Anybody know what a GP9-4 is?

[Anonymous]

A local short line uses several leased locos which belong(ed?) to Railink. In every reference I have found the units are designated as a GP9-4, but I can't find any info how these would be different than a straight-up GP9. I want to know what I can get away with for modelling purposes. I suspect they're just overhauled/refurbished without any major changes, but I'm I can barely recognise a GP9 in any event. Time to turn to the experts!

Rob

[ndbprr]

I've never heard that designation but it wouldn't surprise me. GP-9's are approaching sixty years of age if not older. I doubt if any are still pristine as built units. Owners over the years have probably made upgrades both personal and EMD driven to standardize parts and costs. It may be the owners designation for maintenance crews to know which parts and manuals to use when repairing the engines

[bpickering]

A Google search showed hits on "GP9-4", but not "GP-9-4". Nothing explicitly what was actually DONE to them, but...

pic:
http://naphotos.nerail.org/showpic/?photo=2005111819074725283.jpg&byrail%3A2%3ACape_Breton_and_Central_Nova_Scotia_Railway

http://www.trainweb.org/rosters/CBNS.html states that they are rebuild GP9

Brian Pickering

[Anonymous]

I'm guessing the -4 designation was the standard they were rebuilt to or something like that.

[BentnoseWillie]

A "-3" or "-4" is a rebuild with newer technology in the electrical cabinet.

EMD dubbed their 1972 electrical improvements to existing designs the "-2" line, and subsequent rebuilds to newer electrical standards by other shops have been dubbed "-3" and "-4" to indicate the presence of modular electrical controls, microprocessor-based diagnostic equipment, and/or other modern features.

Short version - a "GP9-4" is a GP9 that's been rebuilt at least once.

[jeffrey-wimberly]

Best way to say it! Model number - GP9. The -4 refers to the rebuild and type of work done, in this case, as said improvements to the electrics, as well as stating how many modifications the loco has had. Find an EMD site and you should be able to find info on it.

[BentnoseWillie]

You won't find "-3" or "-4" on EMD's site - it's not EMD nomenclature. I should have been more clear on that point.

EMD nomenclature uses "-1" and "-2", and "-1" only in the case of the GP15-1, to distinguish it from the "Dash 2" locomotives that were coming out of EMD at the same time. Any other "Dash number" suffix is a rebuilder designation, and may not mean the same thing between different rebuilders.

It often doesn't even indicate the number of rebuildings, but when a rebuilding may have been done. A "-3" rebuild is probably contemporary with 60 and 70 series EMD locomotives, whereas a "-4" was probably done sometime after the mid nineties.

Meanwhile - at the point of the topic [:)] - to model the RailLink GP9-4s on CBNS, your best bet is to get photos of one from all sides and comparing to your starting-point model, to see what external changes are visible.

[jeffrey-wimberly]

Well said. I stand corrected.

[route_rock]

We have a SD9-3 on the BNSF Number 6100 still running strong and even lead qualified!

[Anonymous]

Thanks for all the info guys. I've been away so this is the first chance I've had to see the replies. The short line in question is indeed the CBNS and the linked photos are the locos I'd like to model. I appreciate the help.

Rob

[rayw46]

I'm not super knowledgable of such things, but weren't the original GP-9's high short hoods? If so then it seems that there are some major external changes to the GP-9's in Brian's photo link, including what appears to be an exagerated Dynamic Brake housing although this could be a optical illusion. Also, not many GP-9's came with snow from EMD.