Amtrak to replace Thames River bridge Options

[BillMagee]

It seems as if Amtrak has selected the least imaginative solution to the problem: do nothing. And to say the reason for doing nothing is because the closure will affect too many people is quite creative logic.

So, why not move four cab cars from Springfield or Harrisburg service and make-up four shuttle trains: two on each side of the closure. Operate service every two hours between New Haven and New London and every two hours between Mystic and Boston. Between New London and Mystic have a fleet of ten buses to cover the closed area (11 miles). Shuttle trains would be capacity controlled to five coaches (400 passengers).

It that an ideal solution? No. It would probably add an hour to the trip time. It would require a through passenger to change seats three times. But 5000 or so passengers who otherwise would have to go elsewhere could get transportation and after four days it would be back to normal. I certainly think it is better than nothing, and Amtrak is planning nothing.

[AlanB]

It seems as if Amtrak has selected the least imaginative solution to the problem: do nothing. And to say the reason for doing nothing is because the closure will affect too many people is quite creative logic.

So, why not move four cab cars from Springfield or Harrisburg service and make-up four shuttle trains: two on each side of the closure. Operate service every two hours between New Haven and New London and every two hours between Mystic and Boston. Between New London and Mystic have a fleet of ten buses to cover the closed area (11 miles). Shuttle trains would be capacity controlled to five coaches (400 passengers).

It that an ideal solution? No. It would probably add an hour to the trip time. It would require a through passenger to change seats three times. But 5000 or so passengers who otherwise would have to go elsewhere could get transportation and after four days it would be back to normal. I certainly think it is better than nothing, and Amtrak is planning nothing.

And that's without even offering the alternative of running two or three trains each way on the inland route, something that I can't imagine CSX has denied Amtrak. Heck, take over the LSL's time slot and you could probably squeeze 4 runs each way without causing serious problems for either CSX or the T.

That plus say taking Bill's idea but moving the headways to maybe 3 or 4 hours, rather than 2 hours, would accomodate a fair amount of passengers. But again, it does appear that Amtrak has chosen the "do nothing" path.

I also have to wonder why it's going to take 4 days to do this. That seems excessive if the bridge work is already done. All they really need to do is cut over the two tracks on either side of the river from the old approach to the new approach. That shouldn't take 4 days.

Heck in the recent Trains Mag there was a neat article on how they fixed the Brighton Park Interlocking near Chicago over the course of a weekend. And that involved replacing 10 diamonds on 7 different tracks, owned by three different RR's (so one needs a lot of cooperation and coordination), and going from a manual operation to a computer controlled operation. And since the diamonds now sit 2 feet higher than the old ones, all three companies had to realign their approach tracks and one even had to eliminate a slight curve.

They started work at about 8:00 PM and by Saturday at 9 PM had managed to open one track for a few CSX-UP hotshot intermodel trains, with all tracks open by 10 PM on Sunday night.

So why Amtrak needs 4 days is beyond me. Yes they have the added complexity of moving the overhead catenary, but still their time table seems excessive to me, if CN, CSX, and NS can pull off what they did in one weekend.

[KevinKorell]

I also have to wonder why it's going to take 4 days to do this. That seems excessive if the bridge work is already done. All they really need to do is cut over the two tracks on either side of the river from the old approach to the new approach. That shouldn't take 4 days.

Well the fact that the new bridge will be in the old bridge's footprint (rather than alongside) might have something to do with it.

http://www.encyclopedia.com/doc/1G1-143025711.html (second paragraph)

Time has to be allowed to demolish the old bridge and roll the new one in via barge. With the approaches it is probably a little more complicated than it would have been if they just had to cut the tracks over to a new location.

According to this press release from Amtrak in early 2006, they were going to have a bus bridge. Obviously they have backed off that statement.

[ICGsteve]

According to this press release from Amtrak in early 2006, they were going to have a bus bridge. Obviously they have backed off that statement.

You can be sure that Amtrak got the idea from the freights, ye who are just fine with closing a line for days or weeks to do maintenance. You can also bet given the lack of objection that Amtrak made the pilgrimage to the regional transit and political leaders pleading poverty, and came away with a good measure of what they can get away with.

[BillMagee]

I also have to wonder why it's going to take 4 days to do this. That seems excessive if the bridge work is already done. All they really need to do is cut over the two tracks on either side of the river from the old approach to the new approach. That shouldn't take 4 days.

