Discussion relating to the operations of MTA MetroNorth Railroad including west of Hudson operations and discussion of CtDOT sponsored rail operations such as Shore Line East and the Springfield to New Haven Hartford Line

Moderators: GirlOnTheTrain, nomis, FL9AC, Jeff Smith

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  by F-line to Dudley via Park
 
NH2060 wrote:
DutchRailnut wrote:The design their going for, is a 2x2 lift bridge, so if one span were not to lock you still have two tracks to move trains.
Belated question, but any idea on how high a lift span would have to be? The transmission lines above the bridge would obviously keep the height of the lift span towers to a minimum max height, but is there conceivably enough room to fit in a lift bridge with sufficient clearance (like the Harlem River and Thames River spans?).

If they do indeed go ahead with a lift span I'd imagine they'd build the towers in a similar fashion to how the replacement Thames bridge was constructed. Followed by floating in the span itself. It will definitely require one or more service outages, but that'll likely be the best case scenario.
The way around that is to have the poles on and immediately around the bridge hang the transmission lands pointing outward instead of over the lift span, so it's clear of the lift span's footprint. But as Dutch noted that's unnecessary here because there's no boat traffic tall enough to matter. It doesn't have to be a particularly high lift to satisfy current max boat clearances.
  by Ridgefielder
 
NH2060 wrote:
DutchRailnut wrote:The design their going for, is a 2x2 lift bridge, so if one span were not to lock you still have two tracks to move trains.
Belated question, but any idea on how high a lift span would have to be? The transmission lines above the bridge would obviously keep the height of the lift span towers to a minimum max height, but is there conceivably enough room to fit in a lift bridge with sufficient clearance (like the Harlem River and Thames River spans?).
According to the NOAA chart of Norwalk Harbor, the Washington St. drawbridge immediately downstream has a vertical clearance of 100', while the I-95 bridge upstream has a vertical clearance of 60' above mean high water. So it definitely won't be higher than the former or lower than the latter. Same chart indicates that the power cables are 203' above m-h-w, by the way, so there's plenty of room to build the hoisting towers and still not disturb the wires.

Like Dutch said, the marine traffic at Norwalk is nothing like that on the Thames River. The controlling depth of the channel upstream of the Norwalk River bridge is 7.4 feet at mean-low-water; the channel depth upstream of the New London bridge is 40'.
  by Lincoln78
 
Any attorneys out there? Maybe the president will issue an executive order and close the waterway. CT has already demonstrated that the state can do some interesting things with eminent domain.

Navigable waterway notwithstanding, I would guess there is nobody who has continually used the river as long as the railroad has been crossing it. Who has higher standing-a sailboater moved to CT in 2002 or the successor to an nineteenth century railroad? Would it be a good decision?

With due regard to national security I have heard from reliable sources that the Coast Guard barque doesn't go past the bridge anymore. Keeping the channel for the submarines is slightly more critical and CT does not want to lose the sub base.
  by F-line to Dudley via Park
 
It's moot. Norwalk River has active water freight going up all 1.5 miles of navigable river (up to the Wall St. bridge downtown). Look on Google Maps; there's 3 barges parked at Devine Brothers right next to the Danbury Line tracks. And then look at the 7 sets of recreational piers and several hundred small boats. There is no way eminent domain of a navigable waterway is going to survive lawsuits from one of the city's biggest industrial businesses, over a half-dozen pier owners, and hundreds of boat owners. The bridge will have fallen into the river before that legal mess gets settled, and it'll end up being no cheaper for all the time and money wasted with the two sides trying to extract their pound of flesh.


The crossing is a problem because the current bridge is broken and nobody set aside funding for a replacement until it was too late. It is not a problem because the waterway is navigable and it has to open occasionally. A proper lift bridge opens and closes fast, especially one like this that doesn't have to open all that high. And has the redundancy of two moving decks if something goes wrong. It'll have zilch effect on the train schedule with a normal slate of openings.

This doesn't need outside-the-box thinking or tactical nuclear strikes by the rail interests against the water interests. It requires CDOT to eat their peas and fix infrastructure that's been teetering on point of failure for over 10 years. It's not the Norwalk River boaters' fault they forgot to plan ahead.
  by Noel Weaver
 
The money the State of Connecticut is piddling away in the stupid busway in Hartford would not pay for this but it would have helped a lot and this is a lot more important. It is time for the leadership to put away politics and try for some good old COMMON SENSE.
Noel Weaver
  by DutchRailnut
 
The 9.4 mile Busway funding would have paid for new bridge plus would have had over $ 100 million to spare.
http://en.wikipedia.org/wiki/New_Britai ... ord_Busway" onclick="window.open(this.href);return false;
  by Ridgefielder
 
F-line to Dudley via Park wrote:The way around that is to have the poles on and immediately around the bridge hang the transmission lands pointing outward instead of over the lift span, so it's clear of the lift span's footprint. But as Dutch noted that's unnecessary here because there's no boat traffic tall enough to matter. It doesn't have to be a particularly high lift to satisfy current max boat clearances.
One further thought here. The current swing span is a deck truss. Simply making the lift span a through truss would raise vertical clearance under the span by something like 14'. NOAA says current clearance over MHW is 16'-- if you increase clearance to 30' you're likely to drastically reduce the number of times per day the bridge needs to be be opened. Most leisure powerboats, and plenty of small sailboats, would be able to clear a 30' bridge.
  by NH2060
 
Noel Weaver wrote:The money the State of Connecticut is piddling away in the stupid busway in Hartford would not pay for this but it would have helped a lot and this is a lot more important. It is time for the leadership to put away politics and try for some good old COMMON SENSE.
Noel Weaver
DutchRailnut wrote:The 9.4 mile Busway funding would have paid for new bridge plus would have had over $ 100 million to spare.
http://en.wikipedia.org/wiki/New_Britai ... ord_Busway" onclick="window.open(this.href);return false;
What's even more disturbing is that it was being floated around, pushed, etc. during the same amount of time that the bridge had not been worked on. A news article from last week(?) said that the bridge hasn't had any work done to it since 1992.

