Slowing Trains On Part Of Layout

1. Are you running command or conventional ?

2. How are you powering the layout ?

3. Are all three loops electrically connected ?

4. Have you checked power to the area with a meter to make sure enough voltage is being supplied to the affected area ?

5. Is the layout divided into blocks or districts ?

6. Are you sure there isn't a crossed wire somewhere ?

More info would help.

Thanks for the quick reply.  It is conventionally powered by a vintage ZW-275 recently serviced.  An eight conductor cable runs from the ZW to terminal blocks under the center of the benchwork which the power drops are connected to.  The loops are suppossed to be isolated and powered by three different controls on the ZW (if we fouled that up maybe that is the problem).  Voltage is consistent everywhere on a meter but, of course, the meter does not put a load on it.  There are no block or districts within the loops.  We have checked for crossed wires multiple times but I suppose could have accidently missed one. 

Problems can be had with ac currents being run on wires in a cable with multiple wires.  Example, I separate the common and feed wires that feed the solenoids of a switch.

Charlie

What gauge wires are in the 8-conductor cable?

Is the slowing area one that has a significant curve or curves, or elevation changes?  In other words, consider whether the slowing is caused by mechanical restriction or challenge, rather than electrical. If the area *does* have a significant curve or curves or elevation, you might try manually drawing your typical consist through the area. If you feel more rolling resistance in the area, that may be the source of the problem, and you may need to revisit your track plan, or learn to live with the slowing. OTOH, you might build in a bit of old-school electrical slowing (via low-value, high wattage resistors in series) to the rest of the layout, and limit full voltage to the problem area.

Thanks.  Two of the conductors are 14 gauge and the other 6 are 18 gauge.  I thought about some interaction in that cable but thought that would affect an entire loop.  Also, the track plan we got from Cargraves does not appear to call for insulating pins between the loops and now I am skeptical about that.  When manual pushed through the area in questi\on there is no noticable impediment and the track is level.

Your skepticism is justified. Did you indeed omit the insulating center rail pins, thereby paralleling three of the ZW throttles? That might raise interesting concerns inside the ZW. When the ZW came out in the forties, I actually thought (aided by Lionel catalog hyperbole) it was four transformers in a single case. It is, rather, a single primary/secondary set of windings on a single laminated frame with four roller tipped arms sliding along the winding faces struggling for their fair share of the current. The eight conductor cable is yet another matter.

The short answer is "yes<" and I am wondering whether that isn't the next thing to tackle before removing the cable.  The latter being less likely the problem although still possible.  I suppose we should put plastic pins between the switches that join the loops?  My son got the diagram from GarGraves and I was a little skeptical from the start about not isolating those loops.  I am still, though, not sure why it would only manifest itself on part of the loops.  AC can be nerve racking as most of my experience is in rectified DC with radios.

A picture of the Gargraves track plan might help.

@Edward Titterton posted:

Thanks.  Two of the conductors are 14 gauge and the other 6 are 18 gauge.  I thought about some interaction in that cable but thought that would affect an entire loop.  Also, the track plan we got from Cargraves does not appear to call for insulating pins between the loops and now I am skeptical about that.  When manual pushed through the area in questi\on there is no noticable impediment and the track is level.

I will try to get that diagram from my son in the near future.  The layout in question is at his house.

Think of your track loops like people. They may be perfectly sane when alone, but can you ever predict the nature of conflict they may generate when they get together and discuss  .   .   .   ?