How to build a safe rail crossing

[SwaN_Tai-Lung]

Does anyone know how to build a safe rail crossing that was shown in the factorio facts friday number 140. i am trying to build one but i can figure out how. any help?

[goufalite]

I started myself I found some things to look out for.

First of all (pun intended) : train ;) Do not do it on an existing and working track

Take the picture found in the friday fact and look closely :
- place rails and concrete exactly where there are in the picture
- place the "human" gates one block from the rails
- place walls near the gates, you will see a sort of yellow thing on top of the wall like in the photo (lets call it a pole)
- the trick is DO NOT CLICK on the pole, click ON THE WALL
- if you hover that wall you will see indication on which gate is controlled
- PLACE RAIL SIGNALS as shown on the picture or else your train will be damaged when hitting a closed wall !

Now for the circuit part :
- create a decider module and plug it to the gates (with a red wire) to "debug" and see which signal comes out when you approach the gate : when you approach a gate, the signal sent is G=1 (if you want to get back the wire, rebuild it)
- now that you get it, wire the two poles together and set the "rail" gate to "open gate" and set G=0 => you have just set a NOT boolean gate
- connect the trail signal to the pole and set it "close signal" with G=1

Cannot add pictures, maybe I or somebody will do a guide...

Good luck !

[SwaN_Tai-Lung]

Thanks gonna try this now. ill let you know if it works. Thanks

[不思議種]

I haven't figured out how to make it work like in the FFF without an arithemtic combinator.

With one I've done it this way:
Player gates with open condition H > 0, output G.
Rail gates with H < 1, no output.
Signals with G > 0, yellow and red outputs RED.
Decider combinator with G > 0, output H = 1.
Everything so far connected to one network.
Then finally a decider with input from the network RED > H, output H = 1 to aritmetic combinator that multiplies with -1 and outputs H again to the network.

Edit: Ok, I realized that rail signals output based on the rail block and not their state. Also I was trying to protect against a situation that can never happen (train enters the block when player is inside the crossing). I think goufalite has the correct solution then.

[SwaN_Tai-Lung]

I think i have done it. but i find that if i approach while the train is crossing the rail gate closes and gets damaged by the train

[goufalite]

Did you do the last step ?

- connect the trail signal to the pole and set it "close signal" with G=1

EDIT : I put a locomotive on the opened rail wall and leaved : nothing happened...

[zingo2]

Maybe just put a picture with simple explanations? What does ABC plain text gives you? A picture however is better than 1000 words.

[不思議種]

How to picture: http://imgur.com/b4tXpnL
Don't forget a signal after the crossing :p

[zingo2]

Thank you very much- thats what Im talking about! Easy- plain and doable

[goufalite]

(link to the friday fact : https://www.factorio.com/blog/post/fff-140)

Okay there is a major flaw : if you stand in the middle of the rails, the two player gates will close and the rail gate will automatically open, giving you the "watch your step" achievement.
The solution should be to put one player gate closer to the rails (http://imgur.com/fznWdYT) but apparently there is still a little position which untriggers the gates... Maybe later a RS latch to memorize the fact that the player is entering the area...
BTW there is no need for train gates except when they are at the border of the base, since there are train signals before...

Oh and I'm impressed : it's the gate who takes all the damage, not the train !

[不思議種]

That's interesting because I can't reproduce that behavior. If I stand in the middle of the rails both player gates sense me.

The only limitation I can see is that the train gates will open if a train enters the crossing block when you're there but that should only be possible in a multiplayer scenario. The first solution I posted actually prevents that too which is why it became a bit more complicated.