As I mentioned, I recently acquired Greg McDonnell’s Field Guide to Modern Diesel Locomotives, which has a good coverage of, well, modern diesel locomotives. In the introduction, McDonnell writes: “This work picks up new locomotive production where Louis Marre’s Diesel Locomotives: The First 50 Years (Kalmbach 1995) leaves off,” and he recommends that book for discussion of earlier diesels. Marre’s book is out of print, but I was in the Train Shop the other day, and they had a copy, so I picked it up. It’s a good book; it doesn’t have as much detail as Modern Diesel Locomotives, and it’s black and white instead of color, but it’s about twice as thick, and covers many times more models of locomotive.

I have discovered a problem, though. Diesel Locomotives: The First 50 Years covers, as per its subtitle, “diesels built before 1972.” The Field Guide to Modern Diesel Locomotives picks up in 1972 for EMD, but only covers GE locomotives produced in 1977 and after. I understand this choice; almost every GE locomotive produced in the mid-70s was a model introduced in the ’60s, and GE completely changed their product lineup with the introduction of the Dash 7 series in 1977. Almost every earlier model is covered in The First 50 Years.

Almost.

As near as I can tell, there is exactly one model of North American diesel introduced by General Electric after 1972 but no longer in production by 1977: The P30CH, nicknamed “pooch” because of its name, was a six-axle 3000HP cowl unit built solely for Amtrak in 1975 and early 1976 (roster). I guess, after the failure of the EMD SDP40F, Amtrak tried a similar unit from GE before the four-axle EMD F40PH took its role as ubiquitous Amtrak engine. There is some information about the P30CH on the Web, but I’d really like to read a few pages of well-researched history and description. It seems a real shame that it’s missing from these books.

Update: I’ve discovered a second missing GE diesel, the U36CG, another existing freight model modified for passenger service. The P30CH was essentially a U30C with a head-end power generator and a custom cowl, and the U36CG was a U36C with a steam generator. According to an online roster, 20 were delivered to National de Mexico in 1974.