The principle that trains are not doubled is correct, especially with crews at the head end only. (Who looks after the tail end)? Doubling requires stopping, the crew walking back setting sufficient brakes to hold the part left standing, making the cut, walking back to the head end, pumping up the air, taking the head end forward... then most of that again collecting the second half after going back to collect it.
So most of the time passing sidings will be long enough for close to all the traffic and/or trains will be scheduled to pass on double track or hold back until a too-long meet can be avoided.
One thing no one seems to have mentioned so far is that prior to trucks taking a huge amount of the traffic a lot of RR traffic was very seasonal. Among other things this meant that RR built sidings to take the year's majority normal traffic. When peak periods hit stock was brought out of semi retirement, stock was hired in and trains ran l--o--n--g.
As far as possible RR would get their own extra old stock into place in the weeks ahead of peak until every inch of track was bulging at the seams. This period could mean extra long trains in one direction having to pass ordinary trains going about their normal business. As the traffic started to flow the hired stock would begin to cycle in to replace the loaded outbound cars. This could produce the double saw-bys and more, As the season progressed the old cars might cycle back in passing the out bound hired cars. As the season tailed off the last long drags would then be the old cars which would subsequently be stored on the least expensive track on the system until needed again.
Two things the RR did to help themselves out with this.
Wherever possible they set up one-way-flow systems so that trains had no need or a miniumum need to cross in opposing directions. This is still done, in fact it is done even more in some cases.
Another trick was to make overlapping passing sidings. These provided two normal length passing sidings most of the year - one of which may have been barely used - and one long (wiggly) loop in the peak season.
The wiggle was caused by one of the loops being on one side of the main and the other on the other side.
In some cases one of the loops served industries direct or spurs for most of the year but these would be put on hold or specially worked during the peak rush.
All this can make for much more interesting ops on a layout... especally if you can build in my much liked overlapped passing sidings :-)
jfugate wrote:Another truth regarding train length is as long as one of the two opposing trains will fit into the passing siding the other train can be *any length*. This is what lets the prototype run a really long train once in a while.On my Siskiyou Line, we pay a lot of attention to train length so we don't accidentally make them too long for passing sidings. There's a pretty good discussion thread on dispatching and train lengths over on my web site forum:http://siskiyou-railfan.net/e107_plugins/forum/forum_viewtopic.php?2263Not only do you need to watch train length for siding capacity reasons, you also need to watch train length for loco tractive effort reasons. The thread above talks about these considerations in detail and describes how we handle this on my Siskiyou Line, which models the 1980s SP in southern Oregon.
Joe,Another thing is a train might be held out side of the yard till a yard track clears that is long enough to hold the inbound train.The last thing any crew or YM wants to do is double a train into the yard especially with todays 2 man crews but still remains a evil necessary done daily.
As far as tonnage each trains tonnage can vary on a given day due to several reasons..Let's say my C&HV train #201 has 14,500 tons today due to the traffic pattern cause by our customers shipping pattern..Tomorrow 201 may only have 7,500 tons or less and lots of empties.
As far as truths never happens in real railroading that's why you see same trains longer on some days and shorter on other days or in the case of pig/stack trains you will notice a lot of empty cars on "light" tonnage days.
If there is ONE thing I learned in my 9 1/2 years as a brakeman and its a sure bet that: Nothing is a absolute operation in every day railroading nor is it as cut and dry as modelers make it out to be..There's just to many variables for "truths" in every day railroadin'...
Larry
Conductor.
Summerset Ry.
"Stay Alert, Don't get hurt Safety First!"
Joe, you're certainly right about the tractive effort aspect of the equation. Because I lost about 1/3 of the area for my layout room, the trackplan had to be severely altered. In trying to keep as many of the desired features as possible, I was forced to go with much steeper (up to 2.8%) grades, which severely taxes some locos. The 100 ounce coal train requires a pair of either Bachmann 2-8-0s or Athearn 2-8-2s, both modified (especially the Athearns) to increase their pulling power. The steep grades are made worse, as noted, by the fact that all of them are on multiple curves.
