The International Technical Committee of the IRSE visited the ERTMS Regional pilot line in Sweden during its June 21st, 2011 meeting in Borlänge.
ERTMS Regional is a development of Traffikverket, the swedish infrastructure operator, Bombardier and the UIC. It is aimed at providing a signalling and control system for (very)lightly used regional lines, which account for 21% (2116 km) of the Swedish network and builds on the principles employed in an earlier version of the Swedish Radio block system, based on Sweden’s ATC2 technology, in operation since 1995. Its aim is to reduce the cost of equipping the line with a signalling system by 50%, which we were told is achieved, albeit on the assumption that the cost of providing GSM-R coverage had already been absorbed by the national requirement to provide full GSM-R coverage on the network. Interestingly, the system is based on an open architecture with the interface specifications owned by Traffikverket.
In short, ERTMS regional is based on a combined interlocking and RBC processor which set routes and issues command to local trackside elements which are connected to object controllers. These object controllers communicate with the IXL/RBC computer either over GSM-R (using GPRS), cable of in the trial even an ADSL internet connection. Interestingly the ERTMS part of the specification is unchanged ERTMS level 3 with fixed blocks, based on Class 1 specification (baseline 2.3.0d), so trains equipped for running on ERTMS regional lines have no problem continuing onto the main line, or into main stations equipped to „standard” ERTMS level 1 or level 2.
Since the lines are so lightly used (typically in the pilot line 8 passenger trains and 8 freight trains per day) and the passenger trains are single car DMUs anyway, the risk of train separation is accepted, so the unsolved problem of train integrity proving is left for another day.
Level crossings on stations are controlled trough the object controllers, on the open line there autonomous level crossing installations can be left as is, but there is an option to control them using the functions to be integrated in ERTMS baseline 3. In short a brake curve is established to any level crossing controlled by ERTMS, the strike in point is marked by a balise, the train reports being in the strike in zone and waits for confirmation of the level crossing’s closure before extending the movement authority beyond it.
The ITC was pleased to be taken on a demonstration run of the system between Repbäcken and Mosbjäck and observe its functioning first hand. In fact this turned out to be the final night of formal testing in shadow mode, before a commissioning decision was to be taken.
Some more info and a video can be found on the Traffikverket site.