level with the floor. Cleats are used to secure the plank, as can be seen
in figure 2.5.
Figure 2.5. Widening Flatcar Floor.
b. Using idler car. Some items are so long that they extend beyond one
flatcar, requiring an additional or "idler" car to protect the overhang.
The extra car is called an idler only if it carries none of the weight, as
when a boom extends behind a crane whose entire weight, including boom, is
borne by the car preceding or following the idler. Take a look at figure
Rules 8 and 16 of AAR cover the use of idler cars, giving
permissible lengths of overhang by length of flatcar, width limits for
various lengths of overhang, etc. As the length of overhang increases, the
allowable width decreases. Compare the two examples tabulated here.