Wayne
Joe Fugate Modeling the 1980s SP Siskiyou Line in southern Oregon
jacon12 wrote: Whew! Wayne, you've got a seriously good looking layout there! Thanks for taking the time to answer and especially the pictures, they're always worth a thousand. Your weathering looks great on both structures and cars, maybe one day...
Whew! Wayne, you've got a seriously good looking layout there! Thanks for taking the time to answer and especially the pictures, they're always worth a thousand. Your weathering looks great on both structures and cars, maybe one day...
Thanks for the compliment, Jarrell. Glad to see that you've got enough responses here to allow you to avoid some of the pitfalls that some of us may have made on our earlier layouts. And just for the record, my staging tracks, while separate from the layout, are not hidden. The layout, partially doubledeck, has the start and finish staging yards stacked one above the other. When cars reach their destination, they're usually removed from the layout and new ones cycled back in in their place. The loaded coal train, which is staged from a separate, and lower, staging track, ends up in the highest staging area, where the hoppers are emptied in preparation for their return trip.
Depends on type of yard.
Generally, for a working yard, you want your arrival and departure tracks to be long enough to hold an entire train, while your classification tracks can be shorter. However, it is common to have outbound trains double off two or three tracks, and to have inbound trains arrive of two or more tracks.
For a staging yard, you want the tracks long enough to hold an entire train period.
The real limiting factor for train length, is not the yard capacity at either end, but the length of the passing sidings inbetween. While cool looking, saw-by meets foul up the railroad and are avoided at all costs. For a smooth running raiload all trains should be able to fit in every passing siding. Again, this doesn't always happen. So, it takes a great deal of planning by the dispatcher to set up meets at the approprate length sidings. This can often mean holding a train back, even though timing would indicate a meet further up the road.
As to your other question, there is no reason why your coal traffic can't orginate on-line and then terminate in staging Or vise-versa. Instances, where traffic originates and terminates on the same subdivision (especially today) are far less common then traffic that moves over mulitiple subdivisions.
Nick
Take a Ride on the Reading with the: Reading Company Technical & Historical Society http://www.readingrailroad.org/
Joe said:Resorting to a double-saw-by once in a while can be interesting and fun -- and even the prototype will do this in a pinch. But doing this maneuver all the time means your mainline is clogged bigtime.========================================================
No way! The DS will HOLD the train out side of the passing siding or at the closest longest siding the train will fit even if that means holding the train several blocks away from where the closest meet should have taken place.
SAFETY is the key word here not playing see saw puzzles with trains..
Jetrock wrote:One thing about passing track length: you can also use a "double saw" maneuver (I think it is called) to allow two trains to pass each other on a passing track if they are longer than the passing track itself. So, with a little back-and-forth action, your biggest train can be anything less than twice the length of your longest passing siding--assuming you want to be able to run two trains at once.
jfugate wrote: clinchvalley wrote:As Joe says, it is more common than you think on the prototype to double a train at the initial terminal. So having yard tracks as long as the longest train is a nicety and not a necessity. The key to train length is passing track length.Clinch has this exactly right. Passing track length has huge effect on train length.Also staging track length is a significant factor. It's one thing to double a train in a visible yard, and quite another to double trains in and out of hidden staging yards.In order to help you take all this into consideration when you plan your layout, I've collected all these thoughts (and more) into my Layout Design Analysis article. If you analyze any track plan with this method, you will learn a ton about how the track plan will be to operate (and will find operation problems) well before you ever build it.See: http://siskiyou-railfan.net/e107_plugins/content/content.php?content.32
clinchvalley wrote:As Joe says, it is more common than you think on the prototype to double a train at the initial terminal. So having yard tracks as long as the longest train is a nicety and not a necessity. The key to train length is passing track length.
