Second Ave Subway Construction thru Phase I open

Railsfuture1 wrote:Boston is vastly different and due to its crummy soil, and deep bedrock, TBM tunnels would collaspe behind it. Recall the I-90 connector to the Ted Williams.
Anyway, I guess your right, but I still don't have to like it. Oh, well, they never listen to me anyway.

I didn't mean it like that, I mean Boston's troubles with the cut and cover and all of the noise and reroutes would never work in New York City, much less a major street like Second Avenue.

Look at it this way- the issue between TBM tunnels and cut and cover tunnels are proportional to the collateral damage done by using those methods. TBMs may take a long time to build with but their depth also means less property lost, less reroutes onto major streets, and less noise in the neighborhoods where construction is going on.
Cut and cover is quicker and cheaper, but it also means that an entire avenue will be lost north and or south of 63rd Street for up to two or three years(depending on delays). Add in eminant domain seizures, sidewalk replacements, extra police to patrol the construction sites and to direct traffic, and of course noise complaints and their accompanying lawsuit payments, the rerouting of electrical, telephone, gas, sewer, and fiber optic lines, and finally the bad press regarding the construction.

It's a lose-lose situation, you have to pay alot and have little impact or pay a little and deal with the impact and it's accompanying damages.

Well, as my research has concluded. Cut and Cover is being used on upper 2nd ave and for all of the station. In other words, it does not seem to be about noise and liability. The reason is high bedrock. I guess is just easier for them to bore through the bedrock closer to the surface as opposed to cut and cover because the bedrock is so tough. Although they did do it elsewhere in Manhattan. This can be the only reason, I can see, short of a political corruption conspiracy (hmmmmmmm, lol). Especially since Cut and Cover will be employed in Lowermanhattan near Bridge, the FDR, and some big skyscrapers.

JayMan wrote:The planned SAS is designed to run 30 trains/hour in each direction. That level of service should be more than sufficient for the line without having to have to add express tracks. The two track line will have numerous cross switches and a few stations will have 3 tracks.

It still dosen't cut it. No matter tha signal technology, there will always be a need for four tracks. What if a disruption serious enough to cause a reroute were to occour on one of tha tracks? If it was to be a suitable alternative to tha Lexington Av. Line, it should have no less than four tracks.

i doubt it will be bult

and btw are you form rd n.y state of mind? iam from rd too

Most definitely.

N.Y. State Of Mind wrote:Most definitely.

iam cta from rd

N.Y. State Of Mind wrote: No matter tha signal technology, there will always be a need for four tracks. What if a disruption serious enough to cause a reroute were to occour on one of tha tracks? If it was to be a suitable alternative to tha Lexington Av. Line, it should have no less than four tracks.

That's what the crossovers and extra tracks at some stations are for. But if something severe enough to shut down the line then the SAS will just be out for awhile. That, unfortunately, is the limitation we must accept with extra tracks being prohibatably expensive to construct,

JayMan wrote:That's what the crossovers and extra tracks at some stations are for. But if something severe enough to shut down the line then the SAS will just be out for awhile. That, unfortunately, is the limitation we must accept with extra tracks being prohibatably expensive to construct,

A deep-bore tunnel under tha local tracks (which they plan to do in tha far future) is much more expensive than four tracks on one level.

I had corresponded with the MTA on this issue, and they claimed that Second Avenue is not wide enough for four track operations. I know this to be false, because all of the numbered avenues, Park and Broadway excluded, were built back in 1811 or so to be the same width give or take a few inches. Therefore, adding express or local tracks on the same level would not be impossible. The tough part would be stations as the MTA states it has to make platforms significantly wider than the original system was constructed. Given these restrictions, if, and that's a big if, the MTA built express tracks they would likely go with the more expensive concept of below the existing ones unless they have an attack of common sense before that.

Actually, let's a assume they built new tracks on either side of the ones they're planning to build. With the new tracks they could add side platforms to make a setup like there is at the Penn Station stops. However, during regular service that old middle platform would be closed off. That way if the local line fell out of the commision for repairs and what not, the "express line" could assume its duties without forcing people to skip their stops. However, this would make huge stations and make transferring from local to express tougher.

N.Y. State Of Mind wrote: A deep-bore tunnel under tha local tracks (which they plan to do in tha far future) is much more expensive than four tracks on one level.

With a pricetag of $17 billion for the planned 2 tracks we really, are lucky to get those two. While I agree, building 4 tracks now would be ideal (and I agree it would be nicer if all on one level), unfortunately, it would make it too expensive to construct. If everything goes right with CTBC and we really see 30 TPH on the line we may find that express tracks aren't worth the expense.

Railsfuture1 wrote:Well, as my research has concluded. Cut and Cover is being used on upper 2nd ave and for all of the station. In other words, it does not seem to be about noise and liability. The reason is high bedrock. I guess is just easier for them to bore through the bedrock closer to the surface as opposed to cut and cover because the bedrock is so tough. Although they did do it elsewhere in Manhattan. This can be the only reason, I can see, short of a political corruption conspiracy (hmmmmmmm, lol). Especially since Cut and Cover will be employed in Lowermanhattan near Bridge, the FDR, and some big skyscrapers.

Cut and cover is common at stations, because they need to be open to the street anyway. Also Upper 2nd avenue closures would not be nearlly as disruptive as midtown/lower manhattan.

Sure, bedrock placement plays into it, but in the end it's all a balancing act - cut and cover might clearly be more sensible in places, but it's also clearly far to disruptive to use everywhere

Does anyone know if MTA still proposes to build the $17 billion Second Avenue Subway?

Arthur Thomas

Groundbreaking is due in December and the project is "on track" (according to MTA) for construction.


See the MTA site at http://www.nyct.org/capconstr/sas

Thank you!

If they actually begin construction on the SAS in December, I will eat a rollsign. An R32 rollsign, no less.