Mid Train Locomotive

[bcgfdc3]

I am a railfan and have noticed that there has been an addition of a locomotive to the middle of the trains. I assume this is due to the newest software constructing the trains. I assume these locos are remote controlled or is there an engineer in the cab?

What is the benefits and the drawbacks of this? I assume the benefit is longer trains with the same amount of crew.

[docsteve]

Distributed Power Unit, one or more locomotives remotedo to the lead unit(s). Generally, longer trains with better handling characteristics.