Interior noise reduction techniques using traction rod

The impact and friction energy from the (approximately 0.5 million to 1 million) lead granules packed inside the hollow section of the traction rod damp vibration energy transmitted from the bogie to the car body (in the 200 Hz to 300 Hz region). This reduces interior noise from rotational vibration transmitted from the propulsion system to the body via the traction rods by 2 dB to 5 dB.