One thing to remember if a prototype train exceeds the passing track capacity it is HELD short of the passing siding until the shorter train enters the passing siding.This is not unusual when a train exceeds the normal train length due to traffic densities..Also doubling the yard is done routinely..However..There are guide lines govern these moves.
http://www.youtube.com/user/ClinchValleySD40
http://www.flickr.com/photos/52481330@N05/
http://www.trainboard.com/railimages/showgallery.php/cat/500/page/1/ppuser/8745/sl/c
tomikawaTT wrote: I'd say that the size of your yards (length of arrival/departure tracks) dictates the length of the trains you'll switch, even with doubling. The longest train you can run will be determined by the length of your longest staging tracks. If you have a small yard, use it as a terminus for locals that are down to a short car count when they arrive with loads (and requested empties) for local and nearby industries or interchange tracks. Meanwhile, the cars running between division points go rumbling past in those longer freights that run from staging to staging and only stop to meet passenger trains or opposing freights. My scheme, which has been incorporated into three layouts so far, not counting the one just beginning to be built, calls for several through freights per 'day' that only stop to change engines (catenary to combustion, or vice versa,) at the main yard, a smaller number that drop cuts of cars for local classification, and several locals each way that either originate or terminate. The arrival/departure track can handle the longest through freight (which has to be out of the way of passenger movements while changing engines or swapping cuts of cars.) The lead is long enough to take a complete local (less brake van,) or about half the maximum through freight length. Yard body tracks can accumulate a cut long enough to stick on a through freight that swaps cars, or about half the length of a local. I do have more body tracks than you have, but I'm also dealing with interchange traffic. Still in my scheme, coal originates on my short line as either unit trains (short, not 100-car monsters) or loose cars. Unit trains are interchanged as such, and proceed directly to down staging as soon as the motors are ready to take them away. Loose cars are routed by waybill, some up in locals, some down in locals, a few to on-line industries. Locals arriving from up staging with coal loads pass those loads either to down locals or to 'switching' through freights, which then take them to down staging. All coal arriving in down staging is unloaded there - only empty hoppers and gons move up to the main yard for interchange to the aforementioned coal-originating short line. It could be possible to get creative about an empties-in, loads-out mine that connects to special purpose tracks in staging. Unfortunately, my mines and my staging are not configured to allow it. Chuck
I'd say that the size of your yards (length of arrival/departure tracks) dictates the length of the trains you'll switch, even with doubling. The longest train you can run will be determined by the length of your longest staging tracks.
If you have a small yard, use it as a terminus for locals that are down to a short car count when they arrive with loads (and requested empties) for local and nearby industries or interchange tracks. Meanwhile, the cars running between division points go rumbling past in those longer freights that run from staging to staging and only stop to meet passenger trains or opposing freights.
My scheme, which has been incorporated into three layouts so far, not counting the one just beginning to be built, calls for several through freights per 'day' that only stop to change engines (catenary to combustion, or vice versa,) at the main yard, a smaller number that drop cuts of cars for local classification, and several locals each way that either originate or terminate. The arrival/departure track can handle the longest through freight (which has to be out of the way of passenger movements while changing engines or swapping cuts of cars.) The lead is long enough to take a complete local (less brake van,) or about half the maximum through freight length. Yard body tracks can accumulate a cut long enough to stick on a through freight that swaps cars, or about half the length of a local. I do have more body tracks than you have, but I'm also dealing with interchange traffic.
Still in my scheme, coal originates on my short line as either unit trains (short, not 100-car monsters) or loose cars. Unit trains are interchanged as such, and proceed directly to down staging as soon as the motors are ready to take them away. Loose cars are routed by waybill, some up in locals, some down in locals, a few to on-line industries. Locals arriving from up staging with coal loads pass those loads either to down locals or to 'switching' through freights, which then take them to down staging. All coal arriving in down staging is unloaded there - only empty hoppers and gons move up to the main yard for interchange to the aforementioned coal-originating short line.
It could be possible to get creative about an empties-in, loads-out mine that connects to special purpose tracks in staging. Unfortunately, my mines and my staging are not configured to allow it.
