YARD
1) A system
of tracks branching from a common lead or ladder track, with defined limits,
used for switching, making up trains, or the storing of cars. 2) An area near the terminal used for the
staging and storage of trailers.
YARD JOCKEY
Truck used to move or jockey rolling equipment in
or about truck terminal or yard.
YAW
The maximum rate change of direction for a vehicle;
a sidewise movement of a vehicle in turning; Movement of a vehicle in another
direction than that in which it is headed; sidewise motion produced when
centrifugal force exceeds traction force.
Often the result of overreaction or exceeding the critical speed. Sometimes revealed by tire marks on the
roadway.
YAW INSTABILITY
The lateral acceleration rate at which a vehicle
will begin to yaw.
YAW MARK
The physical
mark on the roadway caused by the rotating tires of a vehicle during a maximum rate change of direction (turn). Yaw marks are also called scuff marks.
YAW VELOCITY
(r) The
angular velocity about the z-axis.
YAWING MOMENT COEFFICIENT
(C M z) is
based on the yawing moment deriving from the distribution of aerodynamic forces
acting on the vehicle.