Prototype GP7 - GP9 Differences?

[luther_stanton]

I was chatting in the ACL thread about the differencew between the GP7 and GP9.  My understanding was that they were externally similar, with the GP9 more often having a dynamic brake blister (maybe this stems from the Lionel differences).  In another thread on GP7 vs GP9 Lioneltrucks there was a mention of the difference in the actual GP7 and GP9 models

I would be interested in better understanding the prototype differences. 

Here is what I found so far:

Car Bodies - Both the GP7 and GP9 shared the same car bodies, the only difference was louver placement. 

GP7 - Prime mover - EMD 567B 16 Cylinder - 1500HP

GP9 - Prime mover - EMD 567C 16 Cylinder - 1750HP

Other than that, information seems scarce.  I assume there were some upgrades in the electrical / control systems?  Were the same trucks and traction motors used?  Were dynamic brakes available on the GP7s?

Thanks for any information you can provide!

- Luther 

[chuck]

Dynamic brakes were available on the GP-7.  Almost all B-B GM diesel's rode on Blomberg trucks.  Only a few switchers and the New Haven FL-9 hybrids had "flexicoil" style truck castings or possibly AARR style trucks.

[Dr. John]

There were upgrades and variations, especially in the GP-9 series. The roof top fans changed over the years and were sometimes changed by individual railroads. Dynamic brakes were options on both the GP-7 and GP-9 but were not universal on either. The handrail stanchions changed slightly between the GP- 7 and 9. Both used EMD's Blomberg trucks, although their were slight variations there as well (bearing covers, etc.) Just like an automobile, different options were available for these locomotives and varied from railroad to railroad: fuel tank size, steam heat for passenger service, various horns, bells, winterization hatches, spark arrestors, et. al.

[locomutt]

I was chatting in the ACL thread about the differencew between the GP7 and GP9.  My understanding was that they were externally similar, with the GP9 more often having a dynamic brake blister (maybe this stems from the Lionel differences).  In another thread on GP7 vs GP9 Lioneltrucks there was a mention of the difference in the actual GP7 and GP9 models

I would be interested in better understanding the prototype differences. 

Here is what I found so far:

Car Bodies - Both the GP7 and GP9 shared the same car bodies, the only difference was louver placement. 

GP7 - Prime mover - EMD 567B 16 Cylinder - 1500HP

GP9 - Prime mover - EMD 567C 16 Cylinder - 1750HP

Other than that, information seems scarce.  I assume there were some upgrades in the electrical / control systems?  Were the same trucks and traction motors used?  Were dynamic brakes available on the GP7s?

Thanks for any information you can provide!

- Luther 

 

The Major body spotting differences are in the battery box louvers under the cab.

The GP-7 has 3-4 of them, the GP-9 only 1-2. 

(does not apply to any of the "Re-builts" whether or not factory or railroad.) 

Check out Kalmbach's "Diesel Spotters Guide for any more. 

[lionelsoni]

Late GP9s had two large fans instead of two pairs of smaller fans.

[locomutt]

Here are a couple of pictures that I just recently took.

9003 is a GP-9,1607 is a rebuilt GP-7 to a GP-16(?)

These were taken in Louisville, Ky. on 24 Mar. 2007

 

 

Sorry I don't have any "Roof" views. The "standard fans" were 36" dia., the dynamic

brake fan was 48".

9003 has "dynamic brakes", 1607 doesn't.

 

 

 

[luther_stanton]

Thanks all for the info - and LocoMutt - the pictures!

 

- Luther 

[locomutt]

Thanks all for the info - and LocoMutt - the pictures!

 

- Luther 

Very Happy  to help;

Hope it does help you. 

(I have 3 Red Caboose GP-9s on my layout) 

("O" Scale 2 rail) 

[fifedog]

Another quick spotting guide.  On the GP-9, the marker lights are set close to the outside of the hoods.  When the first generation diesels started being rebuilt, they sometimes were receiving GP-18 upgrades, making spotting even harder.

If you really love these old Geeps, git yerself down to Romney, WV this year and check out the collection the South Branch Valley has.