Operational Planning in Castlefield Corridor: 1366650

Introduction

 Castlefield Corridor has experienced significant performance challenges since the introduction of May 2018 timetable, especially in the Manchester region. The challenges showed that Castlefield Corridor is a major pinch-points in the country as a result of various services having to be directed onto the two-track section railway. The operation limited timetabling choices for the Corridor hence leading to magnified delays. Even though recognized as a capacity limitation, an increase in the number of trains operating in the area has brought more operational challenges. Schemes under the Northern Hub project had been designed to assist with swelling capacity in the Corridor from 12 to 16tph. Nevertheless, only the Ordsall Chord has been constructed (Molloy, K., 2020, p.23). As a result, there has been an increase in train services without matching the infrastructure necessary to allow smooth flow of trains. Castlefield Corridor also has the complex interaction of routes, particularly in the region around Manchester, which is also complicating the transportation services in the Corridor. Castlefield Corridor is one of the busiest corridors in the United Kingdom. The corridor comprises of two on the periphery of central Manchester, 12 spars running from central Manchester as well as another one from Liverpool. The line runs from Castlefield unction to Ardwick junction. It is normally two-track except at Oxford Road station, which is made up of four through platforms as well as one bay. Off late, the Corridor has turned out to be one of the congested infrastructures in the entire United Kingdom hence limiting operations in the corridor (Yuan et al., 2019, p.7230). The government has conducted a capacity analysis in an attempt to assess several ways of optimizing train services. Some of the suggested ways of reducing the congestion in the corridor including but not limited to retiming as well as changing the routing services while including additional committed services. Moreover, the assessment also identified limitations brought about by the existing operating procedures within the area together with the infrastructure. Castlefield Corridor has experienced significant performance challenges since the introduction of May 2018 timetable, especially in the Manchester region. The challenges showed that Castlefield Corridor is a major pinch-points in the country as a result of various services having to be directed onto the two-track section railway. The operation limited timetabling choices for the Corridor hence leading to magnified delays. Even though recognized as a capacity limitation, an increase in the number of trains operating in the area has brought more operational challenges. Based on the 2019 infrastructure timetable the corridor has experienced numerous limitation brought about by the infrastructure, especially with regards to the number of flat junctions in areas around Central Manchester which leads to countless conflicting moves.

  1. Appendix 1 
Issue/constraintsPotential SolutionsTimescales
TPRs via the Castlefield Corridor do not accurately signify the operational management of the railway, permitting inadequate time for certain movements to take place.   Evaluation and adjust TPR values  Medium term
Inadequate infrastructure characterized by too many trains via the CorridorMinimize total number of trains in the CorridorShort-Medium term
Numerous conflicting train movements across the regionEliminate some services to minimize conflictShort term
Inflexibility on routes feeding into ManchesterProvide overtaking proficiency on feeder routes   Medium term
Shortage of parallel moves in Irwell street and Deal Street junctions.Redesigning of junctions to ensure more parallel movesLong term
Unpredictable headways on routes in and out of Manchester  Re-signal to offer consistent headwaysLong-term

Example of Infrastructural constraints

In the corridor itself, there is no scope for operating extra trains without the provision of additional infrastructure (Mell, Allin, Reimer, and Wilker, 2017, p.335). The railway in the region considered is complex, with numerous routes leading into the Corridor. Once into the Central Manchester region, trains move at deficient speed, line speed is either 20-30 mph. However, services normally travel more slowly as a result of operation restrictions. Services in the Corridor are mixed, many are local travelling services. However, there are long-distance and freight passenger services. These increased services lead to delay in the Corridor, which may be costly to both local and long-distance commuters. Additionally, freight services coming as well as departing from Trafford Park terminal to the west of the Corridor offer an additional complicating aspect for managing the train services since extra time is needed to ensure movement in and out of the location. As a result of the varied nature in the Corridor, services are made up of different rolling stock types, which result in variations in performance characteristics, lengths as well as door configurations (Joglekar et al., 2020 p.103). All these are likely to change with the introduction of new trains into the routes, especially Central Manchester.

