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What's "structurally" wrong with Portal Bridge

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Posted by blue streak 1 on Monday, December 21, 2015 6:57 PM

A question for our draw bridge experts.  Would you say that inspection & maintenance and more inspection of some mechanical portions on any draw but especially swing bridges is so specialized that they would be done by contract personell ?

Another point.  Remember when the Thames river bridge lost all its power due to feeder failures ? That made the bridge unable to raise..

Anyone know if the present Portal bridge has a second set of electrical feeders ?  If its primary electrical source is still the CAT feeders then there is a bigger cost to maintain obsolete 25 Hz mechanisims, motors,  and equipment . As well does it have a standby generator ?  All more maintenance costs.

 

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Posted by 7j43k on Monday, December 21, 2015 7:40 PM

From reading the report, Amtrak/FRA had a professional bridge inspector inspecting Portal Bridge.  It would appear that that person may not have done an adequate job.  Whether that was from lack of training, lack of ability, or negligence is not clear.  I don't see that simply contracting the job out would help.

 

The bridge can be operated manually.  If the power goes out.  It is undoubtedly slower than motor operation.  But if it is infrequent, then manual operation would suffice.  

I do not think there is a standby generator for the bridge.  As built, the bridge had two 70 HP motors.  That's equivalent to 105 kw.  A very rough ball park price for a generator that size would be $10,000.  In fact, before it would all be done, likely the price would go up to at least $50,000.  But properly maintained, that generator could be resold.  Alternately, one could be leased.

I would think an analysis of power failures to the bridge would answer whether an alternate power supply would be a good idea.

The bridge has a data recorder, so that information is certainly available.

 

Ed

Looking a little farther, I think I might raise that price to $100,000.

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Posted by Paul_D_North_Jr on Monday, December 21, 2015 9:52 PM

No idea if this "Movable Bridge Engineers" company ever had anything to do with the Portal Bridge, but it's clear they have a lot of expertise (and include Amtrak as one of their clients):

http://www.sbengineering.net/ 

- Paul North.   

"This Fascinating Railroad Business" (title of 1943 book by Robert Selph Henry of the AAR)
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Posted by MidlandMike on Monday, December 21, 2015 10:01 PM

Paul, thanks for the pro's assesment of this bridge project.  The only quibble I had was your seeming comparison of the Portal project to Hell Gate Bridge.  Hell Gate and Huey P Long Bridges are both 135 ft above water, about 2 1/2 times highe than the Portal project.

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Posted by BaltACD on Monday, December 21, 2015 10:08 PM

Paul_D_North_Jr

No idea if this "Movable Bridge Engineers" company ever had anything to do with the Portal Bridge, but it's clear they have a lot of expertise (and include Amtrak as one of their clients):

http://www.sbengineering.net/ 

- Paul North.

As well as BNSF, CSX & NS, but surpisingly not KCS or UP.

Never too old to have a happy childhood!

              

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Posted by Paul_D_North_Jr on Tuesday, December 22, 2015 4:59 AM

MidlandMike - Right, I did note that the Long bridge was 135 ft.; wasn't sure about Hell Gate, but did think it was higher than the proposed Portal Bridge.  My use of Hell Gate was to point out a similar (though not identical) situation nearby for those familiar with it.

- Paul North.

"This Fascinating Railroad Business" (title of 1943 book by Robert Selph Henry of the AAR)
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Posted by Paul_D_North_Jr on Thursday, December 24, 2015 10:20 AM

Forget to mention (understandably) - there was a rather poor 1968 comedy movie titled "Don't Raise the Bridge, Lower the River" - see:

http://www.imdb.com/title/tt0061591/ 

https://en.wikipedia.org/wiki/Don%27t_Raise_the_Bridge,_Lower_the_River 

. . . never mind . .

- Paul North. 

"This Fascinating Railroad Business" (title of 1943 book by Robert Selph Henry of the AAR)
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Posted by wanswheel on Thursday, December 24, 2015 12:14 PM
One thing hasn’t changed since 1931. You can see it from the Empire State Building.
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Posted by 7j43k on Thursday, December 24, 2015 1:22 PM

 

 

Thanks.  Neat photo.

 

 

Ed

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Posted by AnthonyV on Friday, December 25, 2015 7:32 AM

What would the logistics be in replacing the bridge?  Would a temporary span be built in order to ultimately use the same alignment or would the new bridge be built on a new alignement along side the exsiting?

 

Thanks

Anthony V.

 

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Posted by mudchicken on Friday, December 25, 2015 10:41 AM

The geometry of speed and the fact all the surrounding real estate is occupied on the approaches pretty well keeps a new bridge in the same place.

Mudchicken Nothing is worth taking the risk of losing a life over. Come home tonight in the same condition that you left home this morning in. Safety begins with ME.... cinscocom-west
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Posted by 7j43k on Friday, December 25, 2015 11:24 AM

Here is artwork showing the first bridge installed.  You can see what looks like piers of the old bridge:

 

 

Here is artwork that shows two bridges with the piers removed:

 

 

 

And here is a reminder that artwork does not necessarily reflect reality:

 

 

 

Ed

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Posted by Firelock76 on Friday, December 25, 2015 11:35 AM

Thanks for the photo Wanswheel!  Great shot, and it makes me just a little homesick, especially this time of year. The Hackensack Meadows with "The City" peeking up over the horizon.

Bear in mind I mean absolutely no disrepect to the rest of the country when I say as far as I'm concerned North Jersey is "Christmas Country."  The climate, the lights on homes, the food, all of it.

Or maybe it's because it's home, and with all it's annoyances and frustrations that drive so many of us away it always will be.

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Posted by blue streak 1 on Friday, December 25, 2015 1:49 PM

MC is correct the north side bridge will be as close as possible to the present portal bridge. That will allow for the planned relocation of the approaches long enough so no speed restrictions.  The new bridge appears to have its center span longer than the present swing bridge.  Suspect that is so the new bridge piers will not interfer with  the operation of the present swing.  Also getting enough distance from present piers may be a consideration.

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Posted by timz on Friday, December 25, 2015 5:56 PM

The fact sheet says the new bridge will be good for 90 mph. They've got plenty of room for 90 mph curves to a new bridge that leaves plenty of room for the old bridge to open during construction. (Or after construction, for that matter.)

Remember that EIR (or whatever it was) online a few years ago that had maps and profiles of the two new Portal bridges and their approaches? Can anyone find that now? (Not that any of its plans are going to happen.)

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Posted by 7j43k on Friday, December 25, 2015 6:08 PM

The link for the EIR on the FRA website doesn't work anymore.

 

Ed

 

 

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Posted by blue streak 1 on Friday, December 25, 2015 7:31 PM

On the last paragraph of this link is the statement that the Portal swing bridge will not be decommisioned until Portal south is built as part of the Gateway project.  So once Portal north is in service there will be 4 tracks from near the NJ portals thru Secacus to Newark Penn. 

Note this poster is skeptical that the 4 tracks will be in service shortly after Portal north is in service but maybe.

http://www.nec-commission.com/cin_projects/portal-bridge-north-south/

 

 

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Posted by blue streak 1 on Friday, December 25, 2015 7:51 PM

This link on page 20  ( expect to blow it up to about 400 % ) will give an overview of the portal south bridge as part of Gateway.  ( the link will take a lot of memory ).   Notice how the Gateway plan does not have the new tracks going thru Secacus

http://www.necfuture.com/pdfs/tier1_deis/appendix/app_a.pdf

 

 

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