About GP9 and GP9M differences

[Max Komarov]

Dear all, Hi

Could anybody to inform  me about subject?

Thank you,

Max

[CPRail modeler]

The GP9M is usually a rebuild of a GP9. The short hood would have been chopped down in most cases for better visibility. Certain parts of the locomotive like the trucks would have been remanufactured. The prime mover would have been modified depending on who rebuilt it.

Hope this helps

[ndbprr]

The real question is what happened to GP9A through GP9L?

[Max Komarov]

The real question is what happened to GP9A through GP9L?

Oh yes, I have known GP9B only. Rest indexes is a real enigma...

So as I understand this modification was made carerrs but EMD?

[CSSHEGEWISCH]

As far as as-built from the factory, the only models are GP9B and GP9M.  The GP9B is a standard GP9 without a cab, only PRR (40) and UP (125) bought them.  There are a few others that were de-cabbed in railroad shops.  The factory GP9M is a real rarity, the only ones were GN 900-915, rated at 1350 HP since they re-used a lot of parts from traded-in FT's.

[jrbernier]

  The M&StL also traded in engines that were rebuilt into GP9m configuration by EMD.  The 'Louie' traded in 2 ABA sets of FT's and a ABA set of F2's that were remanufactured by EMD with a 1500 hp rating.  IIRC, they were the 600-608....

  EMD used a lower class 'm' suffix to mark these remanufactured engines.  The 'm' meant 'modified' to something less than a normal rating for the model.  Many early 'slant' nose E's got the make-over into E9Am engines.  During the late 50's as new engine sales slowed, EMD offered a lot of 'deals' to keep the manufacturing floor active. 

Jim

[beaulieu]

As far as as-built from the factory, the only models are GP9B and GP9M.  The GP9B is a standard GP9 without a cab, only PRR (40) and UP (125) bought them.  There are a few others that were de-cabbed in railroad shops.  The factory GP9M is a real rarity, the only ones were GN 900-915, rated at 1350 HP since they re-used a lot of parts from traded-in FT's.

 

Can I open the extra-large can of worms and bring up the GP9R and GP9L models. These designations are not commonly used but did appear in EMD publications, they indicate which air brake system the locomotive was equipped with. The GP9R was the most common, it indicated that the locomotive was equipped with 24RL air brakes, the GP9L had 6BL air brakes, and I think in the earlier GP7 series there was one more possible choice. I think the very last GP9s built in Canada came equipped with the 26L air brake system which rated no letter suffix. The GP9L was fairly rare, but in the earlier GP7 series the GP7L was fairly common, all SL-SF GP7s were built as GP7L locomotives as the Frisco thought of them as purely branchline power. As such they were not normally used on mainline freights because the 6BL brake didn't work well with the 24RL brake found on the F7 and F9 locomotives. 

[Max Komarov]

... There are a few others that were de-cabbed in railroad shops.  The factory GP9M is a real rarity, the only ones were GN 900-915, rated at 1350 HP since they re-used a lot of parts from traded-in FT's.

It is mean what 16-567A engines from FT used on GP9M? It's very interest because 15 years distance between begining of manufacturing above locos more then enough for changing more new engine on more new loco to more old engine from more old loco. Or I have some misunderstanding here?

[Max Komarov]

As far as as-built from the factory, the only models are GP9B and GP9M.  The GP9B is a standard GP9 without a cab, only PRR (40) and UP (125) bought them.  There are a few others that were de-cabbed in railroad shops.  The factory GP9M is a real rarity, the only ones were GN 900-915, rated at 1350 HP since they re-used a lot of parts from traded-in FT's.

...The GP9R was the most common, it indicated that the locomotive was equipped with 24RL air brakes, the GP9L had 6BL air brakes,...locomotives. 

About worms can - I have found some info for above (supposed) modification referenced as GP9RM - in CN roster with road numbers 40xx, 41xx and 72xx... . Also GP9u with reference to CP was found. Here is a closet with sceletons? :)

[jrbernier]

Max,

  Those 're-manufactured' engines can have a de-rated power for a number of reasons.  When EMD made these deals, the railroad many times got a tax advantage(just upgrading an existing locomotive, even though the outcome looks far different).

