Was the C30-7A a bargain basement locomotive?

Doug McDonnell's version of the Kalmbach "Diesel Spotter's Guide" some years back said that the C30-7A (the 12-cylinder version of the C30-7, sold only to Conrail: one order for 50, in 1984) had a GTA-11 main generator, but McDonnell is not infallible, so I didn't pay much attention. BUT: there are some Conrail locomotive rosters (in house Conrail documents) available on the Conrail page of George Ellwood's "Fallen Flags" railphoto site... and they also say the C30-7A had a GTA-11. (In contrast to the B36-7 of 1983 and the C36-7 of 1985, which had the GTA-24.)

Significance. I ***believe*** that the change from GTA-11 to GTA-24 was part of GE's new ("Sentry") adhesion system, introduced at the end of the 1970s. So, with the GTA-11, the C30-7A would have had the same sort of adhesion control as the ordinary C30-7 (of which Conrail had had 10 units for several years when they ordered the C30-7A).

Suggesting that... (i) Conrail felt, on the basis of experience with the C30-7, that "retro-tech" adhesion control was good enough for a 3,000 hp six-axle unit, and
(ii) that when placing a large order in less-than-great economic conditions they were happy to forgo the latest technology in favor of something they knew worked (and was probably cheaper).

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I ***believe*** but am not sure that the 12 cylinder B30-7A units built for Missouri Pacific, Southern, and Burlington Northern all had Sentry adhesion control and GTA-24 traction alternators. Can anyone confirm or disconfirm?

Very good question(s).

Every resource I have lists the C30-7A and C30-7 as having the GTA-11 alternator. The B30-7A is listed as having the GTA-24. Stranger still is that in 1980 GE catalogued a C28-7 and B28-7 both speced with the GTA-24.

Two possible reasons:

1 - to maintain commonality with the existing C30-7 population,
and/or
2 - alternators came from trade-ins.

D. Carleton--
The B28-7 was offered by GE (no one bit): 12-cylinder engine at roughly (maybe a bit more) the per-cylinder rating of the 16 cylinder engine in a B36-7/C36-7. GE had long-term experience with FDL-12 at this rating: it was used in export units from the mid 1970s, and a few L&N U23B were experimentally run at this rating for a time. Domestic purchasers showed up when they raised the rating a bit more to produce the B30-7A. This was a LONG time ago, but my recollection is that Missouri Pacific ordered three B23-7 rated at 3000 hp, then came back and ordered a fair number of B30-7A... but derated the original three to 2250 hp because they didn't have the new adhesion control system of the B30-7A. So-- if I'm right about the GTA-24 being part of the same package as "Sentry" adhesion control, the three B23-7 rated 3000 hp would have had GTA-11, and the later B30-7A would have had GTA-24. (Anybody out there with old MP or GE documentation to confirm of deny?)

... Leaving unanswered questions about the chronology of (i) advertising B28-7 with GTA-24 (ii) upping the power rating of the FDL-12 to 250 hp/cyl (iii) getting somebody at MP to agree to try four axle locomotives with the uprated FDL-12.

(McDonell's book 2002 book says that all B30-7A had GTA-24... but it also says that the FDL-16 powered B30-7 had GTA-24, and I'd want independent confirmation of that. ... The first B30-7 were bulit (for SLSF) at the end of 1977: big question is when GE introduced "Sentry" and the GTA-24.)

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As for Conrail's motives... I've somewhere read that CR asked GE for C30-7, and that GE told them"We're not building that model any more, but you can have an equivalent with an FDL-12 engine." Did CR's management really know what they wanted? They came back the next year and ordered C36-7!

As for the possibility that they were using generators from trade-ins... CR retired a LOT of cex-NYC U30B and U33B at about that time, but many of these units would have had GTA-9 alternators rather than GTA-11.

So, lots of questions, fewer answers!

I was not aware the GTA-9 lasted into the U33 production. All of ConRail's non-EL U33's were 1968 or earlier thus unlikely to have the GTA-11 ergo, there goes the trade-in theory. CR was a rather mechanically conservative outfit, i.e. Flexcoil trucks under their SD40-2's and early SD50's. GE offered the C30-7A with the GTA-11 and there was no reason to make these locomotives any more different than they already were.

