Bridge joints?

[CShaveRR]

This is a term I hadn't come across while working.

I recently got the newsletter from my old UP Service unit, which mentioned that last fall the railroad's Rockwell Subdivision had "existing rail and turnouts" replaced by engineering, signal, construction, and track teams working together.

Included win the article was a paragraph reading, "Benefits of the project include the removal of 189 bridge joints in downtown Chicago, Global I Intermodal Terminal, and major Union Pacific Routes through the city.  It enhances the infrastructure and eliminates potential derailment risk."

Wow!  For something to do so much, I'm surprised I hadn't heard of it/them before.  If they're rail joints, I don't think the Rockwell sub had jointed rail on its lines recently.  There are plenty of bridges on this line, taking the tracks over streets in Chicago's West Side, but I wouldn't know why those bridges would need special joints.

Could we be talking about joints related to signals, and wire that bridges them, ensuring block continuity?  I'm not sure how that eliminates derailments (at least not if rules are complied with).

[mudchicken]

Even with 4 expansion joints(slip joints) and 4 locking joints per track per moveable span bridge.....and figuring multiple tracks per bridge, that's still a lot of bridges.

[CShaveRR]

But none of the bridges on the Rockwell Sub are movable--they were all fixed-span.

[Norm48327]

Carl,

I may be totally wrong but the coefficient of expansion may be totally different between welded and jointed rail may be completely different. Jointed rail has the advantage of a bit of play between lengths  THE JOINTS WILL GIVE A BIT) while welded does not. The bolt holes do allow a bit of expansion or contraction where welded does not.

Just speculation on my part.

[Rader Sidetrack]

"Bridge joints" seem to be a method of describing "ordinary" joints in stick rail on former Chicago & Northwestern lines.  Linked below is a book Google found that has a chapter discussing various joints.  C&NW seems to be the only RR that used that style (at least as far as the article goes).

"Railway track and track work"

 By Edward Ernest Russell Tratman

Published 1901

http://books.google.com/books?id=1Vg5AAAAMAAJ&pg=PA98&lpg=PA98&dq=railroad+uprr+%22bridge+joints%22+frog&source=bl&ots=QPMDqRdzBg&sig=-lF-8ris9N4Vl1URqu9AbjzFWSE&hl=en&sa=X&ei=HyImT_74Moe2twe2_pXWAw&ved=0CCAQ6AEwAA#v=onepage&q=railroad%20uprr%20%22bridge%20joints%22%20frog&f=false

There is a table with statistics, and if you read further, then there is a narrative with a more detailed description.

[Paul_D_North_Jr]

See esp. pages 91 - 98 of that book.  Yet another attempt to strengthen that inherent weak spot in the track. 

Rader, thanks much for digging that out !    I hadn't known of that term, or that book, before this.  Now I want to see if it has an explanation of a "wrap-around" joint bar - I do have a decent photo of one from last summer . . .         

- Paul North. 

[dknelson]

Rader Sidetrack

"Bridge joints" seem to be a method of describing "ordinary" joints in stick rail on former Chicago & Northwestern lines.  Linked below is a book Google found that has a chapter discussing various joints.  C&NW seems to be the only RR that used that style (at least as far as the article goes).

"Railway track and track work"

 By Edward Ernest Russell Tratman

Published 1901

http://books.google.com/books?id=1Vg5AAAAMAAJ&pg=PA98&lpg=PA98&dq=railroad+uprr+%22bridge+joints%22+frog&source=bl&ots=QPMDqRdzBg&sig=-lF-8ris9N4Vl1URqu9AbjzFWSE&hl=en&sa=X&ei=HyImT_74Moe2twe2_pXWAw&ved=0CCAQ6AEwAA#v=onepage&q=railroad%20uprr%20%22bridge%20joints%22%20frog&f=false

There is a table with statistics, and if you read further, then there is a narrative with a more detailed description.

Wow, quite apart from this "bridge joint" topic, that is an incredible resource for those of us with an historical railroading frame of mind.  You'd probably pay a pretty penny for that book at a railroad collectibles show and if what you wanted was the information, not the thrill of ownership itself, now it is free! 

Dave Nelson