The Compound Yard Ladder to the Rescue!

rfbranch's picture

Let me start this out bluntly:  I'm a dummy.  I made an incredibly elementary mistake in the design and construction of my layout that I'm shocked I did not pick up on until just this past week.  While I've only been seriously involved in the hobby for the past two years, a rule of thumb I've heard used quite a bit is that any yard that is at 50% capacity is actually 100% full.  For whatever reason I chose to completely ignore applying that rule to my layout design.  And I did it at my own peril.

The importance of the "50% is full" concept has been explained and discussed in many places (for further reading see commandment 9 on Craig Bisegeier's Housatonic Page) but this is especially critical in my situation as one of my yards serves a very specialized purpose:  it exists solely to load and unload carfloats.  To better understand my problem it's good to understand the basics of carfloat operations on the prototype (again for more detail see the following). To put it simply, carfloat operations are unique due to the necessity to keep the carfloat upright the entire carfloat has to be loaded/unloaded at once to prevent an imbalance of weight distribution caused by the cars on the float.

To demonstrate how this all ties together I thought it would be good to include an image.  Here is a picture from the late summer of my old Yard:


Note the separate tracks at left are stand ins for my carfloat and the four tracks at right are the yard itself.  In the above image, the two strings of cars on the float would be unloaded to the vacant tracks in the yard followed by the carfloat being loaded with the waiting cars in the yard.  On the surface all would appear fine and dandy until you note that the Walters carfloat that I will be using is a 3 track carfloat with a capacity of 13-15 cars versus the 8-10 on the two tracks that are the present stand ins.  This means that the carfloat is inoperable in this configuration as there would not be sufficient space to both store cars due out on the next car float and have enough empty track to accept the cars that first need to come off the carfloat.  How did I miss that one?!?!!  A definite "Hello McFly" moment. 





I came to this realization last week and I was feeling really low.  I couldn't believe I had this problem staring me in the face for an entire year.  It was such a bonehead mistake that would require a major rework of my track plan to try and fix.  Quite frankly, I was crushed by my mistake.

I bought Andy Sperandeo's Kalmbach book on Yard design a few years ago and thought it might be wise to brush up on the basic concepts before I made any other blunders.  During this process I discovered my saving grace was right under my nose: the compound yard ladder!  It's a bit difficult to explain, but for the uninitiated it's a yard ladder in which extra turnouts are placed below the tracks that make up the basic ladder allowing for more tracks in a given length of yard ladder.  This design gives you more space to place usable yard track and takes up less space with turnouts for a given number of yard tracks.

The image at left was taken at approximately the same location as the picture above from 6 months ago.  The increased yard capacity is amazing.  In my old yard using a straight ladder I had about 135" of track in the yard.  With the new design (including that track not yet installed on the 3rd and 4th track) I will have approximately 250" of yard track; that's an 85% increase in capacity just by changing the lard ladder.




The moral of the story, if you're tight on space it's worth considering a compound ladder for your yard design.  While you may not see the same increase in capacity I did (I shifted around the turnouts a bit along the top of the image to allow for a pinwheel entrance to the yard which helped me add capacity) it will definitely help with space constraints.

Finally, I wanted to ask for some honest feedback from the rest of you.  The question is simple:  does this look "too gimmicky" to you?  My railroad is a proto-freelanced New York carfloat operation so tight spaces and creative trackwork would have been a must but has my creativity gone too far and left me with a spaghetti bowl that looks contrived?  I appreciate any and all honest feedback, no feelings will be hurt.

Thanks for reading this far and I hope others can learn from a fellow modeler's elementary blunder!  I look forward to any and all comments.



What a great post!

I really enjoyed reading this.  Very well written.  I'm far from an expert but what you have done seems like a great solution.


Artarms's picture

barging in

I don't understand your problem but probably it's because all I know about railroad barges is that you don't want to capsize them by getting the load too far off-center.

Is it necessary to off-load all the cars before you on-load the out-going cars?  If not, why can't you just off-load the left barge track (should I say port track) and then load the same track with outbound cars.  Then unload the middle track and fill it up with out-bound - then the right track.

If you can do this your yard in photo 1 is big enough?


rfbranch's picture


Hi Art-

Barging in?  Really Art?  You should be ashamed In short I could operate the carfloat in the manner you describe and it had crossed my mind but there are two reasons I didn't do it:

I'm not aware of a float operation in the NYC area that did this on a regular basis.  They were all off/all on operations based on what I know.  I'm sure there may be a one off exception to this somewhere that someone can dig up but in my quest to stick relatively close to proto-plausibility this wouldn't be something I would want to do on a regular basis.

