Detector Rail

Detector Rail

Renewable	Yes
Stackable	Yes (64)
Tool
Blast resistance	0.7
Hardness	0.7
Luminous	No
Transparent	Yes
Waterloggable	Yes
Flammable	No
Catches fire from lava	No
Map color (Java)	0 NONE

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            "field": "Yes",
            "label": "(link to Opacity article, displayed as Transparent)"
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            "field": "Yes",
            "label": "(link to Waterlogging article, displayed as Waterloggable)"
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            "field": "No",
            "label": "(link to Flammable article, displayed as Flammable)"
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            "label": "Catches fire from (link to lava article, displayed as lava)"
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        "Detector Rail.png",
        "Powered Detector Rail.png"
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A detector rail is a type of rail that produces a redstone signal while a minecart is on it.

Obtaining

Breaking

A detector rail can be broken fairly easily by hand, dropping itself as an item. It can be broken faster by using a pickaxe.

Block	Detector Rail
Hardness	0.7
Tool
Breaking time (sec)
Default	1.05
Wooden	0.55
Stone	0.3
Iron	0.2
Diamond	0.15
Netherite	0.15
Golden	0.1
Options
Efficiency	000
Haste	001 1JEBE

Legend

• incorrect tool, drops nothing
• correct tool, drops nothing or something other than the block itself
• correct tool, drops the block itself
• italicized can be instant mined

A detector rail also drops as an item if:

• the block beneath it is removed
• water or lava flows over it‌
• a piston moves it into a space with no floor below it.

Generated loot

Item	Structure	Container	Quantity	[hide]Chance
Java Edition and Bedrock Edition
Detector Rail	Mineshaft	Chest	1–4	27.1% { "item": "Detector Rail", "stacksize": "1–4", "chance": 0.271, "structure": "Mineshaft", "container": "Chest" }

Crafting

Ingredients	[hide]Crafting recipe
Iron Ingot + Stone Pressure Plate + Redstone Dust	6

Usage

A detector rail can be used as a rail that can detect when minecarts are on it or how full container minecarts on it are.

To place a detector rail, use the Place Block control on the face of a block adjacent to the destination space.

A detector rail can be attached to:

• the top of any full solid opaque block (stone, dirt, blocks of gold, etc.), including full-block mechanism components (command blocks, dispensers, droppers, note blocks, and redstone lamps)
• the top of a hopper, upside-down slab, or upside-down stairs.

A detector rail cannot be attached to the side or bottom of any block, but attempting to make such an attachment may cause the detector rail to attach to the top of a block under the destination space. For example, if a fence is on the ground, attempting to attach a detector rail to the side of the fence causes the detector rail to be attached to the top of the ground next to the fence instead.

If updated while on an opened trapdoor, a detector rail (or other rails) breaks drops as an item. Placing a minecart on a detector rail on top of a closed and unpowered trapdoor opens the trapdoor and updates it, causing the detector rail to break. If the trapdoor is powered while the minecart is placed, the trapdoor does not open and the rail does not break. The minecart on the detector rail powers the trapdoor and keeps it closed even if the external power source is removed, allowing the detector rail to stay on.

When placed, a detector rail configures itself to line up with any adjacent rails (including activator rails, powered rails, and other detector rails), as well as adjacent rails one block up. If there are two adjacent rails on non-opposite sides, or three or more adjacent rails, a detector rail lines up in the east-west direction. If there are no adjacent rails, a detector rail lines up in the north-south direction (but if a rail is later placed to the east or west, the detector rail re-orients itself in the east-west direction even if it is already connected to another rail to the north or south). If a rail it would line up with is one block up, a detector rail slants upward toward it (with multiple options to slant upward to, a detector rail "prefers", in order: west, east, south, and north). Other configurations can be created by placing and removing various rails.

Mobs avoid walking across a detector rail (or other rails), but can be pushed onto them.

It cannot be placed suspended in midair, even with commands.

