Accelerating an EMD (commuter/passenger service)

[Jtgshu]

Seems like if you ask 1000 people, you'll get 1000 different answers

For passenger/commuter operations, with relatively light trains, and higher speeds, what is the best way to accelorate an EMD - in my instance, using GP40's and F40's, with the 65:14 gear ratio ( i think thats it, allowing like a 102mph MAS)

Its it better to:

Wipe the throttle all the way to Notch 8 from idle
Move throttle to Notch 4 then go up one by one once amps start dropping
Move throttle to Notch 6 or 7, then about 30mph go to Notch 8
Move thorttle notch by notch one by one from idle up to notch 8
Or something else?

Any ideas? Ive heard things like the delay in the governor reacting to the throttle being moved that quick slows loading down
Also heard that the gear driving the turbo in lower notch positions will accelorate the train better than the free spinning turbo in notch 8, and starting in the lower notches will produce better accoration
And a few other theories.......

Ive noticed that each loco reacts differently to each technique, adn that what might work better on one, won't on another

[DutchRailnut]

With the FL-9's you go to 8 th, back to 6th when train starts to move and back to 8th at 15 mph.

[Jtgshu]

Hmmmmmmm thats a new one - they have the turbo'ed 645's in them, right? Aren't they basically like a Geep, putting out the 3000 hp?

Maybe ill try that tomorrow...thanks dutch

[DutchRailnut]

567 wirh 645 power assemblies, roots blower aspirated 1850 hp

[GOLDEN-ARM]

8th and sand, Jtgshu, then back off a few, as track speed nears, on the clock. Anything less, is just plain foolish............. (on the E units, from Conrail OCS, I could only go one notch at a time, from first to third, due to an interlock, in the throttle mechanism. Once I got to third, it was "straight to eight". On NJT F-40's, I ran idle to eight, every single station start. Same with the NJT Geeps, and the F-7's, from the CNW, back in the late 80's there, too..............

[ExEMDLOCOTester]

On the F40PH-2's the RC module, High Gear ratio and load regulator were designed with the intent of running the HEP and getting out of the station quick.

Golden ARM... Activating the sand (Manual Sanding) also activates the ORS. Did you ever notice a difference in the Traction motor amps when you did this?

The F40PH-2 Load regulator typically ran at the 12 to 1 o'clock position when load testing the unit with both HEP & Traction generators. I never had the opportunity to see one on the road but I know alot less power is available to the traction motors when HEP is running.

[Jtgshu]

HAHAHA thanks GA - thats what the consensus is, but there are a few who swear by notch 5 or 6, then 7 - 8 when the amps start to drop on the load meter - they say that it holds it in the "sweet" zone (between 900 and 1200 amps or so) longer than simply straight to 8.....i haven't noticed a significant difference either way, but the loco I had today (a GP40FH - the 4135) was a real runner - she was getting to speed much faster than the other locos, and seemed to draw more amps when accelorating and even holding steady throttle, and allowing much faster acceloration . I was going straight to 8 with her

EMD, just for your info, NJT"s F40's no longer have the HEP run off the prime mover - they were rebuilt from "screamers" to locos with seperate Caterpillar HEP motors in the mid to late 90's.

What is "ORS"?, and does it make a difference if using manual sanding (all axles) or only lead truck sanding?

[GOLDEN-ARM]

4113 was the favorite loco, to catch on the 425, before the re-electrification was done. She was the quickest of all the F-40's, and the speed of her, running up to 60, was more than half a minute faster, than any other 4100, in that time period. Never saw any difference, with manual sanding, other than less time watching the amps drop, and the WS light pulsing. Over 12-15 mph, I stopped anyways, as the speed was such, that the sand wasn't effective. I did run a train from Gladstone, one night, with a GP-7 on the point, and a F-7 trailing, on the other point. The Geep wouldn't make transition, even while manually shunting the handle, from one end to the other. Rapping her out to 8th, we sat, and waited for the slack to move. Tons of smoke, and vibrations, but little movement. With a top speed, of nearly 20 mph, the trip was "interesting", to say the least. At least there was no communication buzzer, making trips outside the cab necessary, at all stations on curved track. Trying to crawl along, in a screaming loco, that wasn't moving, was one of the better trips I made on the Branch. I can still remember, getting gassed out of the cab, while the exhaust was sucked in, through every seam and seal. Great Times!!!!

[Jtgshu]

ahaha great story, GA!!!

"Good times?" riiiiiiiiiiight - sounds like an adventure!

If you ever get a yearning for feeling like you are running an E60 again, the same loco you are referring to, the 4113 has a HORRENDOUS lateral motion problem.........above about 55, you are simply along for the ride - its quite the adventure - a "seasoned" engineer I was workign with said that the E60's felt EXACTLY like what the '13 was doing - man, was I glad to get off that thing!!!

Ive been using sand at nearly every station stop (lead truck for the most part) because of the bad leaf conditions over the past few weeks - didn't use any today, except once or twice, but on dry and good rail, does dropping sand while taking off make a difference in acceloration?

Thanks for all the replies, this is great!

[Aji-tater]

EMD can correct me if this isn't 100% but IIRC ORS is OverRide Solenoid. It reduces power somewhat when the manual sand is applied. This could be to lessen the forces generated when the wheel finally gets a grip so to speak. Or am I thinking of something else as the brain cells age, LOL?

[ExEMDLOCOTester]

EMD can correct me if this isn't 100% but IIRC ORS is OverRide Solenoid. It reduces power somewhat when the manual sand is applied. This could be to lessen the forces generated when the wheel finally gets a grip so to speak. Or am I thinking of something else as the brain cells age, LOL?

The Over Ride Solenoid is in the Governor and allows oil to be pumped to the load regulator to decrease current in the rotor of the AR 10 Generator, effectively reducing the AR 10 stator output. Sanding or the toggle switch on the (DAMMM I can't remember the name of the module but it was near the WS) xxx module activates ORS. (Someone will know what module!!!)

other than less time watching the amps drop, and the WS light pulsing.

ORS activation.