What's sadly ironic is that -from what has been said on other forums- the state's chances of getting ANY funding for future projects more or less depended on the state accepting the federal funding for the busway. Had they done what Chris Christie did to the ARC tunnel (a decision I agree with) there would have been a much reduced chance of CT getting any more federal funding. And with major bridges on I-95 (Moses Wheeler, Q Bridge, etc.) getting their long overdue replacement over the past few years getting funding for major railroad bridge replacement projects will definitely require major federal bucks.
  by Lincoln78
 
CT just successfully replaced two bridges over a weekend (search "Exit 30 bridge replacement I-84").

Maybe this will help inspire a fast resolution to this issue.
  by F-line to Dudley via Park
 
The bridge-in-a-weekend replacement scheme has proven very successful for conventional bridges: highway, railroad, road crossing, and river crossing. Massachusetts in particular has made good use of it to put a dent in its maint backlog, including on the Fairmount Line commuter rail.

But there is a biiiiiiiiiiig difference between that prefab I-84 bridge and a movable span over a major navigable river. For one, staging space. You have to assemble each span of the bridge whole and be able to set up cranes and jacks to slide it into place. That takes an enormous amount of side room, which is usually available around suburban highways but not so much around densely-packed downtowns and especially densely-packed downtown waterfronts. There's zero room (esp. on the west shore) on the sides of the Norwalk River to stage anything for a replacement, much less a replacement containing all the movable-span machinery. Second, you'd never be able to swap out a replacement deck onto the same pilings here like you would a cookie-cutter 1950's highway bridge. That doesn't work when the bridge is quite this old and would need major remediation work on the supports. This is why the replacements of all remaining NEC movable spans call for the new bridges to be constructed adjacent to the old instead of on top of the old one rail deck at a time...all-new pilings needed as well. They've pretty much replaced all the bridges whose new decks can feasibly be plopped on the same supports...the really hard ones are the only ones left to go.


And finally, the bridge is unreliable in large part because it's an outdated swing design on a river that no longer has water traffic fitting the profile of a swing's specialty. They want to replace it with a fast-opening lift span that has redundancy for lifts one pair of tracks at a time. Lifts work great over navigable rivers where there isn't a need for particularly tall ships...they go up and down fast and can go up to adjustable height instead of all-or-none, don't have a lot of moving parts and aren't as failure-prone or maintenance-heavy as swings or bascules, are (relatively) cost-efficient to build compared to other types, the decks can be much heavier and more durable to maintain without requiring oversize counterweights, and they allow for a wide water channel with least risk of barge strikes because all the parts get stuffed vertical in the towers. For the Norwalk River this is ideal: it still has lots of short barge traffic, but only a little bit of recreational traffic north of the harbor. A lift would significantly widen the channel and let the boats get in and out faster when it's open, in addition to being superior for rail traffic. If they've got to do a permanent fix...it's best to do it as a lift instead of another swing.


BTW...modern swings work best when you've got heavier traffic of tall--but not wide or heavy--boats that need to keep an orderly pace to "the side of the road" when passing each other. Mystic River and Colt's Cove, New London, have those 1984-construction swings on the NEC right by large recreational docks. Lot of taller-mast sailboats that go in and out of the coves near the same time of day and have to form a queue on either side of the bridge to pass each other simultaneously during openings, but not a lot of openings on off- boating hours, offseason, or with anything time-sensitive on a set schedule. They're small boats, not barges, so the bridge-strike risk is minimal and the passing quenes can be allowed to line up before an opening. And because of the strictly rec. nature of the boating if the swing is having mechanical trouble and has to stay in the closed position as fail-safe while being serviced, the rec. boat owners are expected to suck it up and go elsewhere. Whereas you can't really tell a commercial barge, ferry, or the military to go bring their pickup truck to the nearest dock and take their boat out of the water if the swing is temporarily out-of-service.

Everywhere else on the Sound the preference is for lifts (like the Thames River bridge was retrofitted into) or generic bascules (CT River bridge replacement), because those can be built with the span-per-track redundancy and fit the profile of the relatively modest water traffic of the navigable rivers on the NEC. And that's why--when they've only got one shot to do it--they go for purging the swings everywhere except for those 2 specific recent-construction ones in New London County that fit a very specific boat traffic niche.
  by DutchRailnut
 
comparing a overpass with a navigable bridge is ludicrous.
  by Lincoln78
 
Had I qualified my statement we might not have received that outstanding technical assessment from F-line..thank you!

I've been writing my state rep for years asking him to fight the busway but I did write in support of the Norwalk bridge, which is even further out our my district's interests. CT does not set priorities well.
  by fl9m2004
 
It's pretty strange how the thames river bridge was built over a weekend and traffic resumed the monday after
The same with the Cape Cod railroad bridge I believe
  by BobLI
 
After reading Dutche's attachment regarding the bridge its amazing that the bridge was "neglected" for so long. Missing rods, bent rods, misaligned gears, etc.
Was this the result of PC and then MNCR lack of money for maintenance? Some of the fixes sound simple and easy. Grease and replace some easy fixable parts.The report is an amazing read even if you aren't a civil engineer.
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