Rail

Detector rails (and other rails) act as "roads" for minecarts. A minecart that enters a detector rail's space from either end of the detector rail continues to move, losing only a little velocity (which can then be increased again with powered rails). A minecart that enters a detector rail's space from the side turns east or south (depending on the detector rail's orientation), or in the downward direction for a slanted detector rail.

Redstone component

Example for signal strength of a full minecart (right) and a half-full one (left)

A detector rail activates when any part of any number of minecart's bounding box is in contact with it, and deactivates when no minecarts' bounding box is in contact. The duration of the signal is always a multiple of 10 redstone ticks (although lag or unloading/reloading a chunk might affect this). While active, a detector rail:

• powers adjacent redstone dust and adjacent redstone repeaters facing away from the detector rail, to power level 15
• powers adjacent redstone comparators facing away from the detector rail to a level corresponding to the fullness of the minecart if it is a minecart with chest or a Minecart with Hopper.
• strongly powers any full solid opaque block beneath the detector rail to power level 15
• activates any adjacent mechanism components, including above or below, such as pistons, redstone lamps, powered rails, hoppers, etc.

Comparators give a signal for a minecart with chest or a minecart with hopper

If the minecart on the detector rail is a minecart with chest or minecart with hopper, an adjacent redstone comparator facing away from the detector rail outputs a power level proportional to the container's fullness, possibly power level 0. For any other type of minecart (including a regular minecart with a mob riding it) the comparator's output is zero.

A comparator can read the contents of a minecart with hopper or with chest on a detector rail through a solid opaque block, as it can with other container blocks.

Mob interaction

Like other types of rails, spiders, cave spiders, and wardens are the only land mobs that can walk onto detector rails.

Sounds

Java Edition:

[hide] v t e metal sound type
Sound	Subtitles	Source	Description	Resource location	Translation key	Volume	Pitch	Attenuation distance
	​Block broken	Blocks	Once the block has broken	block.metal.break	subtitles.block.generic.break​	1.0	1.2	16
	​Block placed	Blocks	When the block is placed	block.metal.place	subtitles.block.generic.place​	1.0	1.2	16
	​Block breaking	Blocks	While the block is in the process of being broken	block.metal.hit	subtitles.block.generic.hit​	0.25	0.75	16
	​Something falls on a block	Entity-Dependent	Falling on the block with fall damage	block.metal.fall	subtitles.block.generic.fall​	0.5	1.25	16
	​Footsteps	Entity-Dependent	Walking on the block	block.metal.step	subtitles.block.generic.footsteps​	0.15	1.5	16

Bedrock Edition:

[hide] v t e metal sound type
Sound	Source	Description	Resource location	Volume	Pitch
	Blocks	Once the block has broken	dig.stone	1.0	1.1-1.2
	Blocks	When the block is placed	use.stone	1.0	1.2-1.25
	Blocks	While the block is in the process of being broken	hit.stone	0.3	0.75
	Players	Falling on the block with fall damage	fall.stone	0.4	1.0
	Players	Walking on the block	step.stone	0.35	1.0
	Blocks	Jumping from the block	jump.stone	0.12	1.0
	Blocks	Falling on the block without fall damage	land.stone	0.22	1.0

Data values

ID

Java Edition:

Name	Identifier	Form	Block tags	Item tags	[hide]Translation key
Detector Rail	detector_rail	Block & Item	prevent_mob_spawning_inside rails	rails	block.minecraft.detector_rail

Bedrock Edition:

Name	Identifier	Numeric ID	Form	Item ID	[hide]Translation key
Detector Rail	detector_rail	28	Block & Giveable Item	Identical	tile.detector_rail.name

Block states

Java Edition:

Name	Default value	Allowed values	[hide]Description
powered	false	false true	True if rail is activated.
shape	north_south	east_west north_south	Specifies the rail's orientation.
		ascending_east ascending_north ascending_south ascending_west	A rail that ascends toward the direction noted. For example, an ascending_west rail is a straight rail that goes upward from the east toward the west.
waterlogged	false	false true	Whether or not there's water in the same place as this rail.

