Articulated cars?

Question

how many sets of trucks are under a group unit of articulated cars

Answer 1

It depends on the number of cars in the group. usually a set at the front and back and then a set where the cars join.

Answer 2

It depends on the number of platforms.  A five platform well car will have six, in total.  You'll find one on each end, and one under where each of the platforms come together.

But, it can be misleading.  Many old 89'  flats are still running around with a solid draw bar between them.  Here, there are two 'platforms', but four trucks.  Although, these are not true articulated cars, where two platforms come together over a common set of trucks.

This is one of the reasons why, when trying to locate an axle of a car that a track-side detector has identified as defective, it is not permissible to do anything other than to actually count each axle from the rear of the train.  Dividing the number of cars by four is no longer an option, not that it ever was.  Keep in mind, there are TOFC cars with but two axles, as well.  To be sure, you must physically count each axle.

But, there are sagegaurds built into the rules.  If an indicated defect is not found on the axle indicated by the track-side detector, ten axles ahead of and ten axels behind the indicated axle must be inspected, on both sides of the train.