Randy,
The question of how far should the shutdown track extend has changed with the advent of "keep alives". For small layouts, I think snjroy has the right idea, shut the whole layout off. However, for large layouts great care needs to be taken, as with the keep alive a loco can cover a lot of distance before it comes to a hault. Since I frequently see 100 car trains running on modular club layouts with multiple tracks, at train shows. I would think the wiring would be a nightmare to do. Not sure just how one would do it, but I think some sort of block to come up and block the track, firm enough to hold the approaching train.
Sounds like a new project for some of our mechanical engineers.
Anybody got any ideas?
Goos luck,
Richard
As for the electrical interlocking of the lift out, for me it is simple. As a DC operator, the entire block on either side is dead if the section is out. Those blocks are longer than any normally operated train. So it would be hard to even back a train off the edge......
Sheldon
A fold-up will automatically block one side of the gap, and I suppose it wouldn't be too hard to have some sort of block, perhaps not automatic, for the other side as well.
How many of your engines have keep-alive circuits? And are these big engines that handle large trains? Personally, I wouldn't bother with a keep-alive on anything bigger than a tank engine or a trolley.
But you're right. Keep-alives add another complication to a dead track to protect a sometimes-gap.
It takes an iron man to play with a toy iron horse.
I have a simple rule with keep alives - I don't use them. No need to. I've never had any issues with locos stalling , even at speed step 1 over turnouts or anywhere else.
Since I use Loksound for all my sound decoders, if I DO need a keep alive, it will be the 3 wire type. Why? Because the 3 wire type can be programmed to provide keep alive for a set amount of time instead of "as long as the capacitor has charge in it"/ I have one loco with a keep alive, it came that way from the factory. I can pick it up and it runs across my desk and almost goes off the edge - I pick it up and place it back on the desk and it will run off the edge a second time if I don;t catch it. That's ridiculous. You would NEVER EVER need keep alive for that much time. The idea is to get across a short dead section, or an unpowered frog - a second or two is MORE than enough time.
The only other option is, instead of having the bridge being up cutting power, instead it cuts in a circuit that generates a DCC broadcast stop command - that way even a loco with a keep alive will get a stop signal, not loss of power, so it will stop. Momentum might still defeat you, if turned up. Plus this needs to be truly isolated - double gaps are not enough, as metal wheels or an all wheel pickup loco would bridge the gaps and link the main DCC system to the stop generator - perhaps frying something.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
The more I have thought about it I'm going to make some adjustments to build a lift-out so I can run continuous as I'd originally planned with a duck under. I'm going to narrow the benchwork to accomodate a lift out section. I can see hating a duck under in short order, and with a layout height of barely 40" I would have to slide under with a car mechanic or furniture dolly. No fun.
Andy
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Milwaukee native modeling the Milwaukee Road in 1950's Milwaukee.
https://www.flickr.com/photos/196857529@N03/
ATLANTIC CENTRAL As for the electrical interlocking of the lift out, for me it is simple. As a DC operator, the entire block on either side is dead if the section is out. Those blocks are longer than any normally operated train. So it would be hard to even back a train off the edge...... Sheldon
On my layout, also DC, it's equally simple to add a safety zone when the liftout is not in place.I first gap one rail of the approach tracks on either side of the liftout, then run wire from the still-live rails beyond the gaps to a four-pronged female receptacle on the layout's fascia, near the liftout. When the male plug is inserted, it not only activates the rails on the liftout, but also feeds power from those now-live liftout rails to the other two prongs, which in-turn, power the approach rails on either side of the lift-out.
When the liftout is unplugged and removed, the approach tracks revert to non-powered ones.
I'd guess that something similar could be done in DCC, too.
Wayne
On the layout I'm presently building, I have a swing gate, that swings in towards the center of the layout. It has a 24" "door" opening. I haven't figured out quite how to rig it electrically yet (I'm DC). That project is a ways down the road, as I have just gotten the plywood sub roadbed and the backdrop installed. After touching up the backdrop and painting clouds and a horizon, I will be ready to lay track. I chose to use a swing gate, rather than a liftout because I have limited space and where to put the section when not installed is a problem. And, I don't particularly like duckunders, no matter how high the benchwork is.
The Milwaukee Road Warriorwith a layout height of barely 40"
That's the key point. On a former layout I had a duckunder, but the layout height was 58 inches and the height underneath the duckunder was 56.5 inches. It was really easy to duck under even while carrying things.
I've tried lower heights but find them unsatisfactory, my current layout is 50" and fortunately I have the space to avoid duckunders (or liftouts).
Paul
IRONROOSTER The Milwaukee Road Warrior with a layout height of barely 40" That's the key point. On a former layout I had a duckunder, but the layout height was 58 inches and the height underneath the duckunder was 56.5 inches. It was really easy to duck under even while carrying things. I've tried lower heights but find them unsatisfactory, my current layout is 50" and fortunately I have the space to avoid duckunders (or liftouts). Paul
The Milwaukee Road Warrior with a layout height of barely 40"
Having built a double deck layout with upper deck benchwork in that 58" range, I agree that makes for an easy duck under.
I also learned that I would never want benchwork that high again, so a good lift out is necessary.