The railway in the corridor is considered multifaceted with several various routes leading into the corridor. Once into the Central Manchester area, the commuter train travels at deficient speed; the train speed in the line is usually between 30 mph-40mph, even though services travel slower than this as a result of restrictive aspects of operations. One of the factors contributing to this limitation is the TOC driving policies. Generally, trains in the corridor take a longer time to clear junctions than is theoretically expected (Cass, Park, and Powell, 2020, p.234). The signalling operations within the Greater Manchester region as well as the feeder routes on the way to Castlefield Corridor are characterized by a multifaceted set up of various locations together with a blend of technologies including a blend of lever frame, VDU as well as NX signalling.

The meeting point of east, west, north, as well as southern routes, converge at Castlefield Corridor whereby trains go to and from areas controlled Manchester Piccadilly SCC as well as Manchester ROC. Commuter trains coming from the north as well as south are directed towards the Castlefield Corridor by Piccadilly of Manchester and after that the central core by Manchester ROC and once again controlled by Manchester Piccadilly. The complication in the signal control means that managing services within the corridor are not possible, particularly for the Greater Manchester region; therefore, trains are invariably attended based on the first come first served. Lack of regulating points has lead fruitless efforts to both Signallers as well as Train operators to manage service. Moreover, the Corridor is faced with lack of flexibility normally at Manchester Oxford Running.

According to 2019 analysis of there are opportunities to improve services in the Castlefield Corridor. If the report is fully implemented, some of the services likely to benefit from rerouting of minor routes particularly the route to Wales which make reverse moves in the Corridor, or end at Manchester Piccadilly platform 14 and after that to operate as ECS to Mayfield loop where they recess before returning to platform 13 to start another journey (Davies, MacAulay, and Brady, 2019, p.37). These adjustments in the Corridor as well as into the train would be of great benefit in terms of performance. To accommodate the overall quantum of services in the timetable, all services in the Corridor are to be retimed to try to achieve the healthiest timetable possible. As mentioned previously, the line speed in the Corridor is about 20-30 mph as well as the routes immediately ending to the Corridor. Improving line speed in the corridor is not possible since the distance between stations as well as junctions in the region is very short, which cannot allow a tangible benefit (Bensalah, Elouadi, and Mharzi, 2019, p.200).  

Limitation in Corridor 

Castlefield Corridor has numerous constraints which impact the efficiency of the rail operation. The restrictions are ranked as either high, medium or low (Mo, Yang, Wang, and Qi, 2019 p.417). However, these they are not quantifiable and are just an indication of the challenges to the rail operation timetable. Some of these constraints include: TPRs via Castlefield Corridor do not precisely signify the operational running of the railway hence permitting short time for some movements to occur. Inadequate infrastructure with too many trains operating in the area, too many inconsistent train movements coming to and from the Castlefield Corridor, Junction design especially at Salford Crescent creates numerous conflicting moves, lack of flexibility on routes leading into Manchester as well as shortage of lateral movements in Irwell Street and Deal Street junctions (Zhang, Li, and Zhang, 2019, p.570). Other minute limitations experienced in the area include insufficient platform capacity at Victoria station, capacity shortage in terms platform at Manchester Airport station, single-line sections in the space between Bolton and Blackburn and inconsistent headways on routes around Manchester.  

TPR challenges 

The issue with TPR is one of the biggest challenges facing the region. Even though some of the TPS are theoretically correct, they are insufficient for the daily operation of the railway. For instance, the re-occupation times at Manchester Oxford Road station as well as Manchester Piccadilly station (Liu, 2019 p.123). The existing TPRs signify that a train can be designed to arrive at a station 2 minutes after another train leaves the station platform. However, this is only possible with only short trains operating in the corridor. Since trains are about to be lengthened on the train route in the future, additional time will be required to them to depart hence increasing the time for re-occupation beyond 2 minutes time interval (Nellthorp et al., p.40). The result is that 15 trains will no longer be possible to operate in the Corridor without improving the infrastructure or other essential alterations to the train service.

