[MC-3430] Detector rails do not power adjacent powered rails upward on slope Created: 18/Nov/12  Updated: 10/Nov/24

Status: Reopened
Project: Minecraft: Java Edition
Component/s: None
Affects Version/s: Minecraft 1.4.4, Minecraft 1.4.5, Minecraft 1.4.6, Minecraft 1.4.7, Snapshot 13w05b, Snapshot 13w10a, Snapshot 13w10b, Minecraft 1.5, Minecraft 1.5.1, Minecraft 1.5.2, Snapshot 13w24a, Snapshot 13w24b, Snapshot 13w25a, Snapshot 13w25b, Minecraft 1.6.2, Minecraft 1.6.4, Minecraft 13w38b, Minecraft 13w38c, Minecraft 13w39a, Minecraft 1.7.4, Minecraft 14w03b, Minecraft 1.7.9, Minecraft 14w20a, Minecraft 14w20b, Minecraft 14w21a, Minecraft 14w21b, Minecraft 1.7.10, Minecraft 14w27b, Minecraft 14w32a, Minecraft 14w32b, Minecraft 14w32c, Minecraft 14w32d, Minecraft 14w33a, Minecraft 1.8, Minecraft 1.8.1, Minecraft 1.8.3, Minecraft 1.8.8, Minecraft 15w39c, Minecraft 15w44b, Minecraft 15w45a, Minecraft 15w49a, Minecraft 1.10.2, Minecraft 16w32a, Minecraft 16w32b, Minecraft 16w33a, Minecraft 16w35a, Minecraft 17w06a, Minecraft 1.12.2, Minecraft 17w48a, Minecraft 18w05a, Minecraft 18w20c, Minecraft 18w22c, Minecraft 1.13-pre1, Minecraft 1.13-pre2, Minecraft 1.13-pre3, Minecraft 1.13-pre4, Minecraft 1.13-pre5, Minecraft 1.13-pre6, Minecraft 1.13-pre7, Minecraft 1.13-pre8, Minecraft 1.13, Minecraft 18w30b, Minecraft 18w31a, Minecraft 1.13.1-pre1, Minecraft 1.13.1-pre2, Minecraft 1.13.1, Minecraft 1.13.2, Minecraft 18w43b, Minecraft 18w43c, Minecraft 18w44a, Minecraft 18w45a, Minecraft 18w48a, Minecraft 18w48b, Minecraft 18w49a, Minecraft 18w50a, Minecraft 1.14 Pre-Release 2, Minecraft 1.14 Pre-Release 3, Minecraft 1.14.2 Pre-Release 3, 1.14.4, 19w41a, 1.15 Pre-release 5, 1.15 Pre-release 7, 1.15, 1.15.1, 1.15.1 Pre-release 1, 1.15.2 Pre-Release 1, 1.15.2 Pre-release 2, 1.15.2, 20w06a, 20w07a, 20w08a, 20w09a, 20w10a, 20w11a, 20w12a, 20w13a, 20w13b, 20w14a, 20w15a, 20w16a, 20w17a, 20w18a, 20w19a, 20w20b, 20w21a, 20w22a, 1.16 Pre-release 1, 1.16 Pre-release 2, 1.16 Pre-release 3, 1.16 Pre-release 4, 1.16 Pre-release 5, 1.16 Pre-release 7, 1.16 Pre-release 8, 1.16 Release Candidate 1, 1.16, 1.16.1, 20w27a, 20w28a, 20w29a, 20w30a, 1.16.2 Pre-release 1, 1.16.2 Pre-release 2, 1.16.2 Pre-release 3, 1.16.2 Release Candidate 1, 1.16.2 Release Candidate 2, 1.16.2, 1.16.3 Release Candidate 1, 1.16.3, 1.16.4 Pre-release 1, 1.16.4 Pre-release 2, 1.16.4 Release Candidate 1, 1.16.4, 20w45a, 20w46a, 20w48a, 20w49a, 20w51a, 21w03a, 1.16.5, 21w05a, 21w05b, 21w06a, 21w07a, 21w08b, 21w10a, 21w11a, 21w13a, 21w14a, 21w15a, 21w16a, 21w17a, 21w18a, 21w19a, 21w20a, 1.17 Release Candidate 2, 1.17, 1.17.1, 21w39a, 1.18 Pre-release 5, 22w06a, 22w14a, 1.19, 1.19.1 Pre-release 5, 1.19.1, 1.19.2, 1.19.4, 1.20.2 Pre-release 2, 1.20.2, 23w41a, 23w51b, 1.21 Pre-Release 2, 24w40a, 1.21.3
Fix Version/s: Minecraft 15w46a

Type: Bug
Reporter: [Mod] markderickson Assignee: Unassigned
Resolution: Unresolved Votes: 55
Labels: detector, minecart, powered, rail, slope