Chuck
"If you have a small yard, use it as a terminus for locals that are down to a short car count when they arrive with loads (and requested empties) for local and nearby industries or interchange tracks. Meanwhile, the cars running between division points go rumbling past in those longer freights that run from staging to staging and only stop to meet passenger trains or opposing freights."
Thanks Chuck, I like this way of doing it.
You're right about the carfloat, Jarrell. My (barely) modelled interchange partner is the prototype Toronto, Hamilton,& Buffalo, which ran a steam powered carfloat (lake boat) between Ashtabula, Ohio and Port Maitland, Ontario, mostly carrying coal hoppers. The TH&B brings the loads from the far side of Port Maitland (staging) to the modelled portion of the same town. The loose loads refer to my choice of load for the coal hoppers. This is a loose, granular material that is used as locomotive traction grit, instead of sand, in the diesel locomotives of the steel plant where I used to work. It's about the size of medium/coarse HO scale ballast, black in colour, with a bit of a "sparkle" to it, more similar in appearance to anthracite than bituminous coal, but it looks pretty good. Those 12 loaded Athearn 34' hoppers and a four ounce caboose make into a train of 100 ounces weight, which for me is an enjoyable challenge to move around all those curves and overly steep grades, without re-scenicing the layout with loose"coal". I also enjoy wringing better performance out of my locos, so these two interests tie in well together. The "opposing moves" refer to trains moving, or intended to move, in the opposited direction to the train that I'm operating at the present time. As a lone operator, running DC, it's my practice to run only one train at a time. This is usually done in turn: that is, one train runs until it has done all of its scheduled work and has arrived at its destination, then another train takes its turn. On occasion, I'll run a mixed (freight and passenger) train at the same time as a local freight, taking turns running each from one town to the next, sometimes in the same direction, and other times in opposing directions. Eventually, both trains may end up in the same town, necessitating either a passing move or a runaround. I like to keep the pace leisurely, as I'm modelling a secondary main line.
Although I model the '30s, here's a '50s photo of a couple of TH&B geeps heading back to their staging track with a mixed freight. The modelled portion of Port Maitland consists of that tower, a fish packing house, out of sight to the left, and one very large industry, out of sight to the right.
Probably not the clearest view of that "coal" material, but who the heck bothers to take pictures of hoppers in a coal train? That's the stuff in the tender of the loco and also in the hopper spotted in the dump shed of the coaling tower.
Here's an example of a passing move. The big Mikado parked on the left is on a short mixed train, its lone passenger car spotted at the Lowbanks station. The doubleheaded Consolidations on the right are on a time freight, passing the lowly mixed, which will eventually follow. The time freight could just as easily been on this same track, but moving in the opposite direction: this would've been an opposing move.
Surprise, surprise! I managed to find this photo of a hopper of "loose" coal destined for a local dealership.
"No soup for you!" - Yev Kassem (from Seinfeld)
jfugate wrote:Sometimes the prototype will use a trick with short yards called "doubling the train". Just split the train in two and have it take two yard tracks.
-Ken in Maryland (B&O modeler, former CSX modeler)
jfugate wrote:Sometimes the prototype will use a trick with short yards called "doubling the train". Just split the train in two and have it take two yard tracks.Of course, you'll now need twice the yard tracks as before, but in some cases, it can help.If you want to know lots of insight about track lengths and what you can and can't run on your railroad, see my article Layout Design Analysis on my web site:http://siskiyou-railfan.net/e107_plugins/content/content.php?content.32
Thanks for the link and the help, Joe. I'll give it a read!
CSX_road_slug wrote:I simply split my longest trains between two arrival and two departure tracks. Not sure if it conforms to any official rules, but it works fine for me.
