Estonian C3X-7i's

When Estonian Railways was owned by Rail World, they shipped a whole bunch of units to Estonia to replace the tired old Soviet diesels. From what little I can find, these "dozens" of units consisted of 19 ex-Conrail C30-7's and then a chunk of ex-UP/MP C36-7's. Apparently before they shipped out, they were rebuilt as C30-7i's or C36-7i's.

What does the "i" in the model designation mean?
How many locomotives does "dozens" mean?

Also, the units were re-gauged from US to soviet gauge, what is there to this process?

I think GE uses the "i" suffix to mean "international": it distinguishes export models from domestic types that would otherwise have similar designations.
Regauging from 4'8.5" to 5" would basically just be a matter of changing the trucks. (Maybe -- I don't know -- minor changes to things like footsteps to clear the wider trucks, but nothing major.)
Since the new gauge is wider than the old, there would be room to use the original 752 traction motors, though-- since ex-Soviet railways have lower permissible axle loadings than American-- it is possible that lighter motors were substituted. (There is a lighter GE motor for use on standard gauge units: it's used on the Australian NR class, which is otherwise mechanically similar to a Dash-9.) I don't know -- and would be interested if someone else does -- if this retrucking requires new frame castings, or whether it is now possible to cut a cast frame, insert spacers, and weld the thing back together: welding castings used to be a problematic business.

According to this page, they have 19 C30s and 58 C36s.

More info can be found here. I don't know how accurate it is -- take it with a grain of salt -- but it's a starting point.

Thanks much for the answers.

One more question,
The C36's have a box behind the cab, what is this?

Allen Hazen wrote:I think GE uses the "i" suffix to mean "international": it distinguishes export models from domestic types that would otherwise have similar designations.
Regauging from 4'8.5" to 5" would basically just be a matter of changing the trucks. (Maybe -- I don't know -- minor changes to things like footsteps to clear the wider trucks, but nothing major.)
Since the new gauge is wider than the old, there would be room to use the original 752 traction motors, though-- since ex-Soviet railways have lower permissible axle loadings than American-- it is possible that lighter motors were substituted. (There is a lighter GE motor for use on standard gauge units: it's used on the Australian NR class, which is otherwise mechanically similar to a Dash-9.) I don't know -- and would be interested if someone else does -- if this retrucking requires new frame castings, or whether it is now possible to cut a cast frame, insert spacers, and weld the thing back together: welding castings used to be a problematic business.

Is it a 752 motor?
http://www.locopage.net/bd13.jpg

http://www.locopage.net/bd14.jpg

Bengt--
I'm not an expert, I don't come in contact with traction motors in my work, I could be wrong...
But the motor in the pictures you link to LOOKS a bit smaller than a 752. (Hmm. Were these photos taken in Estonia? It the truck is for broad gauge, it could be that the motor looks misleadingly small: certainly the amount of space between the edge of the motor and the back of the wheel on the non-gear-case side makes it look as if the motor was designed for application on a slightly narrower gauge: I assume there would be a space like this with any standard-gauge motor on a borad-gauge truck. Bottom line: I'm not sure.)

Allen Hazen wrote:Bengt--
I'm not an expert, I don't come in contact with traction motors in my work, I could be wrong...
But the motor in the pictures you link to LOOKS a bit smaller than a 752. (Hmm. Were these photos taken in Estonia? It the truck is for broad gauge, it could be that the motor looks misleadingly small: certainly the amount of space between the edge of the motor and the back of the wheel on the non-gear-case side makes it look as if the motor was designed for application on a slightly narrower gauge: I assume there would be a space like this with any standard-gauge motor on a borad-gauge truck. Bottom line: I'm not sure.)

I pics were made on a 1524 mm guage railway and the bogies were new steel-castings.

Bengt--
Thanks for the further information. (Interesting that the "Lift Here" stenciling is in English: are Estonian railway workers all fluent in English? (Grin!)
On looks it could, to my eye, be a 752, with more space between the motor and the wheels than it would have on a 1435mm gauge railway. I don't want to swear to it: I don't know motors well enough. But I don't see any "spotting features" incompatible with it being a 752.

