expanding South Station downward?

Instead of expanding South Station outward, is it feasible and realistic to have trackage gates underneath the existing station, similar to Grand Central Station?

I saw the lower level of the old South Station as it was being demolished, so it could be done. But it would likely cost a lot more and be much more disruptive than moving the Post Office and converting that space back to a similar number of platform tracks. And we apparently can't afford to do that...

jbvb wrote:I saw the lower level of the old South Station as it was being demolished, so it could be done. But it would likely cost a lot more and be much more disruptive than moving the Post Office and converting that space back to a similar number of platform tracks. And we apparently can't afford to do that...

The old lower level was just baggage passageways, with the exception of the loop, which saw exactly one train. Only electrics could use an underground terminal, so that means Amtrak. With existing tunnels to the north, east and south, the grades would be fairly stiff, and the platforms short, ruling out locomotive hauled trains. Amtrak doesn't have any EMUs, though there might be some worn-out M2s and Silverliners on the market. And the T could have electrified the Providence line years ago - no interest.

If the North South Rail Link gets built you would have a station underground.

Red Wing wrote:If the North South Rail Link gets built you would have a station underground.

Yes, very deep to get under the Red Line at about 80 feet below the surface. Assuming a 10 car platform, 850 feet, and a 2% maximum grade means the approach would start almost a mile away, 4850 feet to be exact.

I wouldn't hold my breath for that one, unless someone discovers an infinite cache of cash!

Gerry6309 wrote:

jbvb wrote:I saw the lower level of the old South Station as it was being demolished, so it could be done. But it would likely cost a lot more and be much more disruptive than moving the Post Office and converting that space back to a similar number of platform tracks. And we apparently can't afford to do that...

The old lower level was just baggage passageways, with the exception of the loop, which saw exactly one train. Only electrics could use an underground terminal, so that means Amtrak. With existing tunnels to the north, east and south, the grades would be fairly stiff, and the platforms short, ruling out locomotive hauled trains. Amtrak doesn't have any EMUs, though there might be some worn-out M2s and Silverliners on the market. And the T could have electrified the Providence line years ago - no interest.

The Providence line is already electrified, except for a few station tracks. Fairmont line would also be an excellent candidate for electrification, along with the Framingham Line out to Riverside or possibly Framingham. In order to make electric service feasible they need more storage space, some sort of repair facility, a good rate for use of Amtrak's electric catanery, low price of electricity and good pricing on electric locomotives or DMU's.

And especially fare parity with the subways. Not fair that the fare is more than double for the same or shorter distance.

The New Haven saw the future and it was electric propulsion. They wanted to compete with the street and elevated railways but that didn't work out in Boston. Subways started getting subsidized in the 1920s, commuter rail not until the 1960s/70s.

I don't see why "South Station Under" platforms couldn't be exactly the same length as the surface platforms. At the same time you could rebuild Back Bay as a dual layer station increasing Commuter Rail/Amtrak/Orange capacity & flexibility, possibly accommodating that long approach to North-South rail tunnel, but using Back Bay and North Station and skipping South Station - those wanting to go to South Station or downtown or waterfront or elsewhere take a connecting service from Back Bay.

Going down should be a contingency in case they can't get the Post Office. Or a negotiating strategy to get the Post Office to a better price by threatening to cut them out of the new station. Or long term we might need both the Post Office and "South Station Under".

Another option mentioned for adding more South Station tracks Is to expand on the Atlantic Avenue side, even if it means taking part of the street. It seems extreme but all creative ideas are on the table in case they never get the post office property.

Utilizing the old suburban loop would have engineering issues -- all potentially solvable -- but a large number of fiscal and political issues might be beyond solution.
Next to South Station is South Postal Annex, and next to South Postal Annex is Fort Point Channel, which soon swings around and requires the bridging just past Tower 1. The channel was a human creation to achieve two goals -- maintain navigation inland from the harbor and increase available land by partially infilling a tidal inlet. As with most twin-purposed achievements, there are compromises and conflicts. A quick Google Earth check will show the channel's elevation as 0, Mean Sea Level. The adjacent land and structures are subject to the stresses and instability of varying levels of tides, saturation, and pressure. During the original Big Dig, the approaches to the draws had to be frozen by piped refrigerant to provide stability and alignment. The calculation for expansion -- frost-heaving -- had to be tweaked, showing the lack of stability in that immediate area.
The loop was intended for suburban service and was built with tight curvature for short cars. It was also designed for 600-v. power. Put in current length cars, and push-pull seems the only appropriate operation. Install overhead for Amtrak-level voltage, and the floor would have to be dropped to provide sufficient clearance both above and below the overhead to prevent flash-over. Passenger and emergency-services ingress/egress would also require consideration and impact the station itself.
As "wet" Boston-area transit tunnels -- for the Muddy River and the harbor -- prove, effective seepage control is possible. Tunnels are tubes and far easier to control for seepage than larger and more open structures, even large tunnels like the O'Neil and Ted Williams showing a progression in difficulty.
If a cross-city rail connector had been built instead of being discussed during the original Big Dig, the city and those who travel in and through it would now be better off. Given the delays, disruptions, overruns, and ridicule accrued to Big Dig I, there is little political and/or fiscal likelihood of a Big Dig II, The Sequel.
Maybe the T part of MassDOT and Amtrak could start buying lottery tickets. A few jackpots might meet a stated need:

Gerry6309 » Wed Aug 12, 2015 10:52 pm
...I wouldn't hold my breath for that one, unless someone discovers an infinite cache of cash!

but there would still be the problem of disruption and disrupted and angry voters.

NRGeep wrote:Instead of expanding South Station outward, is it feasible and realistic to have trackage gates underneath the existing station, similar to Grand Central Station?

