Regional Rail (RUR) & North-South Rail Link (NSRL)

F-Line to Dudley said:
Yep. Some undercutting is needed there. The T upgraded the road bridges at Sullivan from Plate E to Plate F a couple years ago by relocating offending drainage pipes that hung underneath. They haven't yet tried any undercutting.


NBI reports pick a random spot on the ground instead of the track centerline, so if ground or structures aren't completely level end-to-end (e.g. "humped") they miss their spot.


EDIT: As an example of BridgeHunter/NBI's general unreliability for this, check out the page for the Cambridge St. overpass in Sullivan Square. Says 13.1 ft. of underclearance. Well...that would tear the whole second level off a bi-level and impale every locomotive on the T roster if it were accurate. It's low by a full third from actual. So you can really only trust BridgeHunter if it shows enough excess clearance to eliminate a structure from consideration.
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Do you know the actual height of Washington St OVER THE CR TRACK, as it is considerably lower than the OL track by then?
 
F-Line to Dudley said:
Yep. Some undercutting is needed there. The T upgraded the road bridges at Sullivan from Plate E to Plate F a couple years ago by relocating offending drainage pipes that hung underneath. They haven't yet tried any undercutting.


NBI reports pick a random spot on the ground instead of the track centerline, so if ground or structures aren't completely level end-to-end (e.g. "humped") they miss their spot.


EDIT: As an example of BridgeHunter/NBI's general unreliability for this, check out the page for the Cambridge St. overpass in Sullivan Square. Says 13.1 ft. of underclearance. Well...that would tear the whole second level off a bi-level and impale every locomotive on the T roster if it were accurate. It's low by a full third from actual. So you can really only trust BridgeHunter if it shows enough excess clearance to eliminate a structure from consideration.
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Of course, 13' 1" might be the height over the OL, which is probably 3ft above the CR track by then
 
Tallguy said:
Do you know the actual height of Washington St OVER THE CR TRACK, as it is considerably lower than the OL track by then?
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Those figures are only kept by the RR's clearance dept., so the exact measurements wouldn't be publicly searchable info. The freight RR's do post clearance maps for customers (Pan Am has a somewhat old one that pre-dates the 2020 Plate F re-clearing for Somerville-Everett), but those just show the routings not the individual structures.
 
Tallguy said:
Ive assumed that there is an allowance for dynamic load, but been unable to find any data. I mean, railcars do bounce a bit.
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Not sure about suspension vs. structural clearance, but the AREMA electrification clearances do factor some fudge for bouncing suspension. So the 31 inches of extra electrification clearance required is inclusive of that. In certain situations of escalating speed restriction on tangent track it can even shrink a couple inches below 31" because of the fact the suspension won't be bouncing as much.
 
F-Line to Dudley said:
Those figures are only kept by the RR's clearance dept., so the exact measurements wouldn't be publicly searchable info. The freight RR's do post clearance maps for customers (Pan Am has a somewhat old one that pre-dates the 2020 Plate F re-clearing for Somerville-Everett), but those just show the routings not the individual structures.
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So...in this case...the MBTA?
 
Tallguy said:
So...in this case...the MBTA?
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MBTA/MassDOT, and CSX as an operator. I'm not sure if they're filed with the FRA or not; the Feds might also get the measurements at each restricting structure for purposes of maintaining the official Plate designations on a given route.
 
"Theoretically possible" to run battery service on Fairmount + Stoughton.

Boy...that's just brimming with confidence. :rolleyes:
 
I'd note that those are the "most energy-intensive service patterns", so who knows what actual service would look like... Hourly service off-peak to Stoughton as the "most energy-intensive" pattern seems off...

Also, I'm not very impressed with the decreases in travel times. I know the TransitMatters report had some unrealistic speeds, but FIVE minutes off the current diesel train to Providence?
 
TrolleybusFoaming said:
I'd note that those are the "most energy-intensive service patterns", so who knows what actual service would look like... Hourly service off-peak to Stoughton as the "most energy-intensive" pattern seems off...

Also, I'm not very impressed with the decreases in travel times. I know the TransitMatters report had some unrealistic speeds, but FIVE minutes off the current diesel train to Providence?
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I hope they did their "most energy-intensive service patterns" calculations for battery capacities at sub freezing temperatures.
 
TrolleybusFoaming said:
Also, I'm not very impressed with the decreases in travel times. I know the TransitMatters report had some unrealistic speeds, but FIVE minutes off the current diesel train to Providence?
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BEMU's don't accelerate like straight EMU's because of the weight penalty for all the additional per-car battery bulk they're carrying around. Really fricking big and/or dense batteries, for powering a train. And of course that bulk is wasted on an already-wired Providence Line (arguably Stoughton, too, since there are zero overhead structures on the whole branch). Since the bids they received are likely variants of the already-heavy bids they received for the straight-EMU RFI, the performance penalty over what could-have-been may indeed be pretty severe.

It's the fervent--and very diversionary--belief in magic pixie dust to get them out of doing things. Just like the "DMU mania" of 10 years ago (that's never been spoken of again).

JeffDowntown said:
I hope they did their "most energy-intensive service patterns" calculations for battery capacities at sub freezing temperatures.
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Is there even an example of cold-weather BEMU's in wide acceptance??? This isn't battery buses we're talking, where there are dozens of large-deployment regional comparisons to reliably benchmark on. BEMU adoption is highly experimental worldwide.
 
I forgot to say this in the post, but, another implication of the 50-50 split between wiring and substation cost is that leaving short sections like Stoughton and Fairmount unwired saves less money than you'd think on a cost/km basis, because neither of these sections requires its own substation, and running battery trains is going to stress the Roxbury substation at least as much as wiring would.
 
Alon said:
I forgot to say this in the post, but, another implication of the 50-50 split between wiring and substation cost is that leaving short sections like Stoughton and Fairmount unwired saves less money than you'd think on a cost/km basis, because neither of these sections requires its own substation, and running battery trains is going to stress the Roxbury substation at least as much as wiring would.
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Probably more
 
Heaven forbid they negotiate away CSXs useless Plate H to Westboro rights. No, spend $200M extra just on Worcester Line rolling stock
 
Tallguy said:
Heaven forbid they negotiate away CSXs useless Plate H to Westboro rights. No, spend $200M extra just on Worcester Line rolling stock
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Westborough occasionally sees double-stacks as a temp parking spot when Worcester Yard is full. Not a frequent occurrence, but it happens. However there's only 6 overhead structures east of Worcester, some of them verifiably over-height for electrification...so the clearance expense is virtually nonexistent out there.

I don't see why any of Worcester should go un-wired. CSX sunset its Beacon Park-Framingham Plate F clearance exemption, and sunset its Plate F+ (autorack) Framingham-Westborough exemption down to Plate F. The height is completely there. It's only the handful of overpasses between Back Bay and Beacon Park in Plate C territory that pose any problems (with Beacon St. next to Landsdowne Station perhaps the one trickiest). Undercut where you can; coast under dead sections of wire where you can't. It's not hard at all.


Inner Worcester is the single service-densest unwired southside trackage. Just as the combined Eastern+Western Routes through Sullivan Square is the single service-densest mainline trackage on the whole northside. There's no place on the whole system where the expense for full electrification would be quicker-amortized than those two places. Those are the two places they are backpedaling the hardest from electrifying at all. If you want evidence of agency sandbagging on this effort, there it is.
👉
 
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