Red-Blue Connector

[F-line to Dudley via Park]

How about they build a tunnel connecting State and Downtown Crossing. Wouldn't that solve the issue without costing a fortune? Sure it would be an expensive tunnel, but it wouldn't cost hundreds of millions of dollars.

Since the loading gauge is damn near the same, if you were going to do that you might as well merge the Blue Line into the Orange Line. An added benefit is that you could now use the pantograph-equipped BL trains on an extension out to Needham, or have them continue straight along the Pike and run to Riverside via Yawkey.

-- The State-DTX tunnel is a pedestrian tunnel. Like the Winter St. concourse connecting Park and DTX. It's been a desire dating back decades to study a pedestrian "three-quarters ring" around the downtown transfer stations...but one totally independent of plans for rapid transit construction.

-- You will spend WAY money trying to do something as bonkers as shotgun-marriage of Blue and Orange rolling stock than you will building Red-Blue. "Costing a fortune" is relative here. The Red-Blue construction estimate is padded by a 40% contingency estimate over the projected base costs to cover unknown mitigations when they dig at the base of Beacon Hill. The price could come down significantly closer to the base than the contingency, but no sane budgeter would plan for it without the contingency because of the risks. So you start with the high estimate. And for the money to be spent the bang-for buck is higher for Red-Blue than anything else downtown...INCLUDING finishing the former Silver Line Phase III link. There is no substitute, no creative thinking, no "cheap" (remember: it's all relative) solution that gets around it or takes an edge off it. Either do it, or spend 3x the money doing something 20% as effective. Or spend none of it at all and blow 5x the sum on South Coast FAIL.


-- As for Blue-Orange compatibility...yes, you sorta can. But it goes the opposite way...running smaller Blue cars on Orange with a littany of "easy", but collectively unsavory fixes to platform heights, etc. With no easy place to link the two because they cross each other perpendicular with zero room at State and aren't anywhere close to each other otherwise. And, by the way, run-thru (assuming you can rig it up) is a net capacity REDUCTION for Orange, which carries far more people. You'd probably have to spend another quarter-billion dollars to do 8-car platforms everywhere to offseat the loss in seating per consist. And another $2B to come up with parallel flanks, because Blue-to-Orange doesn't add capacity...it adds a branch off the downtown nerve center in which run-thru chokes each presently-'mainline' service level endpoints of car supply. That would be a disaster unless you build Atlantic Ave. El II to distribute the load. And why that would be mentioned in alternative to Red-Blue is insane.


Don't waste your energy trying to out-think what a half-century's worth of studies have made plainly obvious. There is no downtown subway enhancement and rider distributor that does more for its money than Red-Blue. None. There may be no non- state-of-repair project on the entire system that does more.

[Gerry6309]

The idea of a pedestrian tunnel along the block from Franklin to Milk is not that farfetched. The major problem is you have to stay level until the NB track drops under the SB platform at Milk St. Some creative taking of basement space in the buildings along that stretch may be needed, as the tunnel squeezes east over that distance to allow for the NB track to occupy the space under the street where the Summer platform is. There may not be enough room for a passageway along the entire distance, without some encroachment into those basements.

[cloudship]

I know I am taking the thread in a completely different direction, but if they are going to use a TBM, would it make more sense to simply start from State, go even deeper, and curve towards South Station? I know you would have to go around that building on the corner of State and Washington, but after that the buildings are small and old enough that they won't have absurdly deep foundations or pilings.

[F-line to Dudley via Park]

I know I am taking the thread in a completely different direction, but if they are going to use a TBM, would it make more sense to simply start from State, go even deeper, and curve towards South Station? I know you would have to go around that building on the corner of State and Washington, but after that the buildings are small and old enough that they won't have absurdly deep foundations or pilings.

The existing ped tunnel under Downtown Crossing used to go in that direction when it was just an empty upper-level shell over the Red Line. It got severed in the 1950's by construction of the I-93 Dewey Square tunnel. No way to reconnect because 'down' is where the Red Line is, 'up' is the surface, and 'level' is where I-93 is. Can't get there from here.

You definitely don't need a TBM for any of this. State-DTX is the ped tunnel that's the shortest distance and does the most good, and you really only need to ring around the transfers for all 4 lines to do the job. State-DTX-Park accomplishes all that. For everything that's at SS, remember that southside commuter rail and the Silver Line Transitway combined have fewer daily boardings than each of the Orange, Green, and Red Lines. SS is orders-of-magnitude less important than linking the foot traffic to/from all 4 subway lines at whichever 3 of 4 transfer stations hits them all (in this case Gov't Ctr. not needed because State-DTX-Park hits them all).

[Gerry6309]

I know I am taking the thread in a completely different direction, but if they are going to use a TBM, would it make more sense to simply start from State, go even deeper, and curve towards South Station? I know you would have to go around that building on the corner of State and Washington, but after that the buildings are small and old enough that they won't have absurdly deep foundations or pilings.