b. Current Timetable Planning Rules

The existing signalling configuration at Oxford Road, trains longer than 80 meters cannot arrive instantaneously with another of the same length a departing the station platform. Hence, despite having two platforms in every direction, to plan, there is a limitation in the operation of trains of this length (Kang, et al., 2019, p.35). Moreover, there are two ending trains at Oxford Road that use the bay platform, which is not supposed to be re-occupied by other passengers. These trains can be either two minutes behind a train using the same platform, which means time taken by the trains is 4 minutes. This means that if the 2-minute platform were to be re-occupied, it would take 56 minutes in an hour. This will leave only four minutes in an hour for the timetable to recover from any inconvenience. Reoccupation of the platform is subject to headway, and hence the re-occupation time can never be longer than the progress.

Consequences on the timetable amending

Subsequently, the headway time must also increase from 2 minutes to 3 minutes, and this will limit the necessary capacity to on 13 times per hour, made up of 11 through trains together with two Manchester Oxford Road terminator, which improve the service to almost 59 minutes in an hour (Mo, Yang, Wang, and Qi, 2019 p.417). Spacing this performance buffer out for more than an hour is more beneficial compared to having the entire spare train path to operate as a fire-break since this will increase the probability of right-time presentation at the success of significant junctions at event terminal of the Deansgate to Manchester Piccadilly Corridor. It is normal to utilize capacity to more than 85% of the theoretical maximum for trains operating in the suburban rail network, therefore, make it possible for recovery of any delay as well as timetable flexibility. 

Other possible solutions

The current issues in the Corridor can also be solved through a defensive driving technique that can be applied in the timetable planning to make train movements TPR complaint with one another. The defensive driving technique ensures the journey time is extended between two locations as well as plans since a late-running train has an option of recovering the lost time and a train that is on time will have to slow down to wait for its allotted time. Conversely, in central Manchester where the junctions are close to one another patting time can have a reverse effect (Rusev, Procter, and Duguid, 2019, p.22). To avoid complete stand as well as reduce the risk of the signal being passed at danger, drivers will have to travel at a slower speed and travel towards a yellow message at speed less than the permitted rate.

In the event a train patting time is added to its schedule to make it on time, it may end up blocking the progress of other trains by curtailing the Signaller setting the line for the second rain. Therefore if the signal is read as a result of a conflicting move three signals alerts ahead of the train, the train’s driver will see the double-yellow message; however he will be able to reach the crossing (Cao, Ceder, Li, and Zhang, 2020, 1220).  The defensive driving technique is a solution that reduces the necessity of patting time by minimizing the number of train’s busy junctions or through an infrastructure intervention that do away with the need for an additional patting time. 

The impact of infrastructure constraint can be solved through numerous solution depending on the issue to be addressed. The question of timetabling especially on high Junction areas can be resolved through high junction utilization to ensure that trains make sure that there is very little unused time left (Molloy, K., 2020, p.30). The increased number of passengers utilizing the facility ensures that there is limited flexibility while reducing performance gaps. The rail utilization cannot be improved without infrastructural intervention since currently, operations in the rails experience significant differences at junctions. The management may introduce the grade separation to any of the intersections to reduce the dependency of the new grade divided junction on the other flat crossroads.

The move will release capacity while improving the performance during perturbation since it minimizes the reliance on lateral movements. To solve the issue of train service, the management may decide to either divert trains away from the junctions or would assist in times of trepidation as there would be spare capacity in which a late moving train could travel while causing less effect to other train services (Meng, and Zhou, 2019, p. 20). This solution will correctly solve issues at Castlefield Junction, where the rail utilization in the area is almost 100%. Hence any delay will continue to knock-on exponentially to other services leading to the cancellation of the train.

Furthermore, grade separation of Windsor Bridge North will offer the most benefit by permitting total deconflict of some services from others hence freeing capacity to flex other rail services in more constraint areas further south (Tian, Shuai, and Li, 2019, p.300). Alternatively, the operators may decide to deconflict the train services to permit fewer crossing movements. This may be done through either routing trains from the Atherton lines along Manchester Piccadilly while having a good number of Bolton line services diverted towards Manchester Victoria. The move will optimize the current rail infrastructure arrangement making it more useful to use in future infrastructure options. 