In 1984 all the catalogued Dash-7 offerings list the "Wheelslip Correction" as "Automatic Sanding and Automatic Unloading of Main Alternator" regardless of alternator spec. However, the then new-fangled Dash-8 series has "GE Sentry" listed for wheelslip. Does this mean the GE Sentry system never made it into a Dash-7 locomotive? Of course not but as of 1984 it was not an available option.

I would wonder if the 3000HP for traction 12-cylinder engine in those Conrail units wasn't a GE field test. That was about the time that GE was making a round of improvements to the engine, and focusing on fuel economies resulting from decreased engine friction. In that pursuit, two concepts were tried - the production of what had been V-16 power from V-12 engines (reducing overall friction loss per horsepower by virtue simply of less piston ring and bearing area) and slowing down the engines back to the 1000 RPM of the original FDL-16A (reducing the total friction loss even further.) It could be, given the long-established nature of GE's field test program, that all of the rest of those Conrail units was totally standard C30-7 and that the existing test program needed road miles on the 3000 HP V-12, which GE would then have substituted in the Conrail units (with permission of course) at no added cost and with the same warranty coverage as originally agreed. (We all know that this kind of thing happened over and over and has led to much confusion as to model numbers, etc -- like the PRR U28C order that contained some units with alternators and FDL-16C {steel head, single exhaust manifold} engines and which were rated 3000 HP.. and on and on.) GE seemed to be able to dispense with extensive demonstrator testing and get realistic field data with this methodology, and it paid off.

I have no sure data on whether this is the case, but since there's always a gray area with GE units built during the U and "New Series" eras it's worth considering.

-Will Davis

D. Carleton--
The only information I have on when the GTA-11 replaced the GTA-9 in GE locomotive production is in the Erie-Lackawanna diagram book on-line at George Elwood's "Fallen Flags" railphoto site: E-L's first order of U33C had GTA-9, the second order had GTA-11.
Will Davis--
GE sold B30-7A to MP in 1980 or 1981 (not sure, but I think 1980 may have been the uprated B23-7, with the official B30-7A the next year), and had delivered about 200 3,000 hp FDL-12 powered units to three U.S. railroads before building the C30-7A for CR, so in the absence of documentary evidence to the contrary I would tend to doubt that the C30-7A was built to field-test the engine. CR was certainly happy to collaborate with GE on experiments, though: the ten C32-8 units (built, according to McDonnell, in September 1984, the C30-7A having been finished in June) were GE test units in Conrail colors! (Five of CR's 16-cylinder C30-7 had white stars painted next to their cab-side numbers, as did five SD40-2: these units were apparently part of some test program, but perhaps a purely CR test not involving GE.)

I looked at a CSX Locomotive Print Drawing Number LB-259 that was updated on 1/4/2000 for the C30-7A units that are numbered 7095-7115. CSX inherited 42% of the C30-7A units which came to a total of 21 units. The Conrail road numbers were 6550-6599 and the order number was PO 1841 with a locomotive wire running list 41A312970. I don't recall working on any of the C30-7A units but I worked on several Conrail GE units. The B23-7 units that I worked on had the GTA-11 Alternator with CHEC Excitation and the CMR type Wheelslip System and these units made traction motor transition. I worked on several Conrail B36-7's and C36-7 units that is Full Parallel and they both had the GTA-24 Alternators in them and the Alternator made transition. The B36-7 & C36-7 units had CHEC II Excitation with the Sentry Wheelslip Panels. When looking at the locomotive schematic for the C30-7A unit, it shows them to have the GTA-11 Alternator with the CHEC II Excitation Panel and the Sentry Wheelslip Panel. The C30-7A units would make traction motor transition.

Ask and thou shalt receive! Thank you, WVU, for reporting on CSX's documentation on their GE units and your own experience with them: given the errors in even the best "railfan scholarship," that's the sort of input these historical questions require!
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One of the things that puzzled me was the relatively short life-spans of many of the C30-7A: some were scrapped and their engines exported to Australia for use in re-engining former Alco locomotives. If IN FACT they had, on average, shorter service lives than other contemporary locomotives, I suppose part of the explanation could be that their "old fashioned" design features made them unattractive. ... Though probably their rarity is enough of an explanation: unusual, nonstandard-design, locomotives tend not to live long.

