On the old 1902 Bromley map of the South Station area, there is a two track turnaround tunnel looping under South Sta., apparently one level below the main station level.
These loop tunnels would be useful for an electrified Indigo Line, to loop around one level below the rest of the South station tracks. If the Indigo Line were outfitted with overhead catenary, the trains could use these tunnels, and a new pedestrian passageway punched through to the Silver Line station level, with easy access to the Red Line.
The Postal service building, scheduled to be removed, would remove one major obstacle to restoring these loop tunnels.
By now, with all of the construction that has occurred in the area since the 1980s (bus terminal, Big Dig, etc.), that those tunnels have long been rendered unuseable. I know during the reconstruction of the South Station terminal in the mid to late 1980s that parts of the tunnels were uncovered and dismantled anyway, but I don't know if the entire tunnel loop was demolished at the time, or only the parts that were "in the way".
That tunnel has been discussed previously in some detail, but maybe on the "old" forum, so I don't know if that material is available.
Mr. White is correct -- the portion of the loop under the station itself was uncovered and filled in during the 1980s reconstruction of the headhouse, the Big Dig and associated track relocation got the approach on the Fort Point Channel side when I-90 burrowed underneath, and the other approach was roughly under the bus terminal and all that associated roadwork. No chance whatsoever of reclaiming it, although most of it was intact until about twenty years ago.
The short history is: South Station was originally built with a double track lower level loop, which was intended for use by commuter trains. A steam-powered ceremonial train filled it with smoke shortly after the station opened, and it was never used in revenue service, although if the New Haven RR had electrified its Boston suburban service at the beginning of the last century, it undoubtedly would have been. Grand Central Terminal has a similar loop, still in use to turn equipment.
There was a lower level waiting room beneath the current station headhouse. It became a bowling alley that was in use into the 1970s.
The South Station lower loop was built for Nantasket Beach Branch RR-type cars, which were State-of-the-Art in the 1890's. This means center 3rd rail DC power for the most part.
I've seen the engineering documents for the "South Union Terminal" (as it was originally called) as presented in the American Society of Civil Engineering (ASCE)'s annual yearbook from around 1900. It was written by the Chief Engineer, George Francis. The drawings show very little overhead clearance for even 1890's equipment.
After the failed attempt to use it with a steam engine, the lower level in addtion to a bowling alley (which my father used once or twice), was also a parking garage with the ramp on Summer St. about half way down the building.
It's virtually an impossibility to re-open and / or re-create the tunnels. Yes, it could be done (the Big Dig proves that), but it would involve digging a large hole underneath several other existing structures (not counting the USPS).
The two best histories of South Station were in the New Haven Railroad Historical & Technincal Association's magazine, "The Shoreliner" Vol. 20 Issue 3, and in the book, "Boston's Depots and Terminals", a fairly expensive hardcover, but well worth it, IMHO.
FYI- I have a copy of "Boston's Stations & Terminals," and it's an excellent book full of illustrations and good text. We offer it for sale at our Chapter's store, if you make a purchase, it supports our museum activities:
vanshnookenraggen wrote:So if the NS-Link is ever constructed would there be a loop or at least a provision? I haven't seen any plans for it. Heck, would a loop even be useful enough to justify it today?
Probably not, because any N-S link plans would've included provision for a "Central Station" somewhere between the existing stations, and I would guess that's where any looping would occur.
But there is no room, assuming the Central Station would be near or at Aquarium Station. I would think that a loop would be good for short run CR service that is only going as far as South Station, but then if you are freeing up all that space by running trains through to the north side then you probably wouldn't need a loop anyway.
I walked the remaining parts of the loop during the S. Station reconstruction.
The straight (southerly) leg from the ramp appeared to have been
demolished when the Postal Annex was built. What remained was much of
the platform area and the northerly curve under the ground-level tracks.
The loop was built for 60-foot equipment using overhead wire, with passenger
access via car steps from a rail-height platform; The platform area was
completely paved with no provision for 3rd rail. The curve through the
platform area was far too sharp for high-level platforms, unless retractable
platform segments were used. Train length was at least 4 cars, but not much
So, had there been profit in it, the New Haven could have run effectively
interurban service to Quincy, Dedham etc. But the Boston Elevated Ry.
made that market unattractive, and the loop was technologically obsolete
On the subject of loors and tunnels, North Station and South Station are just over one mile apart. I cannot understand why a "Central Station" would ever be needed in the North-South Rail Link. If it was constructed, it would be so far underground that you would probably need ten or so escalators to reach the street, since it would be at the lowest point on the line!
Also it would be another delay for a stop a half-mile past either Station. I just cant see it;...the cost and the delay......??? It doesn't make sense to me.