Secondly, and this is more personal preference than anything, that type of operation is VERY boring to me.  To load/unload the carfloat would take a TON of moves by my count just to swap out the cars on the float...that is a bit too Timesaver-ish for me!  Using the traditional method moves are closer to what a prototype would do and give me more of a "real" feel to my operations.

Thanks to you both for reading (I appreciate the positive comments Blue) and I appreciate the feedback!




Proto-Freelanced Carfloat Operation, Brooklyn, NY c.1974

For those interested come check out my Wisconsin Badger Football podcast: BuckAround

Scarpia's picture

With what little I know

With what little I know based on watching Tim's Videos, and hium running the layout at shows, I'm kinda thinking along the lines of what Art said.

Are you considering holding any cars when you switch the floats? 

And if so, you could reduce the yard by one track, and give yourself a little bit of elbow room for more scenery.

Can you also show again the yard lead  in a different picture? Is there room for another turnout up there (curved, maybe?)

I know, questions, questions! 


HO, early transition era local time GMT +4
On30, circa 1900    


Scarpia's picture

Nope, that works

Nope, that picture works fine.

I'm sorry I didn't make myself clear. Watching Tim, I was struck at how he holds cars on his layout for switching (it's a skill that I'm gradually becoming less and less nervous about). It's this observation, not his physical layout, that was my point.

Along the lines as Art mentioned, you could easily switch the float with your original yard by pulling an outbound string, holding that, than pull an inbound string. Put the inbound away, than put the outbound on the float.

I have no idea of that's how they did it, or did they empty the entire float before refilling? And if it's the latter, than just one more AD/track than your original yard would allow you to pull one float track, hold it, pull another, hold it, and than the last before parking it all on the AD/sorting track.

To that effect, I could easily see expanding your yard a track (or maybe even two) to suficent size to hold the outgoing in two or three tracks, and the inbound in one or two. A curved turnout, to the extreme left (leading to the yard)  in your above picture would make the flow smoother, gain you some space, and align the increased yard to a more visually appealing layout. And, would allow you a bit more room for scenery than the full compound you have now.

I hope that makes sense, and be sure to rely on your own judgement here! 

it's the open space here between the yard and the float tracks

that bugs me from a scanic standpoint, but than again it would be a perfect spot for yard office/harbor master office like the B&O one in last months' RMC.

HO, early transition era local time GMT +4
On30, circa 1900    


I'm surprised that they did completely unload the barge

Before reloading.  When I worked in the harbor, the usual method for crane operators on the container ships was to unload the deck, then a hatch would be removed and they would start unloading below deck.  As soon as theyhad unloaded one stack to the bottom, the operator would begin to "double up," that is put an outgoing load in the empty hold, then grab a loaded inbound can to put on the truck for the container stack in the yard.  The trucks would bring up an outgoing load and bring back an inbound until the hold was unloaded. 

Car Float loading and unloading

One had to be extremely careful on how carfloats were loaded and unloaded because of the dynamics of maintaining balance on the carfloat. One of those considerations is that unloading a complete track without some compensating unloading on the other side of the car float would create a serious list on one side which could lead to serious consquences for the carfloat and it's remaining freight cars. And if you don't do this carefully you could easily have individual cars topple off the carfloat and ruin not only your entire day but also upset the schedules for the delivery of the cargos on other carfloats as well.

Let us assume the car float is loaded with 17 cars on its three tracks. This would mean you have 6 cars on each of the outer tracks and 5 on the center track. That would mean that 5/17 of the total weight would be on the center track whch would also mean that we can disregard this weight snce its removal will not create an imbalance. In effect anything on the center of the car flaot will not affect its list. But removal of 6 cars from either side while leaving the 6 cars on the other side of the car foat will create a serious list. Also consider the fact that center track is the last one to be emptied and the first to be loaded because of the configuration of the track (i.e you can't access the center track until one of the side tracks is emptied).

I am pretty sure the solution was found by trial and error at some point in the distant past since car float service already existed in the late 19th Century. The solution to this problem is quite simple. Pick a side track and pull 3 cars of the 6 off the carfloat and leave the other 3 on the float itself. Then pull the 6 cars in the other side completely off the carfloat. Then remove the remaining 3 cars on the first side track off the float. After the side tracks are emptied, pull the 5 cars off the center track. To load the car float you reverse the process.

It is pretty easy for model railroaders to forget this as we don't have carfloats that have realistic operating characteristics to deal with. However if you ever get a chance to watch carfloats in action you'll note that loading and unloading really affect the way the carfloat supported on water lists. That is also why locomotives rarely ran onto the carfloats unless they were compartively light and that really wasn't possible until diesels came along. Locomotives usually used idler cars to load and unload car floats for that reason.

