Factorio Forums

OS: Linux

Version: 2.1.14

When a signal is being held, two spots on this track appear to be valid placements.

When placed, the signals are invalid.

Example rail blueprint with an invalid signal:
To reproduce, paste my blueprint, break the signal and select a signal to replace it. You will see 2 green boxes denoting valid spots where the old signal was. The game says you can place them here.

Upon doing so, the signal immediately does not work.

116405

It is a perfectly valid location for the Rail signal entity; hence it is allowed in the Blueprint and can be placed in-world. It just happens to not be a valid location to split the Rail block.

One would argue that if the game says you can place it there, it would split the block. I was making a blueprint and I had pasted this a good 20-30 times before I noticed I was getting gridlocks because the signals were invalid. If a signal cannot split a block, it should not be placeable there.

There is no (sane) way to prevent Entity placement according to the presence of conflicting Rails. A Signal placed in the middle of a curved segment is totally valid to Split the block, until the Straight Rail is added with an overlapping piece of rail collision - should the Rail Signal be instantly destroyed now that it is Invalid? Should it be marked for deconstruction? Neither of those makes sense - but switching it into “blinking” state is easy and works fine.

In this case, the rail was down first. If a signal is placed in a location the game says is valid but does not work, if it cannot be fixed, it would be nice to get a warning. Rather than having to debug why my new rail block is not working, despite me assuming I had signalled it all up.

If a rail is removed, that is fine, the player is deconstructing the signals.

But placing a signal down, especially VIA bots - like in my situation- you will not know it doesn't work until you find the trains piling up/colliding/gridlocking.