by F-line to Dudley via Park
They want to do fixed replacement spans for Pelham, Portal, Susquehanna, and Bush. Which would eliminate all movable bridges south of Greenwich, CT except for Dock Bridge in Newark (which opens like once every 5 years). All of them are 2-track.
Portal is the only one they're pinned in at doing only a 2-track replacement, because of the limitations of the east-side approach through the swamp. "Portal South", constructed ~1000 ft. downstream, would be an identical-design capacity expander when they need it (originally proposed for ARC, but won't be a thing they need until sometime post- Gateway when we start talking 2040 superduper HSR. The other 3 replacement spans they are facing real dilemmas: ideally they'd like 3-4 tracks on the fixed replacements, but will there be any money for it? Clearly they've got only 1 shot for each replacement to get their idealized track capacity, so it's a doubly difficult advocacy point: not only fund a replacement before the thing kicks, but fund one that serves >50-year traffic needs.
There's also the CT River Bridge, which is replacing that low bascule with a high bascule, with twin draw one for each track for redundancy's sake, that rarely has to open. That got approval for expedited design and EIS a couple years ago, but I don't know what the design completion stands at today or whether much of the construction cost has been appropriated. That solves the single biggest bottleneck on the Shoreline and is what will allow the full Shore Line East commuter rail schedule to get extended to New London (or, later, Westerly) instead of having to truncate most of the time at Old Saybrook. Though the relative media silence on that one's progress has to do more with final funding being in less doubt...USDOT gave it the special EIS waivers to move it near the front of the line, which telegraphs a preference for moving it near the funding/scheduling front of the line.
At least with the other 3 New Haven Line spans they're already quad-track and locked into place by the surrounding density that they must be 1:1 movables-for-movables replacements like Walk. They can't be made fixed even if they wanted, can't be widened even if they wanted. They can only be replaced by better movable spans, such as Walk's replacement being a lift with 2 separate 2-track lifts. Lifts being much faster, stronger, more reliable, and easier to maintain than swings or bascules in *most* situations where maritime traffic doesn't have to be unlimited-height. Which is why Thames River got retrofitted with a lift replacing its former bascule. And in Walk's specific case, since the maritime traffic on Norwalk River is almost entirely short commercial barges it can open adjustable-height and close even faster. So you'll probably see Cos Cob, Saga, and Devon get more or less the same design--and potential for expedited engineering on those designs.
The only issue with those are CDOT and the Feds doing penance for too many years of deferred maintenance and utter lack of planning here. There's no 'existential' questions like there is from Pelham-south on spending the extra $$$ to raise the track approaches so a movable can get replaced by a fixed, or spending the extra $$$ to set capacity needs for life. Just "eat your damn peas". What makes it hard is that having 4 in equally bad condition in 1 state on 1 mission-critical commuter rail line in only 2 Congressional districts (Jim Hines and Rosa DeLauro) doesn't jibe well with the way fed spending gets allotted. Especially with the CT River replacement (Joe Courtney's district) already being a funding recipient. It's much easier to spread funding around several states at once than around several bridges in 1 state at once. So while Portal (NJ) and Walk (CT) are rightfully at the top of the list, it does mean Cos Cob / Saga / Devon (CT)--despite being much more acute concerns--might have to get slotted between Susquehanna (MD) or considerably lesser-concern Pelham (NY) just because spreading the love through different Congressional districts is the way infrastructure funding works. And that Susquehanna / Bush (MD) will be in direct competition with each other AND the fixed-span replacement Gunpowder bridge (MD) AND the B&P tunnels on the priority queue regardless of which is the "worst" (and that's probably the tunnels). So by odd quirk some of the worst-condition bridges in CT and MD may have to outlast some of the least-worst condition bridges for purposes of 'porcine equitability' in Congress.
Portal is the only one they're pinned in at doing only a 2-track replacement, because of the limitations of the east-side approach through the swamp. "Portal South", constructed ~1000 ft. downstream, would be an identical-design capacity expander when they need it (originally proposed for ARC, but won't be a thing they need until sometime post- Gateway when we start talking 2040 superduper HSR. The other 3 replacement spans they are facing real dilemmas: ideally they'd like 3-4 tracks on the fixed replacements, but will there be any money for it? Clearly they've got only 1 shot for each replacement to get their idealized track capacity, so it's a doubly difficult advocacy point: not only fund a replacement before the thing kicks, but fund one that serves >50-year traffic needs.
There's also the CT River Bridge, which is replacing that low bascule with a high bascule, with twin draw one for each track for redundancy's sake, that rarely has to open. That got approval for expedited design and EIS a couple years ago, but I don't know what the design completion stands at today or whether much of the construction cost has been appropriated. That solves the single biggest bottleneck on the Shoreline and is what will allow the full Shore Line East commuter rail schedule to get extended to New London (or, later, Westerly) instead of having to truncate most of the time at Old Saybrook. Though the relative media silence on that one's progress has to do more with final funding being in less doubt...USDOT gave it the special EIS waivers to move it near the front of the line, which telegraphs a preference for moving it near the funding/scheduling front of the line.
At least with the other 3 New Haven Line spans they're already quad-track and locked into place by the surrounding density that they must be 1:1 movables-for-movables replacements like Walk. They can't be made fixed even if they wanted, can't be widened even if they wanted. They can only be replaced by better movable spans, such as Walk's replacement being a lift with 2 separate 2-track lifts. Lifts being much faster, stronger, more reliable, and easier to maintain than swings or bascules in *most* situations where maritime traffic doesn't have to be unlimited-height. Which is why Thames River got retrofitted with a lift replacing its former bascule. And in Walk's specific case, since the maritime traffic on Norwalk River is almost entirely short commercial barges it can open adjustable-height and close even faster. So you'll probably see Cos Cob, Saga, and Devon get more or less the same design--and potential for expedited engineering on those designs.
The only issue with those are CDOT and the Feds doing penance for too many years of deferred maintenance and utter lack of planning here. There's no 'existential' questions like there is from Pelham-south on spending the extra $$$ to raise the track approaches so a movable can get replaced by a fixed, or spending the extra $$$ to set capacity needs for life. Just "eat your damn peas". What makes it hard is that having 4 in equally bad condition in 1 state on 1 mission-critical commuter rail line in only 2 Congressional districts (Jim Hines and Rosa DeLauro) doesn't jibe well with the way fed spending gets allotted. Especially with the CT River replacement (Joe Courtney's district) already being a funding recipient. It's much easier to spread funding around several states at once than around several bridges in 1 state at once. So while Portal (NJ) and Walk (CT) are rightfully at the top of the list, it does mean Cos Cob / Saga / Devon (CT)--despite being much more acute concerns--might have to get slotted between Susquehanna (MD) or considerably lesser-concern Pelham (NY) just because spreading the love through different Congressional districts is the way infrastructure funding works. And that Susquehanna / Bush (MD) will be in direct competition with each other AND the fixed-span replacement Gunpowder bridge (MD) AND the B&P tunnels on the priority queue regardless of which is the "worst" (and that's probably the tunnels). So by odd quirk some of the worst-condition bridges in CT and MD may have to outlast some of the least-worst condition bridges for purposes of 'porcine equitability' in Congress.