Hello,
I am trying to finalize my main classification yard design and I have several questions:
I was wondering if there's such a thing as the optimal length for yard lead tracks relative to the classification track lengths for operational 'interest'?
What about the ratio of yard lead track lengths versus A/D track length?
Thanks for any/all advice and opinions.
Modeling an HO gauge freelance version of the Union Pacific Oregon Short Line and the Utah Railway around 1957 in a world where Pirates from the Great Salt Lake founded Ogden, UT.
- Photo album of layout construction -
Depends on how closely your yard tracks match over the road train length. If average trains fit on one yard track, the A/D track need only be a little longer than the yard tracks. If train length will be longer than yard tracks, then the A/D needs to be at least that long. For instance, if yard track is y length and 2y is train length, then the A/D needs to be 2y long, plus whatever you can for maneuvering the cuts into the yard.
One way to deal with not enough A/D space is to make it double-ended. That way another siding (preferably) or the main (if you must) can be used in the case of extra long trains. Not exactly prototypical, because the prototype usually has plenty of room, it makes a good compromise so long as it's not every train doing it.
Mike Lehman
Urbana, IL
I made my drill track long enough to hold the yard switcher and all of the cars of the longest trains I run. The locos and cabooses get cut off in the yard first. But I have worked layouts where the drill track was only about a half train long. Thie required pulling half of the cars off the A/D track, sorting them, then pulling and sorting the other half. It adds a litle complexity which some find to be more fun.
If you haven't already, take a look at Andy Sperandeo's book The Model Railroader's Guide to Freight Yards. It has lots of good info concerning yards.
skagitrailbird If you haven't already, take a look at Andy Sperandeo's book The Model Railroader's Guide to Freight Yards. It has lots of good info concerning yards.
Amtrak America, 1971-Present.
To avoid frustration, try to make the lead as long as the longest cut of cars you plan to move, plus space for a couple locos, and then a little extra if you can. Longer is almost always better when it comes to a lead.
I'll once again throw in my observation that most of our model yards are far too small for their prototypes to have dedicated a/d tracks. The model press (to some extent) and far too many designers and operators have pushed the idea that a train should arrive or depart from dedicated tracks, and the cars and power moved between them and other parts of the yard. In most examples of yards the size we can model, trains come and go from whatever track makes sense at the time. In design terms, try to have several tracks long enough to hold a train and its power. In many situations, space considerations preclude having sufficient length on every track, but the more you can do this the more flexible your yard will be. In both of my on-stage yards, every track is intended to hold a full train if need be, which keeps operations fluid.
Rob Spangler
We built our yard with equal length double ended yard tracks. One lead is a little longer than the yard tracks which works really well. The other lead is about half a yard track long and it is a bit frustrating working the yard from that end.
I concur therefore with the posts above that suggest the lead should be a little longer than the longest yard track.
Bill
My thoughts based on several club layouts that I have switched cars on was the A/D or yard track capacity plus 5 long car lenghts plus locomotive(s).
Larry
Conductor.
Summerset Ry.
"Stay Alert, Don't get hurt Safety First!"
A lot of my modeling has been based on my real life experiences. Every place I worked on the railroad over my life had it's own way of doing things.
I found that when flat switching, 20 to 25 cars at a time was a comfortable amount to work with. Physics does not scale down to 1:48 or 1:87 but in real life, every time you kicked a cut of cars, you had to stop it with the independent or engine brake. (remember the car inspectors bled the air off the cut so you could switch it to begin with)
We tried to switch cars into one track from which they would depart after being coupled up and having the air run rather than having to assemble them from different tracks to make the train.
On the NYC at E St Louis, inbound trains seldom fit and there was no head room to set the excess cars over into another track, so, we sent the yard engine out to come in behind the train and double it into the yard from the rear.
Departings trains usually had to double out and foul the main in the process so one had to get permission from the block operator to do so while getting their air brake test.
Charlie
For 'interest'...make the lead half as long as the shortest classification track.lol
If you have the space for it, make the lead as long as the longest string of cars your loco(s) can push/pull through the ladder. Having too long of a tail track is impossible! There might be times where you pull most (or all) of one track, then want to pull most (or all) of another track to classify cars. I think the 'recommended' ratio is the lead should be 1 1/2 times as long as the longest track.
Test it out before you ballast and scenic it...it's easier to add/remove track if it's just spiked to cork rather than glued/ballasted down and the area fully sceneicked. While planning, just keep in mind where you can extend the lead if needed. A lot depends on your modeled location, prototype, era and intended function (a 1950's coach yard might be different than a 1990's class 1 classification yard and different than a staging or fiddle yard).
http://delray1967.shutterfly.com/pictures/5
SEMI Free-Mo@groups.io
Thanks for all the great replies! It's much appreciated. I will post a review request for the current yard design in the next day or two.
BTW, the current yard design has two yard leads (260"+) which are slightly longer than the three A/D tracks (240"+) which are in turn longer than any of the 8 classification tracks (160"-210").