Do you mean Grand Central Terminal? Grand Central Station is in Chicago.

With respect to the prospects for the MBTA electrifying its Providence/Wickford Jct. service, there is a counter-example currently playing out 400 miles to the south. MARC has decided to buy more diesels to replace the aging AEM7s and unreliable HHP8s that it runs between Washington and Baltimore, rather than buying new electrics. Reasons: the high cost of buying power from Amtrak, and the inflexibility created by having equipment that can be used on only one line (and MARC has only three). Both factors would apply to the MBTA as well.

As for South Station itself, it all comes down to money (like everything else in railroading). The Postal Service is willing to move and free up the land once occupied by South Station's highest numbered tracks, but they want to paid to move and provided with a new location for their mail facility. At this point the state hasn't met their price and there seems to be standoff. Rebuilding the eastern half of the original South Station is the long term game plan for increasing capacity, but until a big bag of public money appears that isn't going to happen.

If this was an airport expansion it would happen tomorrow.

Diverging Route wrote:

NRGeep wrote:Instead of expanding South Station outward, is it feasible and realistic to have trackage gates underneath the existing station, similar to Grand Central Station?

Do you mean Grand Central Terminal? Grand Central Station is in Chicago.

Yes. Was in Chicago.

The distance from Atlantic Ave. to the I-90 tunnel is about 2000 feet. Since a shallow tunnel under the building and concourse isn't feasible, delete 150 feet. If you now allow for an 850 platform, you have 1000 feet left. A 20 foot rise to the surface on a 2% grade would consume another 1000 feet. That leaves no room for any sort of yard throat. A lead to the yards would require a similar, possibly steeper, down grade to get below the I-90 tunnel.

There aren't many options other than paying the price the postal service wants. And that still leaves the Stone & Webster building at the Summer St. end.

Here is what you have for tunnels surrounding South Station.

Southbound I-93

Under Surface Artery and Rose Kennedy Greenway with its roadway at about -30 feet.

Red Line

Under Summer St. descending from about -40 feet at Chauncy St. to about -70 feet east of Dewey Sq. Descends to about -80 feet, then curves to the southwest and runs under the center of the Fort Point Channel to where the channel curves to the west under Dorchester Av. Bridge. The tunnel continues level to about 1000 feet south of Summer St., where it begins to rise, curving to the south under Dorchester Ave. to Broadway Station at about -50 feet.

There is an upper deck to the Red Line Tunnel between Chauncy St. and the Surface Artery, which is occupied by the AFC shop. It was removed east of that point for a distance of about 90 feet to make room for the present Southbound I-93 in the late 1950s. East of that point was a station lobby and a substation, at which point the upper level ended. I am not sure what became of the substation, but the lobby was replaced by the current Silver Line station under Atlantic Ave.

Silver Line

The Silver Line tunnel runs under Atlantic Avenue at a depth of about 40 feet from a loop south of East St.to the vicinity of Northern Ave. where it curves to the east and dives under the Fort Point Channel.

I-93 Northbound

The I-93 Northbound tunnel was built as part of the Big Dig, to add lanes to I-93 in this area. From a portal at Kneeland St., it descends at a steep grade under Atlantic Ave to dive under the Silver Line and then Red Line, then ascends at a milder grade and curves under the Rose Kennedy Greenway, where it joins the southbound lanes and passes over the Blue Line at State St.

I-90

The I-90 tunnel begins just east of I-93 at a point where the road is already below the local grade. the through lanes are joined by two side tunnels carrying ramp traffic and passes under the rail yard at a shallow level and continues under the Fort Point Channel, passing above the Red Line. The tunnel was a major project as part of the Big Dig owing to unstable ground and the proximity to the roof of the Red Line tunnels.

Although the tunnels to the south and east can be crossed, they require tunneling at deep level. The tunnels to the north and west form walls which require even deeper tunneling to cross. Finally, there are few locations where the rights-of-way are wide enough to allow portals into such tunnels. Steeper grades would work for EMUs but not for locomotive hauled trains, unless there are locomotives with the necessary horsepower in the works.

For starters, here's the Original track layout for South Station. You can see how the restrictive loops underneath still took up the entire footprint of the original station layout- you aren't going to get a loop unless you also reclaim the Post Office land, and even then, it is questionable.

For just stub-ends like there are on the surface now, and you wanted the Old Colony lines to access it, you'd have to build two tunnels: the one for access from the NEC, and then another one underneath the Bass River to the Old Colony lines. It'd be better to just segregate the services anyways, since the only thing the MBTA was considering ever electrifying would be the South Shore Rail, which wouldn't be coming in from the OC lines anyways.

Mentioning South Shore Rail is a good segue to talking MBTA electrification. As mentioned with MARC, there isn't a reason for any commuter rail service in general to invest in buying electric locomotives for the lines that run underneath Amtrak's wires unless they themselves own and operate an electrification system. The MBTA operates a lot of different lines, and the benefit to electrify their first line needs to have a great benefit to get over the investment of an electrification system and electric locomotives. Once they already have a fleet and their own grid and equipment, it becomes much easier to then electrify other lines. I don't know if there's actually any other thing besides from South Shore Rail that the MBTA would ever consider electrifying; and now that the political favoring for that project has had the wind taken out of its sails, and the MBTA's hand is slapped away from the cookie jar of funding, I don't think it will progress anytime soon.

Going back to use of a lower level for Amtrak, if you started having tracks descend prior to Back Bay, you could probably get deep enough for a lower level. It certainly would address capacity issues in the Southwest Corridor going forward, especially for when Amtrak wants to get their NextGenHSR (Inland Route) project through with all the extra traffic that entails.