Jump to content

Attention: In order to reply to messages, create topics, have access to other features of the community you must sign up for an account.
Sign in to follow this  
INDman

London Underground MoW

Recommended Posts

Found this cool vid made by the company that does maintenance work on 3 London Underground line.

I would be cool if NYCTA made a video like this.

Share this post


Link to post
Share on other sites

That is pretty cool.

 

Not only do they got 3rd rail, they got 4th rail too. You think they will ever just use one for power?

 

- A

Share this post


Link to post
Share on other sites
That is pretty cool.

 

Not only do they got 3rd rail, they got 4th rail too. You think they will ever just use one for power?

 

- A

 

I know this is an old post, but I wanted to respond. They will most likely always use a 4th rail on all existing lines. The reason for the 4th rail is the avoid and grounding issues with the large steel tubes that line many of the tunnels. With only a 3rd rail, the other two rails are used as a ground. In the case of using these steel tubes it could cause the ground to come in contact with the steel and corrode it, effectively ruining the tunnel. The 3rd rail runs at about +400VDC and the 4th rail at -200VDC, giving an effective 800VDC current through the traction motors and keeping any electricity from going to the steel tubes used to line the tunnels.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  


×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.