GERALD L MCFARLANE JR Note, notching of arched tunnels is not uncommon, all one needs to do is look at all the arched tunnels that the SP/UP notched between Oakland, CA and Reno/Sparks, NV to accomodate full double stack container trains...no problems what so ever(other than nicks and scrapes on the containers that don't quite make it in to the notches on first try).
Note, notching of arched tunnels is not uncommon, all one needs to do is look at all the arched tunnels that the SP/UP notched between Oakland, CA and Reno/Sparks, NV to accomodate full double stack container trains...no problems what so ever(other than nicks and scrapes on the containers that don't quite make it in to the notches on first try).
Mount Royal Station - 1895
Electric 'helper' has just pulled a steam powered train Eastbound (North) through the Howard Street Tunnel whose East Portal can be made out behind the train.
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blue streak 1 ~snip~ 5. Notching ceiling of an arched tunnel might have unintended consequences. ~snip~
~snip~
5. Notching ceiling of an arched tunnel might have unintended consequences.
kgbw49 BaltACD, thanks for the excellent info! One more question - once Howard Street Tunnel is cleared for double stacks, does that in theory clear that side of the CSX "triangle" for double stacks the full length of the Eastern seaboard? I am not suggesting a specific need for such a service. I just have read quite a bit about the ports in Florida and Alabama trying to ramp up capacity to capitalize on their location to the expanded Panama Canal, which serves as the catalyst for my question. Thanks again!
BaltACD, thanks for the excellent info! One more question - once Howard Street Tunnel is cleared for double stacks, does that in theory clear that side of the CSX "triangle" for double stacks the full length of the Eastern seaboard? I am not suggesting a specific need for such a service. I just have read quite a bit about the ports in Florida and Alabama trying to ramp up capacity to capitalize on their location to the expanded Panama Canal, which serves as the catalyst for my question. Thanks again!
There would still be one major obstical - Boone Tunnel between Twin Oaks, PA and Philadelphia. I am not sure what it will actually clear, the 19'2" multi-level autoracks that are cleared to Twin Oaks are not cleared on the track segment that contains Boone Tunnel. I am thinking it will clear something on the order of 17'3" - a regulare Trailer on Flat Car shipment at the present time. Note - you may see some 'double stack' trash containers on various trains operating on CSX's I-95 corridor - they do not have the same height as normal shipping containers - ocean going or domestic.
The Port of Baltimore has dredged it's harbor and purchased new container cranes for the port to be able to handle the so called 'post-panamax' container vessels that will be transiting the revised Panama Canal. Without double stack rail carriage of containers into and out of the port - those improvements may become wasted capital investment.
RME kgbw49 Do you see the tunnel remaining as two tracks? Although it is not two-tracked, there is adequate lateral space for two tracks if the undercutting were carried down an additional several feet, dependent on what kind of notching of the tunnel arch could be conducted. There was some discussion of this option (along the general lines of 'if you're spending all that money why not go ahead and do a bit more to get double-track for stack traffic). There is a substantial amount more undercutting needed, and here of course the subway problem arises to bite you. This could be solved by putting a vertical sag in the subway at that point, but that's a bunch of time, cost, and politics perhaps best left unroiled. Then any roof removal near the springing of the arch substantially weakens its strength compared to cutting higher up. So if the full capacity of double tracking is not needed it makes better sense just to optimize the one (which can come reasonably close to doubling the effective throughput as well as preserve considerable efficiency in operating consists from other areas through to the port in minimum time with minimal container handling). If I were considering this job, however, I'd look into what methods to use in the future to further expand the tunnel for double-stack. This would involve undercutting the sides and doing drainage, etc. to get to finish grade relative to the roof-arch springing, then repeating the process of putting supports across to hold the existing track while undercutting, and finally using a contemporary track machine to set first one track and then the other (by then we may have units, perhaps optimized for European clearances, that can utilize temporary ROW while leaving an adjacent track clear for traffic even within this tunnel's confines. But I doubt I would live to see the need for that.
kgbw49 Do you see the tunnel remaining as two tracks?
Although it is not two-tracked, there is adequate lateral space for two tracks if the undercutting were carried down an additional several feet, dependent on what kind of notching of the tunnel arch could be conducted. There was some discussion of this option (along the general lines of 'if you're spending all that money why not go ahead and do a bit more to get double-track for stack traffic). There is a substantial amount more undercutting needed, and here of course the subway problem arises to bite you. This could be solved by putting a vertical sag in the subway at that point, but that's a bunch of time, cost, and politics perhaps best left unroiled. Then any roof removal near the springing of the arch substantially weakens its strength compared to cutting higher up.
So if the full capacity of double tracking is not needed it makes better sense just to optimize the one (which can come reasonably close to doubling the effective throughput as well as preserve considerable efficiency in operating consists from other areas through to the port in minimum time with minimal container handling).
