A tandem truck usually refers to the amount of axles on the trailer or tractor. A single drive axle on a tractor would be referred to as a single, or the same for one axle on the trailer.
I have seen it referred to the amount of tires on the end of an axle. When there are two tires on the end of the axle, that would be referred to as a dual, not a tandem.
A tandem truck is a truck with two drive axles.
The "tandem" part means it has two drive axles, although it is possible for a tandem truck to be a 6x2 vehicle, and have only one of those be a live axle.
The average tandem axle truck can carry about 12 cubic yards of soil. Generally, a tandem axle truck has three axles.
A dump truck with two drive axles.
You need to be more specific about the configuration. Is a single axle straight truck, a tandem axle straight truck, a tandem axle straight truck with additional lift axles, a tractor trailer...?
A truck load of topsoil
It could be either. Tandem simply means that the power unit has two drive axles which operate in tandem. It's common in both articulated and straight trucks.
Typically, around 15 tons.
Legally, it's usually around
40,680 lbs.
In idle? The configuration of the tractor has nothing to do with determining that. It's the motor which does, and the consumption rate in idle for a motor would be the same for a tandem axle dump truck as it would be for the same motor in a road tractor, box truck, quad axle dump truck, cement mixer, etc.
17 tons