Need help, identify the reversing loop for me

[railnerd]

You don't need the reversing bit to be as long as a whole train.

Lit passenger trains are really the exception here… at my HO club, we have a full consist of the California Zephyr with lighting that is just long enough to bridge both gaps at once.  The reverser goes absolutely nuts and you just get a blinking light show.  We never had a problem with freight (and we run 100% metal wheels).

-Dave

[peteski]

Lit passenger trains are really the exception here… at my HO club, we have a full consist of the California Zephyr with lighting that is just long enough to bridge both gaps at once.  The reverser goes absolutely nuts and you just get a blinking light show.  We never had a problem with freight (and we run 100% metal wheels).

-Dave

That's because each pass. car has both trucks electrically connected (assuming that both trucks pick up power from both rails).  The long wheelbase of those cars, as they travel across the gap, creates a long-duration short. If the reversing section is shorter than the train, then the odds are pretty good that the gap on both ends will be bridged by the passing cars, creating a dead short across the reverse polarity ends of the loop, bypassing the reversing section.

[railnerd]

That's because each pass. car has both trucks electrically connected (assuming that both trucks pick up power from both rails).  The long wheelbase of those cars, as they travel across the gap, creates a long-duration short. If the reversing section is shorter than the train, then the odds are pretty good that the gap on both ends will be bridged by the passing cars, creating a dead short across the reverse polarity ends of the loop, bypassing the reversing section.

Yup.  Just didn't want to go into the explanation, but thanks for doing so-- and more eloquently than I would have explained it.

[PAL_Houston]

The alternatives Pete provided will work, but here are some other options you could consider, with gaps shown by colored triangles. 

[wm3798]

I keep forgetting about you guys the still carry livestock on the hoof...  The Western Maryland was interested in MAKING money, not frittering it away on Porters and dining car staff...  So yes, take extreme measures for all those travelers.   

[Bangorboy]

In the image below, ignoring the small yard at the top, put a double gap between the two turnouts that face away from each other -- at the end of the double track running down the left wall and the crossover immediately to its right.  Following the double track down the left wall, double-gap each track just before the turnouts for the yard and the crossover immediately below it.

If the image is anywhere near scale and the mainline is 39 feet, this should give you a reversing section about 12-13 feet, more than adequate for 8-foot trains.  It also keeps the reversing section simple enough that you're not likely to have enough trains in the reversing section to overload the capacity of any reverser you select.

By the way, I'm sold on the PSX-AR sold by Tony's.  I use the PSX-ARFB, because the feedback output closes a switch, which can trigger an input to a DS64, which feeds JMRI via Loconet to show the block is occupied.  This eliminates need for a block detector.  But that is digressing.

Keep the reversing section simple!

Bill B
N Scaling in South Okaloosa

[rsn48]

Bill, I'm thinking the reversing loop would be lovely and long if I went from the turnout you indicated (by the way all my track and turn outs are double gapped and their own block electrically) and the turnout just below it.  This way I don't have to worry about train lengths and could have four trains in the reversing section if I wanted.  Those long three tracks at the bottom are actually longer than what I have indicated, originally slated for passenger trains, re-thinking that but still would use at least one track for passenger.

The inner loop is arrival/departure for the series of small yards.  While one train is continuous running from lower level to top level (another reversing loop) while I switched by myself.  So two turnouts in the deck you can see will be auto-throw, in the process of installing that.  Probably won't be done until after Xmas.

[Bangorboy]

The only caution I'd bring up with this plan is the number of trains in the reversing section could get quite demanding amperage wise, especially if there are a lot of passenger trains with lights.  Check the amperage limits on your chosen reversing device.  That's why I suggested the double track down the left side from turnout to the turnouts for the yard and the one directly below the yard, as there isn't likely to be more than one or two trains on each track, and then not for long.

If the reversing section includes both yards, you need to account for the current draw of all the trains in the yards as well as passing by on the double track.  Remember that locos with decoders still draw current, even if parked.  Ditto passenger cars with glowing lights, or with lights turned off by decoders.  If the cars have reed switches turned off by magnetic wand or switch, they don't count.

Otherwise, reversing the whole lower section from the upper turnout all the way to the one just below it would work fine.  Electrically there's no reason it wouldn't as long as you remain within load limits.

Bill B
N Scaling in South Okaloosa

[rsn48]

Hi Bill thanks for the advise.  When you look at the pic below, my room isn't that big, was once a study.  I think only two operators can work it as all the switching action will be on the lower deck, the electrical track plan you have seen.  The upper deck will be mostly a railfanning visual with a city, which will be primarily a staging area for the lower deck.

There are some modifications to the bench work plan you see below, the reversing loop area is longer and wider, and my nolix area (modified helix) isn't as curvy as illustrated [when I build the first table work for that area reflecting my plan, there wasn't enough room inside to move around and work on the nolix for maintenance purposes.  The long and the short of it is, almost all ops will be done in the "throat" of the bench plan.  So only two operators.  But I have assumed three and one train running continuously on its own for amperage planning purposes and the maximum number of engines running (N scale) will be 8 [4 trains double headed], I doubt it will even be that (no sound) so I'm thinking the most I can expect is a 4 amp draw. [5 amp Super Chief system]

[Bangorboy]

Sounds like you are satisfied with your research.  Forgive my repeated comments  -- I guess I should read all of your threads to see what you have posted before replying to what is on only one of the threads.  I answered one thread, found you already addressed my comment on a second thread, replied to that and found you had addressed my comments there on this thread.

Anyway, now that you have considered most of the issues other posters and I commented on, happy railroading and have fun!