I am a Manufacturer
The following text is the result of a study performed by ERTMS Solutions in a vast panel of their customers in March 2014. We asked our Manufacturer customers, prospects and partners what they identified as the major challenges in their implementation of ERTMS projects. Their answers are below. You can propose new ideas by clicking on the button at the bottom of the page.
More and more, Manufacturers need to validate the quality of their work – onboard and trackside – and need evidence of the work quality performed, whether for certification or not, and demonstrate its compliancy with the ERTMS standard.
Speaking of ERTMS implementation, manufacturers also stress the importance of the context. ERTMS specifications are rarely implemented after an operative and economical evaluation. It is forced by local authorities. Also, manufacturers have to cope with already existing signalization (brownfield): combine ERTMS standards with local existing signalling systems, and adapt these standards to local necessities, can be problematic.
Manufacturers have encountered a lot of technical issues on-site due to the different interpretation or ambiguities of ETCS specifications. In most cases, that kind of situation ended up with modification of software and additional testing i.e. additional cost. Furthermore, the ERTMS interoperability is not yet a clear and common understanding and there is no operative ETCS cross boarding in Europe at the moment.
The best way to avoid this situation, is to assess the specifications quality using a formal modelling tool. ERTMS Solutions has developed a fully open tool chain: ERTMSFormalSpecs.
The full understanding of the ERTMS standards and requirements can also lead to difficulties. It can be hard to understand where the standards and requirements come from, and what were the considerations when the work group wrote these standards.
For instance, when implementing the UNISIG Subset-098, and applying it in a control system, a manufacturer had difficulties to understand whether they could use UDP and the network transport layer protocol instead of TCP. The manufacturers did not fully understand why subset -098 chooses TCP as their recommendation. The reason why UNISIG subset-037 do not take SAI as one of its layers, and fully covers the defense against all seven hazards of EN50159, and why must the application layer takes charge of the defense against the time-related hazards is also unclear.
Concrete issues can concern the compatibility between AU1 from Onboard ETCS and other supplier’s RBC, due to the size of data which must be no greater than 23 Bytes, although Subset 037 8.2.5 defines the following. Also, the following TPDU parameters should not be used: the TPDU size (proposed and selected) and the preferred maximum TDPU size (proposed and selected). If these parameters are used, the receiver shall ignore them.
Many of our Manufacturer customers have a real need to embark existing software or libraries. ERTMS Solutions has developed proven-in-use solutions ones. Feel free to have a look at these solutions!
Although ERTMS was designed to be a cheap, simple and interoperable system, the costs and the simplicity are often put into question by manufacturers.
For all these reasons, manufacturers think that a deep reworking of ETCS involving all stakeholders should be done in order to enlarge its scope (including standard interlocking and standard ATS/Control Centre) and to enlarge its applicability (mainline, suburban, urban). The result should be a train control suitable and acceptable for all national bureaucracies and all legal operative rules.
In the framework of the the EVC revamping, a famous manufacturer had to make some material and software modifications on several components of the EVC, notably on the radio part. This manufacturer had two options: make or buy. The first option would have generated additional making costs. This is the reason why the company decided to choose the ERTMS Solutions’ libraries, which enabled to quickly settle an EVC-RBC communication prototype.
Want to know more about the Euroradio library? Feel free to have a look!