railML Extensions – What? Why? How?
by Vasco Paul Kolmorgen (railML.org) (comments: 0)
Just in time for Christmas 2018 Jernbanedirektoratet – the Norwegian Railway Directorate – published railML2.4nor, a Norwegian extension of the established industrial standard railML. railML 2.4nor, which consists of railML2.4 and Norwegian extensions, shall serve as infrastructure data exchange format for the Norwegian railway sector from 2019 onwards. Other railML.org partners such as Bahnkonzept, HaCon, iRFP or Siemens also use extensions of the railML standard.
You might have heard about these developments and ask yourself what exactly a railML extension is, why companies decide to develop it and how this process is enrolled. In the following this is explained exemplarily by the railML2.4nor extension.
The Norwegian extension: railML 2.4nor
Approximately two years ago Jernbanedirektoratet decided to develop a customized version of railML for the Norwegian sector, as not all Norwegian requirements were covered in existing railML schemes, and the tight time plan of Norwegian tool rollout did not allow to wait for the finalisation of railML 3.x. Additionally railML.org aims at developing an international usable and understandable data exchange format. Thus, the modelling focuses on a generic representation that applies to the vast majority of all countries, rather than on country specific specialties and allows more freedom in explanations. The Norwegian development therefore, consists of a proportion of railML2.4 and extends the core railML2.4 by adding extensions to meet Norwegian requirements. Jernbanedirektoratet documented railML2.4nor precisely. This documentation defines additional rules and conventions - in accordance to Norwegian requirements - for adopted ambiguous elements/attributes, where existing railML documentation is open to interpretation and their extended elements/attributes. railML2.4nor is the Norwegian usage of standard railML2.4 plus the Norwegian extensions.
Data and files, which correspond to the publicly freely available description for railML 2.4nor, remain valid and standard railML 2.4 data, which can also be understood in other countries or generally valid programmes (then without Norwegian extensions). railML.org certification, which is mandatory for railML interfaces only certifies core railML2.4. Extensions - Norwegian or other - are not taken into account.
Conclusion and future possibilities
The development of railML2.4nor took place together with railML.org. One of the main principles during the development was to stay conform and compliant to railML2.4. The railML community and schema coordinators were contacted in various topics via the railML Forum to ensure that no unnecessary extensions were integrated, or elements/attributes interpreted wrongly. The more precise Norwegian definitions of several railML core elements were also shared and discussed in the forum. railML.org will take this into account, and decide in the working groups and in the forum if more precise defintions are also necessary for core railML. We would like to thank Jernbanedirektoratet and the whole Norwegian sector for this cooperation which also enriches the railML standard and wish all the best for the implementation of railML2.4nor.
railML.org is always open to support other partners, manufacturers, railways or authorities with railML extensions. Please contact us for this.