Pub Date : 1996-04-30DOI: 10.1109/RRCON.1996.507972
M. J. Collins, J.D. Martin
The data capacity of railway track circuits can be increased by the use of binary block codes. The application of standard block coding techniques is limited because of the fail safe requirement and because each code must be independently synchronisable. Also, the hostile electrical environment suggests that error detection/correction should be employed. The two problems of error detection/correction and synchronisation are simultaneously addressed by cyclic coset codes, without incorporating any special signals or bit patterns for 'start of message' or 'end of message' indicators. Codes suitable for track circuit data are analysed in terms or their synchronisation error performance and a new measure of the comma free properties of these codes, the overlap probability distribution, is introduced. This provides a better criterion for the choice of coset codes than is given by the index of comma freedom alone.
{"title":"Synchronisation of cyclic coset codes for railway track circuit data","authors":"M. J. Collins, J.D. Martin","doi":"10.1109/RRCON.1996.507972","DOIUrl":"https://doi.org/10.1109/RRCON.1996.507972","url":null,"abstract":"The data capacity of railway track circuits can be increased by the use of binary block codes. The application of standard block coding techniques is limited because of the fail safe requirement and because each code must be independently synchronisable. Also, the hostile electrical environment suggests that error detection/correction should be employed. The two problems of error detection/correction and synchronisation are simultaneously addressed by cyclic coset codes, without incorporating any special signals or bit patterns for 'start of message' or 'end of message' indicators. Codes suitable for track circuit data are analysed in terms or their synchronisation error performance and a new measure of the comma free properties of these codes, the overlap probability distribution, is introduced. This provides a better criterion for the choice of coset codes than is given by the index of comma freedom alone.","PeriodicalId":293519,"journal":{"name":"Proceedings of the 1996 ASME/IEEE Joint Railroad Conference","volume":"536 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122764550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-04-30DOI: 10.1109/RRCON.1996.507980
J. Lovegrove
The results of an investigation which occurred at the Docklands Light Railway, London, UK, in the fall of 1994 are presented. Alcatel's SELTRAC system was being installed and commissioned on an operating railway. The existing signaling system for the railway had been installed by General Electric Corporation, Alsthom Signaling Limited (GASL) of the United Kingdom. Both systems are transmission based, and used a cable laid down the center of the guideway for communications with vehicles. Problems were noted at various points of the guideway, and an investigation conducted to determine the source of the problems, and to implement corrective actions. The investigation first focused on external interference, then turned to interference between the two signaling systems, the complex interaction of the systems, the ironwork of the guideway, and the ballast resistance of the track. The steps of the investigation are presented, along with the results, the coupling mechanism which was ultimately responsible, and the corrective actions which were successfully implemented.
{"title":"Electromagnetic compatibility for communications based signaling systems","authors":"J. Lovegrove","doi":"10.1109/RRCON.1996.507980","DOIUrl":"https://doi.org/10.1109/RRCON.1996.507980","url":null,"abstract":"The results of an investigation which occurred at the Docklands Light Railway, London, UK, in the fall of 1994 are presented. Alcatel's SELTRAC system was being installed and commissioned on an operating railway. The existing signaling system for the railway had been installed by General Electric Corporation, Alsthom Signaling Limited (GASL) of the United Kingdom. Both systems are transmission based, and used a cable laid down the center of the guideway for communications with vehicles. Problems were noted at various points of the guideway, and an investigation conducted to determine the source of the problems, and to implement corrective actions. The investigation first focused on external interference, then turned to interference between the two signaling systems, the complex interaction of the systems, the ironwork of the guideway, and the ballast resistance of the track. The steps of the investigation are presented, along with the results, the coupling mechanism which was ultimately responsible, and the corrective actions which were successfully implemented.","PeriodicalId":293519,"journal":{"name":"Proceedings of the 1996 ASME/IEEE Joint Railroad Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129579760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-04-30DOI: 10.1109/RRCON.1996.507977
B. Bhargava
The benefits of a low frequency (15-20 Hz) railway electrification system are presented in this paper. The low frequency railway electrification system has been used in European countries for almost a century. The railway electrification load is one of the worst kinds of load to be fed by an electrical utility. It requires over-sized substation facilities and results in power quality deterioration. With the modern day power electronics technology available for frequency conversion and the high power quality demanded by the utility power customers, the low frequency systems will provide an affordable and desirable railway electrification system.