Conclusion

Castlefield Corridor has experienced significant performance challenges since the introduction of May 2018 timetable, especially in the Manchester region. The challenges showed that Castlefield Corridor is a major pinch-points in the country as a result of various services having to be directed onto the two-track section railway. The operation limited timetabling choices for the Corridor hence leading to magnified delays. Even though recognized as a capacity limitation, an increase in the number of trains operating in the area has brought more operational challenges. Numerous solutions have been proposed to solve these issues, however some of these solutions are more cost efficient and economical than others.

References List

Bensalah, M., Elouadi, A. and Mharzi, H., 2019. Overview: the opportunity of BIM in railway. Smart and Sustainable Built Environment. Pp. 187-208

Cao, Z., Ceder, A., Li, D. and Zhang, S., 2020. Robust and optimized urban rail timetabling using a marshaling plan and skip-stop operation. Transportmetrica A: Transport Science16(3), pp.1217-1249.

Cass, N., Park, G. and Powell, A. eds., 2020. Contemporary Art in Heritage Spaces. Routledge. Pp.230-245.

Davies, A., MacAulay, S.C. and Brady, T., 2019. Delivery model innovation: Insights from infrastructure projects.

Joglekar, S., Quercia, D., Redi, M., Aiello, L.M., Kauer, T. and Sastry, N., 2020. FaceLift: a transparent deep learning framework to beautify urban scenes. Royal Society open science7(1), p.190987.

Kang, L., Zhu, X., Sun, H., Wu, J., Gao, Z. and Hu, B., 2019. Last train timetabling optimization and bus bridging service management in urban railway transit networks. Omega84, pp.31-44.

Liu, T., Zhang, D., Dai, H. and Wu, T., 2019. Intelligent modeling and optimization for smart energy hub. IEEE Transactions on Industrial Electronics66(12), pp.120-140.

Mell, I., Allin, S., Reimer, M. and Wilker, J., 2017. Strategic green infrastructure planning in Germany and the UK: A transnational evaluation of the evolution of urban greening policy and practice. International Planning Studies22(4), pp.333-349.

Meng, L. and Zhou, X., 2019. An integrated train service plan optimization model with variable demand: A team-based scheduling approach with dual cost information in a layered network. Transportation Research Part B: Methodological125, pp.1-28.

Mo, P., Yang, L., Wang, Y. and Qi, J., 2019. A flexible metro train scheduling approach to minimize energy cost and passenger waiting time. Computers & Industrial Engineering132, pp.412-432.

Molloy, K., 2020. Artificial Intelligence in Train Scheduling Problems. Pp.20-104.

Nellthorp, J., Ojeda Cabral, M., Johnson, D., Leahy, C. and Jiang, L., 2019. Land Value and Transport (Phase 2): Modelling and Appraisal-Final report.

Rusev, R., Procter, E. and Duguid, B., 2019, September. Design, procurement and coordination of the Ordsall Chord rail project, Manchester, UK. In Proceedings of the Institution of Civil Engineers-Civil Engineering (Vol. 173, No. 1, pp. 18-26). Thomas Telford Ltd.

Tian, H., Shuai, M. and Li, K., 2019. Optimization study of line planning for high speed railway based on an improved multi-objective differential evolution algorithm. IEEE Access7, pp.123-450.

Yuan, Y., Shao, C., Cao, Z., Chen, W., Yin, A., Yue, H. and Xie, B., 2019. Urban Rail Transit Passenger Flow Forecasting Method Based on the Coupling of Artificial Fish Swarm and Improved Particle Swarm Optimization Algorithms. Sustainability11(24), p.7230.

Zhang, X., Li, L. and Zhang, J., 2019. An optimal service model for rail freight transportation: Pricing, planning, and emission reducing. Journal of Cleaner Production218, pp.565-574.