Composite brake block behaviour under winter conditions

Project description

The use of composite brake blocks (CBB) is becoming common in railway vehicles. The EU is pressurising member states to replace cast iron blocks with composite ones. All new block-braked rolling stock will be fitted with composite brake blocks. This will provide a major advantage regarding noise reduction of railway traffic.
UIC, railway undertakings and brake block manufactures have investigated several properties of composite brake blocks. One investigated property is braking behaviour under winter conditions. A test procedure in UIC Leaflet 541-4 for winter braking properties was created between 2005 and 2010. It is defined for three test methods: line braking test, Vienna Arsenal climatic chamber (RTA) test and Becorit dynamometer test. The current test procedure is suitable for line operation at line speeds of 100 and 120 km/h.
Greater experience of composite brake blocks in use has shown that in some cases braking performance is significantly reduced under winter conditions. This is especially marked at lower speeds during shunting manoeuvres.
It is necessary to improve the current test procedure in order to ensure that composite brake blocks are safe for use in all weather conditions.
The main outcome of this project will be an updated test method for the winter braking properties of composite brake blocks in UIC Leaflet 541-4.