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Baltimore B&P tunnel replacement study


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#21 neroden

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Posted 22 June 2015 - 12:47 PM

Let's not forget that those tunnels are marching towards 150 years old.

What the hell is wrong with them? Most tunnels last forever. Were these tunnels just built really, really badly? I doubt it.

The Hudson tunnels were flooded with salt water. Plus, they're iron tubes buried in mud. That's a real problem.

The B&P tunnels are carved out of stone. Most tunnels of this sort are *extremely durable*. And they were relined in the 1980s, with drainage improved.

Sure, they're slow and form a delay point on the NEC, but they're *just fine* and will last another 100 years with standard maintenance. Is anyone really claiming they'll collapse?

So spend 4 billion to increase capacity on the NEC and save a couple of minutes? Nice to have, but not a high priority.

Do something useful with that money: spend it on buying the NY Central and Pennsy mainlines from NS and CSX so we can start making some real progress on NY-Chicago passenger rail.

 

I don't see how anyone can honestly expect Congress to invest $100 Billion or so making the NEC a true HSR route. Those who argue to drop the rest of Amtrak and concentrate everything on the NEC are playing a trick: Without spending spread around across the country, there will be NO passenger rail spending at all, so good-bye to all of Amtrak, NEC included.


It is a trick, yes. Heck, I live 230 miles from the NEC and I would not be interested in supporting endless billions for miniscule travel time improvements on the NEC and nothing for the rest of the country. Empire Corridor? Keystone Corridor? Virginia Corridors?

Edited by neroden, 22 June 2015 - 12:52 PM.

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#22 west point

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Posted 22 June 2015 - 02:07 PM

Not arguing about money but:

Stonework 150 years ago   --  the mortar used then had too much lime and lime and water don't mix well.  Consequently there is a lot of water entering the tunnel fro above.  the tunnel floor does not drain well and there has already been several times one track has had to be taken out of service with long delays and cancellations.  If a water main in Baltimore should break above the tunnel such as happened in the Howard street tunnel might be long shutdown.



#23 bmorechris

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Posted 22 June 2015 - 02:10 PM

The B&P tunnels are not deep bore solid rock tunnels, the image below is for the Pressman St Alignment, a few blocks removed from the existing tunnels, but largely the same type of profile.  A lot of cut and cover, mixed face tunnel, and only about 25% rock tunnel (with only a max of 30 ft of rock overhead mind you), but not exactly deep and stable.   The walls are masonry, and they lowered the floor and underpinned the walls in 1916 (not an easy task today, let alone 100 years ago!).  The PRR wanted to replace the tunnels in the 1930s before NEC electrification because of the leaks, but couldn't afford to.  Water leaks in, and in the winter freezes further damaging the tunnel structure.  There are utilities and other transit tunnels in close proximity to the B&P which doesn't help things, especially leaky piping and sewer lines. If you have ever ridden through the tunnels, you can see how rough looking they are from the inside.  I would guess that the chances of a catastrophic failure of the B&P tunnels is a heck of a lot more likely than a catastrophic failure for the North River tubes.  Also, since its a single bore, all it takes is a single failure to stop all traffic between Baltimore and DC for a long time, there isn't any quick easy fix.  Even if you lose 1 of the North River tubes, you could still maintain service through one of them.  Bottom line is that the B&P tunnels need to be replaced

Attached File  Tunnel Profile.jpg   61.13KB   26 downloads



#24 afigg

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Posted 22 June 2015 - 05:10 PM

Sure, they're slow and form a delay point on the NEC, but they're *just fine* and will last another 100 years with standard maintenance. Is anyone really claiming they'll collapse?

So spend 4 billion to increase capacity on the NEC and save a couple of minutes? Nice to have, but not a high priority.

To add to the replies, yes, that is what the engineers are saying about the B&P tunnels. You must have forgotten about the emergency repair job on the eroding trackbed last December (or around then) where 1 track was closed at a time leaving the NEC as a 1 track railroad west of BAL. Amtrak minimized the schedule delays to its trains, but MARC took it in the neck.

The 2011 FRA report on the Baltimore Railroad Network stated this in the summary on the existing B&P tunnel:
 

Concerning the B&P Tunnel, there is no realistic No-Build Scenario. The physical condition of the tunnel requires that it be rebuilt or replaced within the next 10-20 years. Rebuilding would contradict the fundamentals of engineering economy. The tunnels basic geometry was substandard when it was completed and is irremediable by any reasonable amount of rehabilitation.

The B&P tunnel is one of the highest priority concerns on the NEC along with the Hudson River tunnels and the Portal bridge replacement in that one of them could fail shutting down or crippling the southern NEC for years. Hence the $60 million replacement study.