If I were considering this job, however, I'd look into what methods to use in the future to further expand the tunnel for double-stack. This would involve undercutting the sides and doing drainage, etc. to get to finish grade relative to the roof-arch springing, then repeating the process of putting supports across to hold the existing track while undercutting, and finally using a contemporary track machine to set first one track and then the other (by then we may have units, perhaps optimized for European clearances, that can utilize temporary ROW while leaving an adjacent track clear for traffic even within this tunnel's confines. But I doubt I would live to see the need for that.
The tunnel itself is the biggest chunk of the double stack issue, however when it comes to double tracking the problems expand geometrically as the Baltimore Belt Line has a number of additional tunnels for street overpasses that would have to be reengineered to allow the 20'2" clearance for a double track configuration rather than single track.
Beyond that the Philadelphia Subdivision from Rossville (about 4 miles East of Bayview Yard - the Easternmost yard in Baltimore Terminal and the gateway to Dundalk Marine Terminal where the port's container operations are) to Philadelphia is a single track CTC operation with effectively 3 passing sidings (there are 5, however one is used in the operation of Wilsmere Terminal at Wilmington, another is used to build and yard trains for the Twin Oaks automotive transloading terminal). 90+ miles with 3 meeting points. This territory was double track back in the passenger days that ended in 1958. Subsequently the line was changed from double track current of traffic operation with multiple train order offices to the single track CTC configuration it has today. IF and it is a very big IF, traffic were to increase well beyond present levels, then some segments of double track might be restored to the line - that will not happen in the foreseeable future.
In light of the earlier problems with Howard Street tunnel and the CSX experience with the Virgina Avenue tunnel, I wonder what was pencilled-in as the local extortion/ mitigation rate?
kgbw49Do you see the tunnel remaining as two tracks?
blue streak 1Several items. 1. Steel ties ? Guess there will be some kind of special ABS ? How will PTC be implemented ? 2. Passing over the MTA subway might require a tunnel bridge since otherwise bottom of track bed too close to top of subway ? 3. Since tunnel is close to sea level the possibility of water flowing into subway will need mitigation. 4. What about a repeat of the flood from Baltimore water ? 5. Notching ceiling of an arched tunnel might have unintended consequences. 6. Light rail trains above tunnel may apply excess weight on tunnel. 7. Besides water and sewer any shifting even temporary of utilities may break lines causing major outages. Might need utility crews on duty in case of breaks.
1. Steel ties ? Guess there will be some kind of special ABS ? How will PTC be implemented ?
2. Passing over the MTA subway might require a tunnel bridge since otherwise bottom of track bed too close to top of subway ?
3. Since tunnel is close to sea level the possibility of water flowing into subway will need mitigation.
4. What about a repeat of the flood from Baltimore water ?
6. Light rail trains above tunnel may apply excess weight on tunnel.
7. Besides water and sewer any shifting even temporary of utilities may break lines causing major outages. Might need utility crews on duty in case of breaks.
Subway bridge is in place and was constructed when the subway was constructed.
kgbw49Thanks for clarifying. I looked at Google satellite maps and it appeared to have two tracks on each end going in to the portals, which prompted my question. Thanks again!
At the North end, under the train shed of the former Mount Royal Station (now MD College of Art) there begins a 4500 foot siding between the control points of Mount Royal and Huntigdon Avenue.
With the building of Baltimore Light Rail and the development of the Camden Station area into ball parks for both the Orioles and Ravens, the South Portal of the tunnel has been moved several hundred feet further South from its original location. The South end is now defined by the control point HB, which controls access to Locust Point Yard as well as continuing as double track from HB to the control point Carrolls. The Baltimore Belt Line is single track from HB to the control point Clifton Park.
Several items.
Thanks for clarifying. I looked at Google satellite maps and it appeared to have two tracks on each end going in to the portals, which prompted my question. Thanks again!
It isn't 2 tracked now - that ended shortly after the B&O quit the New York passenger service. It has been single track for over 50 years.
Do you see the tunnel remaining as two tracks?
My understanding is that what is necessary will be undercutting just the 'center' of the tunnel area to stack depth, then notching the tunnel roof for 'corner clearance' with appropriate reinforcement (probably cross-drilling with tremie and rods, but other systems could be used). I'd expect that some of the expense would involve the necessary beams and temporary track first on one side of the 'passenger ROW' and then the other that will permit the undercutting and regrading, perhaps even placement of the track on the depressed section, with the spoil being extracted to the 'other side' of the available ROW footprint as needed. Then the temporary beams could be extracted in several parallel locations, being removed to both ends and swung for stacking in the side 'lanes' to clear the new track quickly, so cutover would be pretty quick and direct without too much delay to existing traffic. I don't see much likelihood of 'gotchas' or expensive permitting runthroughs, archeological surprises, drainage disasters, or the other usual things, so most of that cost is in the special systems needed to maintain HAL service through the tunnel while the work is proceeding.
