冰雪地带要用“Puller”型的。渥太华前些年引进的这些车都是“Pusher”型的,一到大雪天就Jackknife动弹不得,糟糕透顶。
[ame="http://www.youtube.com/watch?v=8kMkYhc4F2g"]http://www.youtube.com/watch?v=8kMkYhc4F2g[/ame]
Articulated buses can be of
"pusher" or "puller" configuration.[1]
In pusher buses, only the rear C-axle is powered by a rear-mounted internal combustion engine, and the longitudinal stability of the vehicle is maintained by active hydraulics mounted under the turntable. This modern system makes it possible to build buses without steps and having low floors along their entire length, which simplifies access for passengers with limited mobility.
In puller articulated buses, the engine is mounted under the floor between the front and middle A- and B-axles, and only the B-axle is powered. Some consider this an outdated design, as it prohibits floor levels lower than approximately 750 millimetres (30 in), and can produce passenger discomfort due to high noise and vibration levels. On the other hand, the puller bus is cheaper to manufacture, and can be used in very narrow or severely potholed streets. This type of bus also performs better in snowy or icy conditions, as the thrust from the driving wheels does not cause the vehicle to jacknife. Also, the unpowered C-axle is much simpler and carries no engine weight, facilitating the installation of counter-steering mechanisms to further decrease the turning radius.[citation needed]