In the FRA report and in the previous presentations on replacing the B&P tunnel, the concept was a new 2 track tunnel with a possible rebuild of the B&P tunnel to a 1 or 2 track tunnel (after traffic could be moved to the new tunnels). That has changed with 4 new tracks & tunnels for each alternatives. With 4 new tracks, it would make no sense to rebuild the B&P tunnel. I think those conducting the study have internally reached the conclusion that it is not worth it to rebuild the B&P tunnel and keep it in service. The study still has to look at rebuilding the B&P tunnels, but I suspect they are only doing so to document the reasons for shutting the B&P tunnel down and repurposing it (if that is feasible).

In the design boards, all 4 tunnels would be built for plate H clearances. One way to trim costs a bit would be to build 2 tunnels, probably on the northern side to double stack clearances and make the other 2 tunnels smaller with Amtrak/MARC clearances. With the double stack clearances, they are obviously looking to have CSX contribute to the project in return for a route for container trains through Baltimore that would be available to CSX outside of the peak traffic periods. CSX would have to increase clearances from Baltimore to south of Philly, but that would be up to CSX to tackle.

#25 afigg

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Posted 22 June 2015 - 05:10 PM

Double post. please delete..

Edited by afigg, 22 June 2015 - 05:12 PM.


#26 west point

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Posted 22 June 2015 - 06:07 PM

The 2 North River tunnels, Portal bridge, and  B & P tunnels all have an estimated life left of 10 - 20 years.  Any bet that one of the 4 will fail sooner ? 



#27 OBS

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Posted 22 June 2015 - 06:17 PM

Portal Bridge will be first to go (fail) is my prediction...



#28 WoodyinNYC

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Posted 22 June 2015 - 06:58 PM

Portal Bridge will be first to go (fail) is my prediction...

It's the cheapest one to fix, only about a Billion, so it should get done first. As soon as Congress thinks it is important.



#29 jis

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Posted 23 June 2015 - 07:09 AM

Actually the Sawtooth Bridge will probably fail,before the Portal Bridge, considering the amount of toothpicks and baling wires that are already used to keep it from falling over. :)



#30 WoodyinNYC

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Posted 23 June 2015 - 07:35 AM

Actually the Sawtooth Bridge will probably fail,before the Portal Bridge, considering the amount of toothpicks and baling wires that are already used to keep it from falling over. :)

Is the replacement ready? iiuc For the new Portal Bridge, the Environmental studies are done and the construction plans are ready. All it needs to go is a Billion spread over a couple of years.

 

But I'm OK with a new Sawtooth Bridge, for less than a Billion, right?

 

The new Baltimore tunnel, the new Hudson tunnel, and a new Susquehanna bridge are nowhere near ready with environmental studies, construction plans, or the multi Billions needed. But in a sane world (a parallel universe, so to speak), Congress could easily find money to do a bunch of small < Billion projects while preparations continue on the multi-Billion biggies.

 

It's really discouraging that the fast section in New Jersey is running late and over budget (another thread). Makes it harder to convince Congress to start spending on the NEC's line-up of smaller projects.



#31 jis

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Posted 23 June 2015 - 08:29 AM

AFAICT the current plan for the Sawtooth Bridge is to keep patching it within what can be hidden in the regular maintenance budget until one of two things happens:

 

1. It just falls down (hopefully not taking a train with it) - and then it can be fixed using whatever emergency funding may become available or not.

2. Money is found for the quadruple tracking between CP Swift and CP Dock, which will include complete redoing of that entire segment anyway.



#32 afigg

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Posted 11 September 2015 - 10:57 AM

There was a local community association meeting presentation on September 1, 2015 with a new lengthy set of viewgraphs (52 pages total) with renderings of the alternative routes and locations for the tunnel entrance and exit complexes.  The file links are currently on the front page of the B&P Tunnel study website

 

The presentation is split into 2 PDF files, both fairly large at 5 to 6 MB. Here are direct links: Part 1 w Slides 1 to 30 and Part 2 w slides 31 to 52.  The renderings of the alternative tunnel entrances with 4 tracks and 4 tunnels show that some of them will require taking of a fair amount of property and land in west Baltimore.  One of the alternatives is a complete rebuild in place of the existing B&P tunnel with a cut and cover digout of the B&P tunnel along its entire length to increase vertical clearance by 5'. But that would be extremely disruptive to operations, if not requiring the southern end of the NEC to shut down for extended periods.

 

So, anyone want to figure out which alternative is going to be selected? which may not be the one you would pick.