  The second issue is 'how much of the existing locomotive is used'?  The lower rating many times can be due to a rebuilt main generator, traction motors, or the actual engine block and power assemblies.  A 567A diesel can be upgraded to a 567AC, but I suspect EMD will not rate it for more than 1500 hp.  Many times the amount of 'recycled' parts from the original locomotive is very small - It is more of an accounting exercise....

Jim

[SSW9389]

Here are the rest of the factory GP9Ms and dates from A J Kristopans' webpage. These locomotives started as GP7s and then went back to EMD for rebuild after wrecks. They have GP7 internals, GP9 carbodies and are rated at 1500 horsepower.

KCS 162 10/54

CGW 120 1/56

SAL 1798, 1801 3/56

L&N 511, 513 2/57

MV 152-153 4/58 

BRC 471 6/58

CNJ 1531-1532 7/59

 

[Max Komarov]

Thank you all for infos a lot. Take an ours congratulations for July, 4 Holliday.

 

[jwhitten]

The GP9B is a standard GP9 without a cab, only PRR (40) and UP (125) bought them.

As far as relates to PRR, when were they purchased and where were they deployed and in what capacity (over the road, yard switching, some of both, etc)? 

[SSW9389]

jwhitten: I can't answer where they were used, but can answer when they were delivered by EMD. There were two orders for GP9Bs by the Pennsylvania Railroad. The first order for 30 units were built in November and December 1957, road numbers were 7175B-7204B. This order coincided with GP9 orders for #7145-7229. The second GP9B order for 10 units 7230B-7239B was built from October to December 1959.  The Pennsylvania GP9s 7230-7269 were built during the same time. Diesel data from A J Kristopans webpage.

 

The GP9B is a standard GP9 without a cab, only PRR (40) and UP (125) bought them.

As far as relates to PRR, when were they purchased and where were they deployed and in what capacity (over the road, yard switching, some of both, etc)? 

[SSW9389]

Found two more factory GP9Ms:

C&EI 221 8/58

C&EI 229 6/59

Both on A J Kristopans webpage.

 

Here are the rest of the factory GP9Ms and dates from A J Kristopans' webpage. These locomotives started as GP7s and then went back to EMD for rebuild after wrecks. They have GP7 internals, GP9 carbodies and are rated at 1500 horsepower.

KCS 162 10/54

CGW 120 1/56

SAL 1798, 1801 3/56

L&N 511, 513 2/57

MV 152-153 4/58 

BRC 471 6/58

CNJ 1531-1532 7/59

 

[jwhitten]

Actually that helps and I might be able to discover where they were deployed from the unit numbers.

[trolleyboy]

Found two more factory GP9Ms:

C&EI 221 8/58

C&EI 229 6/59

Both on A J Kristopans webpage.

 

Here are the rest of the factory GP9Ms and dates from A J Kristopans' webpage. These locomotives started as GP7s and then went back to EMD for rebuild after wrecks. They have GP7 internals, GP9 carbodies and are rated at 1500 horsepower.

KCS 162 10/54

CGW 120 1/56

SAL 1798, 1801 3/56

L&N 511, 513 2/57

MV 152-153 4/58 

BRC 471 6/58

CNJ 1531-1532 7/59

 

Just to add to the oddness. GMD in Canada built three GP9's with roof top airtanks for the passenger and frieght ops on the TH&B. At the time GMD didn't have a full set of design templates for the GP 9 so these three units 401,402,and 403 had GP9 internals with GP7 bodies.Over time they weer rebuilt and repaired as requirted and eventually looked like regular torpedo tube nines,all three went through the GP9 rebuild program of the CPR and are still floating around as 1500 series units in Western Canada.

Rob

[Alan Robinson]

Interesting question with a simple answer. The GP9 was the factory produced model of EMD road switcher with 1750 horsepower riding on Bloomgerg road trucks. It had a high short hood and was normally designed to run short hood forward. It was essentially the guts of EMD's F9 cab model in a road swither body. GP stands for "general purpose" to symbolize how this one body style could do it all. The first real EMD GP model was the GP7 with the guts of the F7 in essentially the same style of roadswitcher car body.