Well the fact that the new bridge will be in the old bridge's footprint (rather than alongside) might have something to do with it.

Despite the fact that this is often described as "replacing" the bridge, that is not what is being done. Amtrak is only replacing the swing span of the bridge to provide new operating mechansims. The rest of the bridge, which is 95% of the structure, will not be changed.

The existing swing span will be replaced with a new lift span. The work to date involved substructures (foundations and piers), the tower structures for the new lift span, and installation of new electrical cables, motors and mechanisms. During the four-day rail line closure the old swing span will be cut clear of the structure, a barge will position at low tide and lift the existing swing span off the structure using the rising tide, the bridge will be prepped for the new span (including demolition of the pivot pier as required, the new lift span will be barged in at high tide and placed onto the structure as the tide lowers, and everything buttoned up to permit rail traffic to resume. Work will then continue to activate the lift mechanism so the river can be reopened to marine traffic.

When the project is done, the bridge will be the same as today except for one span.

[CNJRoss]

The current bridge is a bascule bridge, not a swing bridge, thus there is no center "pivot" pier to remove. However, there is a massive counter weight that must be removed.

The original plan was to build a temporary support structure to hold the weight until it could be cut apart and removed at some future time. During the construction to date, there has been some unexpected shifting of the towers, and the plan is now to remove the counter weight ASAP. I'm not sure if this is to be accomplished during the 4 day rail embargo or the reuqsted 20 day bridge lift embargo.

Amtrak's original plan was for a 2-day rail embargo and 10 day bridge lift outage. Amtrak has now asked the Coast Guard for a 20 day bridge lift outage. This is not going over well with the commercial or recreational waterway users. I don't know if the Navy has responded to this request yet but a long closure has significant National security implications. Submarines have been known to pass under the bridge at low tide without a lift, but the Navy really doesn't want to be driven by the tides.

Ross

Tom Nanos has a number of photographs of the bridge mixed in here:
Tom Nanos Photo Blog

[CNJRoss]

The Semaphore, South Shore Model Railway Club, Hingham, MA, 11/07:

The extra time - from 10 days to 20 days - would allow workers to remove the 4 million-pound counterweight now used to operate the drawbridge, Amtrak project manager Peter Finch told Connecticut's The Day. The new movable section will lift vertically. Amtrak originally planned to drive piles into the riverbed, creating a temporary platform that would support the counterweight. But because of the problems keeping the bridge piers stable, officials want to avoid any action that could jeopardize their efforts. "We don't want to press our luck, especially at such a critical point in the project," Finch said. There are other reasons to get the counterweight out of the way first: The counterweight itself would be in the way of the bridge-moving effort and it is too heavy to remain attached to the bridge while workers realign the bridge steel for trains to pass. Amtrak plans to cut the weight into six pieces and move them with a special crane onto a barge, eliminating the need for the platform.

[BillMagee]

The current bridge is a bascule bridge, not a swing bridge, thus there is no center "pivot" pier to remove. However, there is a massive counter weight that must be removed.

The original plan was to build a temporary support structure to hold the weight until it could be cut apart and removed at some future time. During the construction to date, there has been some unexpected shifting of the towers, and the plan is now to remove the counter weight ASAP. I'm not sure if this is to be accomplished during the 4 day rail embargo or the reuqsted 20 day bridge lift embargo.

Amtrak's original plan was for a 2-day rail embargo and 10 day bridge lift outage. Amtrak has now asked the Coast Guard for a 20 day bridge lift outage. This is not going over well with the commercial or recreational waterway users. I don't know if the Navy has responded to this request yet but a long closure has significant National security implications. Submarines have been known to pass under the bridge at low tide without a lift, but the Navy really doesn't want to be driven by the tides.

Ross

Tom Nanos has a number of photographs of the bridge mixed in here:
Tom Nanos Photo Blog

The counterweight has to remain as long as the existing movable span must be operated. The problem Amtrak encountered was with driving new piles (to temporarily support the counterweight when it is removed) in the vicinity of the existing pier footers. The driving operation caused some shifting of the existing footers and piers: a really bad thing. So, no piles and no temporary support platform. They are really lucky. That little problem could have resulted in the bridge being condemned. That would have been very interesting.

Funny thing. I knew the counterweight issue, and you sure do not need a counterweight with a swing bridge, but I kept visualizing Spuyen Duyvil instead of Thames.