{"title":"Benefits of a low frequency, low voltage railway electrification system","authors":"B. Bhargava","doi":"10.1109/RRCON.1996.507977","DOIUrl":"https://doi.org/10.1109/RRCON.1996.507977","url":null,"abstract":"The benefits of a low frequency (15-20 Hz) railway electrification system are presented in this paper. The low frequency railway electrification system has been used in European countries for almost a century. The railway electrification load is one of the worst kinds of load to be fed by an electrical utility. It requires over-sized substation facilities and results in power quality deterioration. With the modern day power electronics technology available for frequency conversion and the high power quality demanded by the utility power customers, the low frequency systems will provide an affordable and desirable railway electrification system.","PeriodicalId":293519,"journal":{"name":"Proceedings of the 1996 ASME/IEEE Joint Railroad Conference","volume":"365 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130960974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-04-30DOI: 10.1109/RRCON.1996.507964
C. Swenson, R. Scott
Since Electro-Motive Division's (EMD) 3-axle radial steering bogie for heavy haul freight locomotives was introduced in production in 1993, over 70 million miles of service have already been accumulated on this new design. By the end of 1996, over 800 AC and DC traction locomotives with this new bogie technology will have been put into service. Wheel wear data, which is relatively straightforward to obtain, is showing that wheel flange wear has been virtually eliminated and that wheel tread wear has not increased in spite of dramatic increases in adhesion to 45% for starting heavy trains and to 35% and higher for train operation. Wheel wear data indicates that wheel life will likely double, even in operations where wheels are re-profiled for tread wear. This is due to the profound effect of low flange wear on minimizing metal removed in wheel truing. The wheel wear results also suggest changes to traditional railroad wheel truing policies. The effect of the radial bogie design on rail wear savings is more difficult to assess, and this paper discusses several rail wear considerations. Laboratory tests have provided considerable insight into the influence of wheel-rail angle of attack on wheel and rail wear. An approach is suggested for combining the available field and lab data with a cost model to project the life cycle cost savings for rail wear as well as wheel wear improvements.
{"title":"The effect of locomotive radial steering bogies on wheel and rail wear","authors":"C. Swenson, R. Scott","doi":"10.1109/RRCON.1996.507964","DOIUrl":"https://doi.org/10.1109/RRCON.1996.507964","url":null,"abstract":"Since Electro-Motive Division's (EMD) 3-axle radial steering bogie for heavy haul freight locomotives was introduced in production in 1993, over 70 million miles of service have already been accumulated on this new design. By the end of 1996, over 800 AC and DC traction locomotives with this new bogie technology will have been put into service. Wheel wear data, which is relatively straightforward to obtain, is showing that wheel flange wear has been virtually eliminated and that wheel tread wear has not increased in spite of dramatic increases in adhesion to 45% for starting heavy trains and to 35% and higher for train operation. Wheel wear data indicates that wheel life will likely double, even in operations where wheels are re-profiled for tread wear. This is due to the profound effect of low flange wear on minimizing metal removed in wheel truing. The wheel wear results also suggest changes to traditional railroad wheel truing policies. The effect of the radial bogie design on rail wear savings is more difficult to assess, and this paper discusses several rail wear considerations. Laboratory tests have provided considerable insight into the influence of wheel-rail angle of attack on wheel and rail wear. An approach is suggested for combining the available field and lab data with a cost model to project the life cycle cost savings for rail wear as well as wheel wear improvements.","PeriodicalId":293519,"journal":{"name":"Proceedings of the 1996 ASME/IEEE Joint Railroad Conference","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114688810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-04-30DOI: 10.1109/RRCON.1996.507954
S. Canjea, C. Thornes
After an extensive car design and passenger loading options evaluation in 1994, NJ TRANSIT selected a 70% low-floor car concept for the light rail transit (LRT) systems planned to be modernized or built in New Jersey. The selection process was followed by the preparation of a Technical Specification. After two internal reviews, the third draft was distributed for industry review to vehicle manufacturers and major equipment suppliers. The authors of this paper evaluated various collision scenarios, selected the requirements, and generated the specific provisions for the vehicle specification included in the bid documents. This paper summarizes the report on buff load for NJ TRANSIT's low-floor light tail vehicles (L-F LRV) and includes the following topics: why is a lower buff load required?; advantages of lower car weight; buff load in the US; buff load in Europe; NJ TRANSIT LRT car design loads; and improved passenger safety.
