled trains), would be provided for by train orders. • This used to be a standard method of train operation throughout the country, now is quite rare. 15
Technology and Methods of Operation Telegraph on Early Railroads • 1840 s – Erie Railroad begins installing telegraph. • 1851 – Erie Railroad issues first telegraphic train order.
First Telegraphic Train Order • Superintendent Charles Minot of the To Agent and Operator at Goshen: Erie Railroad was on a train at Turner, thewaiting train for further New. Hold York for a orders. delayed Charles Minot, Superintendent eastbound train. He then. Monroe, hand wrote. New the following order: if • He wired York asking the train had arrived yet. Day To Conductor and Engineer, Express: • Upon receiving a negative reply, he sent Run to Goshen regardless of opposing the following historic wire. train. Charles Minot, Superintendent
The Train Order Method of Train Operation was born on September 22, 1851 This Method of Operation was replaced by Track Warrant Control and Direct Traffic Control In the 1980 s – 90 s.
Train Order • The train order method of operation is an older written form authorizing train movements. • This method required train order operators to be stationed along the route to pass orders to the trains. • Train orders have been mostly replaced with Track Warrants, Track Permits, and Direct Traffic Control systems. 19
Manual Block System • Manual Block is a means of controlling movements of trains in the same direction without automatic block signals. • Sections of railroad would be divided into blocks, which extended between stations or manual interlocking towers attended by operators. • Signals would be controlled by the operators. 20
Manual Block System What is the allowable speed with a manual block system permanently in effect? Refer to 49 CFR 236. 0. 21
Technology and Methods of Operation • American railroads led the way in developing advanced communications systems. • In the 1950 s railroads introduced the widespread use of microwave and radio communication. • By the 1980 s these system led to a fundamental change in rail operations. 22
Track Warrant Control (TWC) • TWC utilizes written forms authorizing trains to occupy designated track segments. • Any two identifiable points on the railroad can be used to designate the segments. • Train dispatchers may transmit instructions by radio to crew members, who will write this information on these forms. • Sometimes referred to as Track Permit method. 23
Direct Traffic Control (DTC) • DTC is a system where a portion of railroad is divided into "blocks", each of which has a name. • Train dispatchers will authorize the occupancy of blocks by naming the blocks authorized. 24
Automatic Block Signal Systems These systems are used as a safety supplement to other methods of operation, e. g. Train Orders, TWC, etc. 25
Automatic Block System (ABS) • ABS is not a method of train operation, but can be used as a supplement to provide safer and more efficient train movements. • Sections of railroad would be divided into blocks, and automatic signals at the entrance of each block would convey the presence of trains ahead. 26
Automatic Block Signal Systems are usually designed for a specific application, e. g. single track, double track, etc. 27
ABS on Multiple Track • Each track is equipped with automatic signals for a designated direction, or "current of traffic". • If necessary to operate trains against current of traffic, one of the methods for non-signaled trackage must be used. 28
Automatic Block Signal Systems • Double Track – Current of Traffic. Trains normally run in only one direction. 29
Automatic Block Signal Systems Current of traffic ABS is designed for movements in one direction on each track. The authority for movement is usually by train order, track warrant, etc. , supplemented by the ABS system. 30
Automatic Block Signal Systems Current of traffic ABS is not designed for movements in reverse direction, this must be accomplished by train order, track warrant, etc. to be done safely. (Wrong Main Moves, same as running in non-signal territory? ) 31
Absolute Permissive Block • APB signals regulate movements in the same direction, and protect against movements of the opposite direction. • APB is not a method of operation, but supplements some other type of train movement authority by increasing safety and efficiency. 32
Absolute permissive Block Signal Systems Absolute Permissive Block Signal Systems are designed to protect train movements from opposing traffic and to allow following movements. 33
Interlocking Signal Systems A method of operation whereby train movements using routes of an interlocking are governed by signal indications which supersede the timetable superiority of trains within interlocking limits. The interlocking signal (when lined) establishes authority for movement into and through interlocking limits. 34
Interlocking (manual) • Interlockings are location where switches and signals are controlled by a control operator. • Switches and signals are "interlocked", meaning that they cannot be set for conflicting or opposing movements. • They are so arranged that when a signal is cleared for a train movement no switch in the route can be changed. 35
Interlocking (automatic) • Interlocking arranged so that an approaching train initiates a request for a route. • The system automatically checks for: – – Plant not occupied Conflicting and opposing movements. Conflicting and opposing signals at “Stop”. Plant not locked. • If these conditions are met the approaching train receives a proceed signal. 36
Interlocking Signal System Signal indication of an Interlocking Signal System will be the authority for train movement at interlockings. (see 236. 301) 37
TCS combines Two Proven Technologies Interlocking Automatic Block And adds in a communications system. 38
Traffic Control System 1927 • The first Traffic Control System (TCS) System was installed in 1927 on the New York Central Railroad between Stanley and Berwick, Ohio. • Combined an automatic block signal system with a series of manual interlocking plants. • Add a communications system. • Gave dispatcher control over train movements. • New method of operation by signal indication only.