For the record: things i might have been remembering having read about X30-7A types:

"Extra 2200 South" issue #75(*), page 12, says that (Missouri Pacific's) "Experimental B23-7's 4667-4669 won't be re# to 4800's because they don't have Sentry wheel slip system, have different governor settings and excitation card." The previous issue, page 12, has a photo of MP 4800 (= the "class unit" for the 55 "official" B30-7A), with a caption saying "Certainly an endorsement of a new idea is MoP's order for 55 12 cyl. B30-7A's (4800-4854). Last June [June 1980? --AH] the last three (4667-4669) of a ten-unit B23 order were delivered at 3000 hp. Perhaps they will be redesignated B30-7A and re# 4855-4857...."

Comment: "Extra 2200 South" tends to be good "railfan scholarship," but differs from academic scholarship in not citing sources, making it hard to gauge its reliability.

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(*) It's not easy to tell when an issue of "E2200S" was actually published, but this one has photos dated up to may 1982 and one news item from June 1982.

Some of the later CR U23B's had CHEC excitation along with CMR wheelslip control-with a GTA-11. GTA-24 had 'alternator transition', -two stator windings conected in series at low speed-and paralleled at higher speed. Or was it the other way around ?

SS

The GE units that made Alternator Transition started out in Parallel and in the area of 29 to 31 mph, the Contactors picked up and the Alternator shifted to Series. The SD50 & SD60 units operate the same way. The 50 made tarnsition around 23 mph and the 60 made transition around 27 mph. It does get confusing. Units with alternator transition are the opposite of unts that make traction motor transition. Traction Motors transition will start out in series and shift to parallel.

Digging up an old discussion...
Recent string on traction motor gear ratios got me interested again, and I looked at the Conrail locomotive book at George Elwood's site,
http://www.rr-fallenflags.org/cr/cr-89lb-3.pdf" onclick="window.open(this.href);return false;
again:
the C30-7A is shown as having GTA11 alternator, but also as having the newer 752AF traction motors with 83:20 gearing (same as on the C36-7purchased the next year). (C32-8, bought the same year as the C30-7A (1984), had 752AG motors.)

So, what does this indicate?

Different topic, but this seems to be a good string for C30-7A trivia...

A U23C looks, in side view, much the same as a U30C: to tell the difference the lighting and photo quality have to be good enough to let you count the tall hood doors. In particular, the air intake for the central blower (the square grill high on the side of the side hood behind the cab) is in the same place. (So, on a U23C, the central blower is located in the same place as on a U30C: the shaft from the engine powering it is extra-long.)

So. Do we have C30-7A:C30-7::U23C:U30C? Apparently not. The blower air intake on a C30-7 is immediately in front of the tall engine room doors, so further back than on a C30-7 or C36-7. (So, position of blower on frame differs between C30-7 and C30-7A, but the C30-7A doesn't need an extension shaft to connect it to the engine.)

Or so I currently think, having spend some time this evening looking at pictures.

Aaaarrrrgghhh! OF COURSE the central air intake isn't IMMEDIATELY in front of the tall engine room doors. (That wouldn't leave room for the main generator between the engine and the blower.) On both the C30-7 and the C30-7A, the central air intake is some distance ahead of the tall doors. BUT -- this is what I should have said in my previous post -- it is the SAME DISTANCE ahead of them. (Five short doors ahead, as it happens.) So the central air intake (and so the equipment blower) is further back on a C30-7A than it is on a C30-7, as I claimed.

In terms of other "landmarks": on a C30-7, the blower intake is above the gap between the lead truck and the fuel tank, whereas on a C30-7A it is over the front of the fuel tank.

Most locomotive photos are taken from an angle, and it's not all that easy to find a direct side view. Here's one:
http://www.rr-fallenflags.org/cr/cr6550bgd.jpg" onclick="window.open(this.href);return false;
the "class unit" of Conrail's C30-7A fleet, from George Elwood's "Fallen Flags" rail image site.

I think CR got the electrical parts commonality with the straight C30, but the FDL 12 for fuel economy. Look at the service that these units were in. They were mainly captive to the Boston Line. They spent the majority of the their lives pulling trains over the Berkshires. I have seen them down to near minimum continuous speed.


I'm not surprised that they did not live much past Conrail. They had tough lives, as described above. Near the end, newer -8 and 60 series had started to already replace them. Next, CR got the 80MACs. Technology and hard use did them in quickly.