FRA Tier II speed upgrade: 150mph to 160mph

I assume that they'll add in the "enhanced variable tension" catenary supports where they failed to install constant tension, as seen here in Hamilton. Again, I can't imagine they spent all this money and did all this work for nothing, but then on the other hand, this is Amtrak we're talking about - the same Amtrak that's sending the rebuilt Turboliners to the scrapper after getting no use out of 'em, and that spent a couple billion on the Chicago - St Louis route only to stay stuck at 79 mph with 110 mph always seemingly promised for "next year" for at least the last five years, and that's currently using the new Viewliner dining cars to serve cold snacks in a box. So, I guess anything is possible.

http://www.railpictures.net/photo/657488/

I guess it is impossible to get through to people that even if there is no speed increase a very significant part of the investment was not for nothing. Afterall minds are made up. Why get confused with facts. That is afterall the fashion of the day.

This is not to say there was not a massive screwup with the catenary project. I am the one that has been reporting on it. But let us also not get carried away with the negative extravaganza [emoji57]

jis said:

I guess it is impossible to get through to people that even if there is no speed increase a very significant part of the investment was not for nothing. Afterall minds are made up. Why get confused with facts. That is afterall the fashion of the day.

This is not to say there was not a massive screwup with the catenary project. I am the one that has been reporting on it. But let us also not get carried away with the negative extravaganza [emoji57]

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Just to briefly explain the third wire in the PRR catenary that continues to be in place with the rebuild. That wire, located immediately above the trolley (contact) wire is called the "auxiliary." It is a high-conductivity, copper wire (originally solid 4/0) that is used to provide current capacity in the catenary system.

The other two wires in the catenary, the sagged "messenger" and the trolley wire are high-strength bronze and a special copper alloy and are not great electrical conductors. Those two combined do not have the capacity to supply the load between the substations and catenary supply taps, located about every eight miles. The auxiliary provides that capacity. In order to eliminate the auxiliary wire, another means to provide capacity or limit load would have to be provided such as locating catenary feeder conductors somewhere else on the structures (tapped to the catenary every couple of miles). My guess is that the easiest solution was to replace the auxiliary wire in-kind.

As a contrast to the PRR system, the New Haven to Boston electrification is 25kV and has catenary feeds every six miles. That is the electrical equal to having 12kV feeds every three miles. The north end electrification does not need an auxiliary wire for current capacity. The south end does.

VT Hokie said:

I assume that they'll add in the "enhanced variable tension" catenary supports where they failed to install constant tension, as seen here in Hamilton. Again, I can't imagine they spent all this money and did all this work for nothing, but then on the other hand, this is Amtrak we're talking about - the same Amtrak that's sending the rebuilt Turboliners to the scrapper after getting no use out of 'em, and that spent a couple billion on the Chicago - St Louis route only to stay stuck at 79 mph with 110 mph always seemingly promised for "next year" for at least the last five years, and that's currently using the new Viewliner dining cars to serve cold snacks in a box. So, I guess anything is possible.

http://www.railpictures.net/photo/657488/

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One minor nitpick, the state of Illinois is in charge of that disaster that is the Chicago to St Louis project.

PRR you are quite right. I keep forgetting that the PRR electrification is not modern 25kV 60Hz, which allows feeders to be spaced much further apart, specially if 2x25kV is used for the feeder. That is the primary reason that most of the modern systems are two cable systems. Many though also have a third return cable strap connected to the track, to keep stray current from getting into stuff causing problems around the track.

Seaboard92 said:

I'm going to be the major opposing opinion here; but I really don't see the point in raising the speed limit at all.

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So in my opinion 150 to 160 is just a waste of time, and money.

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George Harris (internet acquaintance and civil engineer who has worked on rail projects from Washington Metro to Taiwan HSR and CA-HSR) is wont to say, "The best way to go fast is to avoid going slow." In other words, you will get much more bang for the buck in raising a 60 MPH speed restriction to 90 MPH than you will by increasing a 150 MPH top speed to 160 MPH. Baltimore tunnels, anyone?

That is absolutely true, and what is also true is that trying to do anything with Baltimore Tunnels, North Philly through Philly or Wilmington are all individual billion plus projects. Big bucks with big bangs. But with the inability to scare up the bucks, one tends to do things opportunistically when bits of money become available, where you get a whole bunch of SOGR work done and incidentally get a speed increment from 135 to 150. The 150 to 160 increment has very little added cost associated specifically with it. Most of the additional cost is already eaten up in the catenary and signaling and track realignment work for 150, SOGR, added reliability and throughput.

Another incremental piece of work worthy of funding is the Midline Loop to decongest County interlocking and get NJT Jersey Avenue Service out of the way of the main line. It does not increase the speed of anything but removes conflicts which should on an average improve schedule reliability and net average speed through the congestion point.

Another item of changing the PRR CAT to constant tension. Most locations PRR CAT as built has connection wire(s) between the vertical poles on opposite sides of all tracks. Suspended from this connection wire(s) usually is the messenger wire for all tracks. In the case of Trenton north it is 4 tracks occasionally more. Whenever a train's PAN tangles with the trolley wire many time the PAN pulls down the messenger wire as well for its track and also the other track's messenger wires as well taking all tracks out of service.

Constant Tension as being built for the PRR sections instead has a horizontal beam crossing across all tracks to the vertical poles on both sides of all tracks. Suspended from this horizontal beam is a hanger that holds the messenger just for that track so each beam has at least four hangers one each for each track. Note the hanger can move slightly due to the various temperatures of wire. Therefore snagging the trolley wire only pulls down the wire for that track. Of course occasionally wire from one track might foul wire for tracks next to wire down. Still repair is much faster and traffic is not stopped.

Since it appears the NJT snags the trolley wire much more ( maybe as EMU trains have up to 6 PANs ) this constant tension will allow Amtrak to continue running except in vicinity of a snagged wire .

Another factor is PRR CAT has all tracks connected electrically where as the Constant tension can be isolated for each track except at interlockings. If that is being done that would increase the costs significantly as many more CBs / control switches will be needed for each track ? ?

AFAICT all that is being done is replacing variable tension with constant tension with absolutely no9 change made to the overall layout of the feeding system, other than to add more converter capacity. They are adding/have added substations to enhance power capacity, but they are not isolating individual track catenaries anymore than they already are or not.

JIS Have you observed the work to see that individual feeders to each track are not in sight ? Could it be that individual feeders are in place but are connected together ? Since have no plans to visit anytime soon will have to use your best observations ?

Are you referring to these?

https://www.instagram.com/p/BYgidUhlZWJ/

west point said:

JIS Have you observed the work to see that individual feeders to each track are not in sight ? Could it be that individual feeders are in place but are connected together ? Since have no plans to visit anytime soon will have to use your best observations ?

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The feeders have not changed. They are pretty much exactly the same as before except some additional ones from the added substations to bolster the feed. AFAICT there is an added substation in Hamilton at least

VT Hokie said:

Are you referring to these?

https://www.instagram.com/p/BYgidUhlZWJ/

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Maybe = maybe not. Was looking for feeders of the 12 kV to the trolley, aux , or messenger. This picture does not. However the unconverted variable tension on the right side of picture cannot be determined ? has anyone observed feeders at same locations as before and are they bussed together.?