Has EMD ever built a GP larger than a GP60?

[zkr123]

I know EMD has built SD locomotives larger than an SD60, but why have they not created any GP units larger than the GP60?

[DS4-4-1000]

If you mean physical size the GP40P as operated by the Central Railroad of New Jersey was larger at 62 feet 8 inches which is almost three feet larger than the GP60 at 59 feet 9 inches.

[jrbernier]

  The GP60 was sort of the 'last of breed' - High HP 4 axle locomotives fell out of favor with most railroads.   Controlling all that HP to only 4 axles, and weight imbalance when using a 'safety cab' were the most common issues.  GE did sell a 4000 hp - 4 axle locomotive in the same time frame, but did not offer a 4400 hp version when they went to the Dash 9 line.  GE also produced the P42 passenger engine for Amtrak, rated at 4200 hp.

  Current US freight locomotives are usually 4300/4400 hp on 6 axles.  There are 2000-2200 hp locomotive on 4 axles - Usually used for switching or local service.  There just has been no industry demand for high hp on 4 axles.

Jim

[carnej1]

 While neither of the "Big 2" North American builders is offering high horsepower 4 axle locomotives they are do catalog high horsepower 4 Motored locomotives. BNSF has amassed a large fleet of of ES44C4s which have 3 axle trucks but with the center axle unpowered. EMD is offering a similar variant of the SD70Ace called the "P-4".

 I read (in TRAINS,IIRC) that GE did design studies of both 4 axle (BB trucks) and 5 axle(I assume that would have been a B truck in front and a C in back?) GEVO variants as they studied an AC motored unit to replace the ES44DC in the catalog, but there were weight and other issues so they stuck with 6 axles..

  The latest emissions regulations have required larger and heavier split cooling systems for new locomotives and this means a GP60 style layout would be very overweight. The other major consideration is ensuring that the locomotive has a sufficiently large fuel tank as railroads have tried to decrease the refueling intervals on their road power. The last high HP BB freight units offered in North America, especially the Santa Fe's Wide cabs (GP60M/B40-8W) had smaller fuel tanks to accommodate the additional cab weight and thus they had less range on a full fuel load.

 There are some recent rebuilds of older EMDs to 3000HP GP59 equivalents using new 12-710 ECO packages. these are mainly aimed at slug service, coupled to a unit with it's prime mover removed but taking traction power from the "Mother".

[traisessive1]

You must remember that a GP40 and SD40 or the GP38 and SD38 are the same engine on a differing amount of axles. So technically a GP70 would be an SD70 on 4 axles. But no, they never released the 4 axle version.

[carnej1]

traisessive1

You must remember that a GP40 and SD40 or the GP38 and SD38 are the same engine on a differing amount of axles. So technically a GP70 would be an SD70 on 4 axles. But no, they never released the 4 axle version.

 If by "engine you are referring to the entire locomotive (as opposed to just the Diesel Prime mover)That's not completely true in the sense that an SD40-2 is longer and heavier than a GP40-2, so it's not just the C vs. B trucks. It's more accurate to say that 40 series locomotives use the same machinery (prime mover, alternator, electrical system). There are some older GP40-2s that were rebuilt with 3 axle trucks (narrow gauge,IIRC) and exported to South America..

 AFAIK, EMD never officially cataloged a GP70, but had a customer really wanted to order the model they probably would have produced it..Nowadays the upgraded SD70Ace machinery (especially the larger cooling system) is too heavy for 4 axle trucks...

[oltmannd]

zkr123

I know EMD has built SD locomotives larger than an SD60, but why have they not created any GP units larger than the GP60?

The longest ones would be the GP40TCs build for GO Transit.

[GDRMCo]

GP40TCs were really a GP40P built on an SD40 frame, don't see why other than weight other B-B locomotives that needed extra length couldn't be longer than the GP60.

[DavidH66]

If I remember correctly, GP60s were at the absolute threshold of safe weight distribution. Anything bigger likely would have done damage to the rails or frame of the loco depending on the center of mass.