Depth of Subway?

Does anyone know how deep the subways in Boston are? I was in London, and the subways over there are deep enough that they were used as air raid shelters during WWII. I image that most of Boston's stations are not that deep (except maybe Porter Sq ), but any ideas as to how far underground they are on average? Thanks.

Porter is the deepest, I feel Davis is deeper than most in Boston.

The green line is a simple cut and cover, so these are not very good. The red line I would say is the deepest since it crosses uner green at park, silver at South Station, orange at Down town, and davis/Porter beeing so deep the red line is the closest thing to the London one you mention for air rades. My thoughts, orange and green to close to surface. Blue line.... hmmm... not sure how deep those stations/tunnels are.

Just from memory, I think platform level at Porter is around 80-120 feet down. Could be very wrong though, but I thought that's what I heard.

The Aquarium station is also pretty far down...probably the deepest outside of Porter or possibly Davis.

The old Red Line in Cambridge though is very shallow (one story below street level), thru Kendall and Central, and up to the new construction at Harvard.

Red Line only gets real deep around Porter and Davis, and that was done mostly for the benefit of the Porter-to-Davis stretch where the line deviates from the street grid and starts going underneath people's property. It eases back closer to the surface for the Davis-to-Alewife stretch where it mostly snakes underneath the old surface freight line (now a bike path). That ROW has no additional surface grade crossings once it crosses Mass Ave., so it would've been feasible to do simple cut-and-cover for the last leg with minimal surface disruption...especially since there weren't nearly as many residences abutting the old freight line back in the early-80's. Whether or not that's what they actually did 25 years ago, I don't know...but the existing ROW probably had something to do with how deep they went. Once it reaches Alewife the depth is back to about 1 story below ground...and I think the tunnel stays that depth until it ends underneath the Minuteman Bikeway on the other side of Route 2 (right around midfield of the soccer field in that park, if the location of the last emergency exit is any indication). I imagine if they opted to extend the line into Arlington they could've done it cut-and-cover most of the way below the Minuteman, except for maybe Arlington Center when they'd have to go under the big Mass. Ave/Route 60 intersection.

Old-construction RL tunnels are fairly uniform in depth. The Harvard-to-Longfellow tunnel stays 1 story below street level the whole way (sunlight even reaches into the tunnel late-afternoon via the emergency exit on the inbound side right after the animated ad), and the Charles-to-Andrew segment stays 2 stories below street level due to the trolley tunnel/provision built immediately above. The tunnel portions of the Ashmont line are all simple cut-and-cover (and may not technically be below ground for parts of the way).

Green Line is cut-and-cover all the way, save for maybe the last stretches to the C- and D-line portals (they both go below the Mass Pike, and the Mass Pike is below street level at that point...therefore it's at least 2 stories below street level). Given the relatively high number of portals and former portals along the route (Comm. Ave., old Kenmore portal, Huntington Ave., Boylston St., Public Gardens, Tremont St., Haymarket, the "new" Science Park portal)...there's not really any chance along the way for the line to dip too far down.

Blue Line gets real deep just before it goes under the water, but it gets shallower in a hurry. By State it's at the same depth as the Green Line, which is why they had to remove the floor at Court Street in order to extend the line to the other side of the Tremont Street tunnel to Bowdoin and the old portal. And the Maverick end can't be too deep given proximity to the portal.

Orange is either cut-and-cover or just-plain-cut in the SW Corridor, though it gets pretty deep at New England Medical Center (probably to allow for extension above of the almost-adjacent abandoned end of the Tremont Street tunnel). Starting where the new tunnel hooks into the old Chinatown tunnel it's back to just below street level (Chinatown inbound is VERY close to the old portal), and that's where it pretty much stays save for the sudden and dramatic "dip" at State. The Haymarket-North tunnel also goes a little deeper into the bi-level new North Station...and then it feels like a long climb out to the Community College portal.

And of course the Orange line is fairly deep where it tunnels under the Charles River.

I believe the Red Line tunnel is rather deep as it makes its way under the Fort Point Channel.

The section under the Fort Point Channel is sunken steel tubes put in a trench on the bottom of the channel. So that's not so deep...

F-line to Dudley via Park wrote:Red Line only gets real deep around Porter and Davis, and that was done mostly for the benefit of the Porter-to-Davis stretch where the line deviates from the street grid and starts going underneath people's property. It eases back closer to the surface for the Davis-to-Alewife stretch where it mostly snakes underneath the old surface freight line (now a bike path). That ROW has no additional surface grade crossings once it crosses Mass Ave., so it would've been feasible to do simple cut-and-cover for the last leg with minimal surface disruption...especially since there weren't nearly as many residences abutting the old freight line back in the early-80's. Whether or not that's what they actually did 25 years ago, I don't know...but the existing ROW probably had something to do with how deep they went. Once it reaches Alewife the depth is back to about 1 story below ground...and I think the tunnel stays that depth until it ends underneath the Minuteman Bikeway on the other side of Route 2 (right around midfield of the soccer field in that park, if the location of the last emergency exit is any indication). I imagine if they opted to extend the line into Arlington they could've done it cut-and-cover most of the way below the Minuteman, except for maybe Arlington Center when they'd have to go under the big Mass. Ave/Route 60 intersection.

If you're lucky enough to get the open front or back window (works better up front if they use the headlights) on an 01800, you can easily see where the tunnel construction from Harvard to Alewife switches from (probably) cut-and-cover box construction, to deep bored tube (after Harvard) and then back again to box construction near Alewife.

sery2831 wrote:The section under the Fort Point Channel is sunken steel tubes put in a trench on the bottom of the channel. So that's not so deep...

I saw that same documentary on the Discovery Channel John, LOL. I can't remember whether it was MOdern Marvels or something else though.

Um, I think you're thinking of the Ted Williams Tunnel. I don't know how the Red Line under Fort Point Channel was built, but it dates from the early 1900s, so it hardly qualifies as a Modern Marvel.

The Green Line under the Pike was also cut-and-cover, most likely, as it was built long before the Pike went through. Though I'm not sure how they crossed the Boston & Albany line that it was built next to.

The silver line tunnel was sunk into that channel.

I know the tunnel is very old CEO, but there was a special about the Big Dig, which showed how much room there is between the Red Line and the water. It was about the Big Dig, and things that had to be done to the tunnel to prevent problems.

At Broadway station the tunnel is 2 stories deep as there was originally a subsurface tunnel for trolley cars that was only used briefly (until the Dorchester extention was built?) and then used to store records.

I seem to remember from the old days of riding the 0600's when you could still see out front (I'm dating myself!) going inbound from Broadway the tunnel descended until about halfway to South Station then started climbing then leveling off before the curve into SS. At South Station it is farily shallow again.

Yes the Ted Williams is a modern sunken tunnel, but the Red Line tubes under the channel are also very simular! Also on the Orange Line under the Charles is the same!!!

Also, the South Station Tunnels feature that commercial discussed in the Animated Ads thread.