Throughout ConRail's tenure in the Northeast, they had a "working relationship" with the Boston & Maine and, later, Guilford Transportation Industries. Coal trains for the Public Service of New Hampshire coal-fired electrical generating plant at Bow, New Hampshire routinely alternated between a partial CR or all B&M routing, with CR power regularly "running through" onto the B&M. In the early 90's Guilford arranged to run several symbol freights (LASE, NASE, and NESE) over a partial CR routing with the trains interchanged in Worcester, MA. ConRail power regularly ran-through on these trains and Guilford provided several MEC SD40's to CR to balance horsepower hours.
In 1984, when CR was disposing of a large number of their older power, mostly GP40's, Guilford acquired 23 of these units, all but 2 units in the 3200 group. GTI also acquired 9 ex CR U33B's through Lessor ITEL and 6 U33C's. The U33B's were split 1 for 2 between the B&M (CR 2916, 2919, 2925) and D&H (2917, 2918, 2920, 2922-2924), with all the U33C's (CR 6845, 6856, 6860, 6862, 6864-66) becoming D&H 650-656. Evidently, the U-Boats were already "well-worn", since the U33B's went to Naparano by March, 1986.