At 12V (full voltage), I’ve seen tortoises switch in 1 to 1.5 seconds.
Even if you are traveling 30 mph in your yard, (43 feet per second), that would mean 1/2 foot a second in HO scale So you would have to put the detecting block about 6" ahead of the switch at least.
Nice. Monks do not take vows of poverty either. Nor Celibacy!. [For monks those went without saying.]
Our vows are Obedience, Stability, and Conversion to a Christian way of life. Our order is almost 1000 years older than the church’s classic vows of obedience, poverty, and celibacy.
Bottom Line… It works out all the same.
ROAR
For yards you are on your own. You have to look at your iron.
On the main line, the ENTIRE BLOCK ahead of the switch would be RED, and the block ahead of that would be at YELLOW. Out here in BNSF land that means a train would be stopped a MILE from a switch thrown against it. On NYCT that would be about 300 feet.
On the LION’S railroad the main line all the way back to the previous station would be at RED if the switch is thrown against it. (Same on NYCT–they do not want trains stuck in a tunnel when they can be held in a station.
From terminals the signals and railroad must be GREEN before the conductor can close up the train. He must ASK the T/O if this is so before he closes up.
ROAR
Hot frogs with power routing so that a train running into the frog will short and stop, or get two rails of the same polarity and stop.
Loose or spring loaded point railts that will just move over and let the train pass through in the “wrong” direcction. The BNSF yard here in Denver is equiped with those that automatically flip when the train comes through in the “wrong” direction.
Don
Thanks for that information about how long it takes for a tortoise to throw at full power. I may be able to make tortoises work after all. I can’t see me doing 30 scale mph in the yard, and the yard layout will require stationary cars to be more than 6 inches from the turnouts.
Very interesting!
Dave
There is no such thing as “fool proof”. “Fool resistant” is the best you can hope for.
Just keep in mind, no matter how well you design it, someone will find a way to circumvent what you did.
Reminds me of another phrase:
“You just can’t fix stupid”
Chris
Just be aware two things:
Each route, straight and diverging, will need a 6" detecting block past the frog
You can only have one engine at a time working the main yard, or this won’t work. For example: You have a switcher sitting on track 8, and another switcher on the yard ladder. The device would see electrical current usage on each, and it wouldn’t know which way to throw the switch (So it would switch to default…which might not what you have intended.)
If you are pushing the train into the switch (engine at rear), then you will need to make the gap as long as the train yard track length. A potential solution to use would be to use Infrared sensors instead. (break the beam, throw the switch) But I never seen anyone do this.
Best consult with Tony @ Tony’s trains, or www.dccspecialties.com. They would be able to direct you to the proper diagrams.
Hi Don
Actually I am planning on using infrared sensors. They seem to solve most of the problems associated with current sensing such as detecting trains that are running backwards, or having more than one loco running in the yard at the same time. I have found a schematic for making them myself for a reasonable price. I actually built several detectors and they work! I will post the source of the detector plans for those who are interested (when I find the site where the plans are located!).
Dave