{"title":"Buff load and crashworthiness requirements for the NJ TRANSIT low-floor light rail vehicle","authors":"S. Canjea, C. Thornes","doi":"10.1109/RRCON.1996.507954","DOIUrl":"https://doi.org/10.1109/RRCON.1996.507954","url":null,"abstract":"After an extensive car design and passenger loading options evaluation in 1994, NJ TRANSIT selected a 70% low-floor car concept for the light rail transit (LRT) systems planned to be modernized or built in New Jersey. The selection process was followed by the preparation of a Technical Specification. After two internal reviews, the third draft was distributed for industry review to vehicle manufacturers and major equipment suppliers. The authors of this paper evaluated various collision scenarios, selected the requirements, and generated the specific provisions for the vehicle specification included in the bid documents. This paper summarizes the report on buff load for NJ TRANSIT's low-floor light tail vehicles (L-F LRV) and includes the following topics: why is a lower buff load required?; advantages of lower car weight; buff load in the US; buff load in Europe; NJ TRANSIT LRT car design loads; and improved passenger safety.","PeriodicalId":293519,"journal":{"name":"Proceedings of the 1996 ASME/IEEE Joint Railroad Conference","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128302297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-04-30DOI: 10.1109/RRCON.1996.507962
H. Sakamoto, K. Hirakawa, Y. Toya
Vibrations generated at the contact surfaces between rails and wheels have been considered to be the main cause of noise from railroad vehicles. These noises are classified into three types: rolling, impact, and screech noise. The generation mechanism of each noise has not yet been clarified. This study includes the calculation of natural frequencies of wheels based on elasticity theory, the laboratory test to measure the natural frequencies, the field test to measure the sound and vibration of a railroad wheel, and the analysis on the correlation between sound and vibration. Previous studies have not shown an explicit relationship between sound and vibration of a railroad wheel. The goal of this research is to explain noise from wheels by analyzing such a direct correlation. The result of this study designates that the origin of screech noise on a curved track comes from the lateral vibration of the wheel, and suggests that the vibration of the wheel has little direct contribution to rolling noise on a straight track.
{"title":"Sound and vibration of railroad wheel","authors":"H. Sakamoto, K. Hirakawa, Y. Toya","doi":"10.1109/RRCON.1996.507962","DOIUrl":"https://doi.org/10.1109/RRCON.1996.507962","url":null,"abstract":"Vibrations generated at the contact surfaces between rails and wheels have been considered to be the main cause of noise from railroad vehicles. These noises are classified into three types: rolling, impact, and screech noise. The generation mechanism of each noise has not yet been clarified. This study includes the calculation of natural frequencies of wheels based on elasticity theory, the laboratory test to measure the natural frequencies, the field test to measure the sound and vibration of a railroad wheel, and the analysis on the correlation between sound and vibration. Previous studies have not shown an explicit relationship between sound and vibration of a railroad wheel. The goal of this research is to explain noise from wheels by analyzing such a direct correlation. The result of this study designates that the origin of screech noise on a curved track comes from the lateral vibration of the wheel, and suggests that the vibration of the wheel has little direct contribution to rolling noise on a straight track.","PeriodicalId":293519,"journal":{"name":"Proceedings of the 1996 ASME/IEEE Joint Railroad Conference","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130177879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-04-30DOI: 10.1109/RRCON.1996.507978
T. Kneschke, J. Hong, J. Arriojas
New Jersey Transit Corporation (NJ TRANSIT) is planning to purchase new, modern, light rail vehicles (LRVs) to replace the aging fleet of President's Conference Cars (PCCs) operating on the Newark City Subway (NCS). The new LRVs are expected to draw a significantly higher current than the PCCs. Maximum current demand of the LRV type considered by NJ TRANSIT is in excess of 1200 A, while the existing PCCs draw maximum current of about 300 A. In order to evaluate whether the existing NCS facilities can accommodate this increased power demand, it was necessary to review the traction power supply and distribution systems for compatibility with the proposed vehicles. The evaluation confirmed the power supply system needs to be replaced and the distribution systems needs to be upgraded. This paper describes the studies and designs required to implement these system improvements.
