When a train is made up in the yard or elsewhere, who makes the decision as to whether or not to use power in a DPU configuration? What is the criteria? I see some trains with it and some not.
What qualifications are needed to make those decisions? Is the enginerer consulted?
When is the engineer told? How does he (engineer know) the performance effectiveness of the cut-in helpers (DPU) units on his particular train? Does his train handel differently with mid train unit or rear units?
When arriving at the destination, how is the DPU power cut out of the train for re-fueling…etc. If the lead or head units malfunction do the DPU units also malfunction or can the train be run from them? (That seems nuts to me).
Lastly if one of the rear DPU/ helper units have a problem how does the engineer know and what can he do about it from up front in the lead unit? Any good article on the use of DPU power?
Thanks.