The existing ped tunnel under Downtown Crossing used to go in that direction when it was just an empty upper-level shell over the Red Line. It got severed in the 1950's by construction of the I-93 Dewey Square tunnel. No way to reconnect because 'down' is where the Red Line is, 'up' is the surface, and 'level' is where I-93 is. Can't get there from here.

You definitely don't need a TBM for any of this. State-DTX is the ped tunnel that's the shortest distance and does the most good, and you really only need to ring around the transfers for all 4 lines to do the job. State-DTX-Park accomplishes all that. For everything that's at SS, remember that southside commuter rail and the Silver Line Transitway combined have fewer daily boardings than each of the Orange, Green, and Red Lines. SS is orders-of-magnitude less important than linking the foot traffic to/from all 4 subway lines at whichever 3 of 4 transfer stations hits them all (in this case Gov't Ctr. not needed because State-DTX-Park hits them all).

The fact that Government is all island platform makes it difficult to attach any external passageways. Tremont Street is impossible between subway, foundations and the Kings Chapel and Old Granary Burial grounds. Court Street had a temporary passage along the existing tunnel ca. 1912, during which time the floor was lowered to reach Scollay Under. Existing buildings along Court limit any potential for a pedestrian passageway. The old tunnel along Cornhill could connect Government and State using the remains of State's old Adams Sq. exit, but requires stairs and elevators at both ends. This leaves connecting Downtown Crossing (Summer) and State (Milk), a virtual no-brainer, as it can be done without any grade change at all.

[Adams_Umass_Boston]

I would also think that some of those buildings would have pylons buried underneath. That would also be an issue.

[Gerry6309]

I would also think that some of those buildings would have pylons buried underneath. That would also be an issue.

The primary building in the area is the one built for but never occupied by Raymonds in the late 1960s. It was later occupied by Woolworths and now by H&M and TJX. There are three smaller, older buildings between there and Milk St., but the Milk Street Platform probably extends some distance in front of them (about 100 feet). The distance between the north end of Summer and the south end of Milk is very short (about 300 feet per the drawings in the 1905 BTC Report with Summer having since been extended about 30 feet northerly). (A six-car train is 390 feet long)

[BandA]

So, the main advantage vs. walking on the street is avoiding going up & down stairs & weather?

[MBTA3247]

So, the main advantage vs. walking on the street is avoiding going up & down stairs & weather?

That, and paying a second fare.

[Gerry6309]

So, the main advantage vs. walking on the street is avoiding going up & down stairs & weather?

Plus a free transfer and time saved not having to wait for the Orange Line (10 minutes or more at times) ...

[cloudship]

Yeah, I messed that one up big time. I typed South Station when I was thinking Park Street Station. I wasn't so much thinking about a pedestrian tunnel as much as digging the blue line deeper and heading in that direction. Eventually (meaning probably never) that stub might be a way to get another tunnel to Back Bay.

What is under Tremont St, besides the Green line. It is had to find accurate information about where building foundations and old services are located.

[Gerry6309]

Yeah, I messed that one up big time. I typed South Station when I was thinking Park Street Station. I wasn't so much thinking about a pedestrian tunnel as much as digging the blue line deeper and heading in that direction. Eventually (meaning probably never) that stub might be a way to get another tunnel to Back Bay.

What is under Tremont St, besides the Green line. It is had to find accurate information about where building foundations and old services are located.

Check out the Chief Engineer's Report in the Boston Transit Commission Annual Reports. (on-line at Bostin Public Library)

[MBTA3247]

Yeah, I messed that one up big time. I typed South Station when I was thinking Park Street Station. I wasn't so much thinking about a pedestrian tunnel as much as digging the blue line deeper and heading in that direction. Eventually (meaning probably never) that stub might be a way to get another tunnel to Back Bay.

What is under Tremont St, besides the Green line. It is had to find accurate information about where building foundations and old services are located.

Given the existing configuration of Park Street, I don't think it could handle the crowds from 3 subway lines.

[Gerry6309]

Yeah, I messed that one up big time. I typed South Station when I was thinking Park Street Station. I wasn't so much thinking about a pedestrian tunnel as much as digging the blue line deeper and heading in that direction. Eventually (meaning probably never) that stub might be a way to get another tunnel to Back Bay.

What is under Tremont St, besides the Green line. It is had to find accurate information about where building foundations and old services are located.

Given the existing configuration of Park Street, I don't think it could handle the crowds from 3 subway lines.

It does!

[Disney Guy]

Yeah, I messed that one up big time. I typed South Station when I was thinking Park Street Station. I wasn't so much thinking about a pedestrian tunnel as much as digging the blue line deeper and heading in that direction. Eventually (meaning probably never) that stub might be a way to get another tunnel to Back Bay.

I think there is no value in extending the Blue Line towards the Boston Common.

After the Blue Line is extended to Charles/MGH, the next possibly meaningful extension would be continuing along the riverbank more or less following Storrow Drive.

The existing subway stationss should not be converted to shared operation, that is, no sharing of the Orange Line by Blue Line trains.