{"title":"Newark City Subway traction power system upgrade","authors":"T. Kneschke, J. Hong, J. Arriojas","doi":"10.1109/RRCON.1996.507978","DOIUrl":"https://doi.org/10.1109/RRCON.1996.507978","url":null,"abstract":"New Jersey Transit Corporation (NJ TRANSIT) is planning to purchase new, modern, light rail vehicles (LRVs) to replace the aging fleet of President's Conference Cars (PCCs) operating on the Newark City Subway (NCS). The new LRVs are expected to draw a significantly higher current than the PCCs. Maximum current demand of the LRV type considered by NJ TRANSIT is in excess of 1200 A, while the existing PCCs draw maximum current of about 300 A. In order to evaluate whether the existing NCS facilities can accommodate this increased power demand, it was necessary to review the traction power supply and distribution systems for compatibility with the proposed vehicles. The evaluation confirmed the power supply system needs to be replaced and the distribution systems needs to be upgraded. This paper describes the studies and designs required to implement these system improvements.","PeriodicalId":293519,"journal":{"name":"Proceedings of the 1996 ASME/IEEE Joint Railroad Conference","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122847169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-04-30DOI: 10.1109/RRCON.1996.507957
I. Milroy, R. A. Johnson, P. Gaertner
In this paper we report on the application of the train energy model (TEM) simulation package in investigations of fuel consumption and journey time in the operation of intermodal trains operated by Australian National on the route between Adelaide and Port Augusta in South Australia. With the Scheduling and Control Group of the University of South Australia, in collaboration with Australian National, we have been using this route since 1987 as a case study for research into improved train scheduling algorithms, and energy-efficient 'train pacing' tactics. An investigation is carried out into the relative performance of AN's existing modern DC diesel-electric locomotives on this route compared with the performance of a hypothetical generic class of AC locomotives having similar power rating.
{"title":"Performance of AC diesel-electric locomotives in typical Australian tasks","authors":"I. Milroy, R. A. Johnson, P. Gaertner","doi":"10.1109/RRCON.1996.507957","DOIUrl":"https://doi.org/10.1109/RRCON.1996.507957","url":null,"abstract":"In this paper we report on the application of the train energy model (TEM) simulation package in investigations of fuel consumption and journey time in the operation of intermodal trains operated by Australian National on the route between Adelaide and Port Augusta in South Australia. With the Scheduling and Control Group of the University of South Australia, in collaboration with Australian National, we have been using this route since 1987 as a case study for research into improved train scheduling algorithms, and energy-efficient 'train pacing' tactics. An investigation is carried out into the relative performance of AN's existing modern DC diesel-electric locomotives on this route compared with the performance of a hypothetical generic class of AC locomotives having similar power rating.","PeriodicalId":293519,"journal":{"name":"Proceedings of the 1996 ASME/IEEE Joint Railroad Conference","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115137883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-04-30DOI: 10.1109/RRCON.1996.507955
J. Rismantab-Sany
The friction force in the plane of contact, between the wheel flange of a rail vehicle and the rail, reaches its Coulomb's limit only when the direction of sliding coincides with the net resultant tangential force in this plane. Therefore, for derivation of any derailment criterion, it becomes necessary to embed the inequality that relates the friction force to the normal contact force and coefficient of friction into the equations of action and reaction equilibrium between the two contacting surfaces at the point of contact. Assuming a quasi static state, it is natural to ignore all the detailed and microscopic considerations such as whether the lateral creep is due to spin or lateral velocity or both etc.. However, by ignoring the spin moment, the method remains general and it recognizes that there are lateral and longitudinal creep forces which are due to longitudinal, lateral, and spin creepages. The main consideration is based upon balancing the action and reaction between the two contacting surfaces at the point of flange contact. It is further assumed that the effect of wheel yaw in the contact angle is negligible. This can be proved by geometrical considerations. The mathematical solutions show why Nadal's limit (Nadal, 1896) is the most conservative derailment criterion. They also provide the ranges of L/V for which the wheel has potential to climb or slide up the rail. The solutions also reveal why, at times, the wheel withstands a much higher L/V ratio than Nadal's limit without derailing.