Bedrock Edition:

Name	Metadata Bits	Default value	Allowed values	Values for Metadata Bits	[hide]Description
rail_data_bit	0x8	false	false true	0 1	True if rail is activated.
rail_direction	0x1 0x2 0x4	0	0	0	flat track going north-south
			1	1	flat track going east-west
			2	2	sloped track ascending to the east
			3	3	sloped track ascending to the west
			4	4	sloped track ascending to the north
			5	5	sloped track ascending to the south
			6 7 8 9	Unsupported	Unused

History

[hide]Java Edition Beta
1.5							Added detector rails.
[hide]Java Edition
1.0.0			Beta 1.9 Prerelease 6				Detector rails are now broken faster using a pickaxe.
1.3.1			12w21a				Detector rails are now renewable, due to redstone dust being obtainable from trading.
1.5			13w10a				A texture for active detector rails has now been added.
1.8			14w28a				Sloped detector rails no longer decrease their hitbox to 2 pixels of a block when activated.
1.9			15w38a				All sloped rail types' hitbox heights have been decreased from 10 pixels of a block to about 2.5 pixels of a block.
			15w44a				Detector rails can now be found in chest minecarts in mineshafts.
1.10			16w21a				All sloped rail types' hitbox heights have been increased from about 2.5 pixels of a block to a full block.
1.11			16w32b				All sloped rail types' hitbox heights have now been decreased from a full block to a half block.
1.14			18w43a				The textures of detector rails have now been changed.
			19w12b				Detector rails can now be placed on glass, ice, glowstone and sea lanterns.
1.17			20w45a				All rail types can now be waterlogged.
[hide]Pocket Edition Alpha
v0.13.0			build 1				Added detector rails.
v0.14.0			build 1				Detector rails can now be found inside minecarts with chests in mineshafts.
[hide]Bedrock Edition
1.7.0			beta 1.7.0.2				Rails are once again broken by flowing water. Previously it flowed through the rails.
1.10.0			beta 1.10.0.3				The textures of detector rails have now been changed.
[hide]Legacy Console Edition
Xbox 360	Xbox One	PS3	PS4	PS Vita	Wii U	Switch
TU1	CU1	1.00	1.00	1.00	Patch 1	1.0.1	Added detector rails.
TU46	CU36	1.38	1.38	1.38	Patch 15		All sloped rail types' hitbox heights have been increased from 10 pixels of a block to a full block.
TU54	CU44	1.52	1.52	1.52	Patch 24	1.0.4	All sloped rail types' hitbox heights have now been decreased from a full block to a half block.
TU69		1.76	1.76	1.76	Patch 38		All types of rails can now be waterlogged and are no longer destroyed by flowing water. Instead it flows right through them.
			1.90				The textures of detector rails have now been changed.
[hide]New Nintendo 3DS Edition
0.1.0							Added detector rails.

Data history

[hide]Java Edition
1.8			14w10a				Detector rails with numerical metadata variants 6, 7, 14 and 15, which are inaccessible through normal gameplay or even commands and as such require the use of external editors to exist, now have no model . Their appearances prior to this point were unknown.
			14w25a				Detector rails are now defined via block states rather than by numerical metadata. Prior to this version, the numerical metadata variants of the detector rail were as follows: DV [hide]Description 0 Unpowered north-south 1 Unpowered east-west 2 Unpowered ascending east 3 Unpowered ascending west 4 Unpowered ascending north 5 Unpowered ascending south 6-7 Inaccessible - behavior unknown 8 Powered north-south 9 Powered east-west 10 Powered ascending east 11 Powered ascending west 12 Powered ascending north 13 Powered ascending south 14-15 Inaccessible - behavior unknown
			14w26a				Detector rails with metadata values 6, 7, 14 and 15 have now been completely removed from the game.
1.13			17w47a				Prior to The Flattening, this block's numeral ID was 28.

Issues

Issues relating to "Detector Rail" are maintained on the bug tracker. Issues should be reported and viewed there.

Gallery

Screenshots

• 

  Image from Notch’s twitter teasing detector rails.

See also

• Rail
• Activator Rail
• Powered Rail