While I'm at it... The slightly smaller traction motor used in the Goninans-GE NR class locomotives in Australia is the 793A1. I assume that if GE was trying to equip a (DC motored) locomotive for some other standard- or broad-gauge application where low axle weight was desired, they might use this model. I don't, however, know what it looks like, or whether I could tell the defference between it and a 752 in a photograph.

The motors were all 752AF from GE. We added the "i" at Rail World to pattern them off the Mongolian C30-7i units to, as stated, make them "international" locomotives in an effort to get around the influence of people in Estonia who did not want to see the gE's come over, as they did suffer from not being ablt to supply spare parts for the Russian POS locomotives.

GE off set the motors on the longer axles, which "skewed" the traction motor blower ducts a bit, but we never had any issues from this.

As for the rebuild, GE installed Bright Star on all of the locomotives. And the box behind the cabs of the C36-7i units are the dynamic brake grids and blowers. These C36-7 units were ordered by the MOP and were constructed at the same time that GE was starting to build Dash 8 units, thus the similar dynamic brake placement.

Rom Tancula--
Thanks for clearing that up!
Given the programs for re-engining Russian-built ex-Soviet locomotives with GE power plants, GE parts should now be available somewhere in the former USSR ... though whether Estonia would have an easier time getting parts from Kazakhstan or Russia than it would ordering direct from Erie is another question!
--
Funny things happen when a traction motor designed for one gauge is used on a broader gauge. The 761 was clearly designed as the largest traction motor that could be fitted into a meter-gauge truck, but GE also used it on their standard gauge SL144 switcher. In that application the extra space was used to fit in a double-reduction gear box: total gear ratio about 10:1, top speed 35 m.p.h. (enough for an industrial switcher, though perhaps not for the Class 1 applications GE tried to sell the big center-cabs for in the late 1970s), all with less copper than would have been needed to get the same low-speed tractive effort with big standard gauge traction motors! (Thanks Dan Robirds for the information there!)

Gentlemen,
This is very old post but I am still willing to try - I am from Estonia and interested in these locomotives for potential rebuilding and now looking for technical documentation abut the model. Is there anyone who could help? Advise where to search? Hints to sources?
Thanks in advance!
Erik

Hello there. Welcome to railroad.net. I was able to find a general data sheet of the GE C30-7 from a reliable source. In regards to Estonia, I read that these units have been rebuilt in 2018 with some modifications.

I couldn't find the original article, but it was mentioned in Wikipedia. https://en.wikipedia.org/wiki/GE_C30-7

In 2018, Operail (formerly EVR Cargo) announced it had completed its first conversion of the series with #1564. International Railway Journal reported, "Only the frames and bogies of the original locomotive were retained and the C30-M features a new centrally-positioned driver’s cab and a 1.55MW Caterpillar 3512C HD diesel engine." The converted unit has a 1520mm track gauge and weighs 138 tonnes. Operail's redesign makes the units suitable for shunting and line haul. The redesigned units are planned for internal use and export sales.[

Here is the datasheet for the C30-7: https://www.thedieselshop.us/DataC30-7.HTML

Hi Erik and Pennsyfan19!
I don't have much to add. The C30-7 exported to Estonia were originally built for Conrail in 1984, and were of the C30-7A submodel: meaning they had a 12 cylinder engine, uprated to give the same 3,000 horsepower (American rating convention: probably closer to 3300 by the conventions used in much of the rest of the world). GE has used the 3,000 hp version of the FDL-12 engine on some export locomotives, but it was quite rare in the US: perhaps their American owners were happy to sell them off because they were non-standard.
The Wikipedia article linked to reports that 12 were sent to Australia: their bodies were scrapped, and the engines, generators, etc, put in the box-cab bodies of (originally Also-engined) locomotives.

Hi Allen and Pennsyfan19,
Thank you very much for your comments.
I learned that the company that perfomed the conversions-retrofit is called Operail (successor of EVR or Estonian Railways). They mention it on their website https://operail.com/en/services/ - just scroll down and watch the video , as well.
As far I know they stripped the locomotives down to the frame so everything below that line is refurbished and above is new.