{"title":"Another look at the single wheel derailment criteria","authors":"J. Rismantab-Sany","doi":"10.1109/RRCON.1996.507955","DOIUrl":"https://doi.org/10.1109/RRCON.1996.507955","url":null,"abstract":"The friction force in the plane of contact, between the wheel flange of a rail vehicle and the rail, reaches its Coulomb's limit only when the direction of sliding coincides with the net resultant tangential force in this plane. Therefore, for derivation of any derailment criterion, it becomes necessary to embed the inequality that relates the friction force to the normal contact force and coefficient of friction into the equations of action and reaction equilibrium between the two contacting surfaces at the point of contact. Assuming a quasi static state, it is natural to ignore all the detailed and microscopic considerations such as whether the lateral creep is due to spin or lateral velocity or both etc.. However, by ignoring the spin moment, the method remains general and it recognizes that there are lateral and longitudinal creep forces which are due to longitudinal, lateral, and spin creepages. The main consideration is based upon balancing the action and reaction between the two contacting surfaces at the point of flange contact. It is further assumed that the effect of wheel yaw in the contact angle is negligible. This can be proved by geometrical considerations. The mathematical solutions show why Nadal's limit (Nadal, 1896) is the most conservative derailment criterion. They also provide the ranges of L/V for which the wheel has potential to climb or slide up the rail. The solutions also reveal why, at times, the wheel withstands a much higher L/V ratio than Nadal's limit without derailing.","PeriodicalId":293519,"journal":{"name":"Proceedings of the 1996 ASME/IEEE Joint Railroad Conference","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132743570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-04-30DOI: 10.1109/RRCON.1996.507981
H. Nitz, T. Chung
The Chicago Transit Authority (CTA) is embarking on a number of programs to introduce advanced technologies throughout their 100+ year old system. A combination of rehabilitation projects, new construction projects, operational improvements, and public/private partnerships will be the key to achieving the goal of advanced system-wide communications and ultimately may form the basis for a system-wide Intelligent Transportation Systems (ITS). A system-wide fiber optic communications backbone was designed to facilitate all voice, data, and video communications within the CTA. The backbone design was based upon a SONET self-healing ring configuration, with redundant hardware and cabling to prevent a single contingency failure anywhere in the system. Although each transit line would be set up as a unique ring, a common area geographical loop was identified for the primary network ring. This common backbone loop (CBL), routed along various subway, at-grade, and elevated lines, was designed for a dual cable, self-healing SONET OC-12 architecture. The dual OC-12 rings interfaced major nodes with two independent switching points to facilitate disaster recovery. The CBL was designed to allow for ease of expansion as additional lines were implemented. Each line used an OC-3 dual ring self-healing architecture. These rings were routed to two separate OC-12 nodes for network integration on the CBL instead of routing a series of nonnetworked rings back to the control center. This paper describes the original backbone design and the evolution of that design as current and future projects are implemented within the CTA.
{"title":"Evolution of a systems plan for advanced communications within a rapid transit system","authors":"H. Nitz, T. Chung","doi":"10.1109/RRCON.1996.507981","DOIUrl":"https://doi.org/10.1109/RRCON.1996.507981","url":null,"abstract":"The Chicago Transit Authority (CTA) is embarking on a number of programs to introduce advanced technologies throughout their 100+ year old system. A combination of rehabilitation projects, new construction projects, operational improvements, and public/private partnerships will be the key to achieving the goal of advanced system-wide communications and ultimately may form the basis for a system-wide Intelligent Transportation Systems (ITS). A system-wide fiber optic communications backbone was designed to facilitate all voice, data, and video communications within the CTA. The backbone design was based upon a SONET self-healing ring configuration, with redundant hardware and cabling to prevent a single contingency failure anywhere in the system. Although each transit line would be set up as a unique ring, a common area geographical loop was identified for the primary network ring. This common backbone loop (CBL), routed along various subway, at-grade, and elevated lines, was designed for a dual cable, self-healing SONET OC-12 architecture. The dual OC-12 rings interfaced major nodes with two independent switching points to facilitate disaster recovery. The CBL was designed to allow for ease of expansion as additional lines were implemented. Each line used an OC-3 dual ring self-healing architecture. These rings were routed to two separate OC-12 nodes for network integration on the CBL instead of routing a series of nonnetworked rings back to the control center. This paper describes the original backbone design and the evolution of that design as current and future projects are implemented within the CTA.","PeriodicalId":293519,"journal":{"name":"Proceedings of the 1996 ASME/IEEE Joint Railroad Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125948930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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