Can someone explain this?

[bassist118]

While doing some research for my Shoeburyness - Fenchruch Street route I came across this picture of a dimond switch

http://www.flickr.com/photos/walkinmycat/3139687464/in/set-72157610720102139/

Why would this be needed instead of a normal dimond crossing? Just seems a bit of a waste of time to me?

Cheers Trainzers

:Y:

Andy

 

[bassist118]

Think I've found out their reason for existing, just found this about swingnose points

http://en.wikipedia.org/wiki/Swingnose_crossing

Never knew some points had this adaptation, and I think this goes some way to explain why dimond switches exist. We learn somink every day.



Andy

 

[martinvk]

Looks like two mainlines merging with each having oneway traffic on each side. Therefore the two up tracks join into one up track and the two down tracks join into one down track. No need to have the up and down tracks join at the diamond so no need to have a double slip crossing there.

 

[magickmaker]

Believe it or not, this type of switch is a really old design. At least in principle.

Some time ago I ran across this type of switch used in Canada that was designed as a safety switch. Basically, the way the switch worked, there was no frog or break in the running rails. Sounds hard to understand, but it's a pretty neat design.

http://www.catskillarchive.com/rrextra/tkmacph1.Html

Basically, it worked by raising the wheels up and OVER the running rails. When "open" they acted as a derail of sorts for the spur track. Interestingly, they were designed that if you were on the main and were coming through the switch in a trailing position, then the train would just nudge the switch out of the way and open it.

 

[Midland]

Frogless points. So Auran's points were years ahead of their time after all.


Cheers

Nix

 

[magickmaker]

http://mysite.du.edu/~jcalvert/railway/wharton.htm


There's another type that was common in the US.