Dynamic brake usage

slchub wrote:Great replies. The only thing I did not see with the explanations is why we limit or cut-out the dynos. When we use the dynos, they create high buff forces, or alot of pressure on the couplers, especially on a grade, which can result in increase wear on the track as well as the potential for cars to jump the track or if you have an empty aluminum hopper near the front with loads behind it, crush the car. On the railroad I work for we limit the number of axles with dynos to 28 axles and 32 axles on unit trains.

"Axles of power"........to those who dont know, theres a formula to it, so dont go thinking one big unit counts as six axles.

SD40-2= 5.9 axles of DB
SD90AC with 6000 horses puts out 11 axles of DB
Theres quite a bit to it.

ahhhh yes, better explained.

About your earlier querry. Yes, there is a such thing as a brake that is not variable. Rare today, the original DB's came in two styles. Flat, and Tapered. The flat system was an "all-in" type system. You got into the brake, and speed of train determined amps of retardation. Sometimes called Speed System, not the brakes you want, to finesse your train down the mountain. The taper system allows the engineer to vary the amps, at all speeds, to suit what his needs are, not what the manufacturers needs are. These brakes were generally excellent, until speeds reached below 20 mph, the they lost the ability to effectively retard the train. The answer was, "Extended-Range" dynamic brakes, which transition themselves from a fixed length grid, to various lengths of grid, related to speed and load, to affect maximum effort throughout normal speed ranges. They are effective, to below 5 mph, with the newest units being able to load the brakes up to a complete stop! On a long, heavy train, a minimum reduction of air, along with a skilled hand on the dynamics, will run your train down the grades, with the ease of running on flat terrain. A lot more fuel efficient, than power braking, as well. Regards

GOLDEN-ARM wrote:About your earlier querry. Yes, there is a such thing as a brake that is not variable. Rare today, the original DB's came in two styles. Flat, and Tapered. The flat system was an "all-in" type system. You got into the brake, and speed of train determined amps of retardation. Sometimes called Speed System, not the brakes you want, to finesse your train down the mountain. The taper system allows the engineer to vary the amps, at all speeds, to suit what his needs are, not what the manufacturers needs are. These brakes were generally excellent, until speeds reached below 20 mph, the they lost the ability to effectively retard the train. The answer was, "Extended-Range" dynamic brakes, which transition themselves from a fixed length grid, to various lengths of grid, related to speed and load, to affect maximum effort throughout normal speed ranges. They are effective, to below 5 mph, with the newest units being able to load the brakes up to a complete stop! On a long, heavy train, a minimum reduction of air, along with a skilled hand on the dynamics, will run your train down the grades, with the ease of running on flat terrain. A lot more fuel efficient, than power braking, as well. Regards

GA, it's amazing that the IC pays no attention whatsoever to this principle. They'll put an old, hammered SD-40, sans the dynamics, in the lead. Buried behind that, facing the same direction, will be a nice, newer wide-body. I would light a fire under the arses of some roundhouse folks! I guess creating discomfort for the crews takes precedence over fuel-efficiency.

Not for the faint of heart, but I have "heard" that some guys might grab a hammer, from that tool box, and test the effectiveness of the Part 223 glazing, in a forward facing window. (damn kids, musta thrown a rock.....) Now you can put any loco in the lead, that suits you. Not to be performed, in vicinity of Y.O., or Roundhouse, though...........

sorry for all the questions , but whats power braking ??

Power: throttle open, pulling the train.
Braking: brakes applied, slowing the train.
Power braking: pulling the train, while slowing it with the brakes. Works best with highest throttle numbers being used, while applying double-digits of air, at speeds below 10mph!!! The surest way to keep the slack stretched, and the shoes clean of dust, dirt or debris........

GOLDEN-ARM wrote:Not for the faint of heart, but I have "heard" that some guys might grab a hammer, from that tool box, and test the effectiveness of the Part 223 glazing, in a forward facing window. (damn kids, musta thrown a rock.....) Now you can put any loco in the lead, that suits you. Not to be performed, in vicinity of Y.O., or Roundhouse, though...........

Mr. Golden-Arm,
I must say that's the most loathsome, irresponsible, and repugnant suggestion I've ever heard! I like it!!!!!!!!!!

Be sure to have those safety glasses on. Glass bits in the eye really smart.

I encountered a "testing" of the Part 223 glazing one night in Dumont, NJ when a conrete block struck square in the window in front of me at about 50 mph. Luckily my hand deflected the glass from my eyes.

Hey, LCJ, didya stop and swap her out, or knock out the glass completely, and keep on knockin'? I've done it both ways (glass-less in summertime) . UP was a big fan, of "just deal with it", or being ordered to run, claiming the window was only cracked, not shattered. Those windows pop out fairly easy, with enough pressure from your boot, applied around the perimiter of the glass. Was that block hung from a bridge, on a rope, or tossed. Curious as to how you did it........

GOLDEN-ARM wrote: The surest way to keep the slack stretched, and the shoes clean of dust, dirt or debris........

And the surest way to keep your train in one piece while traversing enemy territory like the Paterson Plank Rd. crossing vicinity.

And don't forget to swing that hose wrench from the outside of the cab!

thebigc wrote:

GOLDEN-ARM wrote: The surest way to keep the slack stretched, and the shoes clean of dust, dirt or debris........

And the surest way to keep your train in one piece while traversing enemy territory like the Paterson Plank Rd. crossing vicinity.

And don't forget to swing that hose wrench from the outside of the cab!

Nothing like experience gained from being in the trenches!

Years back, my engineer "modified" a cab window with the brake handle in a fit of rage. Only thing was he did it from the inside. When cooler heads prevailed, we then made it look like vandalism from the outside. That window was about ready to fall out by the time we were done!

GOLDEN-ARM wrote:UP was a big fan, of "just deal with it"

HELL YA..... just as it should be.

GOLDEN-ARM wrote:Hey, LCJ, didya stop and swap her out, or knock out the glass completely, and keep on knockin'?

Kept "knockin'" after immediately reporting to River Line Dispatcher E'Port, who,as I remember it, nonchalantly said, "Roger, SEOI."

GOLDEN-ARM wrote:Was that block hung from a bridge, on a rope, or tossed. Curious as to how you did it........

I believe it was tossed by one of the local intelligentsia. And my only part in it, smart guy, was making the locomotive move along at 50 mph. So there.