When handling a freight train, is it any harder to run and fine tune controls (speed, brake applications) when there are six or seven powered units versus two or three?
Thank you.
Paul
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Originally Posted by Railrunnin:
When handling a freight train, is it any harder to run and fine tune controls (speed, brake applications) when there are six or seven powered units versus two or three?
Thank you.
Paul
In my opinion, there are way too many variables to provide a "quick" answer. Obviously EVERYTHING is dependent on the Engineer's skill. Then there is the size/tonnage/length of the train and the topography the railroad is operating over. A "roller coaster" rail line can be a REAL challenge for ANY Engineer.
One of the things I remember most with a large consist is how long it takes for the independent brake application and release to work. The bigger the consist, the fuzzier it gets. When moving around lite, like making a coupling, the pressure buildup towards the rear comes very slowly, and release can take several seconds longer too. Same when making an automatic set. You need to bail for off several seconds per unit to avoid having brakes start to apply toward the rear of the consist. For instance, If you plan on making a set on a moving train, and you have ten units, you might have to bail off approx. 15-20 seconds to actuate the rear unit before you start your reduction.
Thank you both for your replies.
Paul
Originally Posted by locopilot750:
One of the things I remember most with a large consist is how long it takes for the independent brake application and release to work. The bigger the consist, the fuzzier it gets. When moving around lite, like making a coupling, the pressure buildup towards the rear comes very slowly, and release can take several seconds longer too. Same when making an automatic set. You need to bail for off several seconds per unit to avoid having brakes start to apply toward the rear of the consist. For instance, If you plan on making a set on a moving train, and you have ten units, you might have to bail off approx. 15-20 seconds to actuate the rear unit before you start your reduction.
You are right about that, however, I never liked having more than three (six axle) units with the independent working. If I had four units, I usually left all four hooked up. Over that, I would disconnect the hose behind the third unit and make sure that the trailing unit's independent brakes were bled off and only worked with an automatic brake application. Three units gave more than enough braking effort while switching without too much delay in application and release.
Back to the original question, the engine brakes were only used when moving around lite or when switching, not to control the speed of an entire train over the road. That is what the dynamic brake is for. Of course there are exceptions.
But, when you have a bunch of engines with all of the independent brakes working, it seems like you are spending the entire day getting them to release when you want to make a move. Plus, and this is a big PLUS, with so many brakes working you can get too much braking effort and possibly jack-knife the train. Company rules will dictate how many independent brakes can be in operation in order to prevent such an occurrence.
