Red Line / Blue Line Connector

sneijder

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But State is close enough to Orange specs that demoing Bowdoin for Red-Blue either allows you a very nearly Orange-length car with only slight stubbiness..
Are all the BL platforms (ex. Bowdoin) already long enough to fit a 6-car OL train from CRRC? Once the extension to MGH is complete I'd think we only have a handful of years before needing more capacity than the current rolling stock. The Maverick to GC stretch is already getting packed.
 

Arlington

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^ BL-OL length commonality should be the goal of Blue Line Transformation, but we'll have to wait for our BLT (pun intended).

I would hope by then we'd be buying trains where you can walk from car to car, and that the next BL fleet would be prototyping that too.

{EDIT} Once the Bowdoin loop is gone, it seems like the Orient Heights Yard loop is the next tightest BL curve, and if they eliminate that, then OL == BL for curves.
 
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F-Line to Dudley

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Are all the BL platforms (ex. Bowdoin) already long enough to fit a 6-car OL train from CRRC? Once the extension to MGH is complete I'd think we only have a handful of years before needing more capacity than the current rolling stock. The Maverick to GC stretch is already getting packed.
A 6-car Blue set runs 300 ft. (291 ft. + couplers, rounded-up to nearest 10).
A 6-car Orange set runs 400 ft. (390 ft. + couplers, rounded-up to nearest 10).

  • Wonderland -- '04 lengthening left structural allowances on north end for further lengthening by placing utility boxes beyond reach of future 400 ft. platform. Subtract 7 parking spaces from westerly side and move tail track crossover ~50 ft. Trivial job.
  • Revere Beach -- Offset platforms will fit if extended to max out all space between Beach St. & Shirley Ave. overpasses. Move crossover to other side of Beach St. bridge. Casualty: 1 park bench on Beach St. side. Trivial.
  • Beachmont -- Retaining walls for '04 lengthening extend well south of station. Extend that direction. Trivial.
  • Suffolk Downs -- Offset platforms. Property fence on inbound side has almost 200 ft. of room. Outbound side borders parking lot; 250 ft. available with a re-striping. Better than trivial.
  • Orient Heights -- 150 ft. space available @ full width between end of current platforms and Saratoga St. overpass. Wholesale-rebuilt station seems to provision exactly for this, because no touches to other infrastructure necessary. Better than trivial.
  • Wood Island -- Retaining walls appear to be pre-built in Frankfort St. extension to allow for 100 ft. extension. Pre-provisioned? Trivial.
  • Logan Airport -- Roof at new station is nearly 400 ft. long, extra slack at south end before Pike/1A interchange ramp pilings. Can't verify with certitude, but likely trivial.
  • Maverick -- '04 lengthening did not use all of the space behind the false wall; more than enough still remains. Trivial for subway construction.
  • Aquarium -- '04 lengthening notched narrow platform extensions into the cross-Harbor tunnel. A similar lengthening would just continue that effort. Only utilities at that point are tunnel wall utilities, so that's not much of a problem to tuck on the ceiling. No additional obstructions since just more of the same from the last extension. Moderate difficulty because of higher expense and longer construction timetable, but feasibility not a question.
  • State St. -- ??? There is still a small rump of pre-1924 trolley platform sticking out towards the GC direction. This one will probably require more invasive utility relocation than all others, and thus higher price tag...but is not that big a question mark on feasibility. Consider also that the platform lengthening will be part-and-parcel any curve straightening plans that may result from a "BLT" study. Longer cars immediately become available once Bowdoin is gone as the ruling curve, but the remaining difference between that post-Bowdoin length and pure Orange Line length comes from what they determine @ State.
  • GC -- Still some slack space behind the walls that they didn't use up when they extended onto the old trolley platforms in '04. There will probably have to be a little bit of wall notching, but not nearly as much as State or Aquarium which will keep costs down. The recent big renovation also did a major utilities cleanup both upstairs and down, so the new utility rooms limit the amount of on-wall crap they need to worry about. Moderate work, but feasibility a virtual guarantee and cost should be reasonable.

In short, basically ALL of the surface stops are a piece of cake...in no small part from the fact that the '04 lengthenings, wholesale station renovations, and couple of from-the-ground-up rebuilds seem to have all anticipated Red-Blue enabling longer train lengths in the future. Each individual station project seems to have taken pains to leave further extension as near shovel-ready as humanly possible. In the subway Maverick is no problem and GC is nearly no problem. Aquarium is a bit of a slog...if at least a no-surprises slog. And State's the only one with complications, albeit complications whose fixes might get lumped together in the curve-easing.

They had a much harder job in '04 because of all the surface stations needing significant touches, and much harder subway work in '86 and '87 when Orange and Red were lengthened Haymarket-Chinatown and Central-Ashmont for 6-car trains. I think it'll price out very feasible for whatever net gains in length they can get from Red-Blue straightening out Bowdoin, and the rest all depends on what "BLT" finds at State curve re: whether shooting for straight-up Orange length is the jackpot size.
 

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