eaglestar

Hmmm, interesting... So do your dual modes drop the load when you set the automatic?

Nah, I work out of D.C. I've heard that the Dual Modes have their own list of quirks. I'm curious as to how they'd pull, given that they have a lower HP rating (but only by 400, given that the '42s can only put out 3650 in HEP mode), but AC traction. I'd imagine their dynamic is stronger than the DCs, too. As I understand it, dual modes have no dynamic when operating in third rail mode, not sure if that's the case. I've also heard that the MNRR dual modes have no bail off feature, thus necessitating the use of blend for everything, can anyone confirm?

I wouldn't say "allowed" (although most road foreman probably wouldn't say anything.) If the slack is stretched, it wouldn't be as much of a problem. The electrics (especially the venerable old HHPs) tend to slip, especially if rail conditions aren't anything but ideal. So it's a good idea to ease into it (but again, not everyone does.) The diesels are something of an enigma. Coming from idle to notch 1 or 2 while stopper will result in an instant 300 or 600 amps, respectively. "Racking" it to notch 8 causes a delay of amps for about 5 to 10 seconds and then an almighty surge, usually followed by slippage, followed by the train slamming into the back of the engine, so we usually let the amps stabilize at the lower end and THEN notch out to 8. The diesels also react differently from notch to notch. For example, going from notch 1 to 4 brings your amps up quicker than from 2 to 5, etc. Of course, these are 25 year old GE computers doing the magic, so.... And yes, we sure can dynamics. In fact, they're encouraged as a "fuel conservation" technique. I try to use dynamics as much as I can, but when one factors in the 10 second delay from power to dynamics, or vice versa.... Lots of times, its just better to stretch. The dynamics also drop out insanely early, about 25 MPH they start to fade and are virtually useless below 10. And don't even get me started on the blend...

Thanks, guys. When running the diesels (P42s), we tend to stretch 'em to avoid slack (also, the GEs don't load up so fast- idle to notch 8, and we're talking a good 30-45 seconds to get full horsepower, so keeping the power on cuts down on the delay.) The electrics (ACS-64s) don't allow such a luxury, as they automatically cut the power as soon as the brakes are applied (although the "loading" is instant, so the primary concern is slack, which can be abated by keeping the engine brakes "bailed off" [another alleged no-no, but one they often look the other way on.]) Blended braking (shutting the throttle off and allowing the brakes + dynamics to apply) is the "preferred" method, but one that, depending on your territory and how you do it, may not be enforced. Thanks again for your insight- it makes the rides that much more interesting.

I got to thinking about the relationship between the master controller and brake valve on an SMEE. Let's say a T/O has the master controller in paralell (which is the highest position of power, if I'm not mistaken.) They then take air on the brake valve. I'd imagine that the power automatically gets cut until the air is released. If so, would the master controller need to be brought back to “off” before the car will take power again (as it is on our [Amtrak's] electrics?) Or will the car automatically take power as soon as the brakes are released? Also, would there be any reason for not knocking off the power before grabbing air/ do some T/Os make a habit of it? Obviously wouldn't be possible on an NTT. Thanks in advance, it's fascinating to learn these nuances.