Take the 2-minute tour ×
Arqade is a question and answer site for passionate videogamers on all platforms. It's 100% free, no registration required.

I have placed a powered rail on a slope with a redstone torch underneath it as shown in the following two pictures.

Redstone torch under rail

Powered rail unpowered

Now as you can see, the powered rail is in fact unpowered, despite the redstone torch underneath it.

However, if I place a redstone torch next to the powered rail it is powered, but when I remove it, it continues to remain powered, as it should have done in the first place.

Redstone torch next to powered rail

Powered rail powered without redstone torch

Is this a glitch? Or some behaviour of redstone/minecart tracks that I am unaware of?

share|improve this question
    
Try removing two blocks from the left side of the powered track so that the original torch can "breathe". See if it exhibits the same behavior. I know redstone torches have behaved strangely for me when I completely surround them. –  user9983 Jul 17 '11 at 5:56
    
Hmm I tried that but it doesn't appear to work. It doesn't appear to be a "breathing" problem here. –  DanielGibbs Jul 17 '11 at 7:38
add comment

2 Answers 2

up vote 10 down vote accepted

This is a glitch relating to the updating of blocks.

In short, the issue is that when the powered rail is placed, it does not check to see if the block it is on is already powered, but keeps its state until a nearby block updates, such as might happen when you place a redstone torch that would power it.

When that redstone torch is removed again, the track checks to see if it still powered, and, realizing that it is, stays on. (c.f. the glitch that would give free power to tracks placed on a slope when one was removed from a chain of powered rails).

Anything that causes the track to be updated should make the track powered; such as placing the tracks sequentially from bottom to top, meaning that the initial state of the powered rail will be flat: When the next rail is then placed, pulling the end of the powered track up, it updates and gets power.

Another alternative, as Dan F mentioned, is to simply place the torch after the rail.

share|improve this answer
    
Ok, but this only appears to occur on slopes. Doing the same thing on flat ground (a redstone torch under the block the powered rail is on) powers the rail straight away. –  DanielGibbs Jul 17 '11 at 11:52
    
Ah, that makes sense. Ta! –  Dan F Jul 17 '11 at 13:55
add comment

I don't know if this counts as an answer per se, but I've had this happen to. Not all the time, just occasionally. I'm pretty sure I fixed it by digging down from the side and placing the torch under the block + rail, rather than placing the torch then placing the block + rail.

share|improve this answer
    
Yeah that works for me also. Any idea why it is necessary though? –  DanielGibbs Jul 17 '11 at 7:37
    
@DanielL Nope, no idea. Completely threw me the first time it happened. Hopefully someone who knows what they're talking about will answer :-) –  Dan F Jul 17 '11 at 8:05
    
@DanF: Happy to help. ;) –  Williham Totland Jul 17 '11 at 10:22
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.