Hump Yard Grades

[fuzzybear63]

What kind of grade leads UP to the hump? I saw a post here a while back that said one (not sure which) humpyard had about a 4.25% grade down from the top into the yard, but I have never seen any details about what grade the hump engine has to push up to reach the cut point. Anybody know any protype hump yard IN grades?

Thanks

 

[gfisher]

Interesting question. I suspect that it has much to do with the type of cars being humped, the usual length of cuts and the available motive power to push stuff up an approach grade, as well as the amount of space available within the yard. The only comment John Armstrong makes in his books about it is that it be sufficient to keep slack in the cars prior to their cresting the hump so the personnel can pull the pins on the couplers without problems.

As far as the bowl is concerned he lists 3 to 8 percent grade down to the first turnout to get the cars moving, a downgrade of 1 to 2 percent through the turnouts and retarders, and a 0.25 percent downgrade for "deceleration" to the standing cuts of cars. Most bowls also had an upgrade at the far end to help prevent runaway cars....an issue within Trainz as cars have virtually no friction and will run on for several miles on flat track before stopping.

 

[bendorsey]

Thats why the humpyard kit has two types of retarders. One slows them down - the other stops them (pretty slick). They can also be used outside the humpyard kit. I use them to slow cars down on my kick back dumpers.

Ben

 

[mjolnir]

In the 1917 book, The Elements of Railway Engineering by William Galt Raymond, he writes,

Any grade from a 0.o per cent, or level, grade to a 0.4 per cent grade may be called light; from 0.4 per cent to 1.o per cent, moderate; from 1.o per cent to 2.0 per cent, heavy; and over 2.0 per cent, very heavy. The character of the country through which the road is built will vary these limits somewhat. Eastern trunk lines seek grades 0.3 per cent or under against their heavier traffic, while grades of 4 per cent are frequent in the Rocky Mountains. A little over 4 per cent is the heaviest grade in regular use on any important road, but heavier grades, approximating 6 per cent, exist and are operated on some mountain, mine, and logging roads. A grade of 45 degrees would be a 100 per cent grade. A locomotive having only driving wheels and no tender could theoretically just maintain itself at a uniform slow velocity on a grade of about 24! per cent. The steepest trolley road grades are about 15 per cent.

[Note, the full text of the book is available for download. Go to <books.google.com>, do a search for "railway engineering", in the results page, select "full view", and the book should be one of the first hits. If you want your route to reflect actual US and Canadian practice, there's lots of valuable material here, even though the book is almost 100 years old.]

I'd say that the grade up to the top of the hump would be between 6 and 12 percent; remember that the grade has no impact upon the locomotive until the locomotive is actually on the grade, and the upper limit of the grade is where the locomotive is unable to push the cars ahead of it up the grade to the top.

ns

 

[mjolnir]

IThe only comment John Armstrong makes in his books about it is that it be sufficient to keep slack in the cars prior to their cresting the hump so the personnel can pull the pins on the couplers without problems.

John Armstrong may have written this, but he is incorrect. There is no slack to worry about in a pushed string of cars, unless the string is being pushed downhill at a speed slower than the cars would roll on their own. Otherwise, pushing the cut eliminates the slack.

ns

 

[bendorsey]

Not trying to start an argument here but are you certain about the statement that the grade has no effect on the loco until its on the grade? Physics would indicate that the loco pushing cars on level track only has to overcome the inertia and frictional effects. When one or more cars are on the grade they are effectivly being lifted vertically and that must take more energy then on level track. The loco is the only source of that energy.

Ben

 

[leeferr]

Also not wanting to start an argument here, but I'd have to agree with you Ben. As soon as the first car starts up a grade, then the loco will have to use energy to produce the work required to raise the car.
Mike

 

[mjolnir]

Not trying to start an argument here but are you certain about the statement that the grade has no effect on the loco until its on the grade?

Well, I am certain about what I meant to write, which, unfortunately, was not quite what I actually wrote. Consider a locomotive which couples to a cut of cars in the hump yard, and begins shoving it towards the hump. The locomotive will generate a certain tractive effort, based upon the power of the locomotive, and the amount of the weight of the locomotive on the driving wheels. This is what I meant, and wrote badly in my earlier post. The total energy required for the locomotive to push the cut of cars will go up as the cut begins to ascend the grade, however, the amount of increase in energy required is only the amount required to move the cars on the hump up the grade, and while a bit more energy will be required to shove the cars, when part of the train is on the grade, the available tractive effort will not changed until the locomotive enters the hump itself, at which point the grade will affect the power the locomtive is able to produce.

ns

 

[UP5521]

Could any small steam engine like a 2-6-0 mogul be used for this type of operation?