Just as there were F9A (cab units) and F9B (booster, or cabless units), there were a few GP9B units as well. By this time the railroad's transition to road switcher body styles was well underway, and they had figured out that having boosters (cabless units) didn't make much sense, with locomotive lashups changing so frequently to meet operational needs. Road switchers did away with the practice of keeping cab units and matching boosters in permanently coupled or semi-permanently coupled sets.

The GP9M came along later, through a very distinct origin path. The GP9M was invented, for one reason or another, mostly trying to capitalize on the railroad's existing investment or to gain new versatility, but sometimes to recover parts of a locomotive cab or hood unit that had been damaged or destroyed in a wreck. Usually it was a result of using some part of an older locomotive in a new body to save the cost of an entirely new locomotive. Thus the example of using all or some of an FT's or F3's guts to make "new" GP9 locomotivees but referring to them as GP9M (for "modified") to distinguish them from the normal GP9 model. So, there were no C through L models because the M means modified and is not really a model moniker.

The world of "rebuilds" is so full of odd surprises, including EMD GP models that were repowered with a prime mover from Alco, or riding on trucks from some other trade-in locomotive or even the interesting experiments of rebuilding old cab uints into unique road switcher models on the Santa Fe, the origin of the CF series. If someone could think of it, someone probably did it with more or less success.

[billbtrain]

Great Northern's GP9m's 900-915 had the 16-567C engine used in regular GP9's,but because of the reuse of the main generators,maybe the traction motors,and other electrical equipment,they were rated at 1350HP.Two units,913 and 914,were rated at 1500HP.GN classed these as 'GP5'.

Have a good one.

Bill B

Edit:GN also had GP9m's 733 and 734 built in 1959 with 16-567C engines and F3 electrical components. 

[trainfan1221]

While I can see using rebuilt components, or reusing components in a newer engine,  it seems odd to order a locomotive directly from the manufacturer that has 400hp less than it should.  Wouldn't that have been an issue at a time when the race for more power in a single unit was going on?

[Alan Robinson]

There are a variety of reasons for getting a factory unit with a lower horsepower rating than the normal model. For example, in switching duty, the locomotive spends a lot of time at idle and only short periods working hard. Starting tractive effort, which is what is important to move a cut of cars in switching duty, is pretty independent of prime mover horsepower, but is a function of weight on drivers, gear ratio and the electrical rating of traction moters and the main generator.

Suppose a railroad wants a switcher with capability to occasionally haul a short train at over-the road speeds. An SW model might work but it only has switcher, not road trucks. This sounds like a perfect use for a derated GP9M with only 1350 horsepower. The locomotive will have the same starting tractive effort of the standard model for switching duty and it will have the Blomberg road trucks for good ride and tracking on the occasional over-the-road movement. Of course it wouldn't be able to handle as long a train, but that might suit the need just fine. So, the question for this railroad would be, how much horsepower SHOULD this new locomotive have? The answer, based on the history of the required operating conditions, might be 1,350 horsepower.

Remember, too, that any locomotive is burning fuel when at idle. For switching duty, this could be a substantial part of the operating cost. So, why not get a smaller prime mover to reduce fuel costs?

Another possible scenario from the past would be the need for a switcher with steam generator capability to handle moving passenger equipment in the terminal. Again, a standard SW unit has no steam generator, but a GP model has room for a steam generator and capacity for a water tank on the undercarriage to feed the generator. I believe there are still a few such units in Amtrak service, but they are rapidly disappearing and may be gone by now. Certainly the need for steam is gone.

I'm sure there are other reasons for odd, low horsepower units as well.

[GP 9 lover]

beaulieu-

I was wondering if you had the resources (or could tell me who might be able to) to get the actually original specs of the GP7 braking system and how it would compare to this common 2 brake per truck modification. I am trying to prove that the new system is either equal to or better than the original braking system.

[Texas Chief]

The real question is what happened to GP9A through GP9L?

Think about it. The "M" stands for Modified.

Dick

Texas Chief