Container ships can unload their cargos differently because you can pretty much access any stack you want without seriously affecting the balance of the ship. Car floats can't be accessed the same way.


CAR_FLOATER's picture

Russ, Scarpia, Art - Rich is

Russ, Scarpia, Art -

Rich is right, in NY harbor the "modus operandi" was empty the float first, load it second. Of course, in the world of rail-marine, nothing is ever an absolute, so say for instance in the wilds of Saskatchewan, they did it differently. Also, float bridges were built (overbuilt, some might say) to handle the extreme loads (mostly roll and pitch) placed upon them, and thus simple wooden pontoon float bridges have advantages over electrically operated steel ones, but I digress.....This thread isn't about loading/unloading a carfloat.

Rich, your new yard and it's lead lead looks good, and you were right to make the change (regardless of weather it was precipitated by the "10 Comandments"!) - As a general rule in float yard design, your longest unobstructed track should hold one track's worth of cars. In the real world, it was actually one track per entire carfloat, but none of us, unless it's a club or you're a millionaire, has that kind of room. My yard, which is about 10 feet long, just about has enough room to do the job correctly (I'll find out in about a week when we run the first shakedown). I can hold 15 cars per track, but only 10 cars will fit without fouling each end. If I had built my yard with that in "design tennant" in mind, MAYBE I could have done it "right", but I built my yard based off of a Val map for the yard, and all the turnouts I ended up installing (about 45 just in a 12 foot long/2 foot wide yard area) eat up a lot of room! Oh, did I mention that most (notice I did not say all) railroads in the Harbor used idler cars ahead of the engine as a reacher? (and not because the engine was so heavy that it couldn't operate over the float bridge, that is a myth).

Good job, keep up the progress,


kcsphil1's picture

Good design in . . . .

Design that is functional in YOUR situation.  By going with the compound yard ladder you gave yourself more track, more switching possibilities, and the ability to divid your yard easily into incoming and outgoing sections.  I'd say that it worked, and worked well, so sit back, relax, and enjoy.  Of course, those staggered track ends might give you some trouble, but i expect they are going to be corrected at some point. 

Philip H. Chief Everything Officer Baton Rouge Southern Railroad, Mount Rainier Div.

rfbranch's picture

As Irv has outlined above

As Irv has outlined above there is a prototypical basis for the all on/all off method of loading and unloading carfloats so I do need to work around that limitation. 

Scarpia, some responses to your points:

Working off the all on/all off principle I could have a single, long unloading spur to clear the carfloat as suggested but my thinking was the additional capacity will give me the flexibility to have a small section of the end of one spur as a team track.  The thinking behind that comes from this series of images on Philip Goldstein's excellent BEDT webpage. 

With a little realignment, I could create a space between the 3rd and 4th yard track by aligning the 3 leftmost yard tracks closely to the water's edge and the other 3 running parallel to the stone retaining wall along the backdrop.  This should allow the tracks to diverge enough to put in a dirt or cobblestone driveway allowing truck access to the end of the spur.  So not only would I my yard capacity increase, I would be able to get an additional industry to serve.  I thought it was a pretty good bonus!

On scenery, it's funny you mention the RMC cover; I was thinking that had a neat look for my layout as well, but I already have a structure in mind as a yard office.  In Hartford last July I purchased the Martins Creek Station structure from Stella Scale Models that is going to be my yard/marine office.  I was planning on putting it between the layout edge and the carfloat lead as the two yard tracks in my 2nd picture will probably be in asphalt as the foundation directly to the left of it will be for a freight house with truck access on the near side of the building. 

Vehicles will need to use that area to back up to the freight house, turn their trucks around etc so I thought company offices would be best served closer to the carfloat itself.  But that could all change, I'm looking to nail down the last of the track plan and bulletproof the wiring.  None of the scenic elements are firm in my mind at this point.

Lastly, the yard will use a lot of the same scenic elements that your CV yard on Chainsaw II employs.  While we are modeling completely different locales, I will be stealing a lot of  the elements of how you broke up your scene.  Where your yard has a road running along the edge of the backdrop, I will be installing a retaining wall (you can see it in one of my original images) and building a 3-4" deep back alley scene along it to give the scene some depth and the viewer something else to look at besides yard cinders. 

In the foreground where you have your pond/freight house vignette my scene will be of a sludgy industrial canal complete with a small yard office and tool shed.  Again, the scene will provide for a break from the monotony that the scenic elements of the yard might create.

Well, somehow this post got VERY long but thanks for bringing up some good points!




Proto-Freelanced Carfloat Operation, Brooklyn, NY c.1974

For those interested come check out my Wisconsin Badger Football podcast: BuckAround

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