BOGIES: Anti-vibration specialist Trelleborg and Bombardier Transportation have  developed a hydraulic axle guide element  for Bomabardier’s Flexx family of bogies which provides frequency-dependent longitudinal stiffness. This reduces wheel and track wear, energy consumption and curve squeal noise.

Flexx Curve can be installed in all past and planned Flexx Compact bogies.

‘Moving away from a standard set-up where traction and braking forces are mechanically compensated, the set-up of Flexx Curve capitalises on hydraulic compensation within a cross-coupled layout’, said Alexander Zahnbrecher, Project Engineer at Trelleborg AVS. ‘This enables Bombardier to deliver more efficient products for its customers, increasing comfort for passengers while reducing operating costs’.

source= https://www.railwaygazette.com/news/technology/single-view/view/boosting-bogie-performance.html