AARoads Forum

National Boards => Bridges => Topic started by: Brian556 on May 30, 2020, 04:20:20 PM

Title: Very Odd RR Bridge Construction Beside I-10 near LaPlace, LA
Post by: Brian556 on May 30, 2020, 04:20:20 PM
I have never seen anything like this and can't even tell what he heck is going on
https://www.google.com/maps/@30.0694818,-90.3917535,3a,15y,143.64h,89.16t/data=!3m7!1e1!3m5!1sQtAS2R69c0i2VBw-1Iv71w!2e0!6s%2F%2Fgeo2.ggpht.com%2Fcbk%3Fpanoid%3DQtAS2R69c0i2VBw-1Iv71w%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D310.89233%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192 (https://www.google.com/maps/@30.0694818,-90.3917535,3a,15y,143.64h,89.16t/data=!3m7!1e1!3m5!1sQtAS2R69c0i2VBw-1Iv71w!2e0!6s%2F%2Fgeo2.ggpht.com%2Fcbk%3Fpanoid%3DQtAS2R69c0i2VBw-1Iv71w%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D310.89233%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192)
Title: Re: Very Odd RR Bridge Construction Beside I-10 near LaPlace, LA
Post by: SteveG1988 on May 31, 2020, 10:08:44 PM
Spreading the weight out along a truss to allow for replacement of large sections of the trestle?
Title: Re: Very Odd RR Bridge Construction Beside I-10 near LaPlace, LA
Post by: sparker on June 02, 2020, 03:34:35 AM
Spreading the weight out along a truss to allow for replacement of large sections of the trestle?

That's CN trackage, former Illinois Central; Amtrak uses it for their Chicago-N.O. service.  The viaduct structure is a standard box girder type, configured so the tracks ride over the top of the girders rather than through them in order to take advantage of the weight-bearing characteristics of I-shaped girders.  In this waterlogged location, girders and the hardware securing them tend to rust out over a short time; what you're probably looking at in this picture is a temporary deck-truss bridge being placed where a girder section was/is to be removed.  A permanent bridge section will be constructed offsite and then put into place; the truss is simply a stopgap to keep rail traffic moving in the interim.
Title: Re: Very Odd RR Bridge Construction Beside I-10 near LaPlace, LA
Post by: SteveG1988 on June 11, 2020, 07:56:37 PM
Yeah i just drove by it twice today, it is definitely a weird way to do it first time you see it, but it makes sense when there is no really firm dry land to build your new concrete girder bridge on.
Title: Re: Very Odd RR Bridge Construction Beside I-10 near LaPlace, LA
Post by: M3100 on June 14, 2020, 12:38:06 PM
Here is a picture of the bridge construction from a rainy summer afternoon in 2019; that area is the Bonnet Carre Spillway.  The Army Corps of Engineers opens it up as needed to release water from the Mississippi River into Lake Pontchartrain to reduce the risk of downriver flooding.  IIRC the rail line is closed to Amtrak's City of New Orleans and CN freights for some duration while the spillway is open.

(https://live.staticflickr.com/65535/50005113918_7287e7c75c.jpg)

On another note - it was interesting to see how much of I-10 is built as an elevated freeway, both over water and land.  Many more bridges, and less earthmoving, than in arid California.
Title: Re: Very Odd RR Bridge Construction Beside I-10 near LaPlace, LA
Post by: MCRoads on July 20, 2020, 04:48:39 PM
[...]
On another note - it was interesting to see how much of I-10 is built as an elevated freeway, both over water and land.  Many more bridges, and less earthmoving, than in arid California.

I have been on I-10 in LA, and it is amazing how long they are. They are among the longest bridge structures in the world, actually. If you drive on I-310, from the start of the elevated portion, to the end on I-59, you would go approximately 30 miles, which is a bit longer than the Lake Pmnchatrain Causeway.
My mom got anxious driving them, as they are so remote. She always stopped to get gas before the bridge, easier going East because of Lafayette.
Title: Re: Very Odd RR Bridge Construction Beside I-10 near LaPlace, LA
Post by: sparker on July 20, 2020, 08:24:52 PM
[...]
On another note - it was interesting to see how much of I-10 is built as an elevated freeway, both over water and land.  Many more bridges, and less earthmoving, than in arid California.

I have been on I-10 in LA, and it is amazing how long they are. They are among the longest bridge structures in the world, actually. If you drive on I-310, from the start of the elevated portion, to the end on I-59, you would go approximately 30 miles, which is a bit longer than the Lake Pmnchatrain Causeway.
My mom got anxious driving them, as they are so remote. She always stopped to get gas before the bridge, easier going East because of Lafayette.

I think you meant to say I-55 rather than 59, which is part of the same continuous bridge structure centered around I-10 west of metro NOLA.  You'll hit surface alignment on either I-10 or the I-55/12 combination before even getting near the south end of I-59 near Slidell. 
Title: Re: Very Odd RR Bridge Construction Beside I-10 near LaPlace, LA
Post by: MCRoads on July 20, 2020, 11:08:50 PM
[...]
On another note - it was interesting to see how much of I-10 is built as an elevated freeway, both over water and land.  Many more bridges, and less earthmoving, than in arid California.

I have been on I-10 in LA, and it is amazing how long they are. They are among the longest bridge structures in the world, actually. If you drive on I-310, from the start of the elevated portion, to the end on I-59, you would go approximately 30 miles, which is a bit longer than the Lake Pmnchatrain Causeway.
My mom got anxious driving them, as they are so remote. She always stopped to get gas before the bridge, easier going East because of Lafayette.

I think you meant to say I-55 rather than 59, which is part of the same continuous bridge structure centered around I-10 west of metro NOLA.  You'll hit surface alignment on either I-10 or the I-55/12 combination before even getting near the south end of I-59 near Slidell. 
Well, thatís the second rout Iíve screwed up this week... oh well.
Title: Re: Very Odd RR Bridge Construction Beside I-10 near LaPlace, LA
Post by: froggie on August 04, 2020, 10:20:45 AM
Combined length of viaduct from I-310 south of US 61, via I-10, to I-55 south of Ponchatoula is a little over 38 miles.  22 miles of that is on I-55 alone.  The old non-elevated alignment of US 51 is still driveable, adjacent to the I-55 segment.
Title: Re: Very Odd RR Bridge Construction Beside I-10 near LaPlace, LA
Post by: seicer on August 04, 2020, 10:36:05 AM
It looks like the crossing is being replaced with an overhead gantry crane that's mounted on tracks: https://goo.gl/maps/B7MpjjHPvMNVKSPv9