An alternative would be to perform the undercutting in stages, using some kind of temporary shoring to accommodate track level across each newly-undercut portion, and then do finish grading, track setting, and top-down alignment using a tracklaying machine like the one in use for Springfield; the undercutting in this case would assure whatever lateral clearance at the new grade would be needed into the old passenger ROWs to clear the track machine or access to it as it worked. That would involve a fixed time out of service, but the time saved in running the 'delayed' containers double-stacked would make up for a considerable amount of that time with only a few trains...
BaltACD I suspect there may end up being cost overruns, however, it will be less than the estimated $1.6 Billion to construct a new tunnel (and that would probably get doubled once you entered into the enviornmental permitting process). Getting Howard Street Tunnel double stack capable is critical to the survival of the Port of Baltimore and the economy of the State of Maryland.
I suspect there may end up being cost overruns, however, it will be less than the estimated $1.6 Billion to construct a new tunnel (and that would probably get doubled once you entered into the enviornmental permitting process).
Getting Howard Street Tunnel double stack capable is critical to the survival of the Port of Baltimore and the economy of the State of Maryland.
I would think that the $425M figure came from CSX. Would CSX be less then truthful?
From Progressive Railroading:
Reconstruction of the tunnel has been discussed for years, but was postponed due to concerns that the project would be "highly disruptive" to the surrounding community, state officials said. Project cost estimates have ranged from $1 billion to $3 billion.However, CSX and the Maryland Department of Transportation (MDOT) have determined that recent advances in construction technology — including a technique that involves lowering the floor and notching the crown of the tunnel — make the project more affordable at $425 million with minimal impact to the community.
What is above the tunnel, ie fill, rock, streets and buildings, soil will have a significant bearing on costs and the potential for overruns. If the original tunnel was constructed as a cut and fill, some of those questions can be answered.
I guess the OP's story wasn't directly linked, as the story has moved off the linked page.Anyway, while not really in the same league, but literally the closest major rail freight tunnel project, the Virginia Ave. tunnel project in Washington DC seems to be on schedule. Is it coming in on (or near) budget? Sounds like cut and cover like Virginia Ave. would not work welll in Baltimore.
rrnut282What is above the tunnel, ie fill, rock, streets and buildings, soil will have a significant bearing on costs and the potential for overruns. If the original tunnel was constructed as a cut and fill, some of those questions can be answered.
What is above - the main commercial business area of the City of Baltimore in the 1950's & 60's. Numerous multi-story buildings that in their day were the high level Department Stores line both sides of Howard Street. The Baltimore Light Rail Line that runs between Hunt Valley to the North and BWI Airport to the South runs down the middle of Howard Street. The Baltimore Metro (subway) is beneath Howard Street and I believe, underneath, the Tunnel.
The tunnel was constructed in the 1890's as double track for passenger trains with a gauntlet track for freight running down the middle of the tunnel. Needless to say, freight and passenger operated through the tunnel at separate times. The tunnel was the 1st Electrified segment of railroad in the US. Electric motors coupled to trains (passenger & freight) South of the tunnel and pulled them up hill through the tunnel so the steam engined did not have to work steam and detached on the fly at a point known as Waverly that was North of the tunnel. Southbound trains were able to coast downhill and had no need to work steam while in the tunnel.
Shortly after the B&O abandoned passenger service to Philadelphia and New York, the passenger tracks were removed, leaving only the track in the center of the tunnel. In the middle 70's 17'3" multi-level loads of autos could proceed at a normal 25 MPH through the tunnel; 17'5" multi-levels were restricted to 10 MPH. Since then tunnel enhancements now permit the current 19'2" enclosed auto racks to operate through the tunnel at 25 MPH.
At present, if there are severe Thunderstorms that linger over downtown Baltimore, the tunnel will get water over the top of the rail - there are pumps in place to pump the water out, however since the bottom of the tunnel is nominally at sea level, or maybe a foot or two below, there is no place to actually pump the water to, especially at High Tide.
I believe, but don't know, that most of the work to allow 20'2" Double Stacks and auto racks will be done by notching and rebuilding the tunnel ceiling so that a thinner tunnel section can still support all that is above the tunnel. I am not a civil or construction engineer so anything I say about what they will actually be doing can be taken with a grain of salt.
If I don't believe it, it's gonna be because I've got the feeling the estimate is too low...
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
CSX and Maryland saying tunnel can be enlarged for $425M.
http://www.baltimoresun.com/news/maryland/
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