The behaviour of three coach concepts - standard, highdecker and double-decker coaches - was studied on the basis of the following objective test procedures: (1) Straight-line braking on pavement with different anti-skid characteristics in longitudinal direction (u-split) (2) Braking during steady-state cornering (3) Steady-state cornering (4) Sinusoidal steering input (5) Step steering input. This study shows clear differences in the braking and steering behaviour of different coach concepts. It also indicates that the characteristics and design philosophy of one vehicle category cannot be transfered to another without further consideration. In modern coaches, the load-dependent center of gravity height is an important criterion for prematurely reaching the limits of dynamic vehicle movement. In one coach concept, a change in the load from 60% to 100% increased the stopping distance by 16% on dry pavement and by 5% on wet pavement. It also reduced possible lateral acceleration during cornering by approximately 20%. Braking on u-split without Antilock Braking system (ABS) resulted in a yaw velocity which was 2.3 to 5 times higher than that of coaches with ABS. (A) For the covering abstract of the conference, see IRRD 837684.
Samenvatting