ebtmikado wrote:"Dealing with the current grade crossings at Central Ave and Capen St. would be an issue. The line would have to be elevated, unless we were willing to have RT grade crossings a la the CTA Brown Line."
The Long Island Rail Road has dozens of 3rd rail grade crossings. Very seldom do you see a human-size lump of charcoal at the crossings.
It's not very hard to eliminate those. The ROW is well-buffered and Red Line trains can climb steep enough grades that shortish-distance emankment inclines + a regulation-height rail overpass are no big deal at Capen. Central Ave. likewise would need short embankments + the overpass, with just a boxed retaining wall running 150 ft. west of the crossing and 50 ft. east of the crossing for slipping past the tight squeeze of abutting buildings on the south end of the crossing and the Neponset trail on the north side. The sum total of all other track infrastructure related to a Red conversion just amounts to:
1) Replacing track from lightweight, medium-quality PCC track to heavier-weight, more precisely-ground HRT track and replacing ties for the 3rd rail mounts.
2) Trenching 3rd rail power cable + signal cable, and shoring up any track-level drainage issues that may impact underground conduits. This may be slightly less invasive and cheaper if the HSL has a pre-existing underground power trunk that periodically pops up to feed the overhead lines...in which case that is fully recyclable if the cable is in good enough shape and can be augmented for a load increase without having to permit for a whole additional set of conduits.
3) ROW fencing in any open spots. Already exists around the adjacent trail and through the cemetery, so probably limited to the wooded spots and non-trailed sides. Since the trail is going to be expanded west of Central Ave. in the next 3-6 years, probably won't be many fence gaps left to plug when the trail is done.
4) Any upgrades to the Ashmont Branch power feed above and beyond what's already
scheduled to happen in advance of the new Red Line cars. This power upgrade, which is listed as an unfunded mandate in the T's CIP documents, leaves enough extra slack for LRV's on the HSL. So you'd only be talking further upgrades comprising the difference between a one- or two-car Type 9 at HSL headways to a 6-car 01900 at Ashmont Branch headways. Significant jump, but because of that mandatory 01900-prep upgrade project the it's not as daunting as a jump from today's pre-upgrade feed that can only power one-car PCC's and 015/016/017/018 Red cars.
5) Minor reconfiguration of Codman Yard interlocking for thru service and northbound turnout into the yard + loop. Reconfig of Mattapan to sever the yard and loops for a stub-end terminal.
6) Any closeout bridge weight upgrades not previously completed. I think the last one that's still weight-restricted is the smaller of the two Neponset spans right by Mattapan; all others are up-to-snuff having been replaced in the last 10 years. That last span is no doubt pegged somewhere on the cycled bridge replacement queue and probably will be taken care of many years before Red conversion ever goes on the table. I think they might be bundling that replacement in with the westward trail expansion so a third trail berth can get tacked onto the side...so may be settled sooner rather than later.
That's it for simply getting the end-to-end track infrastructure up to Red-caliber. If a couple things state-of-repair related and security fencing-related have been taken care of much prior by previously-scheduled HSL maint items and trail construction, then the running track can probably be done in-total for no more than $30M and the 2 overpasses for no more than $40M. Then it's on to stations, and the make-or-break necessity of keeping station construction cost control in-check for a change.
-- Cedar Grove, Butler, Valley Rd., and Capen St. are all eliminations, since ridership is low and Mattapan + one Milton intermediate sticks closer to avg. Red Line stop spacing (excluding, of course, the longer jaunt through the Cedar Grove population cavity).
-- Milton/Central Ave.
-- Works better at Milton under the Eliot/Adams overpass instead of Central Ave. Station spacing is more equitable on that side. It's easier for engineering because of the new rail incline and bridge over Central Ave. preventing a station from being build any closer to Central then the mid-block, and tight quarters around the abutting Central Ave. buildings making an elevated station impossible. Milton has more space for headhouses, a surface fare lobby, and an island platform under the existing overhang with no modifications required to the overpass if the rail trail were removed from below and snaked up to a surface crosswalk instead at that spot. Overhang provides weather protection for the eastern third of the platform, limiting the amount to the west that faces open wind Charles MGH-style. The trails flanking both sides of the river, the former rail bridge linking the two trails at the midpoint, and Eliot St. provide multiple pedestrian options for reaching Central Ave. While Central Ave. has more ridership today than Milton, that's mainly because the bus routes on that side are more heavily patronized. Walkup density actually clusters closer to Milton, so sending those Central Ave. buses a block down Eliot St. effectively consolidates 100% the ridership at easier-to-build Milton without any inconvenience to Central Ave. Don't go insane
with the frills and this one should be doable at $30-50M.
-- This one can be done with fairly minimal modification and ample recycling of existing structures. Take the small island platform between Tracks 2 & 3 and extend it both directions to 6-car Red Line length, bumper posts at the end of the platform. Drop the trackbed to achieve the proper platform height. Augment the existing shelters but don't get fancy. Wrap the headhouse around to meet the west end of the expanded island for fare control and one west-side exit. Retain the Track 1 island platform shared with the busway as a tertiary platform; extend 100 ft. east to full 6-car length and likewise drop the trackbed. Fence it off from the busway so it's now a side platform inside of fare control. Buff out the sidewalk on the busway side of the fence to compensate for the lost space. Reconfigure the interlockings coming off the Neponset bridge for choosing platforms. For regular ops immediately turning back in revenue service, use the Tracks 2 & 3 island. Use Track 1 primarily for trains that are going out-of-service and either laying over for a longer spell or deadheading back to Codman. Have electronic signage at the station clearly explaining the platform assignments. If Track 1 isn't scheduled for any turning revenue trains for a long period of time have short swing gates that station staff can open or close to block access. Tear down the trolley yard and maint shed. Total cost: $15-25M if they're disciplined and recycle the existing station building and Track 1/busway platform structures effectively.
Whole project can reasonably can be done for a $250M total price tag if managed shrewdly. Something's very wrong and needs audit + further contracting reform if it ends up topping $300M. Codman remains the yard-of-record, so unless you want a 4th non-platform storage track on the south end for misc. storage there's probably no need to have any more end-of-line track capacity than Orange's seldom-used Oak Grove tail track an equal number of stops from Wellington as Mattapan is from Codman (at lighter Ashmont Branch headways for slipping in deadheads). Trolley viaduct at Ashmont would get torn down or be partially dismantled/partially recycled for a side path on the east side of the Codman embankment linking the former Cedar Grove station entrance direct into Ashmont. Expanded Neponset trail system (to be completed west of Central Ave.) brings Butler, Valley, Capen direct into Milton or Mattapan station catchments. Abandoned trolley yard at Mattapan becomes a possible TOD opportunity to underwrite that station's capital costs with private development.
Ta-da? If Milton were willing to part with its boutique intermediate stops full Red conversion project-managed well is pretty low-hanging fruit, no?