Re: Reversing Section Wiring question



In my original email, I described traffic as follows:

"A train from the junction will visit the sinter mill once daily, arriving by the lower track at right... Generally, all or a portion of the arriving train proceeds straight to the harbour scene, via the track at upper right... The train then returns to the sinter mill, where things get interesting."

So what isn't clear?  trains arrive lower right, exit to harbour,  and return, via upper right.  I didn't say it, but scale is HO, the grid is 12"; trains are expected to consist of 4 SD40-2 units plus 25 +/-  Ortner ore cars (6" ea), for a typical length around 15 feet.  Surely the visual ratio of switch lengths to track lengths gives you some idea of the constraints?  If a track is 4x the length of a switch, in HO or N, or likely G,  the track probably holds 6-8 cars, depending on car length and switch size obviously. 

The issue is, depending upon how one switches that center diagonal track pair, one can easily end up bridging from normal-power main to the reversing section at both ends of the train, even with the augmented large reversing section as depicted.  
But maybe I've found it.  See my new posting to files.  I think this works, satisfying the longest possible trains.  I added clarification info where necessary.

Blair Smith

On 2017-12-06 13:37, 'Vollrath, Don' don.vollrath@... [WiringForDCC] wrote:
Your operating description is a little hard to follow as there are no location names shown on the track sketch.
Also not sure if it is drawn to any scale or if there are other track extensions off to the right of either the upper or lower black stub tracks. Your saving grace is that the plan is to move only one train at a time. The only possible hooker is if you leave a steel wheeled car stuck in a gap at one end while you move the loco out the other end. The fix for that is to make track gaps large enough and fill them with plastic shaped to the railhead so that a steel wheel can never touch both sides of the gap at the same time. A loco is then free to traverse the gaps at the other end and let the A-R unit to do its thing. 

On my home layout I got tired of playing with relay or track switched reversing controllers and put in an OGAR. It auto-polarity trips at ~4 amps and acts as a circuit breaker in the case of derailment. Works like a charm from my 5 amp booster. No headlight blinks or sound disturbances at either end.


-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] 
Sent: Wednesday, December 06, 2017 11:19 AM
To: WiringForDCC@...
Subject: Re: [WiringForDCC] Reversing Section Wiring question

Thanks, Don.  That was my thinking; since the A/D train will often be longer than the green, it makes sense to make the green plus red all one large autoreversing section.  Consists will often be 4 SD40-2 units, lead and trailing units sound equipped, so a relay reverser doesn't really cut it, unless one puts up with the sound resets, or outfits all applicable locos with keep-alive addons to avoid the resets, or artificially restricts the use of the switch at the lower right so that it never needs changing with sound units in the reversing section.  Not prototypical, as they arrived by running LH through that switch, but departed through the RH position after switching the harbour, then the sinter plant.

It does remain a little hairy, however, when I think about all the possible switching patterns, and whether they're adequately covered off by the large reverser.  I'll have to think it through a bit more, and if I see an exposed reversing scenario, I'll be back.

Thanks, both of you


Posted by: Blair & Rasa 

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Posted by: "Vollrath, Don" 

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