Answers.Body: <p>These pieces are frequently used for decoration now, but they were originally used for sliding doors, particularly on train sets. Here's one of the first uses from set 7838 in 1983:</p>
  
  <p><img src="https://i.sstatic.net/5qzEC.jpg" alt="7838 page 8">
  <img src="https://i.sstatic.net/tx3ry.jpg" alt="7838 page 9"></p>
  
  <p>While they could be used in structures, these were frequently used for putting doors on the train cars themselves:</p>
  
  <p><img src="https://i.sstatic.net/uIysv.jpg" alt="7727 page 18"></p>
  
  <p>These parts can also be used to create tracks for other things that need to slide as shown in Container Loading Crane (7823):</p>
  
  <p><img src="https://i.sstatic.net/dW0J9.jpg" alt="7823 page 4"></p>
  
  <p>This class of part also has a 2xn variety that now allows whole 1xn bricks to slide within it:</p>
  
  <p><img src="https://i.sstatic.net/Dy69L.jpg" alt="30586"></p>
  
  <p>This is useful for building sliding doors and walls that are a full module wide. Here's an example from 31009:</p>
  
  <p><img src="https://i.sstatic.net/Tk0fy.jpg" alt="31009"></p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-05-12T17:41:00.130Z
Answers.LastActivityDate: 2015-05-12T18:00:20.293Z
Answers.LastEditDate: 2015-05-12T18:00:20.293Z
Answers.UserDisplayName: jncraton
Answers.Body: <p>In addition to what jncranton wrote, the plate with the rail is a perfect fit for sliding in the <a href="http://rebrickable.com/parts/2653" rel="nofollow noreferrer">brick with groove</a>:</p>
  
  <p><a href="https://i.sstatic.net/IjjU6.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/IjjU6.jpg" alt="enter image description here"></a></p>
  
  <p>You can see an example of that technique in the <a href="http://peeron.com/scans/10123-1" rel="nofollow noreferrer">Cloud City</a> set:
  <img src="https://i.sstatic.net/uZe00.jpg" alt="enter image description here"></p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-05-13T08:08:14.083Z
Answers.Text: And the 2 stud version was often used to secure the old 9V motor (http://www.bricklink.com/PL/71427c01.gif?0) that had two grooves on each sides, allowing it to be removed easily.
Answers.UserDisplayName: Philo
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-05-12T18:25:30.563Z
Answers.LastActivityDate: 2017-04-18T22:25:47.853Z
Answers.LastEditDate: 2017-04-18T22:25:47.853Z
Answers.UserDisplayName: Mr. Shiny and New 安宇
Answers.Body: <p>It can also be used as the eave of a building!</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-11-03T23:26:38.530Z
Answers.LastActivityDate: 2015-11-03T23:26:38.530Z
Answers.UserDisplayName: Samuel L.
Body: <p>I'm looking at the this piece:</p>
  
  <p><img src="https://i.sstatic.net/Td35C.jpg" alt="4510"></p>
  
  <p>Is this piece some kind of a track on which you can build stuff that slides? I see it in sets as a decorative piece from time to time. What does "door rail" even refer to?</p>
  
Tags: <piece-information>
Title: What is the purpose of this plate with door rail?
UserDisplayName: mj_
ThreadText: # What is the purpose of this plate with door rail?
  
  (Asked by: username_0 on 2015-05-12)
  
  I'm looking at the this piece:
  
  ![4510](https://i.sstatic.net/Td35C.jpg)
  
  Is this piece some kind of a track on which you can build stuff that slides? I see it in sets as a decorative piece from time to time. What does "door rail" even refer to?
  
  **Tags:** piece-information
  
  
  ---
  
  ## 3 answers
  
  ### Answer by username_1 on 2015-05-12. Score: 20 | Accepted answer
  
  These pieces are frequently used for decoration now, but they were originally used for sliding doors, particularly on train sets. Here's one of the first uses from set 7838 in 1983:
  
  ![7838 page 8](https://i.sstatic.net/5qzEC.jpg)
  ![7838 page 9](https://i.sstatic.net/tx3ry.jpg)
  
  While they could be used in structures, these were frequently used for putting doors on the train cars themselves:
  
  ![7727 page 18](https://i.sstatic.net/uIysv.jpg)
  
  These parts can also be used to create tracks for other things that need to slide as shown in Container Loading Crane (7823):
  
  ![7823 page 4](https://i.sstatic.net/dW0J9.jpg)
  
  This class of part also has a 2xn variety that now allows whole 1xn bricks to slide within it:
  
  ![30586](https://i.sstatic.net/Dy69L.jpg)
  
  This is useful for building sliding doors and walls that are a full module wide. Here's an example from 31009:
  
  ![31009](https://i.sstatic.net/Tk0fy.jpg)
  
  
  ---
  
  ### Answer by username_2 on 2015-05-12. Score: 15
  
  In addition to what jncranton wrote, the plate with the rail is a perfect fit for sliding in the [brick with groove](http://rebrickable.com/parts/2653):
  
  [![enter image description here](https://i.sstatic.net/IjjU6.jpg)](https://i.sstatic.net/IjjU6.jpg)
  
  You can see an example of that technique in the [Cloud City](http://peeron.com/scans/10123-1) set:
  ![enter image description here](https://i.sstatic.net/uZe00.jpg)
  
  > **Comments:**
  > **username_3**: And the 2 stud version was often used to secure the old 9V motor (http://www.bricklink.com/PL/71427c01.gif?0) that had two grooves on each sides, allowing it to be removed easily.  
  
  ---
  
  ### Answer by username_4 on 2015-11-03. Score: 0
  
  It can also be used as the eave of a building!
  
  
  ---
  
  