by F-line to Dudley via Park
BostonUrbEx wrote:http://farm6.static.flickr.com/5139/546 ... 8d1f_o.pnghttp://www.eot.state.ma.us/redblue/down ... 100210.pdf
Dashed lines are current track which would be eliminated. Solid blue lines are track which would be in place after the project concludes, and the dot-dash-dot-dash lines in the red box are Mass EOT's storage/crossover plans for Charles/MGH. The black boxes west of Bowdoin are for the relocated Bowdoin, roughly between Staniford and Joy Steets.
This leaves two tails for up to three 6-car trains, or up to 2 trains and a work train/equipment, with 2 of these spots at the platforms and one in the current westbound tunnel. The tunnel storage space could be left open then, so a train could be pulled off to allow for the changing of ends off the line, and then they can quickly get out and crossover into Government Center to head eastbound.
Infrastructure is here that can be utilized to our advantage, no need to go in swinging sledgehammers and bulldozing things over because it's not for revenue service.
Also, GC-State-Aquarium is 2300 feet. GC to MGH is ***3000 feet***! I plopped Bowdoin at roughly 1500-1500, compared to the current 2000-1000. I think the better location will also attract more ridership.
Actually, the tail track configuration can't have any crossovers at Charles behind the platform because of the bridge piers for the Longfellow. The link above shows the design. The platform is going to be under the street ahead of the Red Line station. That's why the new station's lobby has such a conspicuously large space around the bend from the Charlie gates to the RL stairs. The stairways and elevators down to the BL level would be right at the wall to cover that horizontal distance under the street where the platform is. Only crossovers would be Alewife-style immediately before the platforms, the only spot possible because the dig from Bowdoin is going to be a double-tunnel with solid center wall instead of a single cut like GC-Bowdoin. The tail tracks would then peel off from the Charles wedge platform on curves in either direction: one following the MGH/hotel side of Charles Circle and terminating under the Mass Eye & Ear parking lot, the other peeling off the Charles St. side of the Circle and ending under the street about where the CVS is. The CVS-side one would have storage for 1 consist, the parking lot side one space for 2 consists back-to-back. Only way it can be done, since the last Longfellow piers supporting the Red Line el right at the station run pretty deep underground at the same level as the BL tunnel.
The upside of this is that if the line were ever extended past Charles on a right turn under Embankment Rd. or a left turn under Storrow on the turn-of-century Riverbank Subway alignment, curves making the turn in either direction would already be built. And you can see on the diagram that even though these tail tracks are single-track in each direction the tunnel walls look to be comparable to the width of the GC-Bowdoin tunnel. The 1-track layover spaces would be equipped with an operator platform and walkway to the station, so if those were ripped out in one direction for an extension you'd have the space for 2 thru tracks. I read somewhere that this engineering future-proofing was intentional, although its primary purpose is just giving personnel the walking space to squeeze comfortably around a 1-track parking spot.