DETECTOR RAIL
A rail that outputs a redstone signal when a minecart passes over it. Comparator can read the contents of container minecarts. Signal lasts while minecart is on the rail.
Crafting Recipe
6 Iron Ingots + 1 Stone Pressure Plate + 1 Redstone Dust → 6 Detector Rails
Signal Behavior
Input
InputMinecart presence on rail
Output
OutputSignal strength 15 (or container fullness via comparator)
Max Signal Strength
Max Signal Strength15
Delay
DelayActive while minecart is on rail
Modes
- Binary detection
- Analog container reading via comparator
Overview: what the Detector Rail is and does
A rail that outputs a redstone signal when a minecart passes over it. Comparator can read the contents of container minecarts. Signal lasts while minecart is on the rail.
As a trigger it watches the world for an event and converts that event into a redstone signal. It is the station sensor of rail systems, detecting carts and reading container minecarts.
The Detector Rail was added to Minecraft in Beta 1.5 and everything described here reflects its behaviour in Java Edition 1.21.
How it works: the redstone mechanics
On the input side, minecart presence on rail. On the output side, signal strength 15 (or container fullness via comparator).
It outputs signal 15 the whole time a minecart sits on that specific rail block, and a comparator placed against it instead reads the fullness of a container minecart passing over. The signal ends the moment the cart leaves that one rail.
It can output a maximum signal strength of 15, which travels 15 blocks through bare redstone dust before fading to nothing.
It operates in the following modes: binary detection and analog container reading via comparator.
How to set it up
- 1Craft the Detector Rail: 6 Iron Ingots + 1 Stone Pressure Plate + 1 Redstone Dust → 6 Detector Rails.
- 2Decide where the signal needs to start or land, then place the Detector Rail against a solid surface so it can see the event you want to detect.
- 3Lead the signal it produces into a repeater or dust line so the rest of your contraption can respond to the detected event.
- 4Test in a creative-mode plot first: trigger the input and confirm the Detector Rail behaves exactly as the timing above predicts before committing it to a survival build.
Uses & applications
- ▸Minecart arrival detection
- ▸Station systems
- ▸Item transport monitoring
- ▸Automatic rail switching
Tips & common mistakes
- !Signal only while minecart is on the specific rail block
- !Comparator reads container fullness, not just presence
- !Only the cart on that exact rail block counts, so place it precisely at the stop point rather than somewhere along the approach.
Detector Rail FAQ
What is the Detector Rail used for in Minecraft redstone?
The Detector Rail is most often used for minecart arrival detection, station systems, item transport monitoring, and automatic rail switching. As a trigger it watches the world for an event and converts that event into a redstone signal.
What signal strength does the Detector Rail output?
Signal strength 15 (or container fullness via comparator). Its maximum signal strength is 15.
How do you craft the Detector Rail?
6 Iron Ingots + 1 Stone Pressure Plate + 1 Redstone Dust → 6 Detector Rails. It was introduced in Beta 1.5.
What is the most common mistake with the Detector Rail?
Signal only while minecart is on the specific rail block. Comparator reads container fullness, not just presence.