using reverse loop units on a double loop line in DC and DCC with shuttle option

[beavercreek]

[font="verdana,geneva"] At the moment the line is a DC point to point autoreverse shuttle using an 8 amp autoreverse unit. [/font]
[font="verdana,geneva"] I will be making it into a twin reverse-loop line that will work with either DC or DCC. [/font]
[font="verdana,geneva"] I am wondering when using DC mode, that if I placed spurs inside the loops but BEFORE the sensors of the 8157001 units would I be able to use the spurs as a point to point auto-reverse shuttle as I do at present? This is only for DC mode. The spurs would not be used (or they would be isolated) when in DCC mode. [/font]
[font="verdana,geneva"]This means that I have the option of DC or DCC reverse-loop or DC autoreverse shuttle on the line (but not at the same time [/font]


When using the loops for DC or DCC
As the distance between the two loops is quite large will the use of two 8157001 modules he okay for both DC and DCC?
The power supplies for the 8157001 units would be switched out if in DCC mode
Here is the diagram, not to scale of what I am after

 

[Cliff George]

Well I think that trying to use reverse loop units to be switchable between DC and DCC is more complicated that you might think.

The reason is that in DCC it is the loop that is reversed, in analogue it is the main track that is reversed (DC locos would not take kindly to the polarity of the track they are running on being instantly reversed, while with DCC that take this in their stride).

What I am tring to say is that you have to wire up the reverse units differently depending if they are working on DC or DCC. It would be possible to use a multipoll switch to instantly change from one configuration to the other.

I don't see any issues with your proposal to still maintain your DC auto reverse shuttle line.

I don't see that distance from one loop to the other has any bearing on what you want to do.

 

[Cliff George]

See this thread:

http://www.gscalecentral.net/tm?m=163190&high=Tim+Brien

 

[beavercreek]

Thanks for the link Cliff it gives a good deal of info on a situation not too dissimilar to my own.

I was pretty sure of the fact that the present DC autoreverse shuttle spurs were okay due to the fact that they 'spur' off before any of the reverse-loop unit sensors etc.

With the use of the 8057001 units with both DC and DCC:
The use of a multi-pole switch by the 8057001 unit for the change over from DC to DCC running is one that I had already taken into the equation due to fact where the 8057001 unit receives its track info from differently and sends polarity differently to the inside of the loop (DCC) or the rest of the line (DC) in both types of scenario. So that will probably be the solution to that conundrum . Also the 8057001 unit's power supply (only when used in DC mode) will also be switched out (or off) when in DCC mode, again by the multi switch if I can find one with enough poles!.

But what I am not sure about is:
With having two reverse-loops, one at either end of my 'local' line, and wanting to be able to run in DC or DCC, and not really wanting to run another long multicore cable around the garden.....will one 8057001 unit be able to control both loops in DC and DCC? or will I need two for either just DC just DCC operation or possibly in both DC and DCC?