145 REQUIREMENTS FOLLOW THE FIRST PRINCIPLES: • Flame Spread • Ignitability • Heat Release • Smoke Emissions • Toxic Gas Emissions EN 45545-2:2013 classifies all onboard materials in groups which have to fulfil specific requirement sets which often includes several test methods. The most important fire tests used in EN 45545-2 are the flame propagation, the cone calorimeter and the smoke and toxicity tests. For requirement set R1 they are all based on radiant panels with heat fluxes 50 kW/m². HAZARD LEVEL OF A VEHICLE Fire safety requirements are part of the European Directive on the interoperability of the trans-European high-speed rail system. The seven-part standard EN 45545 'Railway applications - Fire protection on railway vehicles' has been developed to harmonise classifications and fire testing. EN 45545 introduces a new concept – the hazard level of a vehicle (HL). This is obtained by combining the operation and design categories of the vehicle: CERTIFIED Operation category Design category N: Standard vehicles A: Automatic vehicles D: Double decked vehicles S: Sleeping & couchette cars Surface operation HL1 HL1 HL1 HL2 Metro - Tunnel operation HL2 HL2 HL2 HL2 Inter-City Tunnel operation HL2 HL2 HL2 HL3 Metro - Tunnel operation, restricted HL3 HL3 HL3 HL3 Requirment set Test method reference Parameter unit Requirement definition HL1 HL2 HL3 R1 (for insulation material) Spread of flame ISO 5658-2 CFE kWm-2 Minimum 20 20 20 Heat release, smoke production & mass loss rate ISO 5660-1 MAHRE kWm-2 Maximum 90 60 Ds(4) dimensionless Maximum 600 300 150 V0F4 Minutes Maximum 1200 600 300 CITG dimensionless Maximum 1.2 0.9 0.75 EN 45545