Hot Rods or Slow Pokes?

[Boyd]

For the engine operators out there, what engines are considered Hot Rods and what are considered Slow Pokes?

[wjstix]

Not sure there’s really an answer to that. Railroads buy certain engines for certain duties, and can have their gearing set at the factory (or by the railroad themselves in their shops) based on the speed necessary to do the job they’re expected to do. A GP-38 that’s assigned to yard work may have it’s gearing set for slow-speed running, while the same railroad might have another GP-38 that’s used on mainline trains and geared for high-speed running.

[samfp1943]

Not sure there’s really an answer to that. Railroads buy certain engines for certain duties, and can have their gearing set at the factory (or by the railroad themselves in their shops) based on the speed necessary to do the job they’re expected to do. A GP-38 that’s assigned to yard work may have it’s gearing set for slow-speed running, while the same railroad might have another GP-38 that’s used on mainline trains and geared for high-speed running.

Curious Question:

Is the ‘acceleration’ of a locomotive the product of how fast that particular power “Loads”???

Thanks!

[Train_Guy_3]

Although not directly related to the engine alone you could argue most EMDs are “hot rods” over their GE counterparts due to the fact most new EMD load-up faster. So here the computers and other electronics make it a hot rod.

[tree68]

Up until a few years ago, EMDs were GM. Are you comparing then and now, or did you mean GE?

[edblysard]

Yes,

Gearing ratio plus load speed is what determines how fast a locomotive accelerates.

If I remember correctly, the standard gear ratio is 62/15.

In D/C locomotives, the transition between series and parallel also make a difference, the speed the traction motors “load” is changeable with a thrystor rack.

How fast the prime mover speeds up determines how fast the alternator speeds up, which in turn determines how many amps are available…the quicker the alternator is brought up to speed, the quicker more amps get to the traction motor, the quicker the locomotive picks up speed.

In my personal experience, EMDs smoke GEs…used a refurbished pair of SD 40s switching last week …SD 40Ns was UPs label, those buggers flat out take off from a stand still they move real fast!

wjstix:

Not sure there’s really an answer to that. Railroads buy certain engines for certain duties, and can have their gearing set at the factory (or by the railroad themselves in their shops) based on the speed necessary to do the job they’re expected to do. A GP-38 that’s assigned to yard work may have it’s gearing set for slow-speed running, while the same railroad might have another GP-38 that’s used on mainline trains and geared for high-speed running.

Curious Question:

Is the ‘acceleration’ of a locomotive the product of how fast that particular power “Loads”???

Thanks!

[Randy_Stahl]

I remember a GP-30 going through the roundhouse wall into the parking lot , she was a quick one!

[WSOR_3801]

FMs might have been the fastest. I was told by older heads that FMs in the hand of one guy, well, if you hadn’t gotten on the car when you told him to go, you weren’t getting on.

EMDs are usually quick to load, especially if there is a switch mode setting in use. On MP15ACs in switch mode, notch 4 gets up to 900 amps pretty quick, if they don’t spin out.

[Train_Guy_3]

Yeah sorry about that, I did mean “GE” in place of “GM” there. Once again another mistep with the keyboard.

[CSSHEGEWISCH]

FMs might have been the fastest. I was told by older heads that FMs in the hand of one guy, well, if you hadn’t gotten on the car when you told him to go, you weren’t getting on.

There have been several stories in TRAINS about the rapid acceleration of FM’s. Apparently, the setting of the load regulator allowed these jackrabbit starts. This quirk led to Train Masters often being assigned to suburban operations (CNJ, DL&W, SP) where quick acceleration was an asset.