Heard last night on the scanner that the RTC (dispatcher) for the CN told the A415 (push-pull train) that they are supposed to go into fuel conservation (FC) by NOT exceeding 6th notch (from Neenah to Stevens Point Wis) since they are only 4400 tons. For power, he had an AC4400 on one end and an SD75 pushing.
Ive heard of shutting down engines for FC, but not to exceed 6th notch? And yes, both units were running. What kind of FC would this meet? The layout is pretty flat for the run into Point, small hills here and there. Couldnt one just crank it to 8th and then coast or notch it down a few?
Kinda confused on this one, then again, it could be the green water of Lake Winnebago that I am drinking or the whole Brett Favre saga.
Lower HP/ton = slower running = less overall wind resistance = less fuel.
The energy to move a train on the level goes two places. One is to acclerate the mass of the train to a certain speed. That is only a function of the maximum speed attained, no matter how long it takes to get there. The second is train resistence. The rolling resistance is a linear function of speed, so it doens’t matter how fast you go - the energy rate is exactly offset by the increase in speed.
The killer is aerodynamic drag, which is a funciton of speed squared. It costs you more to go a mile at 50 mph than a mile at 40 mph.
So, if it takes more miles to get up to track speed, there is less energy expended to over come aerodynamic drag.
And, since lower HP/ton means lower acceleration rates, a notch 6 restriction will save fuel.
Beyond a certain point, horsepower is needed for speed, not power. You can probably move a pretty good sized train with a 5 horse Briggs and Stratton - just not very fast.
It would be my guess that speed is/was not an issue with that train, so they could make do with notch 6.
Google Al Krug and look on his site for his chart of fuel usage. It’s quite informative.
…A good example of such is the “power” of an ordinary lawn tractor. Gearing is the key to let the small HP engine move most anything. {if traction is avail.}
We have this on the transcon. The less time you spend above the 5th or 6th notch the better for fuel conservation. Its just like running your car with a light throttle.
On the flat spots I have run most of the time we were in run 5 or less.Now that all being said if it is a Z 7,8,9 then FC is out the window and you run that train like the Devil is chasing you.