Arlington wrote:Red Wing wrote:Yup that's what I'm saying. You go on the Tower A side and then you're dealing with the tunnel exit to 93 south from Storrow Dr. You come in from the other side you have the graded area of the parking lot Straighter approaches for longer platforms and faster speeds. You also can add in more parkland. In reality demolishing all of this would be cheaper than relocating a major entrance ramp to 93.
Maybe you are under the false impression that I think new platforms would go on the Track 1 side (which would oviously create a problem), but this is just about improving throughput at peak times by having more than 4 tracks across the Charles, and no matter where the new track capacity comes in, all new platforms must be at 11 and higher.
So, no, so far you haven't shown that a Tower A / draw #0 routing would impinge on the Storrow-I93 Ramp. Nothing about the Track1-4 platforms changes (so nothing in the neighborhood of the Storrow-I93 underpass changes.
As it is Draw #1 points roughly between Tracks 2/3 and 3/4, with Tracks 1,2,&3 fanning out downstream from draw #1. A draw #0, put tight against #1 (as tight as #1 is to #2), and approached from where Tower A is today, would simply make landfall in Boston aligned with Tracks 2&3, and offer better capacity on tracks 1 to 4 (with 5 through 10+ re-allocated to make better use of the #1 and#2 we have now). With 5 through 10 feeling less crowded, you could install platforms and tracks 11, 12, & 13 (a 30% increase in platforms to go with a 25% increase in tracks across the river.
On the upstream side, putting #3 tight against the current #2 might require new pilings, but on the Cambridge shore would be approached by a single track on the currently-cleared gravel area alongside today's tracks and today's fenceline (beyond which lie a stub path, and bridge supports and just beyond them, the Duck ramp). A new Draw #3 is a very tight fit--you'd have to demolish the current pedestrian-pier-to-nowhere, and it its place, you'd only be able to fit 1 track (and leave a slot on the draw empty) but it would let you slip by Spaulding on the existing extreme upstream track (looks like Track 10). Once tied into that existing track that just skirts by Spaulding, you could fan out to serve a couple more new tracks (maybe 11, and, say, a new shorter 12-13-14). Since Spaulding no longer operates cryotanks alongside Track 10, fanning out is easy. These would (before demolishing Spaulding) share two tracks: the one on new Draw #3 and the existing extreme track on Draw #2.
Later, when Spaulding is gone and you've taken the Duck ramp (but not the bike bridge), you could lay a second track in the empty slot on Draw #3.
You have almost no weaving room to get on-alignment on the Somerville side. At that location end-of-bridge to first Leverett piling is 150 ft.; end-of-bridge to last Leverett piling in 275 ft.; end-of-bridge to BS&G's machinery and the freight siding is 325 ft. Now pick one of those distance increments and bank
HARD left by 50 ft. to merge the furthest-away track on the new draw into the nearest existing track with enough advance distance.
1) Do you know how SHARP and SLOW those S-curves are going to be? The performance penalty or having to crawl through there blunts too much of the edge "gained" by saving a rounding error on the ped bridge vs. doing tracks that are more tangent.
2) Do you know how derailment-prone those S-curves are (relatively) going to be? Or all the crossovers on the Somerville leads if any train other than an Eastern/Western Route has to bank hard to get over to this side? Yard limits and/or the terminal district is where the highest rate of derailments occur on any given rail network (freight, commuter/intercity, rapid transit...all of them). They're all slow-speed whoopsies and with high % of non-revenue vs. total traffic and thus relatively very safe, non-costly, and non-newsworthy derailments. But it is what it is: physics × frequency and time. Take the yearly # of train movements across a given stretch of crush-load busy terminal lead track, factor in the physics of the curvature and the wear put on track-and-wheel by each train. And figure the odds of how frequently something's going to go on the ground and make the news. It happens at South Station with regularity (i.e. more than once per year) by the unmodifiable geography of the due-west NEC and B&A having to make a due-north turn around water. And at SS it's just one continuous curve...not front and rear of the trains twisting simultaneously on both ends of a sharp S-curve between bridge pilings.