 

[bendorsey]

Any loco coiud be used but the smaller the loco the shorter the cut. I seem to remember reading somewhere a cut for an 0-6-0 was 6 cars but an 0-8-0 could push 20 cars up the hump. Some RR's had specialty locos for humpyard service. 0-10-0's, 0-6-6-0's and even 0-8-8-0's I believe.

Seems to me the only differences between a loco pushing a cut on the flat and some on the hump are:
1. When the cars start up the hump the engineer has to give the loco a little more throttle to compensate for the rquirement to "lift" the cars.
2. The possibility of driver slippage increases.

TE and all that stuff remains the same.

Ben

 

[cascaderailroad]

On the "NS Reading Lines" route there is an Allentown hump yard. While the grade and height of the hump may be exactly prototypical, the steep grade on it in Trainz makes cars go unreasonably fast down hill. If I were to make a hump yard, I would experement with what the slightest grade would be needed to get cars going at 2 mph over the hump at the pin-puller, and not exceeding a maximum of 20 mph at the classification yard switches, as most hump yard prototypical operations are generaly slower than that, and collisions between cars on classification tracks are supposed to be @ 5 mph or less. Also a slight upgrade near the tail end or the yard tracks would slow cars, make them roll backwards, and prevent run-through runaway freight cars. The hump yard retarders are something that I have not yet gotten to work properly, but I would like information on to hear how to get them working.

In Camden NJ Pavonia Freight Classification yard I witnessed a loaded coil car full of rolls steel sheet metal being humped...it was clearly stensiled in bold large capital letters "DO NOT HUMP" ! It went downhill at a excssive rate of speed, caught its airhose gladhand in a switch point, ripped the entire air brake trainline out of the bowels of the car, picked a switch, and derailed. All in a matter of 10 seconds, with screaching, tearing, clanking metal noise, and a huge cloud of dust and smoke...it was an awful sight ! They also had regular run-throughs, were a car would pick a switch and be going so fast that it would continue rolling clean out of the yard limits, trigger the River Road crossing lights and gates and roll through unmaned, roll uphill, the gates would go up, and automobiles would cross, and only seconds later the RR crossing lights and gates would come down again, as the runaway freightcar returned again, rolling back downhill and re-entered the tail end of the yard throat. This is why we always lined and locked the rip track switch (repair in place) so runaways could not "come in on us" unexpectedly. I also saw what happens when you hump a 86' automobile parts boxcar...it's air hose gladhand got caught in the switch point, tearing out the air brake trainline, where it inturn tore out the several hundered pound-10' long slack adjuster/hydralic cushion piston, which in turn jammed up into the underside or the freightcar which ripped out the entire airbarke trainline, from coupler to coupler.

 

[mjolnir]

On the "NS Reading Lines" route there is an Allentown hump yard. While the grade and height of the hump may be exactly prototypical, the steep grade on it in Trainz makes cars go unreasonably fast down hill. If I were to make a hump yard, I would experement with what the slightest grade would be needed to get cars going at 2 mph

While trainz is primarily a locomotive (and train) simulator, and simulates other railroad activites as a secondary issue, if someone has not already modeled a working retarder for use in yards, this seems like a good effort if someone is looking for a modeling task. More specifically to answer the comment in the quote, the graded needed to get cars going 2 miles per hour is going to be very slight--perhaps 1/2 percent (one half foot of drop in 100 feet of travel, and would make for a very unprotoypically long yard.

ns

 

[cascaderailroad]

Yes but if you made that gradient say 1-2% the grade could be much steeper and much shorter. Technically if you had a 50' section of track with a slope 1' high it would be a 2% gradient, and a 25' section of track would be a 4% gradient. From the crest of the hump to the classification bowl should be a short distance, several hundered feet.

I measured some parts of the NS Allentown hump and it was very steep over 3%, and upwards of 6%, this is why the cars go so fast down the hump slope.

The Pavonia NJ hump was a huge gradient, in a very short distance....if I duplicated that prototypical gradient in Trainz the cars would go in excess of 60 mph. quick, through the classification switchs.