Traffic Control System Definition § 236. 828 System, traffic control. A block signal system under which train movements are authorized by block signals whose indications supersede the superiority of trains for both opposing and following movements on the same track. 40
Traffic Control System (TCS) • A method of operation whereby train movements are authorized by signal indication only. • TCS territories are controlled from a central dispatching office via a control console. • Train dispatcher directly controls the position of switches and the display of signal aspects. • And on multiple track lines, any track can be used for movements in either direction. 41
Traffic Control System (cont. ) • Combined the operating systems and rule of ABS and interlocking systems. • Generically referred to as Centralized Traffic Control (CTC). 42
Traffic Control System A method of operation whereby train movements are controlled by signal indication only. Signal indications of a TCS system supersede timetable superiority of trains. Usually, signal indications, switch positions, and train location information (track indication) is displayed on the control operator's (or dispatcher’s) visual control equipment. 43
Traffic Control System Signal indication of a Traffic Control Signal System will be the authority for train movement. 44
Block Register Territory (BRT) • BRT is a designation applied to some lightly used segments of track. • In these areas, trains are authorized to move into the territory when a special type of log book is filled out correctly. 45
Method Of Operation & Signal Systems • It is important that all operating and engineering employees know what systems are in place and which rules apply • Refer to Timetables, Special Instructions and General Orders for more info when necessary • Remember - A signal system may be the “method of operation”, (e. g. TCS). • Or it may simply be a supplement to the method of operation, (e. g. ABS). 46
Automatic Cab Signal System • Automatic Cab Signal System will usually be supplemented with train orders or some type of written authority, however the cab signal system is heavily relied upon for safety and keeping trains separated and allows trains to operate at speeds in excess of 79 MPH. 47
Automatic Train Stop (ATS) 48
Automatic Train Control (ATC) 49
Signal Systems - ACS, ATC & ATS Signal Systems • Automatic cab signal, train control and train stop systems are currently installed on many miles of railroad in the U. S. • Today, in most cases, these systems are used as a safety supplement to other methods of operation, e. g. TCS systems, Train Orders, TWC, etc 50
More Information Regarding Methods of Train Operation
Method Of Operation & Signal Systems OPERATING RULES 52
Method Of Operation & Signal Systems Become familiar with the operating rules for your railroad, especially the “General Signal Rule” section and the “Aspects and Indications” section. 53
Timetable & Special Instructions Become familiar with timetable and general bulletin special instructions. Special instructions can be very important regarding how train operation interacts with the signal system. 54
Timetable & Special Instructions Special instructions and notes regarding interlockings, drawbridges and other special signal arrangements should be legible, accurate and posted at the location, in the timetable or both. 55
Timetable & Special Instructions Become familiar with the various signal aspects and indications used on the railroad. These will usually be found in the operating rule book or special instructions. 56
Timetable & Special Instructions There are various signal aspects for each railroad. Sometimes there are more than one set of aspects listed for a railroad. 57
Timetable & Special Instructions Aspects and indications govern train movement All S&TC Employees should be familiar with these rules. 58
Method Of Operation & Signal Systems Operating rules, special instructions and general bulletins should also address the safe functioning and operation of signal systems and highway grade crossing warning devices. For Example: 59
Method Of Operation & Signal Systems Railroads sometime mix various systems and methods of operation which make it difficult for employees to fully understand what systems are in place and what rules regulations may apply. If in doubt contact your supervisor. 60
Methods Of Train Operations and Signal Systems The End
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