Ken, as long as it works!
doctorwayne wrote: A lot depends on the make-up of your layout. Other than staging, I have no yards. I have plenty of industrial sidings, some of which ship goods to other industries on the layout, while others ship to, or receive from, off-line industries. And while my layout is DC, with usually only me as an operator, and with only one train running at a time, my longest train length is determined by the length of my passing sidings. I also like to run coal trains with loose loads, but I have neither mine nor powerplant. The loads arrive by carfloat and then are passed along by a (barely) modelled interchange. The carfloat is represented by a single staging track. After the loads arrive on my railroad, suitable locomotives are coupled on, then the train moves, more-or-less non-stop over the layout. The one hitch is that the locos (steam) need to be turned near the mid-point of the trip and then swapped end-for-end with the caboose, in order to continue to the powerplant, the "final" destination, which is another staging track. The trip is scheduled tri-weekly, with empty moves on alternating days. The general freight staging tracks hold 15 or 16 cars each, while the coal mine/carfloat/powerhouse tracks both hold about 22 hoppers and a caboose. Coal train length is limited by weight ("live" loads) to 12 cars. "Normal" freight train length is also 12 or 13 cars, limited by passing siding length, but if I choose to run trains sequentially, without bothering with opposing moves, I often run 20 or 25 car trains, with lots of en-route switching of industries. In this scenario, the passing sidings can be used as runaround tracks for switching facing-point spurs. I also occasionally run longer trains just to see them run, but these are limited by exteme curvature and heavy grades. Minimum radius is 30", although most are 34" - 36", with some even wider. The problem is that longer trains are strung around so many curves and on so many grades that the drag is more than that which will allow reasonably trouble-free operation. The best that I've managed is 65 cars, but it wasn't really much fun. Wayne Thanks for the information, Wayne. Would you be so kind as to define 'carfloat' (I think it's cars that arrive via barge, ship etc. Also, 'loose loads' and 'opposing moves'
A lot depends on the make-up of your layout. Other than staging, I have no yards. I have plenty of industrial sidings, some of which ship goods to other industries on the layout, while others ship to, or receive from, off-line industries. And while my layout is DC, with usually only me as an operator, and with only one train running at a time, my longest train length is determined by the length of my passing sidings. I also like to run coal trains with loose loads, but I have neither mine nor powerplant. The loads arrive by carfloat and then are passed along by a (barely) modelled interchange. The carfloat is represented by a single staging track. After the loads arrive on my railroad, suitable locomotives are coupled on, then the train moves, more-or-less non-stop over the layout. The one hitch is that the locos (steam) need to be turned near the mid-point of the trip and then swapped end-for-end with the caboose, in order to continue to the powerplant, the "final" destination, which is another staging track. The trip is scheduled tri-weekly, with empty moves on alternating days. The general freight staging tracks hold 15 or 16 cars each, while the coal mine/carfloat/powerhouse tracks both hold about 22 hoppers and a caboose. Coal train length is limited by weight ("live" loads) to 12 cars. "Normal" freight train length is also 12 or 13 cars, limited by passing siding length, but if I choose to run trains sequentially, without bothering with opposing moves, I often run 20 or 25 car trains, with lots of en-route switching of industries. In this scenario, the passing sidings can be used as runaround tracks for switching facing-point spurs. I also occasionally run longer trains just to see them run, but these are limited by exteme curvature and heavy grades. Minimum radius is 30", although most are 34" - 36", with some even wider. The problem is that longer trains are strung around so many curves and on so many grades that the drag is more than that which will allow reasonably trouble-free operation. The best that I've managed is 65 cars, but it wasn't really much fun.
Thanks for the information, Wayne. Would you be so kind as to define 'carfloat' (I think it's cars that arrive via barge, ship etc. Also, 'loose loads' and 'opposing moves'
Aren't you pretty much limited to the size trains you run on your layout by the size of your yards? Running long trains just to run long trains excepted? My one yard will hold about 9 to 10 cars on the A/D track, and I only have two other tracks to make/break up trains. Something else this newbie has wondered about.... when it comes to industries served by my fledging railroad, I'm wondering if I should put in a coal mining business and have long strings of coal filled cars if I don't have another business such as a large power plant to deliver them to unless they're to be delivered somewhere off the layout. Am I thinking right or all wrong about this?