Examination of the effects of non-linear (square-law) damping on the primary suspension of an APT E1T bogie (IM-DOS-019)

The BR designed and developed, Woodhead manufactured dampers at present in use on the APT E1/E1T series of bogies have a non¬linear force/velocity characteristic. Figure 1 shows how the characteristic of a typical BR/Woodhead damper (in this case a primary vertical) differs from the desired linear characteristic. It can be...