Latest hose technology helps rail industry meet new European standard

15 February, 2017

In September 2013, a new European standard EN45545 was introduced for rail vehicles that sought to increase the protection for train passengers and staff in the event of a fire on board. New trains built from March 2016 onwards have to be in line with this new standard. With hoses used extensively throughout rail vehicles such as locomotives, high-speed trains and trams, achieving early compliance was crucial.

It is no secret that the rail rolling stock industry is among the world’s most demanding in terms of the pressures placed on components and systems used, particularly considering the extremes of vibration and temperature that are present in typical operating environments.

Calls for greater survivability

With the advent of trends such as higher speed trains and longer tunnels, the calls for greater survivability in the event of fire led the EU to seek an alternative to the plethora of rail industry standards that previously existed at a national level. Here, with cross-border rail travel abundant throughout Europe, manufacturers and operators had little choice but to meet each individual standard, at elevated time and cost.

Instead, the EU set about creating a single standard that would help ensure the implementation of a safe rail system across the continent. The first outcomes of this 20-year project emerged in September 2013 with the publication of the EN 45545 fire safety standard. However, there are important additions to the new EN 45545-2 standard which demand close attention. For example, nearly every component on a train that weighs in excess of 100g is now subject to testing.

Compliance

So, what are the principal applications for hoses in the rail industry, and what features are demanded of them to ensure compliance with the new EN 45545-2 standard? Well, one of the most notable demands concerns the burning behaviour of materials and components, where products are classified into various hazard levels.

For instance, EN 45545-2 contains specific requirements for: oxygen index to EN 4589-2; smoke density to EN 5659-2; and smoke toxicity to NF X70-100-1 and -2. For classification, the standard divides materials intended for installation into different areas (R22 inside/R23 outside) and three hazard levels (HL1, HL2, HL3), with HL3 being the highest. Furthermore, hose assemblies that are installed within hydraulic/pneumatic circuits that are deemed essential for the running capability of the vehicle have to pass a flame test in accordance with EN 15540 (a minimum of 800degC for at least 15 minutes), while another demand which has to be met to ensure compliance is the maintenance of pollutant emissions within very strict limits.

The fire behaviour of materials and components is not only dependent on their inherent properties, but their application, the shape and arrangement of the materials, the exposed surfaces, and the relative mass and thickness of the material. On this basis, the products listed in EN 45545-2 are further categorised into sub-groups according to: use in accessible or not openly accessible areas (such as the driver’s cabin); general area of application (inside or outside); and specific area of application (furniture, electrical equipment, mechanical equipment).