No, they were not, at least not in regular service. Can't recall off hand if any experiments were done, although my guess is no. If you want to know all about B&O E units, I suggest you buy the book Baltimore & Ohio E-Unit Passenger Diesel Locomotives, 1937-1971 by Douglas B. Nuckles. It is out of print at TLC Publishing, but an internet search should turn up a copy.
Greg
ChristianJDavis1I model Baltimore and Ohio in N scale during the period of the 1940's-1960's, and would like to know whether or not the B&O ever ran their remaining E-units on freights due to the decline in the demand for passenger trains (in the 1960's). I have had a hard time locating any evidence of the E-units being used for freights, but I have been told that they were by others. If anyone can find pictures, that would be great, as I cannot find any.