Attachments: PNG File 2012-11-19_08.14.59.png     PNG File 2012-11-19_08.15.36.png     PNG File 2018-07-04_09.24.55.png    
Issue Links:
Duplicate
is duplicated by MC-18399 detector rails on slope Resolved
is duplicated by MC-79571 Powered rail does not activate from a... Resolved
is duplicated by MC-136543 Uphill Rail Powering Bug Resolved
is duplicated by MC-152712 Detector Rails not powering rails on ... Resolved
is duplicated by MC-163016 Vertical Detector Rails don't power V... Resolved
is duplicated by MC-191839 Rails: Powered rails and Detector rails Resolved
is duplicated by MC-265768 Detector rail not activate powered ra... Resolved
is duplicated by MC-3600 Detector rails not working uphill. Resolved
Relates
relates to MCPE-156386 Detector rails do not power adjacent ... Reopened
relates to MCPE-18950 Detector rails do not power adjacent ... Resolved
relates to MC-99594 Powered rails transmit power to follo... Reopened
relates to MC-92697 Activator Rails and Powered Rails pow... Resolved
CHK:
Confirmation Status: Confirmed
Category:
Block states, Redstone
Mojang Priority: Normal
Area: Platform

 Description   

The bug

When detector rails are placed beside powered rails on the flat, as a minecart travels over the detector rail the powered rails receive power long enough to boost the cart.
This mechanism gives nice clean booster sections on long tracks.

However, the same structure replicated on a slope doesn't behave the same way. As per the screenshot, if a detector rail is placed on a slop with a powered rail above, while the detector rail does function (as per second screenshot), it doesn't supply power to the adjacent powered rail.

I imagine this has something to do with the powered rail being on a block above the detector rail, however, the rails do join diagonally and it would make sense for the power supplied by the detector rail to also flow to adjacent diagonal powered rails.

Edit: Detector rails placed before powered rails when heading down a slope function correctly, again, due to how redstone functions.



 Comments   
Comment by Minecraft386882 [ 10/Nov/24 ]

Can confirm for 1.21.3

Comment by LunizIsGlacey [ 13/Oct/23 ]

Powering the rail in that manner goes against how redstone works in all other situations. Fixing this bug would lead to the creation of a "special case" scenario which may unnecessarily complicate redstone.

On the other hand, intuitively the detector rail should power the powered rail that it is connected to, and so it is worth thinking about.

A solution to this bug may be to allow sloped activated detector rails to not only power the block they are placed on top of (as they do currently), but also the block they lean against; essentially like two levers within the same block space. This is an intuitive solution and would also make sense within the context of redstone as a whole. It would also mean that the same detector rail would also power, for example, a redstone lamp placed on top of the block it is leaning on.

Comment by [Mod] Jiingy [ 11/Oct/23 ]

Applies to 23w41a

Comment by [Mod] Avoma [ 07/Aug/22 ]

Can confirm in 1.19.2.

Comment by [Mod] Avoma [ 29/Jul/22 ]

Can confirm in 1.19.1.

Comment by [Mod] Avoma [ 02/Jul/22 ]

Can confirm in 1.19.

Comment by John Doe [ 07/Feb/21 ]

This is broken again in 21w05b

Comment by [Mod] Avoma [ 25/Nov/20 ]

Can confirm in 20w48a.

Comment by Connor Sleight [ 31/Oct/20 ]

You can use a workaround of using the detector rails to power some redstone and then use that to power the rails which is effectively what should be happening in the first place with the detector rail next to the powered rail. Dimitar is correct, it should act like a flat surface. After all, redstone works on a slope so why shouldn't a rail?

Comment by [Mod] violine1101 [ 26/Mar/20 ]

... that would defy the entire point of detector rails though.

Comment by chenyuxuan [ 26/Mar/20 ]

dimitarplays
I m sorry for my replying too late.

 

I m afraid that I cannot agree with you.

Rails should only share power with rails of the same type.

In your example, detector rails != golden rails .

So it should not.

 

Just as golden rails never share power with activator rail.

Comment by Dimitar B [ 04/Jul/18 ]

For anyone that does not understand the bug (for whatever reason) please look at my attachment.

Comment by Dimitar B [ 04/Jul/18 ]

"Don't you think that is how redstone works ?"

No. It does not work that way.

Look at it this way:

There is an rail which should give redstone power to the upper rails.

The detector rail should give redstone power to the upper rails, just like it does to surrounding rails on a flat surface.

 

Sounds the same, huh? 

Comment by chenyuxuan [ 26/Jun/18 ]

I don't think that is a bug.
Dont you think that is how redstone works?

fixing this will lead to adding a special case,which is not we want.
redstone should keep simple.

(sorry for my pool English)

Comment by Aaron Rhodes [ 08/Feb/18 ]

confirmed in 18w05a, the exact same behavior occurs.

Comment by user-f2760 (Inactive) [ 08/Apr/16 ]

This part of the tracker is for the pc edition only

Comment by Simeon Lodge [ 08/Apr/16 ]

Affects Xbox One, TU34

Comment by [Mod] redstonehelper [ 02/Dec/15 ]

Reopened.

Comment by IDontKnow [ 02/Dec/15 ]

still an issue in 15w49a

Comment by Kumasasa [ 22/Nov/15 ]

The fix of this issue has caused MC-92697

Comment by [Mod] redstonehelper [ 14/Nov/15 ]

Why?

