HERMES modelling for the Digital Railway OBC
HERMES was chosen by the Digital Railway programme to assist with the outline business case for the project. Graffica’s HERMES team was asked to model two UK networks with a variety of scenarios running from the present day until 2043. On each of these networks several digital technologies were applied, with performance metrics including: capacity, energy usage and recovery from disruptions measured.
The networks modelled were the Great Eastern Mainline between London Liverpool Street and Norwich, including the new Crossrail lines from Paddington to Shenfield and the East coast mainline between London Kings Cross and Berwick Upon Tweed. The East Coast model also included the connection to Thameslink and through services were modelled for the future scenarios.
The Digital technologies applied to each of the models included ETCS Level 2 an ETCS Level 2 & 3 hybrid where trains transitioned between the two levels in various areas of the network. Pure ETCS level 3 was also applied, which presented a significant challenge for the team as the specification for ETCS Level 3 is not yet fully defined. A traffic management system developed by Graffica (based upon the ARS system) was also modelled with two pieces of functionality; reordering and rerouting. The reordering functionality enabled the TM system to identify late running services and, where able, change the order of the services across junctions to minimise delays to services which might otherwise have been held up. The rerouting functionality expanded on this, but allowed small local rerouting of trains around disruptions. A train failure at Stratford station in the morning peak was chosen to assess this.
Timetables from 2023 and 2043 were created from specifications laid out by Network Rail. Graffica was able to take these specifications and build conflict-free timetables within HERMES utilising algorithms developed for the project. For each network, a baseline scenario of the present-day timetable was also run for comparison.
HERMES produced detailed logs from 46 different simulation scenarios applying various combinations of timetable and digital technologies as defined by the Digital Railway’s requirements. Each of the logs was then fully analysed before conclusions were drawn and detailed reports created by Graffica summarising the findings.
Graffica was able to demonstrate that the technologies applied gave a clear improvement when utilising the selected performance metrics. With further refinement and development it is likely that these improvements can be increased even further. Graffica and the HERMES platform have been selected to provide further modelling work to the Digital Railway for up to the next five years, allowing Graffica’s successes in modelling the future railway to continue.
