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Switch and Crossing Optimal Design and Evaluation

Periodic Reporting for period 2 - S-CODE (Switch and Crossing Optimal Design and Evaluation)

Reporting period: 2018-05-01 to 2019-10-31

Track switches are a fundamental element of any rail network. Without them it would not be possible to guide trains from one route to another. However, they also limit the capacity & overall reliability of the network. Since the inception of railway track switches very little has changed in terms of their basic layout & operation, apart from the introduction of point machines. In contrast, industries such as aerospace, automotive & manufacturing have made radical improvements to their products & processes through the introduction of advanced materials & new designs incorporating mechatronic technologies.

The challenge addressed by S-CODE was to develop novel and improved solutions for railway S&C. The overall aim was to investigate, develop, validate & initially integrate radically new approaches, technologies, or concepts with the potential to lead to increases in capacity, reliability & safety while reducing investment & operating costs.

Key outcomes & innovations from S-CODE include:
• Development of a modular S&C architecture that allows subsystems to be exchanged over the life of the S&C, enabling innovations to be added as they become available.
• Modelling of the S&C & the modular subsystems to support evaluation of the benefits presented by different technologies.
• Design & prototyping of Next Generation Design components that can be incorporated into the architecture, using new materials & technologies to create a variety of permanent way subsystems.
• Design & prototyping of a Next Generation Control subsystem that can be incorporated into the architecture, which will include an ‘immune system’ capable of self-adjustment & self-correction.
• Design & prototyping of a Next Generation Kinematic subsystem that can be incorporated into the architecture, including concepts such as redundancy & ‘limp-home’ through the use of novel actuators & mechatronics.
• The development of a series of evaluation methodologies that can be applied to concepts & technologies alike. These have then been used to quantify the value of innovations developed throughout S-CODE from the perspective of reliability, life-cycle cost & performance.
S-CODE was delivered in three phases:
Phase 1: Requirements & initial design
Phase 2: Technical concept development
Phase 3: Demonstration & evaluation

Phase 1 focused on understanding the top-level functional requirements for a track switch system. Literature reviews were combined with horizon scanning in order to identify best-practice & over 100 potential innovative technologies. These were considered to produce first 22, & ultimately 5 high level concepts that could be developed in Phase 2.
Phase 2 reviewed the technologies & concepts & produced Innovation Development Roadmaps. These identified key technologies & the level of technology readiness being considered.
Technology Evaluation Forms for each innovation considered the technology, its interdependencies / compatibilities, & the potential for application.
Key technology elements explored in the project include:
• Communication frameworks & data architectures capable of acting as a plug-&-play core for modular sensing & actuation systems.
• Computational simulation to optimise the selection & positioning of embedded sensors appropriate for the different S&C concepts.
• Alternative sensing approaches, e.g. acoustics, optical & laser-based sensing for inspection & monitoring of S&C components & points operating equipment.
• Imaging technologies to direct & monitor the application of other measurement techniques; removing the need for the cognitive aspects of the user role in preparation for autonomous inspection.
• Lightweight acquisition systems & algorithms tuned to evaluate dynamic effects in both the switch & crossing.
• AI to identify vehicles from S&C reaction to their passage allowing S&C performance degradation to be tracked in relation to particular vehicles.
• Novel ballast constructions designed to improve performance & minimise maintenance.
• Alternative materials & production approaches for bearers.
• New concrete formulations to improve the performance of, & to add self-healing capabilities to, bearers.
• Rail surface coatings to provide increased resistance to rolling contact fatigue.
• Rail fastening solutions including active elements that allow embedding sensing or reactive damping.
• Model based condition monitoring, allowing self-analysis of the S&C & the monitoring system.
• Fault tolerant control systems that build on real-time condition monitoring for self-compensating operation.
• A highly redundant actuator has been used to explore different control & redundancy strategies in a non-monolithic actuation solution.
• Alternative locking mechanisms based on novel materials, magnetorheological fluid, & electromagnetism.
• An alternative actuation mechanism based on electromagnetic operation.
• A back-to-back bistable switch, combining gravity assisted locking & lifted actuation at both ends of the panel to create seamless operation.
• The use of BIM techniques for asset management & health data integration as well as visualisation of operational readiness.

Phase 3 focused on evaluation & validation. This key part of the project quantified the benefits attainable. Innovations were evaluated based on their potential to:
• Improve reliability & reduce life cycle costs;
• Reduce the need for inspection & maintenance processes;
• Improve actuation (switching time, reliability & availability).

Technology demonstrators were assessed using RAMS & LCC evaluation to identify technologies for further development & inclusion in projects developing the Technology Demonstrators (particularly TD3.2) described in the S2R MAAP.

To support the wider adoption of S-CODE outputs, the project has been working closely with the S2R/In2Track2. Representatives of In2Track2 have attended the majority of consortium meetings. Hence, In2Track2 has an understanding of the work undertaken & which innovations are considered the most suitable for inclusion in TD3.2. In2Track2 representatives spoke at the S-CODE closing dissemination event & S-CODE outputs will represent S2R at Innotrans2020.
The S-CODE project is part of a larger S2R work stream. As such, it supports a set of top-level targets associated with MAAP TD3.2:

• 100% increase in capacity
Impact scoring in the S-CODE evaluation showed that technologies with the largest impact on capacity were those offering opportunities reduce track access e.g. remote inspection/monitoring, fault tolerance, self-healing. Back to back & single slender switching reduce discontinuities allowing increased speed through S&C. Alternative locking arrangements (MR fluid, electromagnetic) offer opportunities for faster switching & locking.

• 30% reduction in the life cycle costs & increased safety
Most innovations offer an LCC improvement. Control & monitoring technologies offer improvements in Reliability & Maintainability, whilst new design & material elements offer extended life, and kinematic elements both.

• 50% increase in reliability & punctuality
The greatest potential benefits from S-CODE innovations relate to reliability. The back to back & single slender switch concepts reduce discontinuities and contribute to reduced impacts. Fault tolerant control maintains operation during sensor failure & a solution for a highly redundant actuator has been developed.
S-CODE Phases of Work