 

[gfisher]

if someone has not already modeled a working retarder for use in yards, this seems like a good effort if someone is looking for a modeling task.

It's been done by TPR. Look for their Humpyard Kit at their Download Depot.

 

[cascaderailroad]

How are these set up ? I believe you have to do someting technical to make them work ?

 

[UP5521]

I have done this kind of railroad yard switching with a 2-6-0 mogul steam locomotive before but the strange thing is when I uncouple the locomotive from a cut of cars I was pushing, the cars rolled halfway through the yard and derailed which suprised me and the engine did not move a inch after a few seconds after the cars picked the switch and had that happen in the real world of railroading which I'm sure this happened before the outcome could be far worse than what you seen in the game that we are speaking of.

 

[cascaderailroad]

I experimented with a hump approach that was +2% and 100' long, the hump slope is -2% down for another 100' of track. Then the next 100' of track is 0.00...then place 4 spline points. (the middle will have a +1% grade up)...the next 4 spline points will be laid the same and its middle will also have a +1% grade up...the next set of 4 spline points laid the same excpt that the middle will have a 0.5% grade up...thereafter it will be a grade of 0.00. The freight cars will roll down the hump starting at a hump speed of 2 mph, and will gradually go up these series of minute' incline steps, and will come to a gradual halt, with all the cars crashing togther at slow prototypical speeds. All within much less than 1000' of track. Make sure all your series of incline steps have a lead and tail gradient of 0.0%...if not...cars will roll backwards up hill wierdly.

===----> ==(A)==(+2%)==(H)==(S)==(-2%)====(+1%)====(+1%)====(+0.5%)========
I will try to take a screenshot, and place it ^Here^ by editing this post.

 

[cascaderailroad]

Brainstorm...You know how hard it is to run the de-coupling at the hump, as the pin-puller...in conjunction with being the hump tower operator, runing back and forth throwing all the classification yard throat switches, as well as de-coupling cars...WHAT IF a Fixed Track asset was created that would automaticlly de-couple cars, and this de-coupling track be placed at the crest of the hump ? Cars would de-couple all on their own, one by one.

Then all the de-coupling and moving back and forth up, and down the line, would be eliminated...and you could concentrate on just throwing switches, and classifying cars !

There is an Enola Yard route (across from Harrisburg Pa on West Shore of the Susqehanna) I believe it has 2 humps, EB & WB classification yards ...I'm going to study that route. Sadly the yard is twice too long prototypically, and seems to be twice as wide...so merging it to the Checkrail-Harrisburg to Reading route DEM would take some real doing.

 

[bendorsey]

As I said earlier the humpyard kit retarders can either slow or stop a car. Positioning them properly can save a lot of that 1000 ft of track. They do act abruptly tho. My kick back dumpers have an 18% grade on the actual kickback so they are going lickety-split after slowing, stopping, and reversing direction. The first retarder slows them to what seems to be 1 or 2 miles an hour. The second stops them.

NOTE! A switch that is part of the mesh can not be switched in TRS2004 (I think it can in TRS2006 and above). On the other hand a switch included in the mesh can be setup like a spring loaded switch. After unloading the car goes thru the switch (straight path) up the retarder, reverses direction, then goes back thru the switch (curved path). All without derailing.

Those retarders have a lot of possibilities outside the humpyard environment.

Ben

 

[Accipiter777]

Brainstorm...You know how hard it is to run the de-coupling at the hump, as the pin-puller...in conjunction with being the hump tower operator, runing back and forth throwing all the classification yard throat switches, as well as de-coupling cars...WHAT IF a Fixed Track asset was created that would automaticlly de-couple cars, and this de-coupling track be placed at the crest of the hump ? Cars would de-couple all on their own, one by one.

Then all the de-coupling and moving back and forth up, and down the line, would be eliminated...and you could concentrate on just throwing switches, and classifying cars !

There is an Enola Yard route (across from Harrisburg Pa on West Shore of the Susqehanna) I believe it has 2 humps, EB & WB classification yards ...I'm going to study that route. Sadly the yard is twice too long prototypically, and seems to be twice as wide...so merging it to the Checkrail-Harrisburg to Reading route DEM would take some real doing.

For my hump yard I use "uncouple at trackmark" rule. pguy made it for me few years ago. you can set how many cars, or car type. when the consist hits my "Hump uncouple" trackmark, it cuts the user specified cars away... the AI drives that hump engine and my son sorts em....