Would commuter rail ops, who are responsible for the wear-and-tear this puts on their physical plant, be in favor of taking the
least-tangent available path into the station for sole sake of "saving" a rounding error on a ped bridge? Or is that going to end up costing more year-in/year-out in maintenance than it saves by not doing a one-time fix to the ped bridge (if it even needs fixing) and the Duck ramp? Is T management going to be in favor of this when they're the ones who are going to deal with the fallout of every traffic chopper in town beaming live coverage of the latest A.M. commuter walk-of-shame over the Charles the last 1500 ft. to the terminal the next time something goes on the ground under the Leverett in bad weather? Complete with "OMG! It was so close to the water...can you IMAGINE how scary that was at 3 MPH?!?!" histrionics. No way. There are enough cushy management seats who don't want to voluntarily deal with that career hazard that it'll generate legitimate pushback even against the form-over-function decisions that get dictated from the top.
3) It does little for traffic distribution at NS to have to bank across so many lead tracks to reach the unexpandable side of the station. If/when more platforms are added it's the existing draws that are going to shoulder a disproportionate load.
Where is most of the traffic growth going to come from? Not the Western Route, which is at-capacity. Not the Eastern Route, which is already so service-dense it can't handle much more without a solid $100M+ in eat-your-peas mainline and junction fixes...and even then it's only got one more moderately serious gear to reach for before it's as big as it's ever going to get (don't forget...rush hour it very nearly has 15 min. Indigo-ish frequencies
today). Those are the only ones that slot neatly into an upstream draw without having to foul merging traffic.
Now look at the other two mainlines. The NH Main is operating at a fraction of its capacity. Add Nashua and the Lowell service increases that come with a real layover yard. Add Anderson short-turns. Add more Downeasters. Add more Anderson-Haverhills when Haverhill (with or without Plaistow) gets its bigger layover yard. Add ALL the Haverhills when it's decided the only way to give Reading denser frequencies is to trade the end-to-end route back to the Wildcat. Add Concord. And what about Fitchburg? Add the post-Wachusett schedule expansion and long-term expansion of reverse-commute options to Devens and Fitchburg. Add dense Waltham/128 short-turns. Add Grand Junction service from Worcester, add Amtrak Inlands and NYC-Portlands, add the West Station-Kendall-NS dinky if they really think the GJ can handle it.
Where are those service expansions going to pile? The existing draws, and the future expansion platforms in the Spaulding lot. It'll be an unequal distribution with the old draws operating much closer capacity than the new one. And overall northside capacity that gets crimped by all the crossing over that'll have to be done in 1500 ft. between Austin St. and the first pass-over of the Leverett ramps to get everything sorted for the bridges.
This exact weaving/sorting mess is what they are spending a kajillion dollars expanding South Station to fix. It's enough on-the-brain with MassDOT that there's no way in hell they're going to re-create a mini-me version of it on the northside.
It's a flat-out lousy use of resources to intentionally go with the inferior location with all the ops and maintenance complications because...reasons? I'm not even sure what equally-and-oppositely compelling reasons are being argued here (save something disruptive here by doing something more expensive and twice as disruptive there? some "if all feasibility were equal" what-if argument?). I know this state and this city loves to pick form-over-function, but this is a case where that's not going to fly. Want a terminal district to operate safely and as disruption-free as possible...pick the most tangent-possible of the available alignments when the money difference is negligible. Want a terminal district that actually serves permanent demand growth...don't screw up the pre-existing track sorting such that it harms the service density ceiling on some lines, and make damn sure it's aligned with the lines (and the platforms) that are delivering the bulk of this future growth.
Take the "rounding error". If they have to rework one deck span of the ped bridge and somebody makes some "OMG! GOV'T WASTE" exposé on the news...take that one-time hit instead of taking it twice a year when the news rips them a new one over a derailment on a kooky-tight S-curve. This isn't hard.
