Re: Offset Rail Gapping



The only place a short should occur is at a reverse loop or at a "Y. It doesn't matter if the polarities are reversed or not because your reverser, your PM42, or separate booster will make them the same almost instantly when they sense a short. It doesn't matter if the gaps are directly across from each other because when the wheels touch either rail with the reverse polarity, you reversers will correct both rails.

I have noticed that when engines cross a gap between power blocks, especially reverse loops there is sometimes and miniscule spark. No, I am not crazy but it has to be Black Out Dark to see it. 

I have see a decrease in jerks and starts over gaps when I fill in the gap with plastic. It also allows the gaps to be much smaller and keeps the rails from creeping and shorting together. Our layout is in a basement but rails still expand and contract down there. 

Keep you wires in a twist and your fun in a bunch.

On Thursday, March 26, 2020, 10:48:34 AM EDT, Tim <tarumph@...> wrote:

I wonder about this fascination with gap locations. If you're using an autoreverser it will detect the short when when a wheel hits the first gap, flip the polarity, and everything will be fine. As far as wheels connecting power districts (or track circuit blocks) that will happen as long as the wheelbase of the loco straddles the gap (assuming all wheel pick-up). The gap locations don't make any difference (within reason). Steam locos with pick-up on one side of the loco and the opposite side of the tender will pick up from both sides of the gaps. This is why boosters are bonded. Trying to space the gap so that the lead wheel on the loco hits one gap at the same time as the lead wheel on the tender hits the opposite gap can only work for one type of loco moving in one direction.

Having the gap distance longer than the locomotive should probably be avoided, but shouldn't really cause any problem. See steam loco example above. :)

Tim Rumph
Lancaster, SC

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