Comment by chenyuxuan [ 14/Nov/15 ]


That is not a BUG.It should work like that.Don`t fix it!

Comment by [Mod] Torabi [ 17/Apr/15 ]

As far as I can tell from testing, detector rails only power themselves, and the block below them – they will activate redstone-sensitive blocks next to them, but don't actually "power" the blocks around them. Dust placed next to them will be powered, but you can't draw a signal out of a block placed next to a detector rail using a repeater. So when the detector rail is above the powered rail, it powers the block next to the powered rail, which in turn activates the powered rail.

The problem is that the concept of redstone signals isn't actually represented in the code anything like we perceive it to work, which makes the mechanics kind of inconsistent and causes a number of the outstanding redstone bugs. Signals are propagated mostly through block updates and checking the blocks around them, rather than blocks actually carrying power information. Powered rails don't actually follow the normal redstone rules for power propagation, and the way they carry power has some bugs of its own. A few of the developers have mentioned that they'd like to give it a major overhaul to fix some of these bugs, and I believe this was considered a possible target for the next major release at one time. I don't know if that's still the case; I haven't heard any mention of it recently, and 1.9 has already been labeled "The Combat Update". They've always got a variety of things in the works, and focus on different aspects as time, interest, and inspiration allow.

Considering all that, what would be a "pretty straight forward fix"? They can:

  1. Put in a hacky special-case check that defies the redstone rules. This is how Minecraft was originally cobbled together, which is why it has so many bugs that are difficult to fix. The current dev team was practically hired for the express purpose of cleaning up the code, rewriting it to remove all the hacky special-case code, while preserving intended behavior.
  2. Change the redstone behavior of the detector rail to power blocks next to it. This would probably be the simplest clean change, but would also probably break some existing compact builds that depend on the current behavior.
  3. Rewrite the whole redstone system, as previously mentioned. Would take a lot of time and effort. Still wouldn't make everyone happy, because so many users are absolutely dependent on buggy, nonsensical behavior.

So is there a plan to fix this? Sort of. Not this issue specifically, and probably not soon. It would depend on how much negative impact any change would have, and whether it would outweigh fixing this particular case. I haven't made much use of detector rails, and am not familiar with the types of contraptions people have built with them, so I don't know what the impact would be. That would be a good discussion for players and the developers to have in order to find the right solution to the problem.

Comment by Don Grove [ 14/Apr/15 ]

Confirmed in 1.8.3. All I want to know is if there is a plan to fix this: yes or no and what potential time frame? Yes, there are workarounds, but seems like a pretty straight forward fix for the next version.

Comment by [Mod] Sonicwave [ 07/Oct/14 ]

Confirmed in 1.8.

Comment by kbk [ 13/Aug/14 ]

14w33a - not fixed

Comment by kbk [ 07/Jul/14 ]

Still valid for 14w27b

Comment by kbk [ 23/May/14 ]

Still valid for 14w21b

@Christopher Martin
It has been like this all the way since 1.4

Comment by Christopher Martin [ 21/May/14 ]

I can confirm this in 14w20b, 14w18b and 1.7.9. Is this a case of a bug re-emerging, or has it been consistently broken for all this time?

I have to admit it's fairly esoteric, as a redstone torch is much resource cheaper than a detector rail, but there are times I have wanted to use this due to space issues. It also means that up-slope activator rail mob unloaders don't work, and I have a use for that too (a one way mob unloader, for example).

Comment by kbk [ 15/May/14 ]

Still valid for 14w20b

Comment by Darien Shields [ 26/Jan/14 ]

This bug is over a year old and still not fixed?!?!?! Anyway, affects level powered rails attached to sloped detector rail when powered rail is above detector rail. PUHLEEZE fix this? seriously complicates my auto sorter :/ 1.7.4

Comment by kbk [ 26/Sep/13 ]

13w39a - confirmed

Comment by [Mod] CubeTheThird [ 26/Sep/13 ]

Is this still a concern in the current Minecraft version 1.6.4 / Launcher version 1.2.5 ? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

Comment by kbk [ 27/Apr/13 ]

Affects 1.5.2pre as well as 1.5.1.

Comment by Höddi Gúrki [ 06/Mar/13 ]

Also 13w10a.. hope this will be fixed soon.

Comment by kbk [ 01/Mar/13 ]

Affects 13w09b.

Comment by Draven Mueller [ 17/Feb/13 ]

I was also having this issue, please upvote it!

Comment by [Mod] CubeTheThird [ 19/Nov/12 ]

Can confirm.

Comment by Chalmes (Jon) [ 18/Nov/12 ]

Though obviously this is a redstone issue, i'd like to comment that powered rails provide power to each other when placed on a slope. To me, detector rails should also work to provide power to powered rails on a slope for consistency.

Generated at Sun Jan 12 12:01:11 UTC 2025 using Jira 9.12.2#9120002-sha1:301bf498dd45d800842af0b84230f1bb58606c13.