I went back through my photos and found a few of the power cars you mentioned. Funny, the RR folks at the time told me that the B units did provide HEP. I guess they didn't know what they were talking about...
Hadder Wrote:
-------------------------------------------------------
> The FP- B unit behind 29 in the photo is for
> additional HP for the train due to tonnage. These
> units are not capable of supplying HEP to the
> train. HEP is supplied by either under car
> generators (as in this photo) or a separate Power
> Car that runs just behind the motive power.
>
> Eric
-Lee
Flickr photo set of my On30 layout