#33 west point

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Posted 11 September 2015 - 12:01 PM

This poster's choice would be 3C 1st then 3 A.   Reasons.

 

Those routes seem to allow for the gentlest curves allowing for the fastest train speeds in and out of Baltimore station.  It would allow for the fastest speeds also at west Baltimore station.  Another good point would be that new crossovers at the west end of the station are constructed for higher speeds.

If the crossovers are able to be placed far enough west then that gives space for the platforms to be lengthened to the 1200 feet listed in the FRA NEC preliminary EIS.  East side platform length increases might require another Lincoln tunnel. 



#34 afigg

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Posted 21 October 2015 - 05:31 PM

There were a round of public hearings in October to present the results of the Alternative analysis for the tunnel replacement.  The Final Alternative Analysis report has been posted to the website here.  The 111 page report is broken into 2 files, but it is one report. With a lot of renderings, diagrams, and data on the Alternatives. The public comments section is at the end of the report if you want to read what the public reaction is.

 

This a significant step because now that they down selected the Alternatives to Alternative 3 Options A, B, and C. Alternative 11 has been dropped. Hopefully they have or can get enough funding to carry this study through the EIS process.



#35 west point

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Posted 21 October 2015 - 09:27 PM

The Amtrak FY 2016 funds requests shows  $20.0 M for final design and choice for the B&P tunnels.2   Also some $4.0 million repairs to the present B&P.



#36 neroden

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Posted 21 October 2015 - 11:26 PM

Interesting. So the B&P tunnels were fundamentally defective in design when they were originally built. Yeech. They were "just built really, really badly".

There are a lot of tunnels which are a lot older which are in perfectly good condition. Clearly a bad design.

It's interesting to learn that most of the "tunnels" are not rock tunnels, but cut and cover. The classic way to fix those is, um, to take the cover off and put a new cover on. It's been done. It works. It's not even that expensive.

I suppose it's considered to be too disruptive; since the tunnels are considered to be on a bad route anyway, I guess they figure improve the route while they're at it..

It's a little weird that they were built with such a bad design. There are older hard rock tunnels in good condition; there are older cut-and-cover tunnels in good condition. Deep bore (not cut and cover) earth tunnels were avoided whenever possible until the 1990s, after the trouble with Brunel's tunnel under the Thames -- but even Brunel's tunnel is still functioning just fine. Who built the B&P tunnel? If it's really as bad off as people are saying, the original builders were clearly incompetent.

Maybe they just had better engineers in the UK than in the US in 1873.

Edited by neroden, 21 October 2015 - 11:31 PM.

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#37 jis

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Posted 22 October 2015 - 08:23 AM

To be fair though Brunel's tunnel in East London has been completely rebuilt in the last two decades, eventually making it a part of the London Overground route which runs through it now. One critical difference between it and the B&P Tunnel though is that the East London Tunnel is a shield bored tunnel with brick and mortar lining designed specifically to operate under water - indeed the shield technique was invented for building this tunnel, whereas the B&P tunnel is a cut and cover tunnel basically running under various streets, and ancient leaky water supply and sewage conduits.

 

OTOH Severn Tunnel stands as testimony to excellence of British engineering. It will finally get some additional TLC as part of the electrification of the route to Wales through it. And even that tunnel has serious leakage issues, but none that threatens the integrity of the tunnel. It does throw an additional challenge to installing catenary in it. More likely the technology used will be shielded beams instead of catenary to keep it protected from seeping water.

 

I wonder why you say deep bore tunnels were avoided until the 1990s. Are you referring to the inherent higher cost of building deep bore tunnels perhaps? AFAIR almost all of London's tube system, which is deep bore tubes in clay, was built way before 1990. Actually in London, they seemed to prefer going deep bore over cut and cover, once they perfected the technique for building those. And even more oddly, most of the deep bore tubes follow the alignment of major thoroughfares above.


Edited by jis, 22 October 2015 - 08:26 AM.


#38 Andrew

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Posted 22 October 2015 - 03:31 PM

Isn't there a plan to have one of the four tubes cross under another tube? If so, why would this be the case?



#39 jis

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Posted 22 October 2015 - 03:47 PM

Isn't there a plan to have one of the four tubes cross under another tube? If so, why would this be the case?

In the B&P tunnel replacement? Not that I am aware of. What four tubes?


Edited by jis, 22 October 2015 - 03:48 PM.


#40 A Voice

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Posted 22 October 2015 - 05:10 PM

Are there any updated cost estimates for each option buried somewhere in the Alternative Analysis Report (or found elsewhere